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Background: Intensive farming affects farmland biodiversity, and some arable plants in particular. Increasing crop genetic diversity can increase crop productivity or resilience and could also benefit rare arable plants. Aims: We examined whether barley presence, sowing density and genetic diversity impacted the rare plant Valerianella rimosa and explored possible underlying mechanisms. Methods: In a field study near Dundee, Scotland, we sowed plots of five single barley genotypes, and all five genotypes combined, at three densities; we also had barley-free plots. Valerianella seeds were sown into half of all plots. Measured responses included early-season cover and harvest biomass of barley and common weeds, abiotic parameters (soil moisture, light) and establishment, biomass and seed production by V. rimosa. Results: Barley presence promoted V. rimosa establishment early in the growing season, but without barley density or genetic diversity effects. By harvest, the impact of barley presence on V. rimosa abundance was lost; there were no effects on Valerianella seed production. Barley negatively impacted common weeds, but V. rimosa did not benefit from any indirect facilitation by barley, being bigger without barley. Conclusions: Early beneficial effects of barley on V. rimosa abundance appear offset by late-season competition. However, limited impacts of barley on V. rimosa reproductive success, and negative impacts on common weeds, indicate crops might play a role in conservation management of rare arable plants by creating space in the weed community. [ABSTRACT FROM AUTHOR]

Background:In those alpine regions where growing season precipitation is decreasing due to climate change, the capacity of soils to retain water may become an important factor for the persistence of plant species. However, the importance of soil water storage capacity (WSC) for plant species diversity has not been studied so far. Aims:We aim to evaluate the relevance of WSC for species diversity of alpine plant communities in relation to temperature and length of growing season. Methods:Species diversity was determined in 150 plots from a broad range of alpine vegetation types in the calcareous western part of the central Swiss Alps. WSC of soil cores sampled in every plot was determined, as well as rooting zone temperature and snowmelt date. Linear mixed models were used to assess the relationship between environmental data and species diversity. Results:Species diversity was most strongly and positively related to WSC, followed by mean daily minimum temperature (Tmin) of the growing season. Species diversity was significantly related to date of snowmelt only in sites with high WSC and/or Tmin. Conclusions:WSC represents an integrative measure for habitat quality and accounts for differences in species diversity within the study region. In order to understand and predict responses of plant species to climate change in high mountain regions, it may be crucial to also take changes in plant water supply into account. [ABSTRACT FROM PUBLISHER]

Background: Neighbour-removal experiments (NRE) and spatial pattern analyses (SPA) are commonly used methods to investigate plant–plant interactions. Although they address the same issue, they measure different aspects of plant interactions: experiments indicate contemporary processes, whilst observations of spatial patterns integrate the results of interactions that have prevailed in the past. Aim: The aim of this study was to propose a new conceptual approach that takes into account the chronological order between processes and the arising patterns i.e., the time lag between neighbour effects quantified with NRE and SPA, to detect shifts in the balance of plant interactions due to current environmental change. Methods: This conceptual approach was applied to alpine snowbeds. Data from NRE were used to calculate the importance index of current neighbour interactions. Spatial patterns were quantified using variance ratio statistics and were assumed to reflect historic interactions. Results: The results of the two approaches showed a consistent difference in the prevailing type of plant interactions and suggested a shift towards competition in recent times. Conclusions: The simultaneous application of NRE and SPA allows the detection of a recent shift in the balance of plant interactions and provides a deeper and more accurate insight into the temporal dynamics of plant communities that could not be gained using one method alone. [ABSTRACT FROM PUBLISHER]