Functional diversity of shredders, not species richness, drives the decomposition rate of leaf litter in ponds

Leaf litter decomposition is a critical ecosystem-level process in many freshwater habitats. Although ponds are likely to derive a large proportion of their energy from riparian vegetation, allochthonous organic matter decomposition in these water bodies has received little attention. We studied the breakdown rates of black alder (Alnus glutinosa (L.) Gaertn.) litter in ponds and provide the first evidence of the role of the taxonomic and functional diversity of pond-dwelling shredders in this ecosystem process. Despite a strong connection to riparian zones, the litter breakdown rates observed in ponds were generally lower than those reported in headwater streams. It seems that ponds provide less favorable conditions for shredder communities than headwaters. The rate of organic matter decomposition in ponds was significantly positively related to functional diversity, represented by the variability of shredder body size, while shredder species richness did not appear to be a reliable proxy for this ecosystem function. This finding is consistent with theoretical predictions that functional complementarity among species has a systematic effect on ecosystem processes. It also emphasizes that body size is a crucial functional trait mediating the effects of shredder diversity on litter decomposition in ponds

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Climate Change in the Smeda Catchment

katedra hydromeliorací a krajinného inženýrstv

The Fate of Endangered Rock Sedge (Carex rupestris) in the Western Carpathians—The Future Perspective of an Arctic-Alpine Species under Climate Change

Carex rupestris is an endangered and rare arctic-alpine element of the Western Carpathian flora. Given the geographically isolated and spatially restricted peripheral ranges of arctic-alpine species, there is a good chance that many species of conservation concern irreversibly disappear from the regional flora under the ongoing climate change. In this study, we gathered all existing data on the presence of C. rupestris and focused on its current and future distribution in the Western Carpathians. We found that although the distribution of the species is fragmented and scarce, C. rupestris occurs in several mountain ranges, in four distinct plant community types, which differ considerably in altitude, geological bedrock, and other habitat characteristics. In contrast to the relatively broad range of occupied habitats, C. rupestris shows a narrow temperature niche (mean annual temperature range 0.4–4.0 °C). Ensembles of small models based on climatic characteristics and local topography show that regardless of the climate change scenario (rcp2.6, rcp8.5), many current occurrence sites, mainly in the peripheral zones of the range, will face the excessive loss of suitable environmental conditions. It is expected that the Tatra Mountains will be the only mountain range retaining potentially suitable habitats and providing possible refugia for this cold-adapted species in the future. Such severe shrinkage of distribution ranges and associated geographic isolation raises serious concerns for the fate of the arctic-alpine species in the Western Carpathians

The impact of forest management on changes in composition of terricolous lichens in dry acidophilous Scots pine forests

Abstract: This study focuses on dry acidophilous Scots pine forests, well known for their high biodiversity of cryptogams. We hypothesized that dense forests and heavy management were responsible for changes in species diversity, decreasing trends in lichen cover and increasing moss cover. This hypothesis was tested in three types of Scots pine forests maintained under three different management regimes: 1) managed forests (forest plantations regenerated by planting), 2) semi-natural forests (forest plantations regenerated naturally), both located in the Borská nížina lowland in SW Slovakia, and 3) natural forests (primordial vegetation without visible management actions from the association Cladonio-Pinetum Juraszek 1928), located in the Bory Tucholskie National Park, NW Poland. We observed that the cover of the canopy tree layer had the most significant influence on the diversity of lichens. Managed forests are planted and maintained to achieve denser tree stocking, and although the environmental conditions created appear optimal for moss species, they are less suitable for terricolous lichens

Competition for soil resources forces a trade-off between enhancing tree productivity and understorey species richness in managed beech forests

Traditionally focussed on maximising productivity, forest management increasingly has to consider other functions performed by the forest stands, such as biodiversity conservation. Terrestrial plant communities typically possess a hump-back relationship between biomass productivity and plant species richness. However, there is evidence of a reverse relationship in forests dominated by beech, one of the most competitive and widespread tree species in temperate Europe. To fully explore the tree productivity-species richness relationship, we investigated above- and below-ground drivers of understorey plant species richness. We focussed on managed beech forests growing along an elevation gradient in Central Europe. We found that the lowest understorey plant diversity was under conditions optimal for beech. Tree fine root mass, canopy openness, soil C/N ratio, the interaction between tree fine root mass and stoniness, and stand structural diversity explain the variation of understorey species richness. We show that the competition for soil resources is the main driver of plant species diversity in managed forests; maximising beech growth in optimal conditions may thus come at the expense of understorey plant richness