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The Global Index of Vegetation-Plot Databases (GIVD): A new resource for vegetation science
Abstract
Question: How many vegetation plot observations (relevés) are available in electronic databases, how are they geographically distributed, what are their properties and how might they be discovered and located for research and application?
Location: Global.
Methods: We compiled the Global Index of Vegetation‐Plot Databases (GIVD; http://www.givd.info ), an Internet resource aimed at registering metadata on existing vegetation databases. For inclusion, databases need to (i) contain temporally and spatially explicit species co‐occurrence data and (ii) be accessible to the scientific public. This paper summarizes structure and data quality of databases registered in GIVD as of 30 December 2010.
Results: On the given date, 132 databases containing more than 2.4 million non‐overlapping plots had been registered in GIVD. The majority of these data were in European databases (83 databases, 1.6 million plots), whereas other continents were represented by substantially less (North America 15, Asia 13, Africa nine, South America seven, Australasia two, multi‐continental three). The oldest plot observation was 1864, but most plots were recorded after 1970. Most plots reported vegetation on areas of 1 to 1000 m ² ; some also stored time‐series and nested‐plot data. Apart from geographic reference (required for inclusion), most frequent information was on altitude (71%), slope aspect and inclination (58%) and land use (38%), but rarely soil properties (<7%).
Conclusions: The vegetation plot data in GIVD constitute a major resource for biodiversity research, both through the large number of species occurrence records and storage of species co‐occurrence information at a small scale, combined with structural and plot‐based environmental data. We identify shortcomings in available data that need to be addressed through sampling under‐represented geographic regions, providing better incentives for data collection and sharing, developing user‐friendly database exchange standards, as well as tools to analyse and remove confounding effects of sampling biases. The increased availability of data sets conferred by registration in GIVD offers significant opportunities for large‐scale studies in community ecology, macroecology and global change research.
... Vegetation plot databases, which represent a relatively new source of information, record plant species based on vegetation plots. The data stored in these so-called phytosociological relevés (Dengler et al., 2011;Chytrý et al., 2014;Divíšek & Chytrý, 2018) have been used for analysing species richness at the community level (Večeřa et al., 2019;Sabatini et al., 2022), conducting high-resolution and largeextent modelling of plant species richness (Divíšek & Chytrý, 2018;Divíšek et al., 2020), searching for global patterns of species richness in the alpine environment (Testolin et al., 2021), analysing species richness patterns in relation to environmental gradients (Chytrý et al., 2003;Schuster & Diekmann, 2003), and conducting species distribution and species niche modelling (Sporbert et al., 2019). ...
... The PVD stores vegetation records, including information of species co-occurrences (so-called phytosociological relevés), that are typically collected according to the Central European phytosociological method (Braun-Blanquet, 1964). Based on the number of records it contains, the PVD is among the largest vegetation databases in Europe and worldwide (Dengler et al., 2011;Kacki & Sliwinski, 2012). The database is registered in the Global Index of Vegetation-Plot Databases (GIVD) (Dengler et al., 2011) under code EU-PL-001, and it is one of the largest contributors of vegetation data to the European Vegetation Archive (EVA) (Chytrý et al., 2016) and sPlot . ...
... Based on the number of records it contains, the PVD is among the largest vegetation databases in Europe and worldwide (Dengler et al., 2011;Kacki & Sliwinski, 2012). The database is registered in the Global Index of Vegetation-Plot Databases (GIVD) (Dengler et al., 2011) under code EU-PL-001, and it is one of the largest contributors of vegetation data to the European Vegetation Archive (EVA) (Chytrý et al., 2016) and sPlot . The PVD data consist of 117,328 georeferenced vegetation plots, the number of vegetation plots varied from 0 to 693 per square. ...
Mapping of species richness (SR) patterns is pivotal for biogeography and nature conservation. Vegetation plot databases serve as a new source of information, but they are inherently affected by the methodological background of data collection. This background could bias the SR assessment. Here, we compared two different data sources: (1) a vegetation-plot database, the Polish Vegetation Database (PVD), and (2) a species distribution atlas, the Atlas of Distribution of Vascular Plants in Poland (ATPOL). We calculated species richness recorded by the PVD (PVD SR), the ATPOL (ATPOL SR), and the two harmonized databases (total SR). The sampling bias in the PVD (PVD bias) was assessed by calculating the number of species found in the ATPOL, but not recorded by the PVD. Analogically, the ATPOL bias was calculated. We calculated correlation between the PVD bias and both the number of vegetation plots and the number of vegetation classes. Additionally, the completeness of the PVD dataset was assessed using the species accumulation curve approach. The mean slope of the last 1% of plots number was used as a proxy of inventory completeness and correlated with PVD bias. The results show that the SR documented by the PVD is significantly lower than that recorded by the ATPOL, yet it indicates a significantly increased total SR. The PVD SR increased as more plots and vegetation classes were sampled. However, even with the best sampling, the PVD SR was still significantly lower than that in the ATPOL. Further, although the values for the species accumulation curves suggested high sampling completeness in the PVD, the real bias was still substantial, and no correlation was found between PVD bias and species accumulation curve values. In general, the PVD underestimated SR at a landscape level, yet it augmented information stored in the ATPOL. The underestimations could result from limited sampling effort or from focusing on particular vegetation types, as well as the exclusion of transitional vegetation types and/or disturbed patches of vegetation from sampling.
... Vegetation-plot databases have an enormous potential for vegetation ecology, macroecology and global-change studies (Dengler et al. 2011;Wiser 2016) as they allow for generalization beyond the local or regional extent. This potential is increasingly harvested through big continental to global databases such as the European Vegetation Archive (EVA; Chytrý et al. 2016), the global database "sPlot" (Bruelheide et al. 2019) or the specialised high-quality database of Palaearctic open habitats "GrassPlot" (Dengler et al. 2018). ...
... In 2016, the scope was widened to include all grasslands s.l., and thus, the name was changed to "Nordic-Baltic Grassland Vegetation Database" (NBGVD; Dengler and Kozub 2022). NBG-VD is registered in the Global Index of Vegetation-Plot Databases (GIVD; Dengler et al. 2011) under the ID EU-00-002 (see GIVD Fact Sheet). It is one of currently five regional grassland vegetation databases associated with the Eurasian Dry Grassland Group (EDGG; https://edgg.org/), ...
This Long Database Report describes the historical background and current contents of the Nordic-Baltic Grassland Vegetation Database (NBGVD) (GIVD-code EU-00-002). NBGVD is the EDGG-associated collaborative vegetation-plot database that collects vegetation-plot data of grasslands and other open habitats (except segetal and deep aquatic vegetation) from the Nordic-Baltic region excluding Germany, namely Belarus, Denmark, Estonia, Faroe Islands, Finland, Iceland, Latvia, Lithuania, Norway, N Poland, NW Russia, Svalbard and Jan Mayen, and Sweden. Target vegetation types are lowland grasslands and heathlands, arctic-alpine communities, coastal communities, non-forested mires and other wetlands, rocky, tall-herb and ruderal communities. As of March 2024, it included 12,694 relevés recorded between 1910 and 2023. These were mainly digitised from literature sources (84%), while the remainder comes from individual unpublished sources (16%). The data quality is high, with bryophytes and lichens being treated in more than 80% of all plots and measured environmental variables such as topography and soil characteristics often available in standardised form. A peculiarity of the Nordic-Baltic region are the relatively small plot sizes compared to other regions (median: 4 m²). The available data stem from 35 vegetation classes, with Koelerio-Corynephoretea, Festuco-Brometea, Sedo-Scleranthetea, Molinio-Arrhenatheretea and Scheuchzerio-Caricetea being most frequent. We conclude that NBGVD provides valuable data, allowing interesting analyses at the regional scale and fills gaps in continental to global analyses. Still, since there are many more data around, we ask interested readers to contribute their own data or help find and digitise old data from the literature.
Taxonomic reference: TURBOVEG species list “Europe”.
Syntaxonomic reference: Mucina et al. (2016).
Abbreviations: EDGG = Eurasian Dry Grassland Group, EVA = European Vegetation Archive, GIVD = Global Index of Vegetation-Plot Databases, NBGVD = Nordic-Baltic Grassland Vegetation Database
... Despite this persistent effort, Transcaucasian vegetation diversity belongs among the less phytosociologically explored within Europe and adjacent areas (Preislerová et al. 2022). Existing vegetation-plot databases from Transcaucasia within GIVD (Dengler et al. 2011) primarily focus on relatively small fractions of the region or specific habitats. They correspond to five databases originating from Azerbaijan (EU-AZ-001-005) and storing plots recorded for purposes of specific grants and theses in the 2000s. ...
... The current version of the TVD is available upon request via GIVD (Dengler et al. 2011) and EVA (Chytrý et al. 2016). ...
The Caucasus is a hotspot of global biodiversity. However, even in the era of big data, this region remains underrepresented in public vegetation-plot databases. The Transcaucasian Vegetation Database (GIVD code AS-00-005) is a novel dataset which primarily aims to compile, store and share vegetation-plot records sampled by the Braun-Blanquet approach and originating from Transcaucasia (the Southern Caucasus), i.e. the countries of Armenia, Azerbaijan and Georgia. The database currently contains 2,882 vegetation plots. The oldest plots originate from 1929, the newest from 2022, and their collection is ongoing. The data include mesophilous forests (phytosociological class Carpino-Fagetea ) and various alpine and subalpine communities (e.g. Carici-Kobresietea , Loiseleurio-Vaccinietea ) – selected other habitats are also represented. Most of the plots (84%) are georeferenced, 36% with high precision of 25 m or less. The database includes 2,500 taxon names; Asteraceae , Poaceae , Fabaceae and Rosaceae represent the most common families. Vascular plants are recorded in all plots, while data on species composition of bryophytes are available for 11% of plots. The database intends to contribute to the complex biodiversity research of this biologically unique territory. The data might be used in diverse projects in botany, biogeography, ecology and nature protection.
Taxonomic reference : The Plant List (http://www.theplantlist.org/ [Accessed 10 Jan 2023]).
Syntaxonomic reference : Mucina et al. (2016).
Abbreviations : TVD = Transcaucasian Vegetation Database.
... The PVD stores vegetation plots, including information of species co-occurrences (so-called phytosociological relevés), that are typically collected according to the Central European phytosociological method 31 . Based on the number of plots it contains, the PVD is among the largest vegetation databases in Europe and worldwide 32,33 . The database is registered in the Global Index of Vegetation-Plot Databases (GIVD) 32 under code EU-PL-001, and it is one of the largest contributors of vegetation data to the European Vegetation Archive 33 and sPlot 34 derived from each vegetation plot based on its georeferenced location and assigned to particular squares. ...
... Based on the number of plots it contains, the PVD is among the largest vegetation databases in Europe and worldwide 32,33 . The database is registered in the Global Index of Vegetation-Plot Databases (GIVD) 32 under code EU-PL-001, and it is one of the largest contributors of vegetation data to the European Vegetation Archive 33 and sPlot 34 derived from each vegetation plot based on its georeferenced location and assigned to particular squares. The spatial location of plots is estimated based on plot description (e.g., a particular mountain, forest complex or nearest village) or the coordinates measured using the Global Navigation Satellite System. ...
Recognition of species richness spatial patterns is important for nature conservation and theoretical studies. Inventorying species richness, especially at a larger spatial extent is challenging, thus different data sources are joined and harmonized to obtain a comprehensive data set. Here we present a new data set showing vascular plant species richness in Poland based on a grid of 10 × 10 km squares. The data set was created using data from two sources: the Atlas of Distribution of Vascular Plants in Poland and the Polish Vegetation Database. Using this data set, we analysed 2,160 species with taxonomical nomenclature according to the Euro + Med PlantBase checklist in 3,283 squares covering the entire territory of Poland (ca. 312,000 km²). The species were divided into groups according to their status and frequency of distribution, and the statistics for each square were obtained. For purposes of analysis, sampling bias was assessed. The data set promotes theoretical analysis on species richness and reinforces the planning of nature conservations.
... Phytosociological data from the databases "Anthropogenic vegetation of Ukraine" (registration number in GIVD [12] EU-UA-011) and "Pioneer vegetation of Ukraine" [13] were the basis for establishing the syntaxonomic diversity and compiling lists of alien species of the pioneer and ruderal vegetation of Ukraine. A total of 10,423 phytosociological relevés were analyzed. ...
... These data reflect the ancient and various migration routes of alien species due to the various relations of Ukraine with the countries to the east. Among the kenophytes (introduced in 1809-1986), North American species predominate (12), and this group also includes eight Ancient Mediterranean species (6 Mediterranean-Iranian-Turanian, 1 Mediterranean, 1 Mediterranean-Turanian), one Mediterranean-Asian, one Mediterranean-South Asian; one Balkan-Asia Minor, and five European species (1 European, 4 South European), with one species of unknown origin. Archaeophytes and kenophytes differ both in their life forms and in relation to the moisture regime. ...
Invasions of nonnative plants are widely recognized as one of the major threats to the biodiversity of natural ecosystems on a global scale. Pioneer and ruderal habitats are the primary locations for the penetration of alien plants. Both pioneer and ruderal vegetation are very close in their genesis and beginning of development; therefore, a comparative analysis of their alien components and historical trends would contribute to clarifying the direction of successional changes and the possible management of destructive processes caused by anthropogenic influences in different types of habitats. The results of a structural and comparative analysis of the alien fractions of the coenofloras of the pioneer and ruderal vegetation of Ukraine indicated that the systematic, biomorphological, ecological, and geographical structures of these species show a high similarity, according to many of the main indicators, which allows them to successfully implement a strategy of invasion, particularly in communities characterized by instability and weak coenotic connections. It was established that the ecotopes of both types of vegetation are very favorable to the penetration and establishment of alien species; however, disturbed habitats of the ruderal type are more prone to invasions. In the communities of both pioneer and ruderal vegetation, alien species can become successfully established at the coenotic level, forming phytocoenoses of different hierarchical ranks. The results of this study will contribute to the identification of general patterns of invasions and the optimization (management) of disturbed and unstable natural ecosystems.
... In the last century, millions of vegetation plots have been recorded around the world for different purposes, as well as a huge amount of associated environmental information (Sabatini et al. 2021). However, most of these vegetation plots are located in Europe where there is a long tradition in vegetation studies based on the classical phytosociological approach (Dengler et al. 2011). This approach has proven to be a very useful methodological framework for local and regional overviews of vegetation types (Schaminée et al. 2009). ...
... Access to vegetation plot information at regional and global scales was extremely limited prior to the advent of electronic database technologies and digital communication tools (Dengler et al. 2011). In Argentina, large amounts of floristic surveys have been performed (Martinez-Carretero et al. 2016), although most of this information is often unpublished or included in "grey literature" not yet widely available on digital archives. ...
The ArgVeg is a repository of vegetation-plots data registered in the Global Index of Vegetation Databases (GIVD ID: SA-AR-002). This report presents its main characteristics, potential uses, and future perspectives. In September 2022, the database contained 1092 vegetation-plot records, including 1184 valid native and non-native vascular plants. The database covers the main vegetation types of nine vegetation units of the Chaco, Espinal and Pampean phytogeographic provinces in central Argentina. Those types include native forests, shrublands, grasslands, halophytic vegetation and non-native woody communities present in either lowlands or mountain areas. This database represents a significant improvement in the availability of floristic information from subtropical and warm temperate areas in South America, which still represents a major knowledge gap worldwide. ArgVeg reflects the outstanding plant diversity of central Argentina and it is managed by the Plant Ecology and Phytogeography Group at the Multidisciplinary Institute of Plant Biology (Córdoba, Argentina). Not only the high biodiversity but also the complex landscape heterogeneity are the most important characteristics of the vegetation in this region. We hope to increase the number of plots in the near future and to strengthen regional and global networks to enhance the conservation and management of these endangered ecosystems.
... The appearance of databases of relevés, and their compilation in global archives of metadata, meant a paradigm shift in the study of vegetation and biogeography. The GIVD (Dengler et al. 2011) and the sPlot Consortium (Bruelheide et al. 2019) lead this paradigm shift. The Bolivian Vegetation Ecology Database (BOVEDA) was created to fill a gap in the lack of information on the outstandingly biodiverse country, and to facilitate the sharing of data and connect researchers (Figure 1). ...
... BOVEDA, the Bolivian Vegetation Ecology Database (SA-BO-005), is a new project unique in the country, and one of the very few on the South American continent (see Dengler et al. 2011). In this first stage of our project, the relevé count in BOVEDA is already higher than in any other GIVD-registered plot database from Bolivia (https://www.givd.info/info_organisation.xhtml). ...
Bolivia is a country exceptionally rich in biodiversity and home to about 20,000 vascular plant species and 15 plant formations. Therefore, it is particularly important to document the biodiversity of this territory. The aim of the Bolivian Vegetation Ecology Database (BOVEDA; GIVD ID SA-BO-005) is to record floristic and ecological data of Bolivian vegetation. In the first stage, the database hosts 320 relevés from one of the most unique biogeographical units in the country, the Chaco. In total, 633 species belonging to 114 families have been recorded. Data on vegetation structure, soil, flooding regime and geomorphology have also been stored. The following nine vegetation structural types were identified: (1) deciduous forests of alluvial plains on well to moderately well drained soils; (2) deciduous to semideciduous Chaco forests transitional to the Andes; (3) deciduous and sclerophyllous Cerrado thorn-woodlands and shrublands transitional to the Chaco (Abayoy); (4) xeromorphic thorn shrubland and thickets on vertic, poorly drained soils; (5) woodlands and savannas on sand dunes and aeolian surfaces; (6) freshwater swamp forests; (7) saltwater swamp forests; (8) phreatophytic forests; (9) deciduous to semideciduous Chaco forests transitional to the Chiquitania. Further steps will be to incorporate new types of vegetation already recorded in the field such as Altiplano shrublands, Andean wetlands, Andean Polylepis forests, and vegetation of the dry inter-Andean valleys.
Taxonomic reference : Jørgensen et al. (2015).
Abbreviations : BOVEDA = Bolivian Vegetation Ecology Database; GIVD = Global Index of Vegetation-Plot Databases.
... Джерелом флористичних списків були оригінальні повні фітоценотичні описи рудеральної рослинності, виконані із застосуванням геоботанічного детальномаршрутного методу і проведені авторами й іншими дослідниками протягом 2015-2020 років. Використані бази даних «Антропогенна рослинність України», зареєстрована в Global Index of Vegetation-Plot Databases (Dengler et al. 2012) з кодом EU-UA-11 та «Піонерна рослинність України» (Dubyna et al. 2016). Автори публікації керувалися монотипним стандартом виду. ...
Проаналізована систематич на структура флори рудеральної рослинності України, яка нараховує 1476 видів судинних рослин, що належать до 570 родів і 116 родин. Е коло гічно наближена піонерна представлена відповідно 844; 338; 80. Переважна їхня більшість відноситься до відділу Magnol iophyta . Десять провідних родин Asteraceae , Poaceae , Fabaceae, Brassicaceae , Lamiaceae, Rosaceae, Apiaceae, Caryophyllaceae, Scrophulariaceae та Cyperaceae ) у рудеральних угрупованнях об’єднують 59,5% видів. Співвідношення між чисельністю видів і родів ст ановить 2,6 : 1, видів і родин – 12,8 : 1, однодольних і дводольних – 1 : 4. Наведені пропорції вказують на її історичні зв’язки з голарктичними флорами, а також давньосередземноморськими і на відносно молодий вік. Історично рудеральна флора виникла з ча сів початку господарської діяльності людини і перебуває у постійно змінному стані та поповнюється новими видами. Аналіз видових спектрів ценофлор класів рудеральної рослинності відображає своєрідність та змінність факторів середовища. Найбільшою кількістю видів відзначаються угруповання класу Artemisietea vulgaris 1055 (48,6 % всієї флори рудеральної рослинності), середньою класи Stellariete a mediae 718 (48,6 %), Galio Urticetea 570 (38,6 %), Robinietea 460 (31,2 %). Найменша кількість видів в уг рупованнях класів Polygono Poetea annuae 291 (19,7 %), Plantaginetea majoris 286 (19,4 %), Bidentetea 227 (15,4 %), Epilobietea angustifolii 193 (13,1 %). Приведені родинні спектри ценофлор класів рудеральної рослинності. Проаналізовано подібність видового складу ценофлор за коефіцієнтом Жаккара. На основі обрахованих коефіцієнтів побудовано кластерну діаграму. До першого кластеру ввійшли ценофлори класів Artemisietea vulgaris і Stellarietea mediae , другого Plantaginetea majoris і Polygono Poetea annuae третього Robinietea і Galio Urticetea. Менше подібні між собою і з флорами решти класів ценофлори Epilobietea angustifolii і Bidentetea. Розглядається систематична структура синантропної фракції флори рудеральної рослинності. Вона нараховує 526 в идів, що відносяться до 271 роду і 66 родин. Найбільша частка синантропних видів у ценофлорах Polygono Poetea annuae 56 Plantaginetea majoris 51 Stellarietea mediae 49 Bidentetea 45 %, менше їх у Robinietea 41 %, Galio Urticetea 38 Artemisietea vulgaris 38 %, найменше Epilobietea angustifolii 29 %. Співвідношення аборигенних і чужорідних видів вказує на вищу інтенсивність трансформаційних процесів угруповань класів Epilobietea angustifolii, Polygono Poetea annuae та Plantaginet ea majoris Спектр десяти провідних родин адвентивної фракції ценофлори нараховує 190 видів. Його складають Asteraceae (50 видів), Brassicaceae (35), Роасеае (28), Fabaceae (16), Аpiaсеае , Chenopodiaceae (по 14), Lamiaceae (12) Amaranthaceae , Scrophulariac eae , Malvaceae (по 7 видів). Найбільшою їх чисельністю відзначаються ценофлори класів Stellarietea mediae і Artemisietea vulgaris Спектр провідних родин археофітів складають Asteraceae (16 видів), Роасеае (16), Brassicaceae (13), Lamiaceae (9), Chenopodia ceae (6), Boraginaceae (5), Fabaceae (5), Malvaceae (5), Ranunculaceae ( Найбільшою їхньою чисельністю відзначаються ценофлори класів Stellarietea mediae, Artemisietea vulgaris та Galio Urticetea Спектр провідних родин кенофітів: Asteraceae 31 вид), B rassicaceae 23), Роасеае 12), Fabaceae 11), Chenopodiaceae 8), Lamiaceae (12), Amaranthaceae 7), Аpiaсеае 6), Rosaceae ( Solanaceae ( Найбільшою їх чисельністю відзначаються ценофлори класів Stellarietea mediae та Artemisietea vulgaris Інвазій них видів 38, які відносяться до 19 родин і виявлені у ценофлорах класів: Artemisietea vulgaris 28, Stellarietea mediae 24, Galio Urticetea 22, Robinietea 22, Polygono Poetea annuae 15, Plantaginetea majoris 10, Bidentetea 9, Epilobietea angu stifolii 2. У складі рудеральних ценофлор виявлені 7 рідкісних видів: у тому числі 1 вид занесений до Червоного списку Міжнародної спілки охорони природи з категорією “EN” Agropyron cimmericum, 6 видів, занесених до Червоної книги України Chrysopogon gryllus, Stipa capillata, S. lessingiana, S. pulcherrima, Orchis picta, Tamarix gracilis Найбільшою їх чисель ністю відзначаються ценофлори класів Stellarietea mediae та Artemisietea vulgaris.
... de/ de/ splot. html) have substantially expanded the availability of these types of data (Schaminée et al., 2009;Dengler et al., 2011). ...
... de/ de/ splot. html) have substantially expanded the availability of these types of data (Schaminée et al., 2009;Dengler et al., 2011). ...
Balázs Deák 52 | Guillaume Decocq 53 | Iwona Dembicz 54 | Jürgen Dengler 55,56 | Valter Di Cecco 57 | Jan Dick 58 | Martin Diekmann 59 | Hartmut Dierschke 60, † | Thomas Dirnböck 61 | Inken Doerfler 62 | Jiří Doležal 63,64 | Ute Döring 65 | Tomasz Durak 66 | Ciara Dwyer 67 | Rasmus Ejrnaes 68 | Inna Ermakova 69 | Brigitta Erschbamer 70 | Giuliano Fanelli 24 | María-Rosa Fernández-Calzado 71 |
... This becomes particularly valuable in situations where co-occurrence surveys are restricted, either in terms of spatial or temporal coverage. The inclusion of presence-only data also provides a cost-effective way of monitoring ongoing dynamics in species communities, an alternative to more intensive co-occurrence surveys, which are often considered information of the highest quality but can be time-consuming and expensive (Dengler et al. 2011). This study was carried out in Norway where both good-quality co-occurrence plots and presence-only records have been sampled extensively over the last 100 years, making the comparison between the two data types possible. ...
Climate warming has triggered shifts in plant distributions, resulting in changes within communities, characterized by an increase in warm‐demanding species and a decrease in cold‐adapted species – referred to as thermophilization. Researchers conventionally rely on co‐occurrence data from vegetation assemblages to examine these community dynamics. Despite the increasing availability of presence‐only data in recent decades, their potential has largely remained unexplored due to concerns about their reliability. Our study aimed to determine whether climate‐induced changes in community dynamics, as inferred from presence‐only data from the Global Biodiversity Information Facility (GBIF), corresponded with those derived from co‐occurrence plot data. To assess the differences between these datasets, we computed a community temperature index (CTI) using a transfer function, weighted‐averaging partial least squares regression (WA‐PLS). We calibrated the transfect function model based on the species–temperature relationship using data before recent climate warming. Then we assessed the differences in CTI and examined the temporal trend in thermophilization. In a preliminary analysis, we assessed the performance of this calibration using three datasets: 1) Norwegian co‐occurrence data, 2) presence‐only data from a broader European region organized into pseudo‐plots (potentially capturing a larger part of the species niches), and 3) a combined dataset merging 1) and 2). The transfer function including the combined dataset performed best. Subsequently, we compared the CTI for the co‐occurrence plots paired up spatially and temporally with presence‐only pseudo‐plots. The results demonstrated that presence‐only data can effectively evaluate species assemblage responses to climate warming, with consistent CTI and thermophilization values to what was found for the co‐occurrence data. Employing presence‐only data for evaluating community responses opens up better spatial and temporal resolution and much more detailed analyses of such responses. Our results therefore outline how a large amount of presence‐only data can be used to enhance our understanding of community dynamics in a warmer world.
... de/ de/ splot. html) have substantially expanded the availability of these types of data (Schaminée et al., 2009;Dengler et al., 2011). ...
Aims: We introduce ReSurveyEurope — a new data source of resurveyed vegetation
plots in Europe, compiled by a collaborative network of vegetation scientists. We describe
the scope of this initiative, provide an overview of currently available data,
governance, data contribution rules, and accessibility. In addition, we outline further
steps, including potential research questions.
Results: ReSurveyEurope includes resurveyed vegetation plots from all habitats.
Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys
of each plot) from 79,190 plots sampled in 449 independent resurvey projects.
Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with
GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%)
plots are from studies in which plots from the initial survey could not be exactly
relocated. Four data sets, which together account for 28,470 (36%) plots, provide
only presence/absence information on plant species, while the remaining 50,720
(64%) plots contain abundance information (e.g., percentage cover or cover–abundance
classes such as variants of the Braun-Blanquet
scale). The oldest plots were
sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950
and 2020.
Conclusions: ReSurveyEurope is a new resource to address a wide range of research
questions on fine-scale
changes in European vegetation. The initiative is devoted
to an inclusive and transparent governance and data usage approach, based
on slightly adapted rules of the well-established
European Vegetation Archive (EVA).
ReSurveyEurope data are ready for use, and proposals for analyses of the data set
can be submitted at any time to the coordinators. Still, further data contributions are
highly welcome.
... Table 2 provides information on the plant families with geoxyle taxa in Angola, and Appendix 1 lists all endemic geoxyle taxa occurring on the Angolan Planalto. For these taxa we retrieved georeferenced occurrence data from the Vegetation Database of the Okavango Basin (ID AF-00-009) in the Global Index of Vegetation-Plot Databases (Dengler et al. 2011), vegetation databases from Angolan Biodiversity Observatories (SASSCAL ObservationNet 2023), collections stored at the herbarium LUBA in Lubango (Angola) and the Global Biodiversity Information Facility (GBIF 2021). For the latter two we manually georeferenced entries which had precise enough locality descriptions. ...
The Angolan Planalto and adjacent areas are characterised by flammable grassy ecosystems. Within these old-growth grasslands, geoxyles are a dominant component and play a key role in the functioning, diversity and beauty of these ecosystems. Geoxyles are a plant life form characterised by having low aboveground biomass and massive belowground wooden structures from which they can draw stored reserves and resprout quickly after disturbances such as fire. The Angolan Planalto has a high number of geoxyle taxa of which many are endemic to the area. We give an overview of the number of geoxyle taxa in these highlands based on a compilation of all available data, discuss reasons for this remarkable diversity, and point out research and conservation priorities for this important life form that is threatened by upcoming land-use changes.
... Because the WetVegEurope project started in parallel to EVA, which at that time was in the stage of developing technical procedures, the first phase of data compilation was achieved through contacting the owners or managers of national, local and thematic databases (concerning aquatic and wetland vegetation types or habitats) from different European countries (WetVegEurope contributors), rather than through data requests to EVA as it is now common. The main databases were identified using the Global Index of Vegetation-Plot Databases (GIVD), a metadata repository of vegetation databases from across the world (Dengler et al. 2011). Additional experts in the fields of aquatic and wetland vegetation able to provide original data were also contacted and invited to join in the project. ...
... We also used geobotanical materials provided by O. Melezhyk (Chokha, 2005). All relevés were stored in the Turboveg for Windows 2.92 database (Hennekens, Schaminée, 2001) and integrated into the database Anthropogenic vegetation of Ukraine, registered in the Global Index of Vegetation-Plot Databases (Dengler et al., 2011) with the code EU-UA-11 and included in the European Vegetation Archive . All vegetation layers were combined into one. ...
The article is a continuation of the study on ruderal vegetation of Kyiv City and provides summarized results of syntaxonomic research of the class Artemisietea vulgaris. We identified 14 associations and one derivative community belonging to three orders and four alliances. Using ordination and phytoindication analyses, the synmorphology of the communities, their ecological requirements, and habitat preferences were described. It has been shown that the vegetation of Artemisietea vulgaris is distributed throughout all districts of the city. According to ecological requirements, we found that main environmental gradients that determine the ordination of different types of stands of Artemisietea vulgaris within Kyiv City are thermoregime and light. The diversity of man-made habitats and regional environmental conditions appeared as the most important factors affecting the territorial differentiation of this vegetation type within the city. The contributed data can be used for strategic planning and practical implementation of measures for sustainable urban development and optimization of the urban environment.
... Community-weighted mean (CWM) data were obtained for 94,422 unique vegetation plots from 105 constitutive datasets, which were a part of the sPlot dataset at the global scale (Fig. 1). The metadata of the individual vegetation-plot datasets stored in sPlot are managed through the Global Index of Vegetation-Plot Databases (Dengler et al., 2011). CWMs (i.e., plot-level trait values weighted by species abundances) coupled with environmental conditions can reflect the selection of locally optimal phenotypes, which include the substantial interspecific trait variation typically found within ecological communities (Sabatini et al., 2021). ...
... This becomes particularly valuable in situations where co-occurrence surveys are restricted, either in terms of spatial or temporal coverage. The inclusion of presence-only data also provides a coste ective way of monitoring ongoing dynamics in species communities, an alternative to more intensive co-occurrence surveys, which are o en considered information of the highest quality but can be time-consuming and expensive (Dengler et al., 2011). This can also be particularly advantageous in areas where field data is di icult to obtain or in cases where intensive fieldwork is not feasible. ...
Climate warming has triggered shifts in plant distributions, resulting in changes within communities, characterized by an increase in warm-demanding species and a decrease in cold-adapted species - referred to as thermophilization. Researchers conventionally rely on co-occurrence data from vegetation assemblages to examine these community dynamics. Despite the increasing availability of presence-only data in recent decades, their potential has largely remained unexplored due to concerns about their reliability. Our study aimed to determine whether climate-induced changes in community dynamics, as inferred from presence-only data from the Global Biodiversity Information Facility (GBIF), corresponded with those derived from co-occurrence plot data in Norway. To assess the differences between these datasets, we quantified a Community Temperature Index (CTI) from the co-occurrence data set and compared this with CTI obtained from presence-only data. We also examined the temporal trend in CTI (i.e., thermophilization) in both datasets. To do this, we first established a species-temperature relationship based on data before climate warming. In a preliminary analysis, we assessed the performance of this relationship using three datasets: 1) Norwegian co-occurrence data, 2) presence-only data from a broader European region organized into pseudo-plots (potentially capturing more species niches), and 3) a combined dataset merging 1) and 2). The transfer function including both datasets performed best. Subsequently, we compared the CTI for the co-occurrence plots paired up spatially and temporally with presence-only pseudo-plots. The results demonstrated that presence-only data can effectively evaluate species assemblage responses to climate warming, with consistent CTI and thermophilization values in comparison to co-occurrence data. Employing presence-only data for evaluating community responses opens up better spatial and temporal resolution and much more detailed analyses of such responses, our results therefore outline how a large amount of presence-only data can be used to enhance our understanding of community dynamics in a warmer world.
... This database contains 1,121,244 unique vegetation plots and 23,586,216 species records originating from different vegetation plot datasets at regional, national, or continental scales, stemming from regional or continental initiatives [23]. The metadata of each individual vegetation plot dataset stored in the sPlot were managed through the Global Index of Vegetation-Plot Databases (GIVD) [26]. Most of the sPlot database v2.1 data corresponds to natural and seminatural vegetation. ...
The functional composition of plant communities (FCPC) makes a significant contribution to ecosystem properties, functions, and services. Here, we used 18 plant functional traits from the sPlot database v2.1 and the global forest management type dataset to explore the links between forest management and the FCPC. We used the post hoc Tukey test to explore the differences in the community-weighted mean (CWM) and community-weighted variance (CWV) among different forest management types [i.e., intact forests, managed forests with natural regeneration, planted forests, plantation forests (with up to a 15-year rotation), and agroforestry]. We found that different forest management types can result in significant variability in plant communities’ functional composition. Plantation forests could result in significantly higher CWM and CWV compared to intact forests, and significant differences could occur between natural and managed forests with natural regeneration. Furthermore, the relationship between forest management practices and the FCPC depends on ecozone type changes. There were significant differences between natural and plantation forests for CWM and CWV in temperate forests. Our study provides an effective reference for applying plant functional traits to regulate and optimize the functions and services of forest ecosystems.
... To our knowledge, the Historic Square Foot Dataset is the largest standardised vegetation data set in grasslands from the late 19th to the early 20th century, particularly when considering that the oldest known vegetation plot worldwide dates to 1864 (Dengler et al., 2011). The exceptional mean and maximum richness found at small scales in representative grasslands around 120 years ago emphasises the ensuing loss of diversity. ...
Grasslands host a significant share of Europe’s species diversity but are among the most threatened vegetation types of the continent. Resurvey studies can help to understand patterns and drivers of changes in grassland diversity and species composition. However, most resurveys are based on local or regional data, and hardly reach back more than eight decades. Here, we publish and describe the Historic Square Foot Dataset, comprising 580 0.09-m2 and 43 1-m2 vegetation plots carefully sampled between 1884 and 1931, covering a wide range of grassland types across Switzerland. We provide the plots as an open access dataset with coordinates, relocation accuracy and fractional aboveground biomass per vascular plant species. We assigned EUNIS habitat types to most plots. Mean vascular plant species richness in 0.09 m2 was 19.7, with a maximum of 47. This is considerably more than the present-day world record of 43 species for this plot size. Historically, species richness did not vary with elevation, differing from the unimodal relationship found today. The dataset provides unique insight into how grasslands in Central Europe looked more than 100 years ago, thus offering manifold options for studies on the development of grassland biodiversity and productivity.
... Relevé databases represent the basis for large-scale scientific and applied vegetation research (Knollová et al. 2005;Schaminée et al. 2009). An establishment of the Global Index of Vegetation-Plot Databases (GIVD; Dengler et al. 2011; http://www.givd. info/), European Vegetation Archive (EVA; Chytrý et al. 2016; http://euroveg.org/eva-database) ...
... Plant cover assessment is a central methodological step in vegetation ecology, phytosociology and habitat monitoring. While there are many other methods for estimating species importance in plant communities, such as frequency analysis, line-intercept analysis, estimation of basal area or harvest of biomass (Mueller-Dombois and Ellenberg 1974;Dierschke 1994;Kent 2012), the by far most often applied approach is to estimate the cover of individual plant species (Dengler et al. 2011;Bruelheide et al. 2019). However, while percent cover is considered the relevant measure, most researchers do not note percent covers directly, instead using an ordinal cover scale or cover-abundance scale. ...
Question : We explored the error resulting from different methods for recording the cover of plants in vegetation plots, specifically the direct estimation of percent cover vs. the use of ordinal cover scales (7-step Braun-Blanquet and 5-step Hult-Sernander-Du Rietz). Methods : We simulated 121 plant species of different cover, sampled with 13 different levels of estimation precision. Estimation precision was either based on a constant coefficient of variation (0.1–1.0) across all cover values or on empirical data from Hatton et al. (1986, Journal of Range Management 39: 91–92) (× 0.5, × 1.0, × 1.5). Each sampling was repeated 10 times. Subsequently, we determined the mean relative and absolute errors that occurred in the data used for ensuing numerical analyses. Results : Except for few cases with unrealistic settings (very high estimation error and ignorance of species with lower cover values), direct estimation in percent yielded better results than the use of ordinal scales. Based on the empirical values of estimation accuracy, the use of ordinal scales inflated the mean absolute and relative errors nearly 2-fold in case of the 7-step Braun-Blanquet scale and about 1.5-fold in case of the Hult-Sernander-Du Rietz scale if only considering cover values above 1%. Conclusions : From our personal experience, the careful application of an ordinal scale is not faster than the direct estimation of percent cover. For this reason, we see no plausible argument supporting the use of ordinal cover scales when essentially all subsequent analyses are numeric.
Abbreviations : Br.-Bl. = 7-step variant of the Braun-Blanquet scale and its numerical replacement as in Table 2; CV = coefficient of variation; H.-S. = Hult-Sernander-Du Rietz scale and its numerical replacement as shown in Table 1.
... We used 4621 vegetation plots from the "Halophytic and coastal vegetation database of Ukraine" and 1678 vegetation plots included into "Psammophytic vegetation database of Ukraine". Both databases are stored using TURBOVEG software (Hennekens and Schaminée 2001), registered with the numbers EU-UA-005 and EU-UA-010 respectively in the Global Index of Vegetation Plot Databases (Dengler et al. 2011) and available in European Vegetation Archive . We used the Expert System for the automatic classification of European and Mediterranean coastal dune vegetation (Marcenò et al. 2018) run in the JUICE software (Tichý 2002). ...
Coastal dunes are ecosystems significantly affected by the invasion of alien plants. The specific flora and plant communities across these habitats are currently under serious threat. The study was performed on shifting and stable dunes in Ukraine. We aimed to analyze (i) the alien species composition across Ukrainian coastal dunes, (ii) the division of alien plants by life forms, ecological requirements, introduction time, geographical origin, and naturalization degree; (iii) the distribution of alien plants in accordance with coastal zonation of sandy shores of the Black Sea and Azov Sea regions; (iv) which habitats are invaded more frequently.
We found that in the flora of Ukrainian coastal dunes, 16.3% of species are alien; among them, 9.4% are neophytes. Most of them originated from the Mediterranean-Turanian region. Anisantha tectorum, Centaurea diffusa, Bromus squarrosus are the most frequent alien species. Regarding Raunkiaer’s system of life forms, 61.6% of alien plants are therophytes. By the soil moisture, submesophytes (45.2%) are predominant. Ecological spectra according to soil acidity, nitrogen content, and salt regime of the soil showed that the alien plants distribution across Ukrainian coastal dunes are determined by the complex influence of different abiotic gradients. The highest number of aliens was observed on shifting dunes (19.3%). The stable dunes are less invaded (14.6%). The alien flora composition differs considerably across these types of dunes as well as across the Black Sea and Azov Sea coasts. Our results showed that the coastal dunes of Ukraine should be in the focus of conservation and management with the position of preventing biodiversity losses caused by alien plant species.
... Therefore, bioindication using EIVs offers a less time-consuming and cheaper alternative to the direct measurement of local environmental variables (Englisch and Karrer 2001;Diekmann 2003;Didukh 2012;Zelený and Schaffers 2012;Marcenò and Guarino 2015). Finally, most historical vegetation data do not contain measurements of environmental data (Dengler et al. 2011). The ability to reconstruct past environmental conditions from historical relevés (Pignatti et al. 2001;Van Calster et al. 2007;Diekmann et al. 2019) or floristic occurrence data (Finderup Nielsen et al. 2021;Hallman et al. 2022;Scherrer et al. 2022) can thus be very valuable in assessing trends in environmental change and their effects on biodiversity. ...
Aims: To develop a consistent ecological indicator value system for Europe for five of the main plant niche dimensions: soil moisture (M), soil nitrogen (N), soil reaction (R), light (L) and temperature (T). Study area: Europe (and closely adjacent regions). Methods: We identified 31 indicator value systems for vascular plants in Europe that contained assessments on at least one of the five aforementioned niche dimensions. We rescaled the indicator values of each dimension to a continuous scale, in which 0 represents the minimum and 10 the maximum value present in Europe. Taxon names were harmonised to the Euro+Med Plantbase. For each of the five dimensions, we calculated European values for niche position and niche width by combining the values from the individual EIV systems. Using T values as an example, we externally validated our European indicator values against the median of bioclimatic conditions for global occurrence data of the taxa. Results: In total, we derived European indicator values of niche position and niche width for 14,835 taxa (14,714 for M, 13,748 for N, 14,254 for R, 14,054 for L, 14,496 for T). Relating the obtained values for temperature niche position to the bioclimatic data of species yielded a higher correlation than any of the original EIV systems (r = 0.859). The database: The newly developed Ecological Indicator Values for Europe (EIVE) 1.0, together with all source systems, is available in a flexible, harmonised open access database. Conclusions: EIVE is the most comprehensive ecological indicator value system for European vascular plants to date. The uniform interval scales for niche position and niche width provide new possibilities for ecological and macroecological analyses of vegetation patterns. The developed workflow and documentation will facilitate the future release of updated and expanded versions of EIVE, which may for example include the addition of further taxonomic groups, additional niche dimensions, external validation or regionalisation.
... Among the article types, we would like to highlight the Database Reports, resulting from an exclusive collaboration with the Global Index of Vegetation-Plot Databases (GIVD; Dengler et al. 2011;www.givd.info). There were three Short Database Reports and four Long Database Reports in 2022. ...
We report on the completed third volume of Vegetation Classification and Survey (VCS). VCS has been included in the Scopus bibliometric database and will receive its first CiteSore in mid-2023. We announce the 2022 Editors’ Award for a paper selected from the four papers nominated for Editors’ Choice during 2022. We selected Liu et al. (2022; Vegetation Classification and Survey 3: 121–144) for the Editors’ Award. This author team developed a comprehensive hierarchical classification system for the steppe vegetation over China. We present five Special Collections (two concluded and three ongoing) which form a backbone for VCS. Apart from Research Papers, Long and Short Database Reports were the prevailing article category in 2022. By contrast, there were no VCS Methods paper in 2022, and thus we encourage submissions particularly in this category. Finally, we welcome new members to the Editorial Board and open a call for free applications for our Editorial Review Board or as a Linguistic Editor.
Abbreviations : APC = article processing charge; IAVS = International Association for Vegetation Science; VCS = Vegetation Classification and Survey.
... Our data were collected between 2010 and 2011 from plots concentrated in two regions of South Africa: 61 plots in the Cape Point section of Table Mountain National Park and 119 plots in the Baviaanskloof Mega-Reserve (Fig. 1). Following the relevé method (Ellenberg and Mueller-Dombois 1974), a well-established inventory protocol used to classify vegetation and inventory species (e.g., Schaminée et al. 2009;Dengler et al. 2011), each 10 × 5 m plot was sampled for its floristic composition using observations of percent cover. Histograms of the observed percents are presented in Fig. 2a. ...
A frequent challenge encountered with ecological data is how to interpret, analyze, or model data having a high proportion of zeros. Much attention has been given to zero-inflated count data, whereas models for non-negative continuous data with an abundance of 0s are much fewer. We consider zero-inflated data on the unit interval and provide modeling to capture two types of 0s in the context of a Beta regression model. We model 0s due to missing by chance through left-censoring of a latent regression and 0s due to unsuitability using an independent Bernoulli specification. We extend the model by introducing spatial random effects. We specify models hierarchically, employing latent variables, and fit them within a Bayesian framework. Our motivating dataset consists of percent cover abundance of two plant families at a collection of sites in the Cape Floristic Region of South Africa. We find that environmental features enable learning about both types of 0s as well as positive percent cover. We also show that the spatial random effects model improves predictive performance. The proposed modeling enables ecologists to extract a better understanding of an organism’s absence due to unsuitability vs. missingness by chance, as well as abundance behavior when present.Supplementary materials accompanying this paper appear online.
... In the last 100 years, vegetation scientists collected and published impressive amounts of plant co-occurrence data by sampling vegetation plots or relevés (Chytrý et al. 2016;Bruelheide et al. 2019). Various continental or global initiatives are presently active in coordinating the aggregation of vegetation databases, such as: i) the Global Index of Vegetation-Plot Databases (GIVD; see Dengler et al. 2011), that contains metadata of many vegetation databases worldwide; ii) the European Vegetation Archive (EVA), a centralised database of European vegetation plots developed by the European Vegetation Survey working group of the International Association for Vegetation Science (IAVS) (Chytrý et al. 2016); iii) the sPlot Consortium, which is developing a global vegetation-plot database to investigate plant trait-environment relationships across biomes and which recently released an open access version (Bruelheide et al. 2019;Sabatini et al. 2021). Apart from these generalist large-scale initiatives, various others are also carried out and implemented, with a special focus on a particular environment or biogeographical region, i.e. the so-called thematic databases, as for example the GrassPlot database of multi-scale plant diversity in Palaearctic grasslands, which also differs in special data quality requirements (Dengler et al. 2018). ...
The importance of collection, storage and exchange of georeferenced vegetation plot-based data has significantly grown in the recent decades, because of the new potentialities offered by ecoinformatics. In this article we introduce the Alma Mater Studiorum – University of Bologna vegetation database (AMS-VegBank; GIVD code EU-IT-021) compiling 17,505 georeferenced vegetation-plot observations within a time span of 90 years. This database includes 337,799 occurrence data of vascular plant species, belonging to many different habitat types. The historical relevance of the presented database is highlighted by the presence of some of the most ancient vegetation-plot observations in Europe (years 1930–1938). The geographic coverage of the database is mostly for Italian territory but it includes also data from other countries. The thematic focuses represented in the database are various, such as small Mediterranean islands, the Dolomite Mountains and the Italian National Parks. The large amount of historical plots available for the country not previously included in existing databases, combined with the constant action to improve the georeferencing of existing data and the addition of new data, highlight the uniqueness of this database. AMS-VegBank represents thus an important tool for studying plant biodiversity within the context of continental and global vegetation plot databases.
Taxonomic reference : All plant names reported in this article follow the nomenclature by Pignatti et al. (2017–2019).
Abbreviations : EVA = European Vegetation Archive; GIVD = Global Index of Vegetation-Plot Databases.
... Later EIV systems added information on air humidity (A), soil organic matter (M) and soil texture (G) (Julve 1998;Landolt et al. 2010). After the initial proposal of EIVs for the central European flora by Ellenberg (1974) recent and historical floristic inventories available from large floristic data-bases (Gégout et al. 2005;Dengler et al. 2011) have allowed the development of EIVs for Switzerland (Landolt et al. 2010), Italy (Pignatti et al. 2005) and France (Julve 1998). Indicator value systems have then also been adapted for other biogeographic regions (Loopstra and van der Maarel 1984;Hill et al. 2000;Lawesson et al. 2003), often by averaging known values of co-occurring species in field inventories to estimates new indicator values for species lacking EIVs. ...
Bioindication of ecological variables such as humidity, temperature or pH by ecological indicator values of plants is a powerful tool for research in plant ecology, e.g. to detect early vegetation changes. Here, we provide a data set of ecological indicator values including niche width for an entire regional flora. We used an extensive data-base with floristic relevés from Southern France to recalibrate indicator values for light (L), temperature (T), continentality (K), air humidity (A), soil moisture (F), pH (R), productivity (N), soil texture (G), soil organic matter content (O) and salinity (S). Values were recalibrated using average values from co-occurring plants, enabling to develop indicator values for species not yet evaluated previously. Recalibrated values are on a continuous scale and we add standard deviation, median, first and third quartile for each indicator value. Linear regression of average indicator values against measured factors showed higher correlation with recalibrated values compared to original indicator values for temperature, pH and nitrogen, and comparable R2 for moisture. Individual indicator systems performed better than a combination and applying different weighting procedures demonstrated the usefulness of inverse variance. We further illustrate graphically how recalibrated values and niche width increase ecological knowledge on plants.
... This method consumes many human, material and financial resources. Although the vegetation quadrat data is being integrated at present (e.g., [17,18]), the integrated databases are still scattered in space and discontinuous in time scale. ...
Satellite data have been widely used to study changes in vegetation greenness in geographical space; however, this change is rarely considered in climatic space. Here, the climatic niche dynamics of vegetation greenness, represented by the normalized difference vegetation index (NDVI), was quantified in the climate space of the Loess Plateau, a piece of degraded land greening significantly from 2000 to 2018. The niche similarity test was used to examine the niche conservatism of vegetation greenness during the 19 years of restoration. The results show that the climate niche of vegetation greenness is always more similar than expected. The stability niche occupied most parts (83–98%) of their climatic niche, and niche overlap reached 0.52–0.69. Climate niche conservatism suggests that potential greenness constructed by statistical methods could be used as a criterion or baseline for ecosystem function restoration on the Loess Plateau. The study also suggests that the integrated niche similarity test in decision-making for restoration of degraded land will clarify our understanding of the climatic niche dynamics of vegetation greenness and the making of forecasts.
... Another example is the Global Index of Vegetation Plot Databases that indexes the metadata of vegetation-plot data that are publicly available (Dengler et al., 2011). In contrast, DataONE has a broader scope that indexes the metadata of a large variety of biological and environmental data (Michener et al., 2012). ...
Aim
Addressing global environmental challenges requires access to biodiversity data across wide spatial, temporal and taxonomic scales. Availability of such data has increased exponentially recently with the proliferation of biodiversity databases. However, heterogeneous coverage, protocols, and standards have hampered integration among these databases. To stimulate the next stage of data integration, here we present a synthesis of major databases, and investigate (a) how the coverage of databases varies across taxonomy, space, and record type; (b) what degree of integration is present among databases; (c) how integration of databases can increase biodiversity knowledge; and (d) the barriers to database integration.
Location
Global.
Time period
Contemporary.
Major taxa studied
Plants and vertebrates.
Methods
We reviewed 12 established biodiversity databases that mainly focus on geographic distributions and functional traits at global scale. We synthesized information from these databases to assess the status of their integration and major knowledge gaps and barriers to full integration. We estimated how improved integration can increase the data coverage for terrestrial plants and vertebrates.
Results
Every database reviewed had a unique focus of data coverage. Exchanges of biodiversity information were common among databases, although not always clearly documented. Functional trait databases were more isolated than those pertaining to species distributions. Variation and potential incompatibility of taxonomic systems used by different databases posed a major barrier to data integration. We found that integration of distribution databases could lead to increased taxonomic coverage that corresponds to 23 years’ advancement in data accumulation, and improvement in taxonomic coverage could be as high as 22.4% for trait databases.
Main conclusions
Rapid increases in biodiversity knowledge can be achieved through the integration of databases, providing the data necessary to address critical environmental challenges. Full integration across databases will require tackling the major impediments to data integration: taxonomic incompatibility, lags in data exchange, barriers to effective data synchronization, and isolation of individual initiatives.
... Sometimes, publications find their way into the other domain. This has become much easier since the dawn of the digital era with large, easily searchable literature databases, open access and scientific networks expanding online (e.g., Dengler et al., 2011). Nevertheless, only a few research groups bridge both disciplines. ...
Questions
Two scientific disciplines, vegetation science and weed science, study arable weed vegetation, which has seen a strong diversity decrease in Europe over the last decades. We compared two collections of plot‐based vegetation records originating from these two disciplines. The aim was to check the suitability of the collections for joint analysis and for addressing research questions from the opposing domains. We asked: are these collections complementary? If so, how can they be used for joint analysis?
Location
Europe.
Methods
We compared 13 311 phytosociological relevés and 13 328 records from weed science, concerning both data collection properties and the recorded species richness. To deal with bias in the data, we also analysed different subsets (i.e., crops, geographical regions, organic vs conventional fields, center vs edge plots).
Results
Records from vegetation science have an average species number of 19.0 ± 10.4. Metadata on survey methodology or agronomic practices are rare in this collection. Records from weed science have an average species number of 8.5 ± 6.4. They are accompanied by extensive methodological information. Vegetation science records and the weed science records taken at field edges or from organic fields have similar species numbers. The collections cover different parts of Europe but the results are consistent in six geographical subsets and the overall data set. The difference in species numbers may be caused by differences in methodology between the disciplines, i.e., plot positioning within fields, plot sizes, or survey timing.
Conclusion
This comparison of arable weed data that were originally sampled with a different purpose represents a new effort in connecting research between vegetation scientists and weed scientists. Both collections show different aspects of weed vegetation, which means the joint use of the data is valuable as it can contribute to a more complete picture of weed species diversity in European arable landscapes.
... In recent years, species occurrence data have increased in volume and accessibility. This can be ascribed to several initiatives: the digitisation of historic biological records (Page et al., 2015); the proliferation and growth of citizen science monitoring initiatives (Spear et al., 2017); the launch of online data aggregators such as GBIF and similar regional portals (Nelson & Ellis, 2019); and the compilation of more specialist databases focused on particular types of ecological community (Dengler et al., 2011), monitoring data (Dornelas et al., 2018) or other evidence types (Hudson et al., 2017). Thanks to these initiatives, it is now straightforward for ecologists to access large quantities of data, and to use them for research. ...
Aggregated species occurrence and abundance data from disparate sources are increasingly accessible to ecologists for the analysis of temporal trends in biodiversity. However, sampling biases relevant to any given research question are often poorly explored and infrequently reported; this can undermine statistical inference. In other disciplines, it is common for researchers to complete ‘risk‐of‐bias’ assessments to expose and document the potential for biases to undermine conclusions. The huge growth in available data, and recent controversies surrounding their use to infer temporal trends, indicate that similar assessments are urgently needed in ecology.
We introduce ROBITT, a structured tool for assessing the ‘Risk‐Of‐Bias In studies of Temporal Trends in ecology’. ROBITT has a similar format to its counterparts in other disciplines: it comprises signalling questions designed to elicit information on the potential for bias in key study domains. In answering these, users will define study inferential goal(s) and relevant statistical target populations. This information is used to assess potential sampling biases across domains relevant to the research question (e.g. geography, taxonomy, environment), and how these vary through time. If assessments indicate biases, then users must clearly describe them and/or explain what mitigating action will be taken.
Everything that users need to complete a ROBITT assessment is provided: the tool, a guidance document and a worked example. Following other disciplines, the tool and guidance document were developed through a consensus‐forming process across experts working in relevant areas of ecology and evidence synthesis.
We propose that researchers should be strongly encouraged to include a ROBITT assessment when publishing studies of biodiversity trends, especially when using aggregated data. This will help researchers to structure their thinking, clearly acknowledge potential sampling issues, highlight where expert consultation is required and provide an opportunity to describe data checks that might go unreported. ROBITT will also enable reviewers, editors and readers to establish how well research conclusions are supported given a dataset combined with some analytical approach. In turn, it should strengthen evidence‐based policy and practice, reduce differing interpretations of data and provide a clearer picture of the uncertainties associated with our understanding of reality.
... This classification is usually based on plot observations (also known as phytosociological relevés), and classification schemes have a hierarchical structure, where the association is the fundamental unit and class is the highest rank (Westhoff and van der Maarel 1978;Dengler et al. 2008). Despite criticisms regarding the common preferential sampling strategy and the heterogeneity in the use of plot sizes and abundance scales (Dengler et al. 2008;De Cáceres et al. 2015), current development of classification methods including the implementation of expert systems (Tichý et al. 2019;Bruelheide et al. 2021) and the proliferation of initiatives compiling and sharing records in vegetation-plot databases (Dengler et al. 2011;Alvarez et al. 2012), enhance the potential application of the Braun-Blanquet approach as a reference system for the summary of vegetation diversity at a national level. ...
Aims : The Braun-Blanquet approach has been widely implemented to generate classification schemes at the country level and Chile is not an exception. In spite of numerous studies, a revised system for the whole country is still missing and most of the current surveys are restricted to a small set of vegetation groups or specific study sites. To fill this gap, we established a vegetation-plot database and updated the classification into a single syntaxonomic scheme. We also performed a comparison of this scheme with the formation system following the EcoVeg approach. Study area : Continental Chile. Methods : We compiled a database of 1,582 plot observations, which are classified into 29 classes, 43 orders, 65 alliances, and 162 associations according to the Braun-Blanquet approach. Results : These observations were assigned to 7 formation classes, 10 subclasses and 19 formations in the EcoVeg approach. There are several mismatches between phytosociological classes and EcoVeg formations, which indicates some inconsistencies in the current stage of syntaxonomy in Chile. Besides a big contrast on bioclimatic conditions within the country’s territory, the occurrence of intrazonal vegetation may explain the high diversity of phytosociological associations recorded in this database. Conclusions : This work may constitute the basis for the implementation of the EcoVeg classification at the levels of alliance and association and can be extended for other countries in the South American sub-continent.
... Testolin et al. (2021) used data from the global vegetation-plot database sPlot (Bruelheide et al., 2019), and four relied on regional data compilations (Bourgeois et al., 2021;Craven et al., 2021;Kusumoto et al., 2021;Tordoni et al., 2021). This pattern highlights that community efforts of collating extensive collaborative vegetation-plot databases, such as EVA, sPlot and GrassPlot, have the potential to facilitate new research avenues (Bruelheide et al., 2019;Dengler et al., 2011;Wiser, 2016), often beyond the initial scopes imagined by the founders of these databases, not mentioning the aims of most original field workers. ...
Aims
The accurate classification of habitats is essential for effective biodiversity conservation. The goal of this study was to harness the potential of deep learning to advance habitat identification in Europe. We aimed to develop and evaluate models capable of assigning vegetation‐plot records to the habitats of the European Nature Information System (EUNIS), a widely used reference framework for European habitat types.
Location
The framework was designed for use in Europe and adjacent areas (e.g., Anatolia, Caucasus).
Methods
We leveraged deep‐learning techniques, such as transformers (i.e., models with attention components able to learn contextual relations between categorical and numerical features) that we trained using spatial k ‐fold cross‐validation (CV) on vegetation plots sourced from the European Vegetation Archive (EVA), to show that they have great potential for classifying vegetation‐plot records. We tested different network architectures, feature encodings, hyperparameter tuning and noise addition strategies to identify the optimal model. We used an independent test set from the National Plant Monitoring Scheme (NPMS) to evaluate its performance and compare its results against the traditional expert systems.
Results
Exploration of the use of deep learning applied to species composition and plot‐location criteria for habitat classification led to the development of a framework containing a wide range of models. Our selected algorithm, applied to European habitat types, significantly improved habitat classification accuracy, achieving a more than twofold improvement compared to the previous state‐of‐the‐art (SOTA) method on an external data set, clearly outperforming expert systems. The framework is shared and maintained through a GitHub repository.
Conclusions
Our results demonstrate the potential benefits of the adoption of deep learning for improving the accuracy of vegetation classification. They highlight the importance of incorporating advanced technologies into habitat monitoring. These algorithms have shown to be better suited for habitat type prediction than expert systems. They push the accuracy score on a database containing hundreds of thousands of standardized presence/absence European surveys to 88.74%, as assessed by expert judgment. Finally, our results showcase that species dominance is a strong marker of ecosystems and that the exact cover abundance of the flora is not required to train neural networks with predictive performances. The framework we developed can be used by researchers and practitioners to accurately classify habitats.
Habitat assessment plays a critical role in rare plant conservation. In environmental impact assessments, developers often need to evaluate importance of vegetation types as rare plant habitats to mitigate the impacts of development projects. However, information on rare plants is often difficult to obtain owing to rarity or non-disclosure. A practical approach to link species occurrences and vegetation types therefore is needed for estimating distribution of plants within their habitats. This study aimed to classify multiple plant habitats and associate them with the phytosociological classification system. A total of 1129 relevés were classified into 129 plant communities based on a tabular comparison and 29 habitat types based on the occurrence of sixty-nine near-threatened species. These habitat types clearly correspond to upper units of the phytosociological system and roughly correspond to keywords from literature descriptions of species ecology. Habitat classification based on phytosociological plant communities is considered effective for plant conservation and impact mitigation.
The current state and syntaxonomic structure of anthropogenic vegetation of the classes Galio-Urticetea and Bidentetea are revealed. The class Galio-Urticetea is represented by 3 phytosociological orders, 6 alliances, and 32 associations. The class Bidentetea unites 8 plant associations of 1 order and 2 alliances. The territorial differentiation of the studied plant communities is caused by the limiting factors: soil moisture and the changing hydrological regime. Thus the phytocoenoses of these classes are confined to the natural zones of Polissia and forest-steppe. Based on detrended correspondence analysis, the leading factors differentiating vegetation units were identified. Within the class Galio-Urticetea, they include the continentality of climate, precipitation regime, and concentration of mineral nitrogen in the soil. The factors of major significance for Bidentetea were soil moisture and the concentration of mineral nitrogen in the substrate.
Aims: Developing a hierarchical classification system for classes, orders and alliances of the diverse dry grasslands of the Central and Eastern Balkan Peninsula and translating this into an electronic expert system (ES) for the automatic assignment of plots.
Location: Serbia, Kosovo, North Macedonia, Bulgaria and northern Greece.
Methods: We extracted 5734 plots from the Balkan Dry Grassland Database corresponding to eight classes of dry grasslands reported from the region, using the EuroVegChecklist ES. This dataset and later the plots within each derived subunit were subjected to a new numerical approach: Starting with an initial partitioning (expert-interpreted TWINSPAN classification), diagnostic species were determined based on their phi values for the target vegetation type and the differences in phi values to the next similar types. These diagnostic species were fed into an ES to create a new partitioning, a procedure which was iterated until diagnostic species and species of the ES converged. Then the same approach was applied within each of the derived units to define the units of the next-lower level.
Results: The iterative cluster optimisation (ICO) converged in all cases. The resulting hierarchical expert system (HES) classified 95% of all plots to alliances. We distinguished four classes with eight orders and 12 alliances: (1) Tuberarietea guttatae (Romuleion); (2) Stipo-Brachypodietea distachyi (Clinopodio alpini-Thymion striati); (3) Festuco-Brometea with Brachypodietalia pinnati (Chrysopogono-Danthonion calycinae and Cirsio-Brachypodion pinnati), Festucetalia valesiacae (Festucion valesiacae), an unnamed order of rocky steppes (with Pimpinello-Thymion zygioidis) and Koelerietalia splendentis (Centaureo-Bromion fibrosi, Saturejion montanae and Diantho haematocalycis-Festucion hirtovaginatae); (4) Koelerio-Corynephoretea with Sedo acris-Festucetalia (Festucion vaginatae) and Trifolio arvensis-Festucetalia ovinae (Armerio rumelicae-Potentillion and Minuartio montanae-Poion molinerii all. nov.).
Conclusions: We created a unified hierarchical classification with an electronic ES using diagnostic species defined by phi values. Our new approach (ICO-HES: iterative cluster optimisation for hierarchical expert systems) allows dividing large datasets into meaningful units at several hierarchical levels, and thus has high potential for complex classifications. Importantly, it overcomes the divide between expert system species and diagnostic species and re-unites them into one concept.
Questions
What are the main vegetation types of forest and shrubland vegetation in central and eastern Euxine Turkey and SW Georgia? What are the main environmental factors affecting their diversity? What is their syntaxonomic position? Can we integrate them into the European vegetation classification system?
Location
Central and eastern Euxine Turkey and SW Georgia.
Methods
We collected 3104 vegetation plots of forest and shrubland vegetation in the study region and performed Two-Way Indicator Species Analysis (TWINSPAN) classification. We described vegetation types based on the classification results, expert knowledge and information from literature sources. We defined diagnostic species and prepared distribution maps for each vegetation type. To determine the most significant environmental variables on floristic differentiation, we used canonical correspondence analysis. Detrended correspondence analysis with passive projection of most significant environmental variables was run to interpret the environmental variation of vegetation types.
Results
The studied vegetation was divided into 29 vegetation types related to seven main vegetation groups: relict Mediterranean forests and shrubland (mainly along the coastline, beside some inland localities), lowland to submontane forests, central Euxine mountain forests, eastern Euxine (Colchic) mountain forests, subeuxine forests, azonal riparian forests and subalpine and alpine shrubland. Elevation is the most important factor causing the differentiation in vegetation. It is followed by longitude and latitude. Among climatic variables, temperature seasonality, annual precipitation and precipitation of the wettest quarter are the most significant factors for vegetation differentiation. These factors correlate with the reduction of maritime climate and geomorphological features.
Conclusions
Vegetation types mostly correspond to the syntaxa accepted in the EuroVegChecklist. However, some of them do not appear in the EuroVegChecklist since they appear only beyond Europe. We described three syntaxa as new: Abietion equi-trojani, Querco cerridis-Carpinion orientalis and Piceo orientalis-Fagenion orientalis. The study revealed high vegetation diversity of the region that should be taken into consideration in ecosystem management and used as a reference in restoration and mitigation of the effects of global changes.
What would you do if temperatures were getting really warm where you live? You might put on some lighter clothes or maybe even move to a cooler place. Many plants do something similar—they “move” to cooler areas to survive current climate warming. Of course, plants cannot move like animals do, but they can slowly change locations as they release their seeds. How do we know that plants are moving? Scientists are studying areas that were first described hundreds of years ago. However, ecologists have found that even though plants respond to warming by changing locations, the temperature increase is so fast that plants cannot always move fast enough to escape the warming climate. This means that some plants might end up living under much warmer conditions than they prefer, which causes them a lot of stress. Stress makes plants vulnerable to other human influences, like land use change or invasive species, which can put entire plant species in danger.
The classic and current perception of biome in its various meanings is fundamentally based on vegetation types that
are considered as discrete or independent and fragmented entities in the landscape. Vegetation units are characterized
by their physiognomy, which is based on the dominant life forms and mainly determined by climatic conditions.
However, vegetation units are associated and mutually interacting at a landscape level. They are determined by local
or regional, climatic, topographic and edaphic gradients within a given territory or geographic area. In this work, we
propose a new conceptual and methodological approach aiming to better understand the biome concept in a landscape
framework, developing ideas already partially advanced by us. In this sense, we consider the biome as a landscape
complex (geocomplex), that spatially includes one to several vegetation geoseries which, in turn, each comprise the
following possible geomorphologically linked vegetation series: i) the potential natural climatophilic vegetation (zonal
vegetation) and their seral successional stages which occur repeatedly in the landscape; ii) edapho-xerophyllous
vegetation (azonal vegetation such as occurs on rocky outcrops or sandy soils); and iii) edapho-hygrophilic vegetation
(azonal vegetation such as flooded vegetation on river banks). Based on surveys and field data (more than ca. 300
transects) obtained by the authors in most South American countries from 1990 to the present, 33 South American
geocomplex biomes and 16 macrobiomes were identified and synoptically characterized, through graphic general
zonation models (phyto-topographic type-profiles) extrapolated from numerous observations along representative
bioclimatical, geomorphological and biogeographically stratified transects. Field data and transect-plots are currently
being processed to be included into the “GIVD database”
Between 2015 and 2020 a study was conducted on the diversity of ruderal vegetation of the Stellarietea mediae class on the territory of Ukraine. It was discovered that this class consists of 48 associations from 12 alliances and 5 orders (Aperetalia spicae-venti, Atriplici-Chenopodietalia albi, Eragrostietalia, Papaveretalia rhoeadis, Sisymbrietalia sophiae). Based on the results of ordination analysis it was found that the distribution of annual ruderal communities is determined by the variation of moisture, soil aeration as well as carbonate and nitrogen content.
For the identification of the restoration potential, the selection of suitable restoration or management measures, the coordination and, if necessary, the resolution of conflicts of land use with the stakeholders and the financing of restoration activities, it is indispensable to determine the objectives in advance of a restoration project. The corresponding reference systems can be found in the pristine natural landscape or the historical and current cultural landscape, or they can be constructed hypothetically.
High-quality ground-truth data are critical for developing reliable Earth Observation (EO) based geospatial products. Conventional methods of collecting these data are either subject to an unknown amount of human error and bias or require extended time in the field to complete (i.e., point-intercept assessments). Digital photograph classification (DPC) may address these drawbacks. In this study, we first assess the performance of a DPC method developed through licensed software to estimate ground cover percentage (%) of bright lichens, a critical caribou forage in fall and winter when other food resources are scarce. We then evaluate the feasibility of replicating this workflow in an open-source environment with a modified U-net model to improve processing time and scalability. Our results indicate that DPC is appropriate for generating ground-truth data in support of large-scale EO-based lichen mapping within the boreal forests of eastern Canada. Our final open-sourced classification model, Lichen Convolutional Neural Network (LiCNN), is comparably accurate yet more efficient than the licensed workflow. Therefore, the LiCNN approach successfully addresses the mentioned shortcomings of conventional ground-truth data collection methods efficiently and without the need for specialized software.
Global patterns of regional (gamma) plant diversity are relatively well known, but whether these patterns hold for local communities, and the dependence on spatial grain, remain controversial. Using data on 170,272 georeferenced local plant assemblages, we created global maps of alpha diversity (local species richness) for vascular plants at three different spatial grains, for forests and non-forests. We show that alpha diversity is consistently high across grains in some regions (for example, Andean-Amazonian foothills), but regional 'scaling anomalies' (deviations from the positive correlation) exist elsewhere, particularly in Eurasian temperate forests with disproportionally higher fine-grained richness and many African tropical forests with disproportionally higher coarse-grained richness. The influence of different climatic, topo-graphic and biogeographical variables on alpha diversity also varies across grains. Our multi-grain maps return a nuanced understanding of vascular plant biodiversity patterns that complements classic maps of biodiversity hotspots and will improve predictions of global change effects on biodiversity.
The increasing CO 2 in the Earth’s atmosphere is directly increasing global temperatures. Plant species around the world must directly and indirectly respond to this temperature change, either by adapting, migrating, or perishing. To evaluate the effect of temperature rises on European plant species, we combined vegetation data with the local average temperature to estimate the temperature range per species. Subsequently, for every 1°C increase in average temperature, we determined the species currently occurring in the Netherlands for which the expected temperature is outside its range, but also the species currently absent from the country for which the expected temperature has moved within its range. We show that up to 40% (427 out of 1239) of the species currently occurring in the Netherlands may become locally extinct if the average annual temperature rises from 9°C in 1950 to 14°C in 2085. We also show that over 1000 species potentially could arrive as climate refugees; however, it is questionable whether these species could reach the Netherlands due to limitations in dispersal capacity. Moreover, these species will have to adapt to the pre-existing ecosystems. Results have major implication for both nature policy as well as nature management.
The paper describes the initial concept of development of Biodiversity Information System (BIS) in India. BIS is customized in GIS domain. The system is to display spatial and non-spatial data on plant species in query shell in GIS domain.
Leaf size influences many aspects of tree function such as rates of transpiration and photosynthesis and, consequently, often varies in a predictable way in response to environmental gradients. The recent development of pan-Amazonian databases based on permanent botanical plots (e.g. RAINFOR, ATDN) has now made it possible to assess trends in leaf size across environmental gradients in Amazonia. Previous plot-based studies have shown that the community structure of Amazonian trees breaks down into at least two major ecological gradients corresponding with variations in soil fertility (decreasing south to northeast) and length of the dry season (increasing from northwest to south and east). Here we describe the results of the geographic distribution of leaf size categories based on 121 plots distributed across eight South American countries. We find that, as predicted, the Amazon forest is predominantly populated by tree species and individuals in the mesophyll size class (20.25–182.25 cm2). The geographic distribution of species and individuals with large leaves (>20.25 cm2) is complex but is generally characterized by a higher proportion of such trees in the north-west of the region. Spatially corrected regressions reveal weak correlations between the proportion of large-leaved species and metrics of water availability. We also find a significant negative relationship between leaf size and wood density.
Taxonomic information models The first step in the implementation of a database driven application is the definition of an appropriate information model, which has to be complex enough to meet the needs of the application and at the same time simple enough to be usable (GÜNTSCH & al., 2002). The taxonomic model has to incorporate nomenclatural rules and the traditional taxonomic relationships (synonymy, taxonomic hierarchy, etc.). In addition, it has to be capable of representing different taxonomic views in order to enable the system to express arbitrary relationships between potential taxa. The solution presented here is based on the IOPI model (BERENDSOHN, 1997), but the process of implementation has led to several changes in the overall design. Other concept-oriented models published over the past 6 years are cited by GEOFFROY & BERENDSOHN (2003a). The Berlin Model is addressing botanical data, but should serve for zoology as well, with some changes in the names section and the composition of nomenclatural reference citations. Because this is a physical model (i.e. the actual database design used in the implementation), the possibility of future changes to the design here presented cannot be excluded. These are and will be documented in the databased documentation attached to BERENDSOHN & al. (2002) on the WWW. That documentation also provides links to the different projects using the Berlin Model (among others, Euro+Med, IOPI / EuroCAT, Med-Checklist, the Dendroflora of El Salvador and AlgaTerra). The core model covers nomenclatural relationships, potential taxa and their relationships, bibliographical information, and a general structure for factual data. The core model is extensible in order to meet specific project requirements by means of adding further entities and relationships. Nomenclatural type designation, for example, is a central subject of the AlgaTerra project and is thus covered in a model extension (see KUSBER et al., 2003). For pragmatic reasons it was decided to base further specification on a relational model for the underlying database. There are clear advantages in other data models, but with the general aim of realising an implementation in the near future, the choice of using a relational model was based on the assumption that – for some time to come – relational database management systems (DBMS) will remain the standard tool for data storage. The DBMS used must be capable of processing stored procedures, functions, and triggers so that maximum integrity of taxonomic data can be achieved at database level. An MS SQL-Server 2000 database has been implemented as a documentation database, serving to store a model implementation of all core and extension tables, a reservoir for program elements related to the model (triggers, user defined functions, stored procedures), and to manage the documentation of the tables and attributes. Documentation of the core model as well as existing extensions is available on-line (BERENDSOHN & al., 2002), the list of tables and attributes being generated dynamically from the documentation database.
Swiss forest releves were analysed in order to answer the two questions: a) which are the predominant gradients causing differences in forest vegetation all over the country and b) how does a calculated gradient system of forests fit Ellenberg's ecogram of a well defined region. Two large species data sets (6488 and 1600 releves each) were analysed with Correspondence and Canonical Correspondence Analyses (CA, CCA). Averaged Landolt's indicator values for moisture, nutrients, reaction, temperature and light served as primary environmental variables, averaged indicator values for humus and continentality, soil-, temperature- and precipitation variables served as secondary. Moisture, soil warmth, soil reaction and light turned out to be the most important factors when referring to the whole country. Soil reaction in combination with soil warmth and moisture were found to influence the submontane forests of the northern parts of the Alps predominantly. With respect to Ellenberg's ecogram, our results confirm the usefulness of the old system. In contrast, recent propositions on paralleling acidity and nutrient richness on the first ecogram axis, prove to be misleading when comparing calculated and expert-derived gradients. We consider our quantitatively derived ecogram a valuable alternative to hitherto available expert-solutions in forest classification projects.
We present a flexible protocol for recording vegetation composition and structure that is appropriate for diverse applications, is scale transgressive, yields data compatible with those from commonly used methods, and is applicable across a broad range of terrestrial vegetation. the protocol is intended to be flexible in the intensity of use and commitment of time, and sufficiently open in architecture as to be adapatible to unanticipated applications. The standard observation unit is a 10 × 10 m (0.01 ha) quadrat or 'module'. Where the extent of homogeneous vegetation is sufficient, multiple modules are combined to form a larger, more representative sample-unit. All vascular species are recorded by cover class and in intensively sampled modules as present or absent in sets of nested quadrats. For each module, tres stems are tallied by diameter class; species with exceptionally high or low stem density can be sub- or supersampled to allow efficient collection of data and assessment of population structure. The most common plot configuration consits of 10 modules arranged in a 2 × 5 array with four modules sampled intensively; this size is often necessary to capture the complexity of a forest community. For rapid reconnaissance or inventory purposes, fewer modules are typically employed, and less information is collected.
Question: Collaborative research efforts and synthetic vegetation analyses are often limited by difficulties in sharing or combining datasets. Can we facilitate these activities by means of an exchange standard for plot-based vegetation data? Methods: In 2003, the Ecoinformatics Working Group and the Council of the International Association for Vegetation Science endorsed the development of a standard exchange schema for vegetation-plot data. In 2007, a first workshop was held to formulate a common set of goals, concepts, and terminology for plot-based vegetation data. At a second workshop in 2008, this ontology was developed into an XML (extensible markup language) schema representation designed to be maximally compatible with existing standards and databases. Results: The exchange standard for plot-based vegetation data (Veg-X) allows for observations of vegetation at both individual plant and aggregated observation levels. It ensures that observations are fixed to physical sample plots at specific points in space and time, and makes a distinction between the entity of interest (e.g. an individual tree) and the observational act (i.e. a measurement). The standard supports repeated measurements of both individual organisms and plots, allows observations of entities to be grouped following predefined or user-defined criteria, and ensures that the connection between the entity observed and taxonomic concept associated with that observation are maintained. Conclusions: Establishment of exchange standards followed by development of ecoinformatics tools built around those standards should allow scientists to efficiently combine plot data over extensive spatial and temporal gradients in order to perform analyses and make predictions of vegetation change and dynamics at local and global scales.
The project "Die Pflanzengesellschaften Mecklenburg-Vorpommerns und ihre Gefährdung" (The plant communities of Mecklenburg-Vorpommern and their vulnerability) is published as a two-volume series consisting of a table volume (2001) and a text volume (2004). Based on a huge vegetation-plot database and a consistent and well-documented methodology, the complete vegetation of this federal state in NE Germany was phytociolociologally classified de novo. The result are 34 phytosociological classes, 12 subclasses, 70 orders, 6 suborders, 125 alliances and 284 associations.
This text volume cotains synoptic tables based on more than 50,000 vegetation plots for all taxonomic ranks from association to class. As a unique feature, the so-called “Gesamtklassentabelle” (synoptic table of all classes) is provided that shows the frequency distribution of all species across the 34 vegetation classes and the resulting assessment of sociological preferences.
An Introduction and summary for English-speaking readers (M. Isermann & J. Dengler; pp. 16–21 of the text volume 2004) makes most of the content of both volumes accessible to persons not comprehending German.
Aim The aims of this study are to resolve terminological confusion around different types of species–area relationships (SARs) and their delimitation from species sampling relationships (SSRs), to provide a comprehensive overview of models and analytical methods for SARs, to evaluate these theoretically and empirically, and to suggest a more consistent approach for the treatment of species–area data.
Location Curonian Spit in north-west Russia and archipelagos world-wide.
Methods First, I review various typologies for SARs and SSRs as well as mathematical models, fitting procedures and goodness-of-fit measures applied to SARs. This results in a list of 23 function types, which are applicable both for untransformed (S) and for log-transformed (log S) species richness. Then, example data sets for nested plots in continuous vegetation (n = 14) and islands (n = 6) are fitted to a selection of 12 function types (linear, power, logarithmic, saturation, sigmoid) both for S and for log S. The suitability of these models is assessed with Akaike’s information criterion for S and log S, and with a newly proposed metric that addresses extrapolation capability.
Results SARs, which provide species numbers for different areas and have no upper asymptote, must be distinguished from SSRs, which approach the species richness of one single area asymptotically. Among SARs, nested plots in continuous ecosystems, non-nested plots in continuous ecosystems, and isolates can be distinguished. For the SARs of the empirical data sets, the normal and quadratic power functions as well as two of the sigmoid functions (Lomolino, cumulative beta-P) generally performed well. The normal power function (fitted for S) was particularly suitable for predicting richness values over ten-fold increases in area. Linear, logarithmic, convex saturation and logistic functions generally were inappropriate. However, the two sigmoid models produced unstable results with arbitrary parameter estimates, and the quadratic power function resulted in decreasing richness values for large areas.
Main conclusions Based on theoretical considerations and empirical results, I suggest that the power law should be used to describe and compare any type of SAR while at the same time testing whether the exponent z changes with spatial scale. In addition, one should be aware that power-law parameters are significantly influenced by methodology.
Development and evaluation of new approaches in phytosociology with special regard to vegetation classification
Phytosociology had its starting point in the beginning of the 20th century as one of several schools which deal with vegetation from a scientific point of view. Josias Braun-Blanquet, who-se textbook ‘Pflanzensoziologie’ had been published in its first edition in 1928, could be seen as the founder of this school. Basic ideas of the Braun-Blanquet approach of vegetation science are the following:
• Plant stands on plots are documented in a standardised manner, the so-called vegetation relevés, which form an adequate mean between being too superficial and being too lavish. They comprise information on location, site conditions and vegetation structure as well as a complete list of the occurring plant species each of those quantified by means of a combined cover-abundance scale.
• Concrete plant stands (phytocoenoses) are thought to be assignable to abstract plant communities (phytocoena), which are characterised and separated one from another with regard to their whole species combination (floristic-coenological method). Since each of its constituent species has a certain ecological optimum and a specific geographical range it should be expected that they as a whole result in a clearly limited ecological space and synareal in which the community is distributed. Therefore it is not necessary to use the accordance in site conditions and geographical range as additional classification criteria.
• Phytocoena are arranged into a hierarchical system according to their floristic similarity. The principal ranks of this system are bottom to top association, alliance, order and class. Those so-called syntaxa are given scientific names deriving from one or two species names.
• As means for recognition and distinction of syntaxa diagnostic species are derived from the phytosociological data: Species which are restricted to a large extent to one such syntaxon are called character species, whereas differential species only differentiate one side only.
Phytosociology has undergone an enormous impetus within the last century and has integrated most of the other former schools of vegetation science step by step. By means of the Braun-Blanquet approach, millions of relevés from all continents have been collected until now. For several countries comprehensive overviews of the plant communities occurring on their territories have been published. Since the 1960s numerous attempts have been made to automate the classification process by means of computer programs (numerical syntaxonomy). Phytosociology also found its way into legislation in the field of nature conservancy as protected habitats defined by the occurrence of certain syntaxa.
In spite of this quantitative success phytosociology was always exposed to intense criticism, going as far as to blame it for not being scientific. Indeed, it must be stated that consistent and generally accepted methods are missing in syntaxonomy as one of the core subjects of phytosociology – even though a huge amount of phytosociological papers have been published and also numerous textbooks. Therefore the major aim of this Ph.D thesis is to develop such methods and to back them up from a theoretical point of view.
As a first step, the three major purposes of vegetation classifications are determined: (1) Naming of the research object to enable communication about them. (2) Reduction of data and making them representable. This means that instead of determining and describing the distribution of numerous species doing the same only for several plant communities will be suitable generally. (3) Framework for the ‘inductive generalisation’: The floristic-coenological delimitation of phytocoena results into a far reaching accordance of the phytocoenoses belonging to them with regard to species combination and site conditions. Phytocoena therefore are suitable reference entities especially for ecological research and nature conservation. Moreover they can be used for bioindication.
These purposes lead to the requests to be made on vegetation classifications which preferably should be meat. Most important are both the inner coherence of the separated units with respect to their major properties and their simple and clear discernibility. As further criteria the following should be mentioned: (1) completeness of the system. (2) Stability of the classification. (3) Tolerance against heterogeneous data. (4) Supra-regional applicability. (5) Applicability for different purposes. (6) Hierarchical structure. (7) Equivalence of syntaxa of the same rank. (8) Adequate number of discerned entities.
As a whole these criteria are already fulfilled in the ‘classical’ form of the Braun-Blanquet approach. Nevertheless some weak points remain:
• Until now precise and operational definitions for major concepts are missing. Syntaxonomy therefore is often difficult to comprehend for laymen. Instead of clear and verifiable criteria for and against a certain classification authors of phytosociological papers often refer to their own ‘expert knowledge’ or quote the opinion of a renowned phytosociologist.
• Even though it has been well known for a long time, that numerous phytocoenoses and phytocoena are lacking character species, there is no generally accepted and methodically sound way to include them into the phytosociological system. As a result such plant stands frequently are not documented by relevés or at least not taken into account in the final syntaxonomic treatment.
• Among phytosociologists belief in minimal areas is widely distributed. These should be relevé areas, beginning with which the species number does not increase substantially any more with further enlargement of the area. But it is well known for a long time by numerous empirical data as well as via theoretical arguments that every increase in area will cause an increase in the mean species number. The only problem ist that this increase is hardly recognizable when plotting the two axes of a species-area-curve in a linear scaling. This is because the function more or less follows a power function. The assumption of the existence of minimal areas lead many phytosociologists not to draw their major attention to relevé areas in syntaxonomy as long as they approximately correspond to the assumed mimimal areas. Relevé sizes for different vegetation types suggested by various textbooks differ by 150,000. Due to the dependence of species numbers from area it is not permissible to compare relevés of different area sizes. Most of the synthetic properties of plant communities as well are influenced by area size. This especially holds true for constancy which is the percentage of occurrences of a certain species within a set of relevés. By means of a conceptual model and empirical data a function is derived which approximately describes this dependence: St (A) = 1 – (1 – St0)(A / A0)^0,42, where St is the constancy and A the area size.
The classification method put forward is formulated as an axiomatic system comprising twelve suggestions of definitions:
1. Phytocoenoses are defined in a pure operational manner as the plant individuals of different species growing in a time-space unit of a certain dimension. Neither discreteness nor integration are demanded a priori. This definition includes expressively all synusiae thriving in that time-space unit as for example epiphytes.
2. The so-called ‘basic syntaxonomic axiom’ states that every phytocoenosis belongs – within a syntaxonomic system – to exactly one syntaxon of a certain rank.
3. The classical definition of fidelity degrees by SZAFER & PAWŁOWSKI (1927) is both contradictory and impractical. Therefore a new differential species criterion is presented in which it says that a species can be called differential of one syntaxon versus another syntaxon of the same rank if its constancy is at least twice as high and this difference in commonness most probably is not due to chance. This formulation goes back to BERGMEIER & al. (1990) but uses constancy percentages instead of constancy classes as otherwise there would be unreasonable changes in the minimum requirements for differential species below and above the class borders.
4. Whereas constancy at association level and below is defined as percentage of relevés in which the species occurs, a constancy reference value (short: constancy) of a higher syntaxon should be calculated as a mean of the constancy values in all associations belonging to it. This me-thod of calculation is due to the fact that associations are considered the basic units of the system and prevents the results from being influenced from different examination intensities in different associations.
5. A differential species below the vegetation class must fulfil the differential species criterion against all other syntaxa of the same rank within the syntaxon of the next higher rank. To a-void both taxa from being named differential species which nearly do not contribute to the discernibility of the syntaxa and effects due to chance a restriction has to be appended: Only those taxa should be given the status of differential species which have at least 20 % constancy within the particular syntaxon and not more than 20 % in the compared syntaxa.
6. As common differential species of a class are those taxa named which are a nowhere seen character species within the particular structural type, but fulfil the differential criterion of two or three classes against all other classes of this type.
7. Character species of a syntaxon are those taxa which meet the differential species criterion compared with all other syntaxa of the same rank within a structural type. The function of character species is twofold: (1) In the classification process the principal demand of the existence of character taxa ascertains the approximate equivalence of syntaxa of one rank, which especially holds true for associations. (2) When a classification is done on the basis of the complete species combination, character species as those taxa which have a clear sociological optimum in a particular syntaxon can be used best as a means for recognition and discrimination of the entities. If the next higher syntaxa occur nowhere together, as an exception from the general rule, one taxon could be named character species in two independent syntaxa. The major reason for restricting the character species to structural types is the dependency of constancy from area size. Since the customary relevé sizes widely differ between different vegetation types, which seems to be sensible at least to some extent, it is not acceptable to classify all of them within one system. It seems to be appropriate to discern two (vegetation types with and without phanerophytes) or three (vegetation types with phanerophytes, without phanerophytes, but with other vascular plants and those built up solely by one layer of mosses, lichens and algae) floristically defined structural types a priori. Some problems related to the practical implementation of this rule are discussed and a pragmatic approach is recommended.
8. Species which meet the character species criterion within more than one syntaxon fitted into one another, which is often the case, are called transgressive character species.
9. With regard to syntaxa not possessing character species of their own it is recommended to apply the central syntaxon concept of DIERSCHKE (1981) at all syntaxonomic levels below the class. Accordingly, at a maximum one central syntaxon not or not sufficiently characterised by character species of its own can be distinguished within a syntaxon of the next higher rank. This is named in the same manner as all other syntaxa. As compared to the ‘deductive meth-ode’ developed by KOPECKÝ & HEJNÝ (1971) and other approaches to deal with negatively characterised syntaxa the suggested method has several theoretical and practical advantages. These are discussed in detail. Most important is probably the fact that the presented approach avoids the introduction of different ways of naming syntaxa, which unavoidably gives the impression that there would be an ecological difference – which in fact does not exist.
10. Syntaxa from association to class level either must be sufficiently characterised by character species of their own or be the central syntaxon of the next higher entity. ‘Sufficiently’ in this case means a constancy sum of all character species of at least 100%.
11. The association is the lowest syntaxon that could be characterised by character species of its own and not divided further in such syntaxa or otherwise it can be regarded as the central syntaxon of a (sub-) alliance.
12. The class is the highest syntaxon characterised well by character species within one structural type. To measure the ‘quality’ of a syntaxon the sum of the constancy values of its character species seems to be appropriate. An adequate classification then would be one in which the constancy sums of all classes are as high as possible. Both the minimum and the mean of those should be maximised.
Some further recommendations for syntaxonomic work are presented which do not form part of the above axiomatic system:
• ‘Graduated’ hierarchies are – from an information theoretical point of view – favourable to ‘flat’ ones. In many cases they reflect the structure of syntaxonomic data better.
• Below association level it seems inappropriate to prolong the linear-monohierarchical classification from above. Here a multidimensional-polyhierarchical approach in which different complexes of differentiating factors stand aside with equal importance has its advantages.
• Formal syntaxonomic classification above class level is to be rejected since the class is ac-cording to the suggested definition 12 the uppermost syntaxon.
The syntaxonomic concept leads to requests upon the drawing up of relevés, the most important of which are the following:
• Since – as has been shown – sound syntaxonomic classification is only possible on the basis of relevés of the same (or at least a similar) size, standard sizes for relevés in different structural types are proposed.
• Due to the above definition of phytocoenoses and to the often high diagnostic value of non-vascular plants it is requested to document in relevés of phytocoenoses (holocoenoses) in principle all macroscopically visual photoautotroph organisms, including all synusiae such as epiphytes.
The practical application of the presented syntaxonomic concept could be understood as a problem of optimisation which has to be treated in an iterative process: The most similar relevés on a floristic basis are to be combined together until the emerging units either possess character species of their own or can be regarded as the central association of a higher unit which evolves from the further joining of these basic units (associations).
The treatment continues with analyses on the question which quotients and differences of percentage constancy values accord to statistical significant differences in commonness. They lead to the recommendation to complete – in case of low numbers of relevés – the requested constancy quotient q > 2 from the differential species criterion by an minimal constancy difference of Δ = (2 ⋅ n1)-1/2, where n1 is the number of relevés in the particular syntaxon.
Additionally, some recommendations concerning the adequate presentation of syntaxonomic data in form of tables arise from the presented syntaxonomic concept:
• It is essential always to give the (mean) sizes of the relevé areas, also in the case of constancy tables.
• Constancy values should be presented as percentages and not in form of constancy classes to allow the application of the differential species criterion.
• To make the results transparent, it is advisable, to give columns for all syntaxonomic levels in constancy tables and not only for associations and their subdivisions.
Nomenclature is the second indispensable part of syntaxonomy besides the classification. It is ruled by the ‘International Code of Phytosociological Nomenclature’ (ICPN), which has been published in its third edition by WEBER & al. (2000). The basic function of the ICPN is to guarantee unambiguity and stability of the scientific names of syntaxa. To achieve this, two major principles are employed, that of priority and that of nomenclatural types. Although this construction and the Code as a whole have proven to be useful, some possibilities for improvement remain, of which the following should render prominent:
• It seems necessary to clearly separate the system of phytocoena and that of synusiae. It is a logical contradiction if one entity at the same time is regarded as syntaxon and synusia as it is common practice at the time being. It is therefore recommended to put the synusial system on a clear nomenclatural basis, by reserving separate endings for its ranks within the ICPN.
• The demands for original diagnoses of associations should be increased, to avoid the further accumulation of nomenclatural ‘ballast’ in literature. It should be pointed out in the ICPN that the requested full species list for a description of an association has to include bryophytes and lichens as well.
• The ruling of subassociations by the ICPN should be omitted, especially due to the fact that it is incompatible with multidimensional subdivisions.
How the presented ideas work when practically applied is shown in detail by several examples, most of which are taken from the comprehensive treatment of the plant communities in the German state Mecklenburg-Vorpommern by BERG & al. (2001b), where they have been use in a large scale survey for the first time. In particular, it is shown how more equivalent classes could be achieved in the system and how central syntaxa could solve classificatory problems about which has been debated at length but to no avail.
Distribution maps of syntaxa have been published rarely so far. One possibility to generate such synchorological maps is the superimposition of distribution maps of their diagnostic species. This results in maps of ‘potential synareals’. This method is both applicable to outline and lattice maps. How this could be done is described in detail. Examples of either case are shown and their interpretation is discussed.
Finally, the presented syntaxonomic concept is examined as a whole: Due to the axiomatic construction it is consistent. It meets the above given requests for vegetation classifications better than any other known approach. It has proven its practical suitability in BERG & al. (2001b), where it enabled the establishment of a syntaxonomic classification of the extant vegetation types within a region, based on a large databank. A major strength of the approach could be seen in the fact, that clear criteria are given to evaluate different classifications with respect to which of those is conform with the method at all and – if there being more – which is the best of them. Likewise high importance has the applicability of the presented method both in manual table work and as basis for an implementation in a numerical classification algorithm. The latter will be a necessary property of any syntaxonomic approach with which the data of one of the large national and supranational vegetation-plot databases arising can be analysed one day.
This paper documents research taking place in the midst of a series of shifts in biodiversity policy in the UK. It examines recent attempts to enrol volunteer naturalists and lay citizens into biodiversity action planning, suggesting that such attempts can be seen as a nascent form of environmental citizenship, which is based on the exchange of knowledge of nature among the different communities involved (policy makers, volunteer naturalists and lay citizens). By focusing on a range of knowledge practices, the paper explores the selective appropriation of some ways of knowing over others. It documents ways in which some actors involved are beginning to reflect on what it might mean for biodiversity policy to accommodate each others' knowledge and practices. The paper suggests that an increased sensitivity to the range of practices and knowledges embodied within these different domains may result in a redefinition and expansion of the category of citizen, and may in turn have implications for the way in which ‘biodiversity’ comes to be defined. Copyright , Beech Tree Publishing.
Berendsohn, W. G.: The concept of “potential taxa” in databases. – Taxon 44: 207‐212. 1995. – ISSN 0040‐0262.
The concept of a “potential taxon” as a name‐ and literature‐related data area in botanical databases is introduced. A potential taxon is a name with taxon circumscription information attached to it by means of one or more literature references. As a compromise solution between linking information in database systems entirely to specimen data or only to accepted names, using potential taxa can effectively preserve information links without hindering rapid database input and information processing. It is suggested that a potential taxon be cited by its name, followed by the abbreviation “sec.” (for secundum = according to) and at least one of the literature references used to define it.
The vegetation relevés stored electronically in the Czech National Phytosociological Database are reviewed. The database was established in 1996, with the central database located in the Department of Botany, Masaryk University, Brno (www.sci.muni.cz/botany/database.htm). On 15 November 2002 this central database contained 54,310 relevés from the Czech Republic, collected by 332 authors between 1922-2002. Ca. 54% of the relevés were taken from published papers or monographs, 21% from theses and the rest from various unpublished reports and field-books. These relevés include 1,259,008 records of individual plant species. Territorial coverage of the country by the reléves is irregular as the areas with attractive natural or semi-natural vegetation are more intensively sampled, with gaps in coverage of less attractive or poorly accessible areas. Most relevés are of broad-leaved deciduous forests (Querco-Fagetea), meadows (Molinio- Arrhenatheretea), dry grasslands (Festuco-Brometea), and marsh grasslands (Phragmito- Magnocaricetea). The quality of the data is discussed, such as researcher bias, preferential selection of sampling sites, spatial autocorrelation and missing values for some data elements.
The Global Index of Vegetation-Plot Databases (GIVD) is a metadatabase of vegetation databases worldwide that was initiated by an international Steering Committee in 2010 and that is hosted on a server in Greifswald. GIVD aims at providing a better overview on the growing number of vegetationplot databases and increasing their accessibility for overarching analyses. In this article, we analyse which data from central Europe (including the Benelux countries) are available in GIVD. On 20 March 2011, 1.35 million of the total 2.45 million registered relevés originated from one of the covered twelve countries. With more than 600,000 digitally available relevés, corresponding to a density of 18 km-2, the Netherlands are globally leading in this respect.
Vegetation and its correlation with environment has been traditionally studied at a single scale of observation. If different ecological processes are dominant at different spatial and temporal scales, the results obtained from such observations will be specific to the single scale of observation employed and will lack generality. Consequently, it is important to assess whether the processes that determine community structure and function are similar at different scales, or whether, how rapidly, and under what circumstances the dominant processes change with scale of observation. Indeed, early work by Greig‐Smith and associates (Greig‐Smith 1952; Austin & Greig‐Smith 1968; see Greig‐Smith 1979; Kershaw & Looney 1985; Austin & Nicholls 1988) suggested that plant‐plant interactions are typically important at small scales, but that the physical environment dominates at large scales.
Using a gridded and mapped 6.6 ha portion of the Duke Forest on the North Carolina piedmont for a case study, we examined the importance of scale in vegetation studies by testing four hypotheses. First, we hypothesized that the correlation between vegetation composition and environment should increase with increasing grain (quadrat) size. Our results support this hypothesis. Second, we hypothesized that the environmental factors most highly correlated with species composition should be similar at all grain sizes within the 6.6‐ha study area, and should be among the environmental factors strongly correlated with species composition over the much larger extent of the ca. 3500 ha Duke Forest. Our data are not consistent with either portion of this hypothesis. Third, we hypothesized that at the smaller grain sizes employed in this study (< 256 m ² ), the composition of the tree canopy should contribute significantly to the vegetation pattern in the under‐story. Our results do not support this hypothesis. Finally, we predicted that with increased extent of sampling, the correlation between environment and vegetation should increase. Our data suggest the opposite may be true.
This study confirms that results of vegetation analyses can depend greatly on the grain and extent of the samples employed. Whenever possible, sampling should include a variety of grain sizes and a carefully selected sample extent so as to ensure that the results obtained are robust. Application of the methods used here to a variety of vegetation types could lead to a better understanding of whether different ecological processes typically dominate at different spatial scales.
Berendsohn, W. G., Anagnostopoulos, A., Hagedorn, G., Jakupovic, J., Nimis, P. L., Valdés, B., Güntsch, A., Pankhurst, R. J. & White, R. J.: A comprehensive reference model for biological collections and surveys. – Taxon 48: 511‐562. 1999. ISSN 0040‐0262.
The article describes an extended entity‐relationship model covering biological collections, i.e. natural history collections of biotic origin; data collections used in floristic or faunistic mapping, survey, and monitoring projects; live collections such as botanical or zoological gardens, seed banks, microbial strain collections and gene banks; as well as novel collection kinds such as of secondary metabolites or DNA samples. The central element in the model is the unit, which stands for any object containing, being or being part of a living, fossilised, or conserved organism. The unit may be gathered (observed or collected) in the field and derived units may recursively emerge from it through specimen processing, breeding or cultivation. In addition, units may form associations (e.g. host/parasite), ensembles (lichen on a rock with fossils), and assemblages (herd, artificial grouping). Gathering events, specimen management (acquisition, accession, storage, preservation, exchange, ownership), and taxonomic or other identifications relate to the unit and are treated in detail. Geographic and geo‐ecological data have not been fully modelled; taxonomic (name) data and descriptive information are treated by reference to other published models.
Bioinformatics, the application of computational tools to the management and analysis of biological data, has stimulated rapid research advances in genomics through the development of data archives such as GenBank, and similar progress is just beginning within ecology. One reason for the belated adoption of informatics approaches in ecology is the breadth of ecologically pertinent data (from genes to the biosphere) and its highly heterogeneous nature. The variety of formats, logical structures, and sampling methods in ecology create significant challenges. Cultural barriers further impede progress, especially for the creation and adoption of data standards. Here we describe informatics frameworks for ecology, from subject-specific data warehouses, to generic data collections that use detailed metadata descriptions and formal ontologies to catalog and cross-reference information. Combining these approaches with automated data integration techniques and scientific workflow systems will maximize the ...
Many incompatible classifications have in the past been applied to the class of European montane-subalpine tall-herb communities (Mulgedio-Aconitetea). The aim of our paper is to develop a consistent classification of all vegetation types of this class from temperate and boreal Europe, derived from a database of individual relevés. We compiled available relevés from central, western and northern Europe. After excluding plots dominated by woody species, those outside the range of 9 - 50 m² size, and stands with prevailing diagnostic species of other classes, 993 relevés remained for the classification, mainly from central Europe. We used cluster analysis (group linkage with flexible beta and Sørensen index) to analyse the structure of the dataset, and translated the results into a syntaxonomic system. The major division is between the temperate order Calamagrostietalia villosae and the newly described northern European order Epilobio lactiflori-Geranietalia sylvatici. The temperate order can be subdivided into five alliances: (i) subalpine tall-forb communities (Adenostylion alliariae), (ii) tall-forb communities of montane-subalpine eutrophic pastures (Rumicion alpini), (iii) subalpine tall-forb and tall-grass communities that are closely related to alpine meadows (Calamagrostion villosae), (iv) mainly montane tall-grass and fern communities of acidic soils (Calamagrostion arundinaceae), and (v) montane tall-forb communities (Arunco dioici-Petasition albi). The northern European order was not divided further at present because too few data were available. We characterise all syntaxa from the alliances upwards ecologically and floristically, provide a revision of their nomenclature, and list the included associations. We also discuss the methodological problems any supra-national classification has to face due to the high heterogeneity of such data and the lack of a continent-wide relevé database of all vegetation types. The use of a priori lists of diagnostic species for the delimitation of the focal syntaxon and the restriction of the analysis to relevés with similar plot sizes turned out to be crucial to derive consistent results. This study demonstrates that the analysis of a comprehensive supra-national database of individual relevés can provide insights that go beyond what is achievable at a regional scale or by comparison of synoptic tables.
The National Vegetation Survey (NVS) databank is designed to safeguard the investment of millions of dollars spent over the last 50 years collecting, computerising and checking New Zealand vegetation data and to optimise the potential knowledge gains from these data. Data such as these can be synthesised across a range of spatial and temporal scales, allow novel ecological questions to be considered, and can underpin land management and legal reporting obligations. The NVS databank builds largely on the base of data collected under the auspices of the New Zealand Forest Service from the 1940s to 1987. In more recent years, it has incorporated data from Protected Natural Area (PNA) surveys and from new and remeasured plots in a range of ecosystems collected by staff of, among others, the Department of Conservation, Landcare Research, regional councils and universities. The databank currently stores data from approximately 14 000 permanent plots, 52 000 reconnaissance descriptions and PNA plots, and 14 000 timber volume plots measured in the 1940s and 1950s. Ecosystems that are best represented are grasslands in montane and alpine areas and indigenous forests. Geographic coverage is widespread but patchy. As the NVS databank continues to develop and grow, a range of data management issues are being addressed. These include (i) developing mechanisms to meet the needs of both data users and data providers and incentives to encourage individuals and organisations to deposit data into the databank, (ii) ensuring that metadata are adequate to allow raw data to be interpreted, and (iii) ensuring that the data stored meet set quality standards. In the future, the databank will take advantage of changing technology to best meet the needs of data users and providers. Further information about the NVS databank can be obtained from www.landcare.cri.nz/science/nvs.
Problem: The increasing availability of large vegetation databases holds great potential in ecological research and biodiversity informatics, However, inconsistent application of plant names compromises the usefulness of these databases. This problem has been acknowledged in recent years, and solutions have been proposed, such as the concept of “potential taxa” or “taxon views”. Unfortunately, awareness of the problem remains low among vegetation scientists.
Methods: We demonstrate how misleading interpretations caused by inconsistent use of plant names might occur through the course of vegetation analysis, from relevés upward through databases, and then to the final analyses. We discuss how these problems might be minimized.
Results: We highlight the importance of taxonomic reference lists for standardizing plant names and outline standards they should fulfill to be useful for vegetation databases. Additionally, we present the R package vegdata, which is designed to solve name-related problems that arise when analysing vegetation databases.
Conclusions: We conclude that by giving more consideration to the appropriate application of plant names, vegetation scientists might enhance the reliability of analyses obtained from large vegetation databases.
Question: What are the differences in trait compositions that enable native plants to colonise comparable natural and man-made habitats? Are these traits independent of phylogenetic relationships between species?
Location: Czech Republic.
Methods: The relative importance of biological, ecological and distributional traits of native species was studied, using a dataset of 75 species growing in rock and wall habitats in the Czech Republic. Species preferences for individual habitats due to climatic conditions and proportions of different vegetation types in their surroundings were partialled out using partial canonical correspondence analysis. The pattern of plant traits along a gradient from natural rock habitats to secondary wall habitats was analysed using regression trees and generalized linear models with and without phylogenetic correction.
Results: The most common native species colonising rock habitats are phanerophytes, mostly woody juveniles, with a CSR life strategy and most are adapted to epizoochory. Summer green leaves, annual life span, CR life strategy, reproduction mostly by seeds and dispersal by ants are all traits positively associated with the ability of species to colonise wall habitats. These species are also characterised by their high demand for nutrients, temperature, base-rich substrates and light. Biological and ecological traits are more important for colonising new habitats than traits related to species dispersal ability or phylogenetic relationships between species. Biological and ecological traits alone explained 29.3% of variability in the species dataset, while dispersal characteristics and phylogeny alone explained 9.1% and 4.8%, respectively.
Conclusions: We outline how the process of environmental filtering determines native species assemblages and identify a set of species traits that enable them to persist in particular habitats. We conclude that although urbanisation generally results in loss of natural habitats, there are new, man-made habitats potentially suitable for native species.
Question: How can quantitative data from vegetation surveys best be assembled in a large regional vegetation database? What effects have intellectual property rights concerns of individual and institutional data holders on data contribution and how can incentives to contribute data be generated?
Location: West Africa, with discussion of a possible approach to dealing with property rights concerns being of wider interest.
Methods: The management of data property rights in the West African Vegetation Database was developed based on consultations with institutions and scientists in five West African countries over 2 years. It was agreed in two successive Memoranda of Understanding.
Results: The West African Vegetation Database addresses property rights concerns by leaving the control over data access with the data owners, and provides incentives to build a distributed research community by fostering data sharing.
Conclusion: We present a potential solution to the problem of intellectual property rights issues being an impediment to data sharing and the compilation of large regional vegetation databases. The data property rights management approach implemented in the West African Vegetation Database provided incentives for the contribution of recently acquired and unpublished data. Numerous phytosociological and dendrometric vegetation surveys have been made available by institutions and individual researchers for regional‐scale analyses. The structures developed may serve as a model for regional‐scale vegetation databases in collaborative settings involving multiple data owners.
Abstract Future biodiversity research will make increaseduse of distributed datanetworks, scientific workflows, and powerful mechanisms for resolving a broad spectrum of primary data. This paper outlines the anatomy,of an ecological niche modeling workflow,and concomitant needs for taxonomic,resolution. Contemporary Linnaean names and synonymy,relationships are shown to be too imprecise too support these needs. Taxonomic concepts (i.e., the meanings of names as specified in a particular source) and a new vocabulary for expressing their semantic interrelationships are introduced as a more reliable long-termsolution. The concept approach has so far been implemented,with success in select taxonomic,databases and regional floristic
The rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119 monitoring plots in 10 countries concentrated in Amazonia and Borneo. In most sites, larger trees are disproportionately at risk. At least within Amazonia, low wood density trees are also at greater risk of drought-associated mortality, independent of size. For comparable drought intensities, trees in Borneo are more vulnerable than trees in the Amazon. There is some evidence for lagged impacts of drought, with mortality rates remaining elevated 2 yr after the meteorological event is over. These findings indicate that repeated droughts would shift the functional composition of tropical forests toward smaller, denser-wooded trees. At very high drought intensities, the linear relationship between tree mortality and moisture stress apparently breaks down, suggesting the existence of moisture stress thresholds beyond which some tropical forests would suffer catastrophic tree mortality.