David Zelený

David Zelený
National Taiwan University | NTU · Institute of Ecology and Evolutionary Biology

PhD

About

76
Publications
31,569
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Introduction
I am vegetation ecologist, assistant professor and PI at Vegetation Ecology Lab at National Taiwan University, Taiwan. Some of the questions that fascinate me right now: What causes diversity patterns in plant communities along gradients like elevation, the frequency of cloud and intensity of wind? What is the relative importance of primary ecological processes like ecological drift, dispersal or selection, in maintaining species coexistence in real plant communities? How useful is the trait-based approach in vegetation ecology? Why do we feel that we should apply more and more complicated analyses to answer more and more trivial questions?
Additional affiliations
June 2009 - July 2015
Masaryk University
Position
  • Researcher
July 2005 - May 2009
Masaryk University
Position
  • Research Assistant
July 2004 - June 2005
University of South Bohemia in České Budějovice
Position
  • Research Assistant

Publications

Publications (76)
Article
Several processes are hypothesised to mediate the relationship between local (microsite) plant species richness and the topographical heterogeneity of the surrounding landscape. In a topographically heterogeneous landscape with various habitats occurring close to each other, local species richness may be enriched by species from surrounding habitat...
Article
1. Fridley et al. (2007) introduced a technique of species habitat specialization assessment based on co-occurrence analysis of large species-plot matrixes, with a continuous metric (θ value) intended to reflect relative species niche width. 2. They used simulated data in order to demonstrate the functionality of the new method. I repeated their si...
Article
Question Mean Ellenberg indicator values (EIVs) inherit information about compositional similarity, because during their calculation species abundances (or presence–absences) are used as weights. Can this similarity issue actually be demonstrated, does it bias results of vegetation analyses correlating mean EIVs with other aspects of species compos...
Article
Full-text available
Variation partitioning of species composition into components explained by environmental and spatial variables is often used to identify a signature of niche- and dispersal-based processes in community assembly. Such interpretation, however, strongly depends on the quality of the environmental data available. In recent studies conducted in forest d...
Article
Full-text available
Aim Species on islands are at high risk of extinction due to environmental changes, including global warming, land‐use alterations and invasions. At local scales, extinctions can be offset by strategies promoting in situ persistence. We explored how persistence‐related traits of plants—that is, linked to belowground resource conservation, growth, s...
Article
Although the relative importance of climate in abiotic filtering is higher for woody than herbaceous species assemblages, it is unclear whether this pattern is also reflected between the woody overstory and herbaceous understory of forests. The understory might respond more to small‐scale soil variation, next to experiencing additional abiotic filt...
Article
Aim: Trait-based approaches are being used increasingly in island biogeography, providing key insights into the eco-evolutionary dynamics of insular systems. However, the determinants of persistence of plant species after they have arrived and established on an island remain largely unexplored. Here, we used three edaphic island systems (i.e., habi...
Article
Current climate warming and extended droughts have major impacts on plant performance, with consequences for biodiversity and ecosystem functioning. However, unlike in trees, little is known about species-specific responses in grassland plants and the role of their different life histories in mitigating climate change impacts. We studied the climat...
Article
Questions We aim to 1) investigate and describe the species composition of vegetation that has recolonised landslides and describe its relationship to environmental variables, and 2) propose a set of plant species and restoration strategies applicable for speeding up the restoration process. Location Elevation between 240 and 1350 m a.s.l. in cent...
Preprint
Full-text available
Community weighted means (CWMs) are widely used to study the relationship between community-level functional traits and environment variation. When relationships between CWM traits and environmental variables are directly assessed using linear regression or ANOVA and tested by standard parametric tests, results are prone to inflated Type I error ra...
Preprint
Full-text available
While the relative importance of climate filtering is known to be higher for woody species assemblages than herbaceous assemblage, it remains largely unexplored whether this pattern is also reflected between the woody overstory and herbaceous understory of forests. While climatic variation will be more buffered by the tree layer, the understory mig...
Preprint
Full-text available
While functional trait-trait and trait-environment relationships are well studied in angiosperms, it is less clear if similar relationships, such as the leaf economics spectrum (LES), hold for ferns and lycophytes. Similarly, studies exploring potential differences in trait-trait and trait-environment relationships between terrestrial and epiphytic...
Preprint
Full-text available
1. Species extinction risk at local scales can be partially offset by strategies promoting in-situ persistence. We explored how persistence-related traits of clonal and non-clonal plants in temperate dry grasslands respond intra- and interspecifically to variation in environmental conditions (soil, climate) and insularity. 2. We focused on edaphic...
Article
Full-text available
The theory of island biogeography postulates that size and isolation are key drivers of biodiversity on islands. This theory has been applied not only to true (e.g. oceanic) islands but also to terrestrial island-like systems (e.g. edaphic islands). Recently, a debate has opened as to whether terrestrial island-like systems function like true islan...
Preprint
Full-text available
Aim Trait-based approaches are increasingly implemented in island biogeography, providing key insights into the eco-evolutionary dynamics of insular systems. However, what determines persistence of plant species once they have arrived and established in an island remains largely unexplored. Here, we examined links between non-acquisitive persistenc...
Preprint
Full-text available
Recent climate warming is associated with the increasing magnitude and frequency of extreme events, including heatwaves and drought periods worldwide. Such events can have major effects on the species composition of plant communities, hence on biodiversity and ecosystem functioning. Here we studied responses of Central European dry grassland plants...
Article
Full-text available
The Pladias (Plant Diversity Analysis and Synthesis) Database of the Czech Flora and Vegetation was developed by the Pladias project team in 2014-2018 and has been continuously updated since then. The flora section of the database contains critically revised information on the Czech vascular flora, including 13.6 million plant occurrence records, w...
Article
Full-text available
We develop a novel class of measures to quantify sample completeness of a biological survey. The class of measures is parameterized by an order q ≥ 0 to control for sensitivity to species relative abundances. When q = 0, species abundances are disregarded and our measure reduces to the conventional measure of completeness, that is, the ratio of the...
Article
Dispersal is important for the formation of biodiversity patterns. However, studying dispersal is difficult, particularly in established communities. We examined local dispersal processes in forest herbaceous layer by looking at the abundance of plants in the neighbourhood of the surveyed plots and using dispersal traits and fecundity‐related attri...
Article
Full-text available
During the Bremen Symposium, the new Council meeting on Wednesday 17 July, a new IAVS Governing Board has been elected: Susan Wiser: President, David Zelený: Secretary. Martin Diekmann: Vice President, Alessandra Fidelis: Vice President, Monika Janišová: Vice President, Javier Loidi: Vice President, Peter Minchin: Vice President. In order to introd...
Article
Full-text available
Since 2013, the International Association for Vegetation Science every year allocates some money to support students and researchers in financial needs to participate at the IAVS Annual Symposium. This year, at the 62nd IAVS Symposium in Bremen, we met with awarded participants to explain where the travel award money come from, how the GSC committe...
Article
Full-text available
Theoretically the concept of species ecological specialization is very useful, however, practically it is often difficult to quantify due to a lack of relevant environmental data. We introduce the Ecological Specialization Index (ESI), which describes the degree of specialization of a species based on its realized niche along multiple environmental...
Presentation
Full-text available
In 2012, together with André Schaffers, I published the “Too good to be true“ paper in JVS. It described inflated Type I error rate in analyses testing the relationship of mean Ellenberg indicator values (mEIV) to sample scores on ordination axes (or other variables derived from a species composition, like species richness or assignment of samples...
Article
Full-text available
A new dataset of ecological indicator values for species, subspecies and some varieties, hybrids and infrageneric species groups has been compiled for the vascular flora of the Czech Republic. Indicator values for light, temperature, moisture, (soil) reaction, nutrient availability and salinity were assigned to 2275 species and 801 other taxa, usin...
Article
Biodiversity of semi-natural grasslands depends on the management practices used. However, management systems suitable for one taxon, such as plants, can be detrimental to other taxa, such as insects, and vice versa. This study attempts to support conservation management planning by clarifying the effects of different grassland management practices...
Presentation
Full-text available
One way to analyze the relationship between species attributes and sample attributes via the matrix of species composition is to calculate the community-weighted mean of species attributes (CWM) and relate it to sample attributes by correlation, regression or ANOVA. This weighted-mean approach is frequently used by vegetation ecologists to relate s...
Preprint
Full-text available
One way to analyze the relationship between species attributes and sample attributes via the matrix of species composition is to calculate the community-weighted mean of species attributes (CWM) and relate it to sample attributes by correlation, regression or ANOVA. This weighted-mean approach is frequently used by vegetation ecologists to relate s...
Article
Species attributes are often used to explain diversity patterns across assemblages/communities. However, repeated species co-occurrences can generate spatial pattern and strong statistical relationships between aggregated attributes and richness in the absence of biological information. Our aim is to increase awareness of this problem. North Americ...
Article
Full-text available
Soil pH is a key predictor of plant species occurrence owing to its effect on the availability of nutrients and phytotoxic metals. Although regional differences in realized soil pH niche (‘niche shifts’) have been reported since the 19th century, no study has disentangled how they are influenced by spatial differences in substrate availability, mac...
Article
One of the fundamental tools in biogeography is the classification of the Earth surface into spatially coherent units based on assemblage distinctiveness. However, spatial coherence of biogeographical regions may be scale-dependent, that is, it may change with changing the size of spatial units used. We ask (1) how the clusters resulting from the c...
Data
Table S1. Locations of the six areas for the test communities and the representation of the vegetation types considered. Table S2. Variables used in the species distribution models with Biomod.
Article
Ecological specialization refers to a restricted ecological niche breadth for a species, resulting from the trade-off between range of the resources it can exploit and efficacy in exploiting a specific resource. One hypothesis predicts that specialist species should be dominant in stressful environments, whereas generalist species should be dominan...
Article
Montane cloud forest is one of the most endangered ecosystems. However, there are few comprehensive studies on the distribution of subtropical montane cloud forest (SMCF). Chamaecyparis forest is one type of SMCF in Taiwan, distributed across the whole island. This study describes eleven types of this forest in Taiwan based on the Braun-Blanquet ap...
Article
Several hypotheses postulate that species invasion is affected by an interplay between the phylogenetic position of the invading species and the phylogenetic structure of the invaded community type. Some of them suggest that phylogenetic relatedness of invaders to native species promotes naturalization, because phylogenetically related alien specie...
Article
Full-text available
Urban habitats differ in their disturbance regimes, which act as an environmental filter determining plant community species composition. This is why plant communities in different urban habitats provide a suitable model for studying the effects of disturbance on phylogenetic diversity. We explore how phylogenetic diversity varies across urban plan...
Article
Studies that explore species–environment relationships at a broad scale are usually limited by the availability of sufficient habitat description, which is often too coarse to differentiate natural habitat patches. Therefore, it is not well understood how the distribution of natural habitats affects broad-scale patterns in the distribution of anima...
Article
Full-text available
It is generally recognized that the number of land snail species increases with the number of individuals in samples. This correlation may be an artefact of sample size, but it may also reflect the similarity in microhabitat preference of many species. Biotic interactions (competition) might also influence this relationship: an upper limit to coexi...
Presentation
Full-text available
Community-weighted mean of species trait values (CWM), one of functional diversity indices, became a standard tool to scale-up functional traits from individual to community or ecosystem level. Common practice is to test the relationship between CWM and environmental variables or ecosystem properties, e.g. using regression or correlation. In this s...
Presentation
Full-text available
Ellenberg indicator values represent estimated optima of plant species along main ecological gradients. Values assembled by Ellenberg are valid mostly in central Europe, but similar systems were developed also in other parts of Europe (e.g. Landolt’s values for Switzerland, Borhidi’s for Hungary, Jurko’s for Slovakia, Zarzycki’s for Poland, Hill’s...
Article
We studied changes of terrestrial snail assemblages over a gradient of soil moisture using 60 sampling plots in the White Carpathian Mountains of the south-eastern Czech Republic. We used within-site design to control for confounding effects of site characteristics other than humidity, and we directly measured soil moisture along nine transects at...
Article
Full-text available
We focused on the gradient in moisture along transects of from 8 to 30min length from spring fen to semi-dry grassland vegetation. We selected an area in the calcium-rich part of the Western Carpathian flysch zone (Czech and Slovak Republics) where small spring-fed fens occur in close contact with semi-dry grasslands. Altogether 126 vegetation plot...
Article
Some regions and habitats harbour high numbers of plant species at a fine scale. A remarkable example is the grasslands of the White Carpathian Mountains (Czech Republic), which hold world records in local species richness, however the causes are still poorly understood. To explore the landscape context of this phenomenon and its relationships to d...
Article
Full-text available
We identify the main forest vegetation types in Taiwan, provide their formal definitions and describe their species composition, habitat affinities and distribution. Taiwan. A data set of 9822 vegetation plots with environmental characteristics recorded in the field or derived from digital maps in GIS was compiled from historical literature and an...
Article
To what extent do semi-natural grasslands differ in community specificity (i.e. the representation of habitat specialists in a community)? Does the community specificity coincide with evolutionary history and nutrient availability of the habitats? West Carpathian semi-natural grasslands (Czech Republic, Slovakia, Poland). Habitat specificity of ind...
Article
Biomass is an important ecological property, but its measurement is destructive and time-consuming and therefore generally missing for historical vegetation plots. Here we propose and test indirect estimation of herbaceous biomass using models based on easily obtainable variables, namely plant height and cover. We compare these models with Ellenber...
Article
Full-text available
Vegetation of boreal coniferous forests has been extensively studied in many areas of northern Eurasia and North America, but similar forests in the high mountains of subtropical and tropical eastern Asia have been poorly documented so far. This paper, focusing on such forests, is the first phytosociological study at a national scale in Taiwan. The...
Article
Questions We discovered forests with very high local numbers of vascular plant species in southern Siberia. Are these the most species-rich forests of the Eurasian boreal and temperate zones, and which factors cause such high species richness? Location Altai Mountains in southern Siberia, Altai Republic, Russia. Methods We sampled vegetation a...
Article
Full-text available
Ellenberg indicator values (EIVs) represent valuable expert information on ecological behaviour of vascular plant species in the western and central parts of Europe. The mean of EIVs for species in vegetation relevés and floristic inventories are considered to be a good proxy of habitat characteristics and a relevant surrogate for environmental fac...
Presentation
Full-text available
Mean Ellenberg indicator values (EIVs) for vegetation samples are calculated as a mean of species EIVs present in the samples, possibly weighted by species abundances. Mean EIVs are therefore derived from two information sources, compositional data about occurrence of species in samples (vegetation matrix) and external data about species ecological...
Article
Aim In contrast to non-forest vegetation, the species richness–productivity (SR-P) relationship in forests still remains insufficiently explored. Several studies have focused on the diversity of the tree layer, but the species richness of temperate deciduous forests is mainly determined by their species-rich herb layer. The factors controlling herb...
Article
Full-text available
Habitat productivity and vegetation biomass are important factors affecting species diversity and ecosystem function, but factors determining productivity are still insufficiently known, especially in the forest herb layer. These factors are difficult to identify because different methods often yield different results. We sampled the herb layer bio...
Article
Questions Does plant species richness and composition of eastern Mediterranean dwarf shrubland (phrygana) correlate with soil pH? How important is the effect of pH on species diversity in relation to other environmental factors in this ecosystem? What is the evolutionary background of the diversity-pH relationship? Location Western Crete, Greece. M...
Conference Paper
Full-text available
Background/Question/Methods Fridley et al. (2007) introduced an algorithm estimating habitat specialization of plant species using information from large species co-occurrence datasets (typically composed of vegetation samples). The measure reflects betadiversity among vegetation samples containing given species: lower betadiversity is considered...
Article
Question: Large databases contain many plots, but few subsets with measured environmental data. To obtain broader datasets, researchers use expert-based indicator values as surrogates; alternatively, these can be estimated by imputation. Does imputation provide more exact approximations than indicator values?Location: West Carpathians (Slovakia, Po...
Article
Aim: To propose a modification of the TWINSPAN algorithm that enables production of divisive classifications that better respect the structure of the data.Methods: The proposed modification combines the classical TWINSPAN algorithm with analysis of heterogeneity of the clusters prior to each division. Four different heterogeneity measures are invol...
Presentation
Full-text available
Generally accepted rule states that in order to avoid circularity of reasoning, one should not use as an explanatory the variable, which is directly derived from explained variable. This is also the case of mean Ellenberg indicator values (EIVs), which are frequently used by European vegetation scientists as surrogates for measured environmental va...
Article
Aim  Water pH and conductivity are known to be major environmental factors controlling the species composition of nutrient-poor wetlands. Based on the analysis of two large data sets of species co-occurrence, sampled along the entire pH/calcium gradient, we explored whether species exhibit similar or different ecological behaviour in the two region...
Article
Full-text available
The aim of this study is phytosociological description of natural and semi-natural forest vegetation in a part of deep valley of the Vltava river between Zlatá Koruna and Boršov nad Vltavou. A total of 173 phytosociological relevés have been recorded and classified into 16 vegetation associations or communities, which have been supplemented with li...
Article
Full-text available
The study brings results of the study of dry acidophilous grasslands with patchy occurrence in agriculture landscape in wide surrounding of Třebíč (west Moravia, Czech Republic). All together 48 relevés of this vegetation at the elevation range 400–500 m a.s.l. were sampled. Following formalized classification approach introduced in Vegetation of t...
Article
Full-text available
The pattern of natural vegetation on non-calcareous soils in two deep river valleys of the Bohemian Massif (Vltava and Dyje rivers, Czech Republic) was analyzed in order to determine the main topographic and soil variables affecting the composition of the vegetation.Vegetation data together with topographic and soil variables were collected along t...
Article
The Evolutionary species pool hypothesis (ESPH) predicts that historically more common habitats will be richer in species because they have had greater opportunity for the evolution of suitably adapted species. We explored the relationship between mire species richness and pH, an important environmental variable in mires, in two regions that differ...
Article
Full-text available
The vegetation of silver fir forests in southeastern Bohemia (Czech Republic) was studied using the Braun-Blanquet approach. On the basis of 57 phytosociological relevés, three associations were subjec- tively distinguished: (1) oligotrophic Vaccinio vitis-idaeae-Abietetum, (2) oligo-mesotrophic Luzulo luzuloidis-Abietetum, and (3) mesotrophic Gali...
Article
Full-text available
The aim of this paper is to describe occurrence of broad-leaved semi-dry grasslands of the Bromion alliance, distributed on a patch of crystalline dolomitic limestone north of village Nová Ves (district of Třebíč, south-western Moravia, Czech Republic). In the study area, vegetation of the Bromion alliance reaches the upper altitudinal limits of it...

Questions

Questions (3)
Question
We are searching for an R package that can calculate and draw the curves for the DBH size-class structure of the forest (see figs) to decide whether the species distribution is J-shaped, L-shaped or fluctuating. Any hints would be greatly appreciated!
Question
What system do you use for retyping and storing measured plant trait data in your lab? By traits, I mean e.g. leaf traits like leaf area, leaf weight, leaf thickness etc., used to calculate SLA, LDMC, succulence etc.
Are you using Excel, Access, or some other software? Or is there even some dedicated database software which can be used for this purpose? In my lab, we have measured trait data from several different projects, measured using the same standard protocol, and I hope to introduce workflow how these data can be merged together into a single trait database, which can be further extended for new data (retyped or imported). And also workflow which allow students to easily use it for their own data measured within their theses (and then merged with the other data in the lab).allows
Any suggestion and experience sharing is very welcome, thank you!
Question
When analysing relationships between two spatially autocorrelated variables using linear regression (with ordinary least squares), one has to be aware of the inflated Type I error - you are more likely to get significant results even if you should not (e.g. Legendre 1993). On the other side, it seems that regression coefficients are not biased, so to estimate the slope of regression is safe. But how is it with explained variation in this regression, i.e. R2? Is it also inflated, similarly to Type I error rate? I read the paper of Lennon (2000) in Ecography, pointing out that R2 will increase with increasing spatial autocorrelation of one of the variables. But I can’t find other references dealing with this issue (there are plenty dealing with Type I error rate and shifts in regression or correlation coefficients, but I am not aware of other one dealing with R2). Can somebody please help me with that?

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