Eresus kollari (Araneae: Eresidae) calls for heathland management
Northwest Europe’s largest heather-dominated sandy habitats are located in the nature reserve Lu¨neburgerHeide, Germany. Yet, even these appear to be losing their ability to support some of their stenotopic species such as theladybird spider, Eresus kollari Rossi 1846, and are thus becoming increasingly important for the preservation of thesespecies. The habitat requirements of this endangered spider species were investigated in order to obtain data that will helpstabilize the last remnants of the species’ population in northwest Germany. Several heathland habitats were surveyed bypitfall trapping during the mate-search period of the males. Two statistical methods were applied: logistic reg…
Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests
Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-rat…
Light availability and land‐use history drive biodiversity and functional changes in forest herb layer communities
International audience; A central challenge of today's ecological research is predicting how ecosystems will develop under future global change. Accurate predictions are complicated by (a) simultaneous effects of different drivers, such as climate change, nitrogen deposition and management changes; and (b) legacy effects from previous land use. We tested whether herb layer biodiversity (i.e. richness, Shannon diversity and evenness) and functional (i.e. herb cover, specific leaf area [SLA] and plant height) responses to environmental change drivers depended on land-use history. We used resurvey data from 192 plots across nineteen European temperate forest regions, with large spatial variabi…
Drivers of above-ground understorey biomass and nutrient stocks in temperate deciduous forests
The understorey in temperate forests can play an important functional role, depending on its biomass and functional characteristics. While it is known that local soil and stand characteristics largely determine the biomass of the understorey, less is known about the role of global change. Global change can directly affect understorey biomass, but also indirectly by modifying the overstorey, local resource availability and growing conditions at the forest floor. In this observational study across Europe, we aim at disentangling the impact of global-change drivers on understorey biomass and nutrient stocks, from the impact of overstorey characteristics and local site conditions. Using piecewi…
Plant functional trait response to environmental drivers across European temperate forest understorey communities
Functional traits respond to environmental drivers, hence evaluating trait-environment relationships across spatial environmental gradients can help to understand how multiple drivers influence plant communities. Global-change drivers such as changes in atmospheric nitrogen deposition occur worldwide, but affect community trait distributions at the local scale, where resources (e.g. light availability) and conditions (e.g. soil pH) also influence plant communities. We investigate how multiple environmental drivers affect community trait responses related to resource acquisition (plant height, specific leaf area (SLA), woodiness, and mycorrhizal status) and regeneration (seed mass, lateral s…
Environmental drivers interactively affect individual tree growth across temperate European forests
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global-change drivers such as climate change or atmospheric deposition, as well as to local land-use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global-change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global-change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus exc…
Poleward range expansion without a southern contraction in the ground beetle Agonum viridicupreum (Coleoptera, Carabidae)
We investigated the extent of poleward shifts in the distribution range of Agonum viridicupreum due to climate change in the western Palaearctic. Species' records were obtained from extensive literature sources as well as from collections, and consistent amateur entomologists' recordings. Within the general geographic range of the species, we analyzed in detail two parts of both, the northern and southern distribution range boundaries: (1 and 2) north-western Germany (leading or high-latitude edge), (3) Israel and (4) southern Italy (rear or low-latitude edge). Temporal changes in the occurrence data of the species indicated a northward shift of the leading edge of a minimum of 100 km withi…
Evaluating structural and compositional canopy characteristics to predict the light-demand signature of the forest understorey in mixed, semi-natural temperate forests
Questions: Light availability at the forest floor affects many forest ecosystem processes, and is often quantified indirectly through easy-to-measure stand characteristics. We investigated how three such characteristics, basal area, canopy cover and canopy closure, were related to each other in structurally complex mixed forests. We also asked how well they can predict the light-demand signature of the forest understorey (estimated as the mean Ellenberg indicator value for light [“EIVLIGHT”] and the proportion of “forest specialists” [“%FS”] within the plots). Furthermore, we asked whether accounting for the shade-casting ability of individual canopy species could improve predictions of EIV…