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Species richness is the most commonly used metric to quantify biodiversity. However, examining dark diversity, the group of missing species which can potentially inhabit a site, can provide a more thorough understanding of the processes influencing observed biodiversity and help evaluate the restoration potential of local habitats. So far, dark diversity has mainly been studied for specific habitats or largescale landscapes while less attention has been given to variation across broad environmental gradients or as a result of local conditions and biotic interactions. In this study, we investigate the importance of local environmental conditions in determining dark diversity and observed richness in plant communities across broad environmental gradients. We use the ecospace concept to investigate how abiotic gradients (defined as position), availability of biotic resources (defined as expansion), spatiotemporal extent of habitats (defined as continuity), as well as species interactions through competition, relate to these biodiversity measures. Position variables were important for both plant richness and dark diversity, some with quadratic relationships, e.g., plant richness showing a unimodal response to soil fertility corresponding to the intermediate productivity hypothesis. Competition represented by community mean Grime C showed a negative correlation with plant richness. Besides position, organic carbon was the most important variable for dark diversity, indicating that in late succession habitats such as forests and shrubs, dark diversity is generally low. The importance of Grime C indicate that intermediate disturbance, such as grazing, may facilitate higher species richness and lower dark diversity. Comparing various biodiversity metrics and their influencing factors might reveal important drivers of biodiversity changes and result in better conservation decision-making.

Correlations among plant traits often reflect important trade-offs or allometric relationships in biological functions like carbon gain, support, water uptake, and reproduction that are associated with different plant organs. Whether trait correlations can be aggregated to “spectra” or “leading dimensions,” whether these dimensions are consistent across plant organs, spatial scale, and growth forms are still open questions. To illustrate the current state of knowledge, we constructed a network of published trait correlations associated with the “leaf economics spectrum,” “biomass allocation dimension,” “seed dimension,” and carbon and nitrogen concentrations. This literature-based network was compared to a network based on a dataset of 23 traits from 2,530 individuals of 126 plant species from 381 plots in Northwest Europe. The observed network comprised more significant correlations than the literature-based network. Network centrality measures showed that size traits such as the mass of leaf, stem, below-ground, and reproductive tissues and plant height were the most central traits in the network, confirming the importance of allometric relationships in herbaceous plants. Stem mass and stem-specific length were “hub” traits correlated with most traits. Environmental selection of hub traits may affect the whole phenotype. In contrast to the literature-based network, SLA and leaf N were of minor importance. Based on cluster analysis and subsequent PCAs of the resulting trait clusters, we found a “size” module, a “seed” module, two modules representing C and N concentrations in plant organs, and a “partitioning” module representing organ mass fractions. A module representing the plant economics spectrum did not emerge. Synthesis. Although we found support for several trait dimensions, the observed trait network deviated significantly from current knowledge, suggesting that previous studies have overlooked trait coordination at the whole-plant level. Furthermore, network analysis suggests that stem traits have a stronger regulatory role in herbaceous plants than leaf traits. © 2018 The Authors. Journal of Ecology © 2018 British Ecological Society

Rapporten er udarbejdet af DCE – Nationalt Center for Miljø og Energi, Aarhus Universitet, til Landbrugsstyrelsen og beskriver en række forskellige potentielle indikatorer på biodiversitet til test og eventuel efterfølgende anvendelse i en effektbaseret areal-tilskudsordning. Vi har taget udgangspunkt i, hvad der karakteriserer arealer og forskellige naturtyper i god naturtilstand og med høj biodiversitet. Vi har tænkt i de processer, som skaber levesteder for biodiversiteten – ikke mindst i en økosystemkontekst, hvor høj naturtæthed og arealstørrelser er vigtige. Indikatorerne omfatter indikatorplanter, rødlistede arter, levesteder, naturlige processer, driftshistorie, arealstørrelser – og variation og indikatorer på negative påvirkninger som fx eutrofiering og afvanding. Blandt indikatorerne er en række kendte strukturparametre fra tilstandsvurderingssystemet, fx bar jord, fritliggende sten, tuer osv. Yderligere er der suppleret med nye indikatorer, såsom stor lort, bid og barkskrælning, som indikatorer på græssende dyrs påvirkning af naturen og deres bidrag til at skabe levesteder for biodiversiteten. Vi har udviklet et sæt af indikatorplanter, som indikerer god naturtilstand. Vi har beregnet plantearternes hyppighed i naturtyperne eng, mose, hede, overdrev og strandeng baseret på data fra 5 m-cirkler fra NOVANA og § 3-kortlægningen. Plantearterne forekommer relativt hyppigt på gode naturarealer og gør dem derfor egnede som indikatorer. Vi har evalueret indikatorplanterne og fandt en positiv sammenhæng med både antallet af plantearter og med den gennemsnitlige artsscore som proxy for naturtilstanden. Sammenhængen bliver mere tydelig, jo flere indikatorarter man registrerer. Vi anbefaler, at indikatorerne kombineres, så de omfatter artsindikatorer og strukturindikatorer på god naturtilstand samt strukturindikatorer på effekten af græssende dyr. Udvælgelsen og kombinationen af indikatorer vil foregå i en efterfølgende proces ledet af Landbrugsstyrelsen og med deltagelse af DCE, Aarhus Universitet, og interessenter. Tekniske rapporter til registreringen af indikatorer i felten er ikke inkluderet i rapporten.

Der er langt fra det moderne kulturlandskab med monotone marker og netværk af bebyggelser med veje og jernbaner til det vildnis, som var biodiversitetens vugge. De arter, der udgør biodiversiteten i dag, opstod i de forhistoriske økosystemer, hvor floderne gik over bredderne, stormfald og brande raserede skove og krat, og elefanter, næsehorn, heste, urokser og andre store dyr trampede og gnavede sig gennem økosystemerne. Det er netop menneskets tæmning af vildnisset, som er årsagen til biodiversitetskrisen. Det traditionelle svar på biodiversitetskrisen har været, at naturen er syg og truet og derfor har brug for vores pleje og omsorg. Denne forvaltningsmodel udfordres i dag af rewilding, som i stedet foreslår, at vi bygger på naturens evne til selvforvaltning, og i særdeleshed de store dyrs vigtige funktioner i økosystemerne. Uanset om målet er traditionel naturpleje eller rewilding, så lider biodiversiteten under pladsmangel, så der er brug for en rumlig planlægning, hvor naturen indgår som planmål. Rewilding kræver desuden store sammenhængende områder, og dem får vi kun, hvis der er politisk vilje til det., Tidsskrift for Kortlægning og Arealforvaltning, Vol 123 No 48 (2017)

Humans have modified most ecosystems on Earth to a degree where even the largest “wild” nature reserves need management to avoid the loss of biodiversity. Native large herbivore grazing has potential as an efficient and natural tool in this management because they create dynamics and keep landscapes open. However, in order to use this tool properly, we need to know more about what the animals eat compared to what is available in different habitats and how access to supplementary fodder influences the grazing effect on the vegetation. Using DNA barcoding of feces, we are investigating the diet preferences of deer (red deer and roe deer) in Klelund Deer Park in Denmark. Over one year, we collect feces samples every month from different habitat types (e.g., heath, marsh, meadow, open forests and coniferous plantation) within the park. DNA barcoding can not only tell us which plants are consumed but also in which proportions. We intend to uncover the variation in deer diet over a year and among different habitats and how supplementary fodder influences the diet preference. The results will contribute to a better understanding of deer management as well as how deer grazing can be used as a tool in management of open landscapes.

Species distributions are often constrained by climatic tolerances that are ultimately determined by evolutionary history and/or adaptive capacity, but these factors have rarely been partitioned. Here, we experimentally determined two key climatic niche traits (desiccation and cold resistance) for 92–95 Drosophila species and assessed their importance for geographic distributions, while controlling for acclimation, phylogeny, and spatial autocorrelation. Employing an array of phylogenetic analyses, we documented moderate-to-strong phylogenetic signal in both desiccation and cold resistance. Desiccation and cold resistance were clearly linked to species distributions because significant associations between traits and climatic variables persisted even after controlling for phylogeny. We used different methods to untangle whether phylogenetic signal reflected phylogenetically related species adapted to similar environments or alternatively phylogenetic inertia. For desiccation resistance, weak phylogenetic inertia was detected; ancestral trait reconstruction, however, revealed a deep divergence that could be traced back to the genus level. Despite drosophilids’ high evolutionary potential related to short generation times and high population sizes, cold resistance was found to have a moderate-to-high level of phylogenetic inertia, suggesting that evolutionary responses are likely to be slow. Together these findings suggest species distributions are governed by evolutionarily conservative climate responses, with limited scope for rapid adaptive responses to future climate change

1. Environmental sorting, historical factors and neutral dynamics may all drive beta diversity (change in species composition across space), but their relative importance remains unresolved. In the case of European mammals, key potential drivers of large-scale beta diversity include current climate, neutral dynamics and two historical factors: Pleistocene glaciations and peninsular dynamics (immigration from extra-regional eastern faunal source areas and inter-linked relictual survival and evolutionary differentiation in isolated areas). 2. We assessed the relative importance of these drivers using a novel analytical framework to deconstruct beta diversity of non-volant mammals in Europe (138 species) into its turnover (change in species composition because of species replacements) and nestedness components (change in species composition because of species richness differences) at continental and regional (250 000 km2) scales. 3. We found continental-scale mammal beta diversity to be mainly caused by spatial turnover (99·9%), with only a small contribution (0·1%) from nestedness. 4. Current climate emerged as an important driver of beta diversity, given the strong continental-scale turnover, particularly in north–south direction, i.e., in line with the latitudinal climate gradient, and, more directly, the strong correlation of climate with spatial turnover at both continental and regional scales. 5. However, there was also evidence for the importance of non-climatic drivers. Notably, the compositional variation purely accounted for by space was greater than that purely accounted for by environment for both the turnover and the nestedness component of beta diversity. Furthermore, the strong longitudinal turnover within Southern Europe is in accordance with the region’s long-term climatic stability having allowed multiple refugia and local evolutionary diversification. As expected from peninsular dynamics, there was increasing dissimilarity with geographic distance in an east–west direction because of nestedness, but only in Central and Northern Europe. 6. In conclusion, European mammal beta diversity mainly reflects spatial turnover and only to a limited extent nestedness and is driven by current climate in combination with historical – and perhaps, neutral – dynamics. These findings suggest that a key challenge for climate-change predictive studies will be taking the influence of non-climatic factors