TY - JOUR A1 - Reinecke, Jennifer A1 - Klemm, Gunther A1 - Heinken, Thilo T1 - Vegetation change and homogenization of species composition in temperate nutrient deficient scots pine forests after 45 yr JF - Journal of vegetation science N2 - QuestionDoes eutrophication drive vegetation change in pine forests on nutrient deficient sites and thus lead to the homogenization of understorey species composition? LocationForest area (1600ha) in the Lower Spreewald, Brandenburg, Germany. MethodsResurvey of 77 semi-permanent plots after 45yr, including vascular plants, bryophytes and ground lichens. We applied multidimensional ordination of species composition, dissimilarity indices, mean Ellenberg indicator values and the concept of winner/loser species to identify vegetation change between years. Differential responses along a gradient of nutrient availability were analysed on the basis of initial vegetation type, reflecting topsoil N availability of plots. ResultsSpecies composition changed strongly and overall shifted towards higher N and slightly lower light availability. Differences in vegetation change were related to initial vegetation type, with strongest compositional changes in the oligotrophic forest type, but strongest increase of nitrophilous species in the mesotrophic forest type. Despite an overall increase in species number, species composition was homogenized between study years due to the loss of species (mainly ground lichens) on the most oligotrophic sites. ConclusionsThe response to N enrichment is confounded by canopy closure on the N-richest sites and probably by water limitation on N-poorest sites. The relative importance of atmospheric N deposition in the eutrophication effect is difficult to disentangle from natural humus accumulation after historical litter raking. However, the profound differences in species composition between study years across all forest types suggest that atmospheric N deposition contributes to the eutrophication, which drives understorey vegetation change and biotic homogenization in Central European Scots pine forests on nutrient deficient sites. KW - Eutrophication KW - Litter raking KW - Canopy closure KW - Cryptogams KW - Species diversity Y1 - 2014 U6 - https://doi.org/10.1111/jvs.12069 SN - 1100-9233 SN - 1654-1103 VL - 25 IS - 1 SP - 113 EP - 121 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Schulze, Kiowa Alraune A1 - Buchwald, Rainer A1 - Heinken, Thilo T1 - Epizoochory via the hooves - the European bison (Bison bonasus L.) as a dispersal agent of seeds in an open-forest-mosaic JF - Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft N2 - Large herbivores are significant vectors for the long-distance dispersal of seeds in various habitats, both attached to animals (epizoochory) and via gut passage (endozoochory). The majority of studies on epizoochory have examined dispersal in the fur of domesticated ungulates. Studies on wild ungulates are important to understand dispersal processes in many habitats, but rare due to methodological constraints. We studied epizoochory of seeds by European bison in an open-forest-mosaic (nutrient-poor grassland and heathland, mixed forest) in NW Germany, where bison had been introduced for the purpose of nature conservation. At the study site it was possible to apply a method by which hoof material of free-ranging bison was non-invasively collected. We identified a total of 1082 seeds from 32 plant species in the hoof material. The three most abundant species were Polygonum aviculare, Agrostis capillaris and Betula spp. Seed species originated from various habitat types of the study area, while the majority of seeds derived from trampled areas. Compared to the non-dispersed plant species of the study area, dispersed plant species had a higher seed longevity index, suggesting that many seeds were picked up from the soil seed bank. Epizoochory ranking indices of dispersed seed species, classifying the importance of epizoochory, revealed that transport in the fur may be of minor importance for many species, i.e. epizoochory by the hooves turned out to be negatively correlated to epizoochory in the fur. We conclude that European bison disperses a considerable number of seed species through trampling. Further research should consider epizoochory via the hooves and include integrative approaches to understand the different dispersal mechanisms by ungulates and their long-term synergetic effect on plant communities. KW - diaspore KW - external dispersal KW - large ungulate KW - secondary seed dispersal KW - trampling Y1 - 2014 SN - 0722-494X IS - 34 SP - 131 EP - 144 PB - Floristisch-Soziologische Arbeitsgemeinschaft CY - Göttingen ER - TY - JOUR A1 - Baeten, Lander A1 - Warton, David I. A1 - Van Calster, Hans A1 - De Frenne, Pieter A1 - Verstraeten, Gorik A1 - Bonte, Dries A1 - Bernhardt-Römermann, Markus A1 - Cornelis, Johnny A1 - Decocq, Guillaume A1 - Eriksson, Ove A1 - Hedl, Radim A1 - Heinken, Thilo A1 - Hermy, Martin A1 - Hommel, Patrick A1 - Kirby, Keith J. A1 - Naaf, Tobias A1 - Petrik, Petr A1 - Walther, Gian-Reto A1 - Wulf, Monica A1 - Verheyen, Kris T1 - A model-based approach to studying changes in compositional heterogeneity JF - Methods in ecology and evolution : an official journal of the British Ecological Society Y1 - 2014 SN - 2041-210X SN - 2041-2096 VL - 5 IS - 2 SP - 156 EP - 164 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Caron, Maria Mercedes A1 - De Frenne, P. A1 - Brunet, J. A1 - Chabrerie, Olivier A1 - Cousins, S. A. O. A1 - De Backer, L. A1 - Diekmann, M. A1 - Graae, B. J. A1 - Heinken, Thilo A1 - Kolb, A. A1 - Naaf, T. A1 - Plue, J. A1 - Selvi, F. A1 - Strimbeck, G. R. A1 - Wulf, Monika A1 - Verheyen, Kris T1 - Latitudinal variation in seeds characteristics of Acer platanoides and A. pseudoplatanus JF - Plant ecology : an international journal N2 - Climate change will likely affect population dynamics of numerous plant species by modifying several aspects of the life cycle. Because plant regeneration from seeds may be particularly vulnerable, here we assess the possible effects of climate change on seed characteristics and present an integrated analysis of seven seed traits (nutrient concentrations, samara mass, seed mass, wing length, seed viability, germination percentage, and seedling biomass) of Acer platanoides and A. pseudoplatanus seeds collected along a wide latitudinal gradient from Italy to Norway. Seed traits were analyzed in relation to the environmental conditions experienced by the mother trees along the latitudinal gradient. We found that seed traits of A. platanoides were more influenced by the climatic conditions than those of A. pseudoplatanus. Additionally, seed viability, germination percentage, and seedling biomass of A. platanoides were strongly related to the seed mass and nutrient concentration. While A. platanoides seeds were more influenced by the environmental conditions (generally negatively affected by rising temperatures), compared to A. pseudoplatanus, A. platanoides still showed higher germination percentage and seedling biomass than A. pseudoplatanus. Thus, further research on subsequent life-history stages of both species is needed. The variation in seed quality observed along the climatic gradient highlights the importance of studying the possible impact of climate change on seed production and species demography. KW - Acer platanoides KW - Acer pseudoplatanus KW - Climate change KW - Seed traits KW - Latitudinal gradient Y1 - 2014 U6 - https://doi.org/10.1007/s11258-014-0343-x SN - 1385-0237 SN - 1573-5052 VL - 215 IS - 8 SP - 911 EP - 925 PB - Springer CY - Dordrecht ER -