Data from: Plant functional diversity and nutrient availability can improve restoration of floating fens via facilitation, complementarity and selection effects

Peat-forming wetlands, and particularly floating fens forming the initial stages of these ecosystems, are globally declining due to excavation, dehydration and eutrophication. Restoration of these valuable ecosystems typically involves re-establishment of early-successional open-water stages with oligotrophic conditions that are characteristic for these systems. However, restoration success is notoriously limited and a potential solution may be to initiate succession by re-introduction of target plant species. Knowledge is needed on (a) which plant functional groups should be re-introduced to stimulate fen formation; and (b) how to manage nutrient levels during restoration, considering that plant growth may be slow in oligotrophic conditions. 2. We hypothesized that (1) increasing functional diversity of introduced species would stimulate the formation of peat-forming target communities, their biomass accumulation and expansion onto open water; and that (2) nutrient availability would mediate the relative contribution of specific functional groups to these effects. We experimentally investigated this in 36 artificial outdoor ponds by manipulating plant functional diversity (clonal dominants, clonal stress-tolerators and interstitials) on constructed rafts with fen-forming communities and subjected these to a range of nutrient loadings over two years. 3. Increasing functional diversity as well as increasing nutrient loadings had stimulating effects on plant biomass accumulation, cover formation and rhizome growth onto open water. Both complementarity (due to niche partitioning or facilitation) and selection effects were mechanisms underlying the diversity effect, with a constant relative importance over the entire range of nutrient availabilities. Different functional groups were important for biomass production at different nutrient availabilities. Rhizome formation by clonal stress-tolerators contributed disproportionately to open water colonisation, identifying this functional group as key across all nutrient levels. 4. Synthesis and applications Restoration of floating fen communities (1) can be stimulated during the first two years by introducing a high functional diversity of plant species, including fast-growing clonal species, clonal stress-tolerators and interstitials, which facilitate each other, (2) is dependent on the presence of clonal stress-tolerators such as Calla palustris, Comarum palustre and Menyanthes trifoliata for expansion onto the open water, (3) can start under a wide range of water nutrient levels, including eutrophic conditions.11-Jul-201

Konkurenční analýza stavebního spoření

Seznámení s problematikou stavebního spoření a jeho využití při řešení bytové situace. Porovnání současných podmínek s podmínkami platnými do 31.12.2003. Zhodnocení dané problematiky u jednotlivých staveních spořitelen. Zhodnocení SS do budoucna a jeho dopady do státního rozpočtu

Species distribution modelling: contrasting presence-only models with plot abundance data

Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on a large plot dataset for Amazonian tree species, using inverse distance weighting (IDW). We also propose a new pipeline to deal with inconsistencies in NHCs and to limit the area of occupancy of the species. We found a significant but weak positive relationship between the distribution of NHCs and IDW for 66% of the species. The relationship between SDMs and IDW was also significant but weakly positive for 95% of the species, and sensitivity for both analyses was high. Furthermore, the pipeline removed half of the NHCs records. Presence-only SDM applications should consider this limitation, especially for large biodiversity assessments projects, when they are automatically generated without subsequent checking. Our pipeline provides a conservative estimate of a species’ area of occupancy, within an area slightly larger than its extent of occurrence, compatible to e.g. IUCN red list assessments