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Can we compare lichen diversity data? A test with skilled teams
Abstract
Epiphytic lichens have long been used as ecological indicators. Lichen biomonitoring surveys were carried out by five experienced teams and the results compared across the entire process, from sampling design planning to species counting. The five teams received the same background information and worked in parallel but independently in the same area. European standard operating procedures (SOPs), which are still in preparation, were followed in order to identify possible critical issues and improve consistency. Five exercises with progressive reduction in the degree of operational freedom were carried out by the teams. The results revealed differences between teams on each exercise and showed that investigations run by different teams in the same area and at the same time may not be entirely comparable. This was partly due to inherent differences between crews (skills, familiarity with local flora, and accuracy in applying SOPs), partly to ambiguities in the SOPs, and partly to insufficient training with the SOPs. The results may be valuable in improving biomonitoring procedures and in achieving high-quality, consistent lichen diversity data.
... The operator effect (non-sampling error) has been tackled in numerous studies that have tried to evaluate it on the basis of intercalibration tests between individual operators or groups of operators [29][30][31][32][33]. These tests represent basic activities for the assessment of quality assurance [34]. ...
... These tests represent basic activities for the assessment of quality assurance [34]. As lichen biomonitoring is based on the identification of all epiphytic lichen species within a sampling grid, it requires very high levels of taxonomic knowledge [6,[29][30][31][32]35,36]. In this regard, it has been shown that the effect of the operator can sometimes be relevant, even when expert lichenologists are involved in the sampling procedure. ...
... Although several tests [30][31][32] evaluated the accuracy of single operators, none have assessed the results obtained in cases of rotation or partial change of team composition in long-term biomonitoring programs. To fill this gap of knowledge, in this work we investigated temporal variations of epiphytic lichen diversity in relation to the composition of the teams involved in repeated biomonitoring surveys. ...
Lichen biomonitoring programs focus on temporal variations in epiphytic lichen communities in relation to the effects of atmospheric pollution. As repeated surveys are planned at medium to long term intervals, the alternation of different operators is often possible. This involves the need to consider the effect of non-sampling errors (e.g., observer errors). Here we relate the trends of lichen communities in repeated surveys with the contribution of different teams of specialists involved in sampling. For this reason, lichen diversity data collected in Italy within several ongoing biomonitoring programs have been considered. The variations of components of gamma diversity between the surveys have been related to the composition of the teams of operators. As a major result, the composition of the teams significantly affected data comparability: Similarity (S), Species Replacement (R), and Richness Difference (D) showed significant differences between “same” and “partially” versus “different” teams, with characteristics trends over time. The results suggest a more careful interpretation of temporal variations in biomonitoring studies.
... The process of standardization started in 2007 and took into account the previous European and national guidelines (Asta et al. 2002;VDI 2005;AFNOR 2008). In the meantime, some field tests have been performed to obtain information on the type and size of errors and the uncertainty of the methodologies under standardization (Brunialti et al. 2012a, Cristofolini et al. 2014. To fill this gap, the tests dealt with the entire process from survey design to field measurements. ...
... For instance, a recent comparative test to identify critical issues in lichen biomonitoring demonstrated that different teams may select different target populations when planning the work (Brunialti et al. 2012a). Although all of them may be formally correct, these differences are a source of inconsistency in the results and could potentially lead to differing conclusions. ...
... The results of a comparative test carried out of operators on the same area and with the same standard procedures by five independent groups partly confirm this statement. In this study, in fact, most teams adopted a stratified random sampling (Brunialti et al. 2012a). Although they largely agreed on selection of the sampling scheme, considerable differences occurred in subsequent steps of the sampling design: For example, the number of selected land cover categories ranged from 2 to 8 and the sampling density 23-43. ...
Although lichen diversity values are broadly used as bioindicators, mainly for air pollution
, lichen communities can be substantially influenced by other ecological factors, such as tree species and forest structure, and microclimatic conditions. In particular, species composition may be a suitable indicator for climate
and land-use effects as well. For effective utilization of lichen diversity data in biomonitoring
studies including air pollution, ecosystem
functioning
, and forestry studies, standardized sampling procedure and avoiding sampling and non-sampling errors are the important aspects to be considered. Further interpretation of lichen diversity data requires careful data analysis for providing affirmative results related to ambient air quality. In any lichen biomonitoring program, expected deliverables are based on a hypothesis, which may be achieved by standardization of the sampling procedures
based on the functional requirement of the dependent environmental variables. The chapter discusses the procedures and methodology for sampling and interpreting lichen diversity data for biomonitoring
purposes.
... CEN SOPs include sampling design (plot allocation and tree selection) as well as lichen diversity assessment. A national comparative test to identify critical issues was carried out in Italy (Brunialti et al., 2012) and demonstrated that the frequently reported observer error (Giordani et al., 2009) In bold standard trees selected by the control team. ...
... The new CEN guidelines on lichen biomonitoring attempt to promote the harmonization among studies carried out across Europe. This is an ambitious task, as the field performance of even skilled teams may vary considerably (Brunialti et al., 2012). These earlier results were somewhat confirmed in the present study with skilled teams from six different European countries. ...
... Taxonomic accuracy remains a critical issue in the biomonitoring with lichen diversity (e.g. Brunialti et al., 2012). While there was a partial agreement between each test team and the control team in terms of total number of taxa (especially after training), this was not so for the identification at the species level. ...
... Although counting plant species in a plot may seem a conceptually simple and operationally clear measurement, there actually are many potential sources of bias and a number of alternative methodological options: it is often overlooked that biodiversity metrics and indices are comparable only if data are collected with the same methods and conventions through the whole sampling process (Chiarucci et al., 2011;Brunialti et al., 2012). In particular, for environmental monitoring through time, or for comparing the effects of different management regimes, it is necessary that the observed species richness data are not systematically biased by a difference in sampling protocol or quality across the considered time span or treatments (Archaux et al., 2009;Bacaro et al., 2009;Kercher et al., 2003;Morrison, 2016). ...
... Our results underline that even apparently simple indicators can hide pitfalls, and confirm a basic (but often overlooked) principle in biodiversity monitoring, i.e. that diversity metrics can be compared across time or space only if data are collected with the same methods through the entire sampling process (Brunialti et al., 2012;Bacaro et al., 2009;Scott and Hallam, 2003). We tested the two alternative conventions for considering a plant species as "present" in a plot: at fine spatial grains (0.1-0.01 m 2 ), the recording method influenced the estimated alpha-diversity of grasslands to such an extent that the two datasets were statistically different. ...
Plant diversity measures (e.g., alpha- and beta-diversity) provide the basis for a number of ecological indication and monitoring methods. These measures are based on species counts in sampling units (plots or quadrats). However, there are two alternative conventions for defining a vascular plant species as “present” in a plot, i.e. “shoot presence” (a species is recorded if the vertical projection of any above-ground part falls within the plot) and “rooted presence” (a species is recorded only when an individual is rooted inside the plot). Very few studies addressed the effects of the two sampling conventions on species richness and diversity indices. We sampled mountain dry grasslands in Italy across different plot sizes and vegetation types to assess how large is the difference in alpha- and beta-diversity values and in sample-based rarefaction curves between the two methods. We found that the difference is greatly dependent on plot size, being more relevant, both in absolute and percentage values, at smaller grain; it is also dependent on habitat type, being larger in shallow-soil communities, as they have a sparser vegetation structure and host life-form types with a larger lateral spread. At fine spatial scales (<1 m²) the difference is large enough to bias statistical inference, and we conclude that at such scales one should not attempt to compare plant diversity indices if they were not obtained with the same sampling convention.
... This small-scale trial of survey methodologies leads to the clear conclusion that differences between surveyors are an important issue when planning and implementing any survey of lichen species. Other studies have also found significant differences between teams of highly skilled lichenologists (McCune et al. 1997;Brunialti et al. 2002Brunialti et al. , 2012Giordani et al. 2009). Brunialti et al. (2012) classified the sources of error as sampling errors and non-sampling errors (including instrumental accuracy and subjectivity). ...
... Other studies have also found significant differences between teams of highly skilled lichenologists (McCune et al. 1997;Brunialti et al. 2002Brunialti et al. , 2012Giordani et al. 2009). Brunialti et al. (2012) classified the sources of error as sampling errors and non-sampling errors (including instrumental accuracy and subjectivity). Sampling errors are generated by the nature of the sampling itself and by the degree of variability in the target population. ...
The criteria set out by the International Union for Conservation of Nature to identify
threatened species requires information on population trends which, for priority lichen species within
Scotland, is lacking. Collecting such data is problematic as there is a lack of empirical information
on the performance of different sampling designs and survey methodologies. Using Pseudocyphellaria
norvegica as an example species, we tested differences in the efficiency of 3 transect patterns and a 20
minute search for surveying 100 � 100 m cells of potentially suitable habitat. The methods were not
intended to census the total population of the cells but, rather, to provide a standardized, repeatable
estimate of the population density to allow detection of trends through time. We also tested the repeatability
of the methods between surveyors. The results provided no evidence to suggest that controlled
survey methodologies using fixed transect patterns were any better in terms of consistency between
surveyors or numbers of occupied trees found than 20 minute searches of the areas within each
100 � 100 m cell deemed suitable for the target species by an experienced surveyor. Given that following
the fixed transect patterns took approximately twice as long as a 20 minute search, the search
method would clearly be more cost-effective when there are large numbers of cells to survey. For all
survey methods variability between surveyors was high, meaning that it would be extremely difficult
to detect temporal changes in populations, and hence identify population trends. We also examined
the extent to which recording presence/absence at the 1 ha scale might improve consistency between
surveyors and found that it reduced, but did not eliminate, the surveyor variability. Recording only
presence/absence would allow greater numbers of cells to be surveyed using the same level of resources,
but would reduce the amount of information available per cell for use in analysis of population trends.
We conclude that controlling inter-surveyor variability while collecting adequate data for population
trend analysis is a major issue when planning and implementing any large-scale survey of lichen species.
... This small-scale trial of survey methodologies leads to the clear conclusion that differences between surveyors are likely to be an important issue when planning and implementing any larger scale survey of priority lichen species. Other studies have also found significant differences between teams of highly skilled lichenologists (McCune et al., 1997;Brunialti et al., 2002Brunialti et al., , 2012Giordani et al., 2009). Brunialti et al. (2012) classified the sources of error as sampling errors, and non-sampling errors (including instrumental accuracy and subjectivity). ...
... Other studies have also found significant differences between teams of highly skilled lichenologists (McCune et al., 1997;Brunialti et al., 2002Brunialti et al., , 2012Giordani et al., 2009). Brunialti et al. (2012) classified the sources of error as sampling errors, and non-sampling errors (including instrumental accuracy and subjectivity). Sampling errors are generated by the nature of the sampling itself and by the degree of variability in the target population. ...
Background
Understanding trends in species populations, range and habitat quality is a principle
requirement for conservation evaluations. Such evaluations are vital if we are to direct
conservation resources to protect species that are in most urgent need of action and for
which Scotland has greatest international responsibility. Detecting species trends is also an
important step in understanding the impact of environmental pressures on these species.
Surveillance is a priority for lichen species on the Scottish Biodiversity List (SBL) as
transcribed from the pre-devolution UK Biodiversity Action Plan. Surveillance is also required
for statutory reporting against delivery of Scotland’s Biodiversity Strategy and the wider UK
Terrestrial Biodiversity Surveillance Strategy. However, there has been relatively little
development of statistically robust, cost effective protocols for direct surveillance of priority
lichen species. This report outlines a series of studies that will help implement future
repeatable and comparable surveillance protocols.
Main findings
Surveillance capabilities will always be limited by resource availability, so the first step in
this project was to explore how the comparatively large list of lichens on the SBL could be
further prioritised. A number of methods are compared and it is recommended that a
system which focuses on those species which are endemic or for which Scotland hosts
internationally important populations is used.
The next phase of the project considers the approaches required to develop a costeffective
suite of surveillance methods. The objectives and parameters of lichen
surveillance are discussed and this is related to the lichens on the SBL. To identify the
range of surveillance methods required, species are grouped by their geographic
distribution and habitat requirements. This demonstrates that the largest group of SBL
lichens are corticolous with the most common broad habitats being general closed
woodland, trees in open habitats and oceanic western woodland.
Identification and mapping of suitable habitat for the target species is a prerequisite to the
design of any surveillance protocol. Chapter 4 of this report considers how to do this for
the oceanic woodland lichen Pseudocyphellaria norvegica (Norwegian Specklebelly). The
method presented here overlays the distribution of native broadleaf woodland with 1 km squares that contain records for P. norvegica and/or a suite of other ancient oceanic
woodland indicator lichens.
Using the above information, a number of survey methods were tested to assess their
feasibility and statistical robustness. In particular the methods compared inter-surveyor
and between-method variability in target species detection and duration of survey. The
results are analysed and discussed in detail, but the largest source of variation in the data
was between surveyors rather than between methods. However, surveyor variability was
substantially reduced by restricting the survey to time-limited presence/absence surveys
of individual 1 ha cells.
In order to calculate the sample size required to detect a particular percentage change in
a lichen population over a particular time, an estimate of the rate of turnover within a
population is needed. Limited data from pre-existing survey reports were available to help
perform this power analysis. Although assumptions are made, it is estimated that baseline
surveillance of 1400 1 ha cells would need to be established across 30 1 km squares to
have an 80% chance of detecting a 10% decline in P. norvegica. These should be
stratified to cover the full range of the lichen in Scotland.
The report concludes by recommending the next steps to develop and implement a
surveillance programme for priority SBL lichens across Scotland.
... By providing publicly available ITS sequence data for the majority of specimens collected for this study, our results can be integrated in future research using the formal barcoding marker for fungi (Schoch et al. 2012). Rather than relying exclusively on phenotype-based identifications that may be biased in comparisons with other studies (Giordani et al. 2009, Brunialti et al. 2012, Brunialti et al. 2019, these ITS data can be directly integrated into a wide range of studies using the standard fungal DNA barcode. The data reported here provide an important resource for subsequent biodiversity research in the area, including novel perspectives on species distributions and vouchered collections representing any potentially undescribed species that can be used for phenotypic comparisons. ...
The Colorado River and its tributaries on the Colorado Plateau are home to unique desert river ecosystems and changing environmental conditions. Within this region, the Glen Canyon National Recreation Area (GCNRA) is composed of rugged, high desert terrain and is managed by the United States National Park Service as both a recreational and conservation area. Despite the ecological and economic importance of GCNRA, significant components of the ecological communities therein remain poorly characterized, including lichens. Accurately characterizing lichen-forming fungal diversity is challenging due to poorly known taxonomic groups, underexplored regions/habitats, and varying interpretations of morphological differences, including the recognition of environmentally modified forms. To better understand lichen diversity in GCNRA, we used an integrative taxonomic approach, incorporating both traditional morphology-based identification and information from the standard fungal DNA barcoding marker, the ITS, to compile a thorough inventory of lichen-forming fungi in Fifty-Mile Canyon. Vouchered lichen specimens were collected in 2019, and from these the ITS marker was sequenced. Candidate species-level lineages were delimited from family-level multiple sequence alignments using the Assemble Species by Automatic Partitioning web server. Specimens comprising DNA-based candidate species were then evaluated using traditional taxonomically diagnostic characters to link these, where possible, to currently described species. For Fifty-Mile Canyon, we document 100 putative species in 15 families, each represented by vouchered specimens, ITS sequence data, and photographic documentation. For comparison, a survey of historic records from GCNRA revealed a total of 124 documented lichen-forming fungal species throughout the NRA and adjacent land. Approximately 50% of the species documented in Fifty-Mile Canyon had not previously been found in GCNRA, and similar proportions of species diversity have been documented in GCNRA but not observed in our survey. We report 3 species new to North America-Calogaya ferrugineoides (H. Magn.) Arup, Frödén & Søchting, Endocarpon deserticola T. Zhang, X.L. Wei & J.C. Wei, and Xanthocarpia ferrarii (Bagl.) Frödén, Arup & Søchting-verified using ITS sequencing data. In addition, Circinaria squamulosa sp. nov. is formally described here, currently known only from sandstone slabs in Fifty-Mile Canyon. However, the taxonomic identity of many of the candidate species from Fifty-Mile Canyon remained ambiguous at the species level, and some collections likely represent undescribed species-level lineages. Our results revealed unexpected, high species-level diversity of lichen-forming fungi at local scales and that overall lichen diversity across the entire GCNRA is likely vastly undercounted. These data-including DNA barcodes for the vast majority of lichen-forming fungi occurring in this canyon-provide an important resource that can be integrated into subsequent lichen biodiversity research in the southwestern United States and other semiarid climates.
RESUMEN.-El río Colorado y sus afluentes en la meseta de Colorado albergan ecosistemas fluviales desérticos úni-cos y condiciones ambientales cambiantes. Dentro de esta región, el Área Recreativa Nacional de Glen Canyon (GCNRA, por sus siglas en inglés) se compone de un terreno desértico irregular y elevado, el cual es administrado por el Servicio de Parques Nacionales de los Estados Unidos como área recreativa y de conservación. A pesar de la importan-cia ecológica y económica de GCNRA, varios componentes importantes de las comunidades ecológicas que allí se encuentran permanecen mal caracterizados, incluidos los líquenes. El caracterizar la diversidad precisa de los hongos formadores de líquenes representa un desafío debido a que se trata de grupos taxonómicos poco conocidos, regiones/hábitats escasamente explorados y diversas interpretaciones de las diferencias morfológicas, incluido el reconocimiento de formas modificadas por el medio ambiente. Para comprender mejor la diversidad de líquenes en GCNRA, utilizamos un enfoque taxonómico integrador, incorporando tanto la identificación tradicional basada en la morfología como la información del marcador de código de barras de ADN de hongos estándar (marcador ITS), para compilar un inventario completo de hongos formadores de líquenes en Fifty-Mile Canyon. En 2019 se recolectaron
... By providing publicly available ITS sequence data for the majority of specimens collected for this study, our results can be easily integrated in future research using the formal barcoding marker for fungi (Schoch et al., 2012). Rather than relying exclusively on phenotypebased identifications that may be biased in comparison with other studies (Brunialti et al., 2012(Brunialti et al., , 2019Giordani et al., 2009), these ITS data can be directly integrated into a wide range of future studies using the standard DNA barcoding marker for fungi. Our molecularbased approach for initial species delimitation using ASAP provided only an initial perspective into diversity, providing important direction for future taxonomic research. ...
Lichens are major components of high altitude/latitude ecosystems. However, accurately characterizing their biodiversity is challenging because these regions and habitats are often underexplored, there are numerous poorly known taxonomic groups, and morphological variation in extreme environments can yield conflicting interpretations. Using an iterative taxonomic approach based on over 800 specimens and incorporating both traditional morphology-based identifications and information from the standard fungal DNA barcoding marker, we compiled a voucher-based inventory of biodiversity of lichen-forming fungi in a geographically limited and vulnerable alpine community in an isolated sky island in the Colorado Plateau, USA-the La Sal Mountains. We used the newly proposed Assemble Species by Automatic Partitioning (ASAP) approach to empirically delimit candidate species-level lineages from family-level multiple sequence alignments. Specimens comprising DNA-based candidate species were evaluated using traditional taxonomically diagnostic phe-notypic characters to identify specimens to integrative species hypotheses and link these, where possible, to currently described species. Despite the limited alpine habitat (ca. 3,250 ha), we document the most diverse alpine lichen community known to date from the southern Rocky Mountains, with up to 240 candidate species/species-level lineages of lichen-forming fungi. 139 species were inferred using integrative taxonomy, plus an additional 52 candidate species within 29 different putative species complexes. Over 68% of sequences could not be assigned to species-level rank with statistical confidence, corroborating the limited utility of current sequence repositories for species-level DNA barcoding of lichen-forming fungi. By integrating vouchered specimens, DNA sequence data, and photographic documentation, we provide an important baseline of lichen-forming fungal diversity for the limited alpine habitat in the Colorado Plateau. These data provide an important resource for subsequent research in the ecology and evolution of lichens alpine habitats, including DNA barcodes for most putative species/species-level lineages occurring in the La
... Bryophytes and lichens are frequently used as ecological indicator species (Cristofolini et al., 2014;Mölder et al., 2015), but in experimental environmental change studies bryophytes and lichens are not usually identified at species level Hill and Henry, 2011). This is probably because ecologists commonly have problems identifying bryophytes and lichens to species level (Brunialti et al., 2012;Turetsky et al., 2012). It is unsatisfactory that modelling studies on the impact of climate change often lack data on bryophytes and lichens, as the resulting simulations will be of lower value for high altitude, polar and desert regions due to the major importance of bryophytes and lichens in such severe environments. ...
Global change is predicted to have large and rapid impact on polar and alpine regions. Bryophytes and lichens increase their importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning at higher latitudes/altitudes. Here we report from a seven year factorial experiment with nutrient addition and warming on the abundance of bryophytes and lichens in an alpine meadow and heath community. Treatments had significant negative effect on relative change of total abundance bryophytes and lichens, the largest decline to the nutrient addition and the combined nutrient addition and warming treatments, bryophytes decreasing most in the meadow, lichens most in the heath. Nutrient addition, and the combined nutrient addition and warming brought rapid decrease in both bryophytes and lichens, while warming had a delayed negative impact. Of sixteen species that were included the statistical analyses, we found significant negative effects on seven species. We show that impact of simulated global change on bryophytes and lichens differ in in time and magnitude among treatments and plant communities. Our results underscore the importance of longer-term studies to improve the quality of climate change models, as short-term studies are poor predictors of longer-term responses of bryophytes and lichens, similar to what have been shown for vascular plants. Species-specific responses may differ in time, and this will likely cause changes in the dominance structures of bryophytes and lichens over time.
... Brunialti et al. [73] investigated the intercomparability of lichen diversity biomonitoring results obtained by different, but well-experienced, field crews faced with the same problem, at the same time, under the same field conditions, and following the same standard operating procedures. The results showed that surveys run by different teams may be poorly comparable and suggested that comparison of the results of different lichen surveys may lead to incorrect evaluation if there is no formal expression of the acceptable uncertainty. ...
Epiphytic (tree inhabiting) lichens, well-known biomonitors of atmospheric pollution, have a great potential for being used in environmental forensics. Monitoring changes in biodiversity is a useful method for evaluating the quality of an ecosystem. Lichen species occurring within an area show measurable responses to environmental changes, and lichen biodiversity counts can be taken as reliable estimates of environmental quality, with high values corresponding to unpolluted or low polluted conditions and low values to polluted ones. Lichen diversity studies may be very useful in the framework of environmental forensics, since they may highlight the biological effects of pollutants and constitute the base for epidemiological studies. It is thus of paramount importance that great care is taken in the interpretation of the results, especially in the context of a rapidly changing environment and facing global change scenarios. For this reason, it seems advisable to produce several zonal maps, each based on different species groups, and each interpreted in a different way. This exercise could also be a valid support in the framework of a sensitivity analysis, to support or reject the primary results. In addition, a clear and formal expression of the overall uncertainty of the outputs is absolutely necessary.
... A recent paper comparing epiphytic lichen data gathered from specialists from six different European countries found discrepancies in methods, and in identification of taxa, which made it difficult to compare findings across space (Cristofolini et al., 2014). A similar assessment of the same region by five teams of investigators found that, despite being given identical standard operating procedures (SOPs), each of the teams interpreted procedures differently, with the result that sampling strategies and resultant data were not consistent (Brunialti et al., 2012). ...
Arboreal lichens have a wide range of tolerance to habitat disturbance. As a result, they have been used globally as bioindicators of environmental change, particularly for monitoring atmospheric pollution. Here, we use lichens to monitor air quality and ecological integrity (EI) at Kejimkujik National Park and National Historic Site in Nova Scotia, Canada. We provide descriptions of two protocols and compare the results using data gathered in 2006, 2011, and 2016. To monitor air quality, we established 12 monitoring sites throughout the park and used a suite of lichens that are intolerant to air pollution to develop an index of air purity (IAP) that we compared every 5 years. Our protocol for monitoring EI of forest ecosystems was set up at these same 12 sites. We selected 50 regionally common field-identifiable lichen species and genera ranging in sensitivity from disturbance-tolerant to intolerant, and compare their presence in spatially constrained zones on a variety of tree species every 5 years. Our results suggest that air quality in Kejimkujik has increased slightly in the 10 years since monitoring was implemented, which is consistent with improvements in local air quality. Species richness also increased slightly, suggesting that EI has not declined. The maintenance of EI, through protection and restoration of natural resources, is a key priority in the management of national parks in Canada. Our protocols will provide early detection of changes to EI, enabling park managers to take responsive action. We are confident that our protocols can be replicated in other parts of the world with different suites of regionally common lichens.
... Several studies were devoted to assess the relationship between levels of total suspended particles (TSPs) and biomonitors' responses (including lichens) [31,84] and the assessment of human health risk connected with the airborne metals deposition [85]. Nonetheless, ecological monitoring is vulnerable to different error sources that need to be considered as emphatically addressed by Ferretti [86] who listed the main causes as (1) sampling errors [87,88] (sample scheme and sample size), (2) measurement and classification errors in field and laboratory [89], (3) prediction errors caused by models [90], and (4) nonstatistical errors caused by different events related to data entry, transfer and calculus. ...
The ability of lichens to accumulate different air pollutants beyond their needs in line with the atmospheric levels has conducted to their widely acceptance as biomonitors of inorganic and organic air pollution. Either by determining the concentration of accumulated pollutants or by tracking for damages in their health promoted by pollutants, lichens are used for environmental assessment worldwide.In this chapter we review the state of the art on the use of lichens as biomonitors of heavy-metal pollution considering new findings and applications in recent years. To aim on the acquiring of reliable results in inorganic air pollution using lichens, we critically review different alternatives of sample collection and treatment, analytical determination and data analysis for carrying out biomonitoring studies.In this context the main features of lichens as metal bioaccumulators and the related analytical problems in their use are debated.
... Thus, the present DQRs can only be considered as provisional and future revision will be necessary. New exercises have been suggested to obtain a reference value for the assessment on vascular species of the herb layer and for epiphytic lichens (Brunialti et al., 2012;Canullo et al., 2009). ...
Vegetation-related response variables adopted in the ICP Forests are related to health, growth, phenology, and diversity. Their assessment and measurement is subject to errors, which need to be controlled and documented. To do this, data quality requirements (DQRs) and intercomparison exercises were implemented. During 2009 and 2010, 111–260 field crews took part in different exercises organized across Europe. Results revealed that, while for some variables (e.g., tree diameter, standing basal area, ozone injury, species diversity) DQRs were substantially achieved, problems still exist for other measurements/calculations (tree height, volume and increment, crown base height, crown symptoms identification and description). In some cases, achievement of DRQs was partly due to relaxed DQRs. While the recent progresses in Quality Assurance/Quality Control for field surveys are promising, further effort is necessary to sharpen DQRs, refine standard operating procedures, and reinforce training.
... Bryophytes and lichens are frequently used as ecological indicator species (Cristofolini et al., 2014;Mölder et al., 2015), but in experimental environmental change studies bryophytes and lichens are not usually identified at species level Hill and Henry, 2011). This is probably because ecologists commonly have problems identifying bryophytes and lichens to species level (Brunialti et al., 2012;Turetsky et al., 2012). It is unsatisfactory that modelling studies on the impact of climate change often lack data on bryophytes and lichens, as the resulting simulations will be of lower value for high altitude, polar and desert regions due to the major importance of bryophytes and lichens in such severe environments. ...
Environmental changes are predicted to have severe and rapid impacts on polar and alpine regions. At high latitudes/altitudes, cryptogams such as bryophytes and lichens are of great importance in terms of biomass, carbon/nutrient cycling, cover and ecosystem functioning. This seven-year factorial experiment examined the effects of fertilizing and experimental warming on bryophyte and lichen abundance in an alpine meadow and a heath community in subarctic Sweden. The aim was to determine whether short-term responses (five years) are good predictors of longer-term responses (seven years). Fertilizing and warming had significant negative effects on total and relative abundance of bryophytes and lichens, with the largest and most rapid decline caused by fertilizing and combined fertilizing and warming. Bryophytes decreased most in the alpine meadow community, which was bryophyte-dominated, and lichens decreased most in the heath community, which was lichen-dominated. This was surprising, as the most diverse group in each community was expected to be most resistant to perturbation. Warming alone had a delayed negative impact. Of the 16 species included in statistical analyses, seven were significantly negatively affected. Overall, the impacts of simulated warming on bryophytes and lichens as a whole and on individual species differed in time and magnitude between treatments and plant communities (meadow and heath). This will likely cause changes in the dominance structures over time. These results underscore the importance of longer-term studies to improve the quality of data used in climate change models, as models based on short-term data are poor predictors of long-term responses of bryophytes and lichens.
... We also believe that the time is ripe to (i) carry out a revision of the Italian guidelines, including also lichen transplants, and (ii) use the Italian experience to contribute to a desirable European standardization process on this topic, as recently happened for the lichen bioindication method [84]. ...
Biological monitoring by means of lichens as accumulators of trace elements is a very suitable tool to assess and monitor air pollution and it has been adopted in several surveys in Italy in the last 30 years. In this paper, we try to make a critical analysis of this topic in order to understand the state of research and applications in this field. For this purpose, a database of the main field studies carried out in the last 30 years in Italy was prepared. The paper reports a survey of the characteristics of these studies. The aim is to take stock of the situation at present and to give a boost to the scientific community’s efforts to standardize the method at national and international level.
... Thus, the present DQRs can only be considered as provisional and future revision will be necessary. New exercises have been suggested to obtain a reference value for the assessment on vascular species of the herb layer and for epiphytic lichens (Brunialti et al., 2012;Canullo et al., 2009). ...
21.1 INTRODUCTION
The response of forest vegetation to the variety of biotic and abiotic stressors
can be evaluated by several methods and techniques (e.g., Innes, 1993;
Niinemets, 2010). Besides methods concerning biochemistry (e.g., Chapter 12),
physiology, and morphology (mostly used for research purposes), measurements
of tree growth and assessment of tree health, phenology, and species diversity are
essential and represent the core of the “response” investigations within the International
Co-operative Programme on Assessment and Monitoring of Air
Pollution Effects on Forests (ICP Forests; see Chapters 8–11, 13, and 14). These
investigations are based on measurements and visual assessments carried out
in the field on a number of sample trees (health, growth, phenology) or sample
locations (foliar ozone—O3—injury, species diversity) within or nearby the
sample plots (see the chapters referred to above). Measured and visually assessed
data are both subject to the same source of errors (e.g., Ko¨hl et al., 2000), with
sampling error and measurement error being particularly important, and information
on the reliability of the data is essential: “what we measure affects what
we do: and if our measurements are flawed, decisions may be distorted”
(Stiegliz et al., 2009, p. 7).
While sampling errors can be controlled by adequate monitoring design (see
Chapter 7), measurement errors can only be controlled by proper methods and a
continuous Quality Control (QC). It is therefore important to have an agreed set
of procedures to promote, implement, and control the quality of the data
(e.g., Cline and Burkman, 1989). Such a set of procedures has been recently
adopted within ICP Forests and has been summarized in Chapter 20. In this
chapter, we focus on measurement/assessment error related to tree condition,
phenology, growth, foliar injury due to O3, and species diversity as described
in Chapters 8–11, 13, and 14. The occurrence of measurement errors in some
of these investigations is well known (e.g., Bussotti et al., 2003; Chapman,
2005; Dobbertin et al., 1997; Innes et al., 1993; Kitahara et al., 2009;
Neumann and Stowasser, 1986; Sastre and Lobo, 2009; Scott and Hallam,
2002). Here, we present the methodologies adopted within the ICP Forests to
promote and control data quality in investigations based on field measurements
and visual assessments, hereafter referred to as field-based investigations.
Results from recent tests are also presented.
This preliminary exploration of marine lichenized fungi (lichens) as bioindicators of water pollution examined the distribution of intertidal lichen communities in the Boston Harbor Islands National Recreation Area with respect to recorded pollution throughout the harbor. We found significant negative associations between pollution measurements and the health of the lichen community based on cover and species richness. We also observed significant differences in species composition between areas of higher pollution and areas of lower pollution, though not enough data are available to establish the pollution sensitivity or tolerance of individual species. We note that difficulties in the collection and identification of marine lichens hamper efforts to use them broadly as bioindicators. This study suggests that marine lichens could prove useful as bioindicators, but more research is needed to understand the differential effects of pollution on individual species as well as to establish practical procedures both for quantifying marine lichen community health and for widespread bioindication using marine lichens. Finally, one species collected during this study, Verrucaria ceuthocarpa, represents a first report for the Boston Harbor Islands National Recreation Area.
Ecological studies require quality data to describe the nature of ecological processes and to advance understanding of ecosystem change. Increasing access to big data has magnified both the burden and the complexity of ensuring quality data. The costs of errors in ecology include low use of data, increased time spent cleaning data, and poor reproducibility that can result in a misunderstanding of ecosystem processes and dynamics, all of which can erode the efficacy of and trust in ecological research. Although conceptual and technological advances have improved ecological data access and management, a cultural shift is needed to embed data quality as a cultural practice. We present a comprehensive data quality framework to evoke this cultural shift. The data quality framework flexibly supports different collaboration models, supports all types of ecological data, and can be used to describe data quality within both short- and long-term ecological studies.
Various methods have been developed to monitor environmental quality, including biomonitoring using lichen. In this paper, a total of 143 previous studies from the last decade were analyzed to gain insight into current practices, progress, and challenges. Content analysis was employed to systematically characterize and classify the existing biomonitoring using lichen studies into several groups based on research area and scope. Various aspects of current biomonitoring applications using lichen were analyzed and it was found that the number of related studies increased significantly in recent years. Two main techniques for biomonitoring using lichen were identified, with varying research scope and types of parameters that were measured in the studies. Finally, the current practices, progress, and challenges of biomonitoring using lichen as the biological indicator were discussed, and future recommendations were provided.
Species richness is a key variable in measuring diversity of ecological communities. It is crucial to get reliable estimates for the number of plant species in space (mapping) and – even more important in the context of monitoring – over time. Therefore, knowledge on error rates related to recordings of species numbers should be considered in such inventories. The performance of observers in four field tests to capture species numbers carried out in forest ecosystems in central and southern Europe were compared. Observer-related species accumulation (rarefaction) curves and derived efficiency curves were analysed, resulting in mean error rates of 29.7% and 39.4% over series of plots sized 4 m² and 100 m² respectively. As a new approach individual rarefaction and efficiency curves reveal site-specific and spatially differentiated capabilities of observers to register plant species. Since expertise and individual searching strategies are difficult to parametrise, reasons for variation in error rates remain largely unknown. However, statistical modelling with site- and scale-specific mean error rates gave an overview on important influential factors like location, scale, spatial integration, and their interactions. Our results underline the importance to incorporate specific training and inter-comparison measures in monitoring programs and critical perception of results on temporal changes of species richness.
Local species richness is a crucial biodiversity measure also in monitoring projects. This study was carried out in a species-rich beech forest on limestone within the communal forest of the city of Gottingen. It compares species richness estimates from nine surveyors (five individuals and two teams of two) on plots of 4, 100, and 400 m(2) size. The influence of surveyor and elapsed time on the outcome was investigated. Additionally, species-specific overlooking and misinterpretation rates were estimated. As a further source of error, wrong assignment of plant specimen to plots was considered. Analysis of recorded questions of the probates did not reveal a differentiated familiarity with the on-site vegetation on the base of their professional embedding in regional terms. Outcomes have therefore to be seen as the result of individual training and experience. On the spatial level of the 4 m(2) plots relative deviances between expected values of species richness and estimates of individual surveyors varied between 8 and 26% (1 to 4 species absolutely). At the 100 m(2) plots differences between surveyors were with 9 to 27% (2 to 6 species absolutely) even more pronounced. With increasing plot area effects from plot identity tend to decrease, while observer effects distinctly increase. For the 100 m(2) plot level an effect of processing time was detectable. None of the species were found by all surveyors at all subplots on which they occurred. Closely related or otherwise similar species, and those which were in an unfavourable developmental stage, had a higher chance of being overlooked or misinterpreted. Species with peculiar morphological features were considered to be misallocated. For all three types of error respective rates were calculated. The relationships found have generally to be considered in monitoring projects focusing on vegetation changes; however, in large-scale cross-sectional surveys respective error rates should be considered. An organized controlling system is outlined.
Local species richness is a crucial biodiversity measure also in monitoring projects. This study was carried out in a species-rich beech forest on limestone within the communal forest of the city of Göttin-gen. It compares species richness estimates from nine surveyors (five individuals and two teams of two) on plots of 4, 100, and 400 m2 size. The influence of surveyor and elapsed time on the outcome was investigated. Additionally, species-specific overlooking and misinterpretation rates were estimated. As a further source of error, wrong assignment of plant specimen to plots was considered.
Analysis of recorded questions of the probates did not reveal a differentiated familiarity with the on-site vegetation on the base of their professional embedding in regional terms. Outcomes have therefore to be seen as the result of individual training and experience. On the spatial level of the 4 m2 plots relative deviances between expected values of species richness and estimates of individual surveyors varied between 8 and 26% (1 to 4 species absolutely). At the 100 m2 plots differences between survey-ors were with 9 to 27% (2 to 6 species absolutely) even more pronounced. With increasing plot area effects from plot identity tend to decrease, while observer effects distinctly increase. For the 100 m2 plot level an effect of processing time was detectable.
None of the species were found by all surveyors at all subplots on which they occurred. Closely re-lated or otherwise similar species, and those which were in an unfavourable developmental stage, had a higher chance of being overlooked or misinterpreted. Species with peculiar morphological features were considered to be misallocated. For all three types of error respective rates were calculated.
The relationships found have generally to be considered in monitoring projects focusing on vegeta-tion changes; however, in large-scale cross-sectional surveys respective error rates should be consid-ered. An organized controlling system is outlined.
Repeated ecological assessments based on permanent plot data require sufficient data quality to detect a signal of change against a background of noise (sampling error of various kinds). We analyzed several components of error in the time-constrained method for sampling lichen communities used by the Forest Health Monitoring program: between-crew (Technicians), crew-to-expert, between-expert, and seasonal variation. Data were from the southeastern United States and Oregon. Two types of dependent variables were used: species richness and scores on lichen community gradients (responses to climatic and air quality gradients). Gradient scores were repeatable to within 2-10% for experts and technicians alike and did not differ between those groups. Species richness is much more difficult to estimate reliably. Despite relatively low species capture by technicians, the high repeatability in gradient scores demonstrates the statistical redundancy in information provided by various lichen species. These results simply that repeated assessments of species richness will contain considerable observer error, but that shifts in community composition may nevertheless be detected reliably.
Different error budgets are approximated for the First Swiss National Forest Inventory. An error budget displays the effects of individual errors and groups of errors on the accuracy of estimates. The goal of developing the error budgets was to account for the significant sources of errors that can be expected in the national survey. Sources of error included measurement error of quantitative and qualitative attributes, regression error, and sampling error. It was found in general that the national survey system was not very sensitive to unbiased random errors but was sensitive to systematic measurement errors. For. Sci. 38(3):525-538.
Widespread changes in natural and managed environments in the last century have been associated with rapid development of technology with the capacity for massive destruction of natural environments. This has been accompanied by large-scale natural disasters such as floods and droughts and by large-scale technical failures such as Chernobyl, impacting greatly on human existence and welfare. It is the impact on social conditions that has led to increasing interest in maintaining environmental quality and ensuring that human activities do not threaten the ecosystem on which we depend. The threats to human health by water and air pollution led to early research on bioindicators in order to map and monitor the effects of pollution on selected organisms. However the range of objectives to which biomonitoring is applied has grown steadily from water quality and atmospheric pollution to heavy metal accumulation, climate change, and to environmental issues involving management of natural resources such as the effects of fragmentation and habitat alteration, effects of development on biodiversity as well as assessing conservation practices for rare or endangered species.
In the last decades, several methods were proposed for assessing environmental quality — mainly air pollution — on the basis of lichen data (see chapter 4, this volume). At the end of the 80s the predictivity of 20 different methods with respect to instrumental pollution data was tested in Switzerland using multiple regression [1, 5]. The highest correlation was found with the sum of frequencies of lichen species within a sampling grid of 10 units positioned on the trunks of free-standing trees. This method was immediately and widely adopted in several other countries, esp. Italy and Germany, with some modifications, chiefly concerning the size of the sampling grid. Since 1987, hundreds of studies were carried out with this approach, which led to its standardization in the form of guidelines both in Germany [13], and in Italy [7].
The mid-Atlantic region of the United States has a wide diversity of natural resources. Human pressures on these natural resources are intense. These factors have resulted in the collection of substantial amounts of environmental information about the region by EPA (both Regional and Research Offices), other governmental agencies, industry, and environmental groups. EPA Regional Offices comprehend first hand the importance of environmental data and are extremely supportive of investments in these data. Environmental data are used prominently in a variety of strategic planning and resource management initiatives. In EPA Region 3, the use of scientifically-sound environmental data is, in fact, one of our strategic programmatic goals. Environmental information is captured and assessed continuously by Regional staff, sometimes working in partnership with other Federal and State agencies, to derive relevant resource management conclusions. The restoration goals for the Chesapeake Bay are based on environmental indicators and resulting data. Attainment of the water quality objectives for streams and coastal estuaries are predicted on monitoring data. Our initiative in the Mid-Atlantic Highlands area uses environmental indicators to measure the condition of forests and streams. Landscape-level indicators will provide unique opportunities for the use of data in planning and management activities in support of the principles of community-based activism and sustainable development. Significant value is added to these data during their use by Regional managers. Regional programs, such as the Chesapeake Bay Program and several National Estuary Programs, are founded in environmental data. Environmental information is used by the Regional program managers to ascertain whether programs are accomplishing their intended objectives. Finally, Regional programs provide a crucial means for disseminating this information to broad segments of the public, so that a better informed and educated client base for effective environmental protection will develop.
Changing land use has a major impact on lichen diversity. This study attempts to identify patterns or trends of lichen functional groups along a land use gradient, ranging from natural forests to open agricultural landscape. In eight countries, covering six main European biogeographic regions, lichen vegetation was assessed according to a standardized scheme. Data on reproductive, vegetative and ecological traits was compiled and relative species richness for all classes of all traits calculated. Relationships between the land use gradient and relative species richness of trait classes were analysed. Open and intensively managed landscapes harbour more fertile species while sterile species are relatively more important in forests. This finding is also supported by analyses of different classes of dispersal propagules. The importance of species with the principal photobiont Trebouxia s.l. increases linearly with intensification of land use. A converse pattern is revealed by species with Trentepohlia. Concerning substratum specialization only generalists show an effect along the land use intensity gradient. Their relative species richness decreases from landscapes dominated by forests to open agricultural landscape. A considerable decline in the rare lichen species richness as a result of land intensification is predicted.
The distribution of lichen species in upland regions of Aberdeenshire, Scotland, is investigated along a landuse gradient from natural forest to intensive agriculture. Quantitative data on lichen communities on saxicolous, epiphytic and terricolous substrata were collected from 16 hectares in one km2 in each landuse type. Multivariate analyses, NMDS and Cluster analysis were used to identify lichen communities associated with environmental factors including landuse, substratum type and age. The epiphytic community of native pinewoods was distinguished from all others by the highest species richness, the presence of indicators of ecological continuity and the absence of nitrophytes, while the epiphytic communities of farmland were distinguished by absence of acidophytes and a high contribution of nitrophytes. Plantations of conifers were distinguished by low species richness and an increase in tolerant species. Saxicolous communities were frequent on walls in all sites except native pinewood, where saxicolous substrata were rare. Intensively farmed sites were distinguished by an increase in percentage contribution of nitrophytes. The high acidophyte contribution in all sites suggests that crustose species of acid rocks may not respond rapidly to an increase in applied nitrogen. In landscapes where tree cover is sparse or non-existent combined assessment of habitat diversity and nitrophyte indicator species can be used to assess changes associated with agricultural intensification.
Information about airborne pollen concentration is of concern for health authorities across Europe. The reliability of data estimates depends on the accuracy and precision of pollen counts. In Italy, pollen counts are carried out on slides for microscopic evaluation and are regulated by the national Standard UNI 11108:2004. Our results showed that counts performed according to the Italian standard may result in a significant bias in the number of pollen grains counted and this will have an impact on final estimates of pollen concentration. For the same sample size, confidence intervals vary in relation to pollen abundance, either in terms of number of grains or of number of species. The sample size suggested by the standard (20% of the target surface) may result in errors in pollen counts ranging from 7-55% of the mean value, and in missing 22-54% of the taxa present on the slide.
Two groups assessed ozone symptoms on tobacco leaves: one was represented by young students and the other by scientists with experience in plant biology, but not experienced scorers. In the first case, results demonstrate that in the first week of exposure the extent of injury is almost always overestimated, but in the second week it is correctly evaluated or slightly underestimated: this can be due to the variable ambient ozone levels. In the second case, the average accuracy levels ranged from 40 to 82%, with an average repeatability of 95.2%. Central classes of damage are more difficult to evaluate: this may depend on the fact that two leaves may have similar total injured area, but substantially different number and spatial distribution of the lesions. Some practical suggestions in order to reduce non-sampling errors and to improve operator training are given.
“Design”, “sampling” and “quality” are highly relevant to the subject of this book for different reasons. First, although there is a wealth of experience in monitoring the effects of atmospheric pollution by plants (e.g. [35, 61, 62, 87]), it seems that the importance of an appropriate sampling design is often underestimated [63, 112]. Indeed subjectivity in sampling procedures was found to be the main source of data variability in bioindication studies based on lichens (e.g. [88]). Similarly, field sampling of plants for chemical analyses was proven to introduce errors exceeding 1000%, whereas all the subsequent steps (e.g. storage, drying, homogenisation and chemical decomposition) may cause errors of up to 100–300% (e.g. [5, 63, 112]).
Much of our knowledge about the status of and changes in ecological systems and their response to environmental stresses has originated from ecological monitoring. However, concern exists about the ability of monitoring to provide 'good' data. The value of monitoring is often questioned and monitoring itself is seen as an exercise with little contact with true science. Such concerns are justified given several examples of abuse and misuse of monitoring data and failure in documenting errors and flaws. When data are flawed, even the most sophisticated statistical and modelling technique is useless. As a consequence, there are risks that the environmental policy decisionmaking process may be severely compromised, leading to wrong decisions and additional costs to society. Data quality is therefore essential for decision quality. However, data quality goes beyond the traditional perception of metrological quality, and the process of obtaining 'good' data needs to consider all the steps involved in the monitoring. Ecological monitoring cannot survive outside a rigorous scientific context, and a comprehensive quality assurance framework is necessary to drive the design and the implementation of a monitoring programme.
Biomonitoring has become a key concept in environmental management since it is the most ecologically-relevant means for assessing pollution impact. Its broad applicability, however, raises the need for harmonization, optimization and standardization. The main difficulty met in the development of a generalized methodological framework for standardizing biomonitoring surveys is to reconcile a theoretical approach with an operational approach: in any set-up the survey strategy should ensure that the measured values represent the status of the environment. This leads, inevitably, to the application of a variety of methods, techniques and strategies in order to accommodate the special ecogeomorphological characteristics of each area and handle adequately the knowledge gaps related to local species stress response mechanisms and tolerances. Thereby, comparability of the results, even between subsequent surveys in the same area or concurrent surveys at neighbouring areas, is unfeasible, yet indispensable in defining spatiotemporal pollution patterns in large ecosystems. This inevitably requires some kind of normalization/harmonization that would strengthen any observed correlations between exposure and health effects, which ultimately may point at potential causal relationships. The aim of this work is to design/develop a knowledge management tool, built on a cybernetic infrastructure for (i) localizing the variation source(s) in each project that prohibit inter-survey normalisation/comparability, (ii) determining the path of error propagation as a causal chain when a fault is identified, (iii) testing the ultimate causes suggested as mostly responsible for this fault, and (iv) proceeding to remedial proposals (including a feedback possibility in case that the suggested remedy is proved to be inadequate) with a view to improving quality and reliability of biosurveillance. The presented tool relies on Fuzzy Fault Tree Analysis (FFTA) to identify, categorise, sort and analyse all possible sources of variation and error in biomonitoring; thereby, an expert system is developed, where the tree (dendritic) structure serves as the Knowledge Base (KB) and the fuzzy rules based decision mechanism is the inference engine. This scheme, relying on a collaborative model building methodology and a systemic modeling formalism by using 2nd order cybernetics in order to include human judgement and reasoning, enables knowledge to be used not only for representation but also for reasoning at functional level.
In the search for cost-effective methods for measuring and monitoring lichen diversity, we tested the performance of two possible indicators: lichen genus diversity and macrolichen diversity. We studied the lichen vegetation of eight European countries situated in six different biogeographic regions. In each country, six land-use units (each 1 km(2)) representing a land-use gradient ranging from old-growth forest to farmland were sampled (n=48) for terricolous, saxicolous, and epiphytic lichens at 16 plots each. We found 768 different lichen species belonging to 157 genera. Relationships between richness and density of genera and species, species and macrolichens, and crustose lichens and macrolichens were highly significant (p<0.001) for all substrates combined and for epiphytic and saxicolous lichens. Richness and density of genera and macrolichens explained a large amount. of variation of the species richness and density (R(2): 71.9%-98.0%). The relationship between crustose lichens and macrolichens explained less of the variation (R(2): 37.7%-70.1%). Effects of land-use intensity on the richness and density of genera, species, and crustose lichens were similar, except for a strong difference between the forested and the more open land-use units for epiphytic crustose lichens. For epiphytic macrolichens there were fewer significant effects. Detrended correspondence analysis indicated similar ordering of sites along the major gradients and similar length of these gradients for genera, species, macrolichens, and crustose lichens. Both genera and macrolichens are useful indicators of total lichen species richness and density. Macrolichens, however, are more suitable indicators than genera owing to (1) their more stable taxonomy of species than of genera, (2) the potential that nonspecialists could do the sampling, (3) the limited use of genera data for species conservation, and (4) the fact that species extinctions will not be indicated by nonmonotypic genera.
Multi-national statistics are frequently based on data, whichoriginate from national surveys. The systems of nomenclatureapplied for key attributes often show national differences.Different error sources which are incorporated in multi-nationalstatistics are discussed. The paper presents approaches forharmonisation and standardisation of multi-nationalenvironmental statistics and gives examples from the forestrysector. The effect of differences of national forest areaestimates on multi-national figures is quantified. An examplefrom forest health surveys is presented that shows the impact ofdifferent interpretation and application of the attribute crown transparency that is already harmonised on theEuropean level.
Basic and applied studies based on biodiversity data need accurate information on the distribution of species. However, several studies clearly show that this information is frequently biased, mainly as a consequence of aggregated survey patterns in which taxonomists repeatedly select localities with specific characteristics. In this study, we have constructed three different but simple virtual species richness scenarios to simulate the capacity of random, aggregated or regular survey designs to reveal the true biodiversity pattern. We are specifically interested in the effect of taxonomist insistence on surveying those localities that guarantee success in the collection of as many species as possible (species richness bias), and on the coordinated or uncoordinated character of the efforts carried out by the whole community of taxonomists. In all simulated species richness scenarios, a survey directed towards those localities that were previously recognized as having a higher species richness value is not recommended if the aim is to recover the true geographical pattern of species richness in a given territory. This aggregated process of allocating survey localities is probably caused by the primary aim of taxonomists, which is to acquire specimens of rare species and/or as many species as possible. However, an increase in taxonomist curiosity towards non-surveyed localities near those previously identified as the richest allows one to obtain better results, provided that the species richness pattern is not too patchy and the effort for discovering the true map is not too difficult. Our results suggest that planned survey designs are necessary when most of the data comes from studies not specifically designed to reveal the distribution of biodiversity. The capacity of this data to represent the real geographical pattern of biodiversity may depend on the capacity of the taxonomist community to be self-motivated.
A Working Ring Test (WRT) was organised in the framework of the EU Regulation (EC) No 2152/2003 ("Forest Focus") and of the UN/ECE Program "ICP Forests" to evaluate the overall performance of the laboratories monitoring atmospheric deposition and soil solution in European Forests. Seven natural samples of atmospheric deposition and soil solutions and 5 synthetic solutions were distributed to 52 laboratories, which analysed them using their routine methods. Thirteen variables are considered in this paper: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulfate, nitrate, chloride, total alkalinity, total dissolved nitrogen and dissolved organic carbon. For each variable, the relative standard deviation of the results was evaluated, after outlier rejection, to estimate the analytical error of the measurements. The results are evaluated considering the Quality Assurance/Quality Control (QA/QC) procedure included in the ICP Forests monitoring manual: consistency check of the data and use of control charts and internal standards. A Data Quality Objective (DQO) is defined for each of the variables and the number of data meeting the DQOs are discussed in relation to the QA/QC procedures adopted. Although 38% of the results did not meet the DQO, the laboratories adopting QA/QC procedures produced a larger proportion of results meeting the objective and a consistent part of the outliers could be detected a posteriori checking analyses consistence.
Rapid Biodiversity Assessments (RBAs) of lichen communities, obtained by means of simplified sampling lists based on morphospecies, showed good correlations with Lichen Diversity Values (LDVs), based on the complete identification of lichen species only when performed by operators with high levels of taxonomic knowledge. Furthermore, the use of highly simplified sampling lists did not lead to significant advantages in terms of time needed for field operations. This approach proved to be especially unreliable in high diversity ecological contexts where variation of morpho-structural composition within lichen communities is frequent (i.e. co-occurring crustose- and foliose-dominated communities); it may also lead to weak results if applied for conservation purposes. Hence, the use of simplified RBA sampling lists in lichen monitoring has to be carefully evaluated and, in any case, should be based on sound taxonomic knowledge on the part of those in charge of data collection. The proper assessment of descriptors of lichen abundance and/or frequency, however, strictly depends on the skill, taxonomic knowledge, and willingness to learn of the lichenologist-in-training.
A graphical abstract is available for this content
A total of 65 operators involved in lichen mapping studies in central and northwestern Italy underwent quality control tests during five lichen biomonitoring workshops organized between 1999 and 2000. The results showed that 75% quantitative accuracy and 90% quantitative precision can be regarded as satisfactory levels for lichen biodiversity data; 65% proved to be sufficient for accuracy of taxonomic identification in the field. Average correct assignment of the interpretative naturality/alteration class was only 48.7%. The results indicated the need for taxonomic training.
Statistica (Data Analysis Software System), Version 8
- I Statsoft
StatSoft I, 2007. Statistica (Data Analysis Software System), Version 8.0.
Biosurveillance de l'environnement -Détermination d'un indice biologique de lichens épiphytes (IBLE)
AFNOR, 2008. Biosurveillance de l'environnement -Détermination d'un indice
biologique de lichens épiphytes (IBLE). NF X43-903.
Biologische Messverfahren zur Ermittlung und Beurteilung der Wirkung von Luftverunreinigungen mit Flechten (Bioindikation) Kartierung der Diversität epiphytischer Flechten als Indikator für Luftgüte. VDI/DIN-Handbuch Reinhaltung der Luft, Band 1a, VDI-Handbuch Biotechnologie
- Vdi-Richtlinie
VDI-Richtlinie 3957, Blatt 13, 2005. Biologische Messverfahren zur Ermittlung und
Beurteilung der Wirkung von Luftverunreinigungen mit Flechten (Bioindikation) Kartierung der Diversität epiphytischer Flechten als Indikator für Luftgüte.
VDI/DIN-Handbuch Reinhaltung der Luft, Band 1a, VDI-Handbuch Biotechnologie, Band 2, Beuth-Verlag, Berlin.
Monitoring With Lichens: Monitoring Lichens. Kluwer Academic Published in Association with the NATO Scientific Affairs Division
- P L Nimis
- C Scheidegger
- P A Wolseley
Nimis, P.L., Scheidegger, C., Wolseley, P.A., 2002. Monitoring With Lichens: Monitoring Lichens. Kluwer Academic Published in Association with the NATO Scientific
Affairs Division, Dordrecht, London.
La storia naturale della Toscana meridionale
- P Barazzuoli
Barazzuoli, P., 1993. Il Clima. In: Giusti, F. (Ed.), La storia naturale della Toscana
meridionale. Amilcare Pizzi Editore, Milano, pp. 141-171.
Performance of macrolichens and lichen genera as indicators of lichen species richness and composition
- Bergamini
Repeatability of community data: species richness versus gradient scores in large-scale lichen studies
- McCune