@article{CaronDeFrenneBrunetetal.2014,
  author    = {Caron, Maria Mercedes and De Frenne, P. and Brunet, J. and Chabrerie, Olivier and Cousins, S. A. O. and De Backer, L. and Diekmann, M. and Graae, B. J. and Heinken, Thilo and Kolb, A. and Naaf, T. and Plue, J. and Selvi, F. and Strimbeck, G. R. and Wulf, Monika and Verheyen, Kris},
  title     = {Latitudinal variation in seeds characteristics of Acer platanoides and A. pseudoplatanus},
  series = {Plant ecology : an international journal},
  volume    = {215},
  journal   = {Plant ecology : an international journal},
  number    = {8},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {1385-0237},
  doi       = {10.1007/s11258-014-0343-x},
  pages     = {911 -- 925},
  year      = {2014},
  abstract  = {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.},
  language  = {en}
}
@article{LeuschnerWulfBaeuchleretal.2014,
  author    = {Leuschner, Christoph and Wulf, Monika and Baeuchler, Patricia and Hertel, Dietrich},
  title     = {Forest continuity as a key determinant of soil carbon and nutrient storage in beech forests on sandy soils in Northern Germany},
  series = {Ecosystems},
  volume    = {17},
  journal   = {Ecosystems},
  number    = {3},
  publisher = {Springer},
  address   = {New York},
  issn      = {1432-9840},
  doi       = {10.1007/s10021-013-9738-0},
  pages     = {497 -- 511},
  year      = {2014},
  abstract  = {Forest (or tree) age has been identified as an important determinant of the carbon (C) storage potential of forest soils. A large part of Central Europe's current forested area was affected by land use change with long periods of cultivation in past centuries suggesting that the organic C stocks in the soil (SOC) under recent forest may partly be legacies of the past and that stand age effects have to be distinguished from forest continuity effects (that is, the time since re-afforestation). We examined the influence of mean tree age and forest continuity on the SOC pool and the stores of total N and available P, Ca, Mg, and K in the soil (mineral soil and organic layer) across a sample of 14 beech (Fagus sylvatica) forests on sandy soil with variable tree age (23-189 years) and forest continuity (50-year-old afforestation to ancient ('permanent') forest, that is, > 230 years of proven continuity). Ancient beech forests (> 230 years of continuity) stored on average 47 and 44\% more organic C and total N in the soil than recent beech afforestation (50-128 years of continuity). Contrary to expectation, we found large and significant C and N pool differences between the forest categories in the mineral soil but not in the organic layer indicating that decade- or century-long cultivation has reduced the subsoil C and nutrient stores while the organic layer element pools have approached a new equilibrium after only 50-128 years. PCA and correlation analyses suggest that forest continuity cannot be ignored when trying to understand the variation in soil C stocks between different stands. Forest clearing, subsequent cultivation, and eventual re-afforestation with beech resulted in similar relative stock reductions of C and N and, thus, no change in soil C/N ratio. We conclude that the continuity of forest cover, which may or may not be related to tree age, is a key determinant of the soil C and nutrient stores of beech forests in the old cultural landscape of Central Europe.},
  language  = {en}
}
@article{WulfKolk2014,
  author    = {Wulf, Monika and Kolk, Jens},
  title     = {Plant species richness of very small forests related to patch configuration, quality, heterogeneity and history},
  series = {Journal of vegetation science},
  volume    = {25},
  journal   = {Journal of vegetation science},
  number    = {5},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1100-9233},
  doi       = {10.1111/jvs.12172},
  pages     = {1267 -- 1277},
  year      = {2014},
  abstract  = {Questions: (i) Is plant species richness related to patch configuration, quality, heterogeneity and history in very small forest patches? (ii) Is there a similar effect of patch configuration, quality, heterogeneity and history on all plant species or does it vary for different plant groups? (iii) Does the importance of patch configuration, quality, heterogeneity and history vary for plant species richness between patch size classes? Location: Prignitz region, western part of Brandenburg, Germany Methods: Plant species lists for 183 forest patches (0.08-12.7 ha) were compiled. We conducted a hierarchical partitioning analysis to test which of the four patch variables - configuration, quality, heterogeneity and history - explained most of the variance in plant species richness and richness of various plant groups. Results: Irrespective of patch size class, species richness is mainly predicted by patch quality and heterogeneity. In particular, generalists are primarily affected by the soil moisture and nutrient level, and specialists additionally by patch heterogeneity and history. A higher historical habitat quality, together with long habitat continuity, led to an increase in forest specialists and geophytes in all patches. In the >5-ha patches only historical habitat quality accounted for a significant increase in the number of species with short-distance dispersal capacity in all species. Regardless of patch size, the number of locally infrequent species increased significantly with historical habitat quality. The effect of patch configuration was negligible, except for space-filling trees and shrubs, when considering all patches. Conclusions: Our more comprehensive statistical approach shows, in general, that all complex variables have an effect on species richness and should be considered in future studies. The fact that patch heterogeneity and quality are the main predictors of species richness indicates that very small forest patches covered a range of highly structured patches and sites having various growth conditions. We assume that the century-old tradition of private ownership with smallholder social structure is the main reason for variability in stand structure and species assemblage, resulting in the uniqueness of each patch. Since the number of locally infrequent plant species increases significantly with historical habitat quality, we suggest that it is particularly important to consider this variable in future studies on the decline of infrequent plant species.},
  language  = {en}
}