@article{PlueDeFrenneAcharyaetal.2013, author = {Plue, Jan and De Frenne, Pieter and Acharya, Kamal P. and Brunet, Jorg and Chabrerie, Olivier and Decocq, Guillaume and Diekmann, Martin and Graae, Bente J. and Heinken, Thilo and Hermy, Martin and Kolb, Annette and Lemke, Isgard and Liira, Jaan and Naaf, Tobias and Shevtsova, Anna and Verheyen, Kris and Wulf, Monika and Cousins, Sara A. O.}, title = {Climatic control of forest herb seed banks along a latitudinal gradient}, series = {Global ecology and biogeography : a journal of macroecology}, volume = {22}, journal = {Global ecology and biogeography : a journal of macroecology}, number = {10}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {1466-822X}, doi = {10.1111/geb.12068}, pages = {1106 -- 1117}, year = {2013}, abstract = {Aim Seed banks are central to the regeneration strategy of many plant species. Any factor altering seed bank density thus affects plant regeneration and population dynamics. Although seed banks are dynamic entities controlled by multiple environmental drivers, climatic factors are the most comprehensive, but still poorly understood. This study investigates how climatic variation structures seed production and resulting seed bank patterns. Location Temperate forests along a 1900km latitudinal gradient in north-western (NW) Europe. Methods Seed production and seed bank density were quantified in 153 plots along the gradient for four forest herbs with different seed longevity: Geum urbanum, Milium effusum, Poa nemoralis and Stachys sylvatica. We tested the importance of climatic and local environmental factors in shaping seed production and seed bank density. Results Seed production was determined by population size, and not by climatic factors. G.urbanum and M.effusum seed bank density declined with decreasing temperature (growing degree days) and/or increasing temperature range (maximum-minimum temperature). P.nemoralis and S.sylvatica seed bank density were limited by population size and not by climatic variables. Seed bank density was also influenced by other, local environmental factors such as soil pH or light availability. Different seed bank patterns emerged due to differential seed longevities. Species with long-lived seeds maintained constant seed bank densities by counteracting the reduced chance of regular years with high seed production at colder northern latitudes. Main conclusions Seed bank patterns show clear interspecific variation in response to climate across the distribution range. Not all seed banking species may be as well equipped to buffer climate change via their seed bank, notably in short-term persistent species. Since the buffering capacity of seed banks is key to species persistence, these results provide crucial information to advance climatic change predictions on range shifts, community and biodiversity responses.}, language = {en} } @article{DeFrenneGraaeBrunetetal.2012, author = {De Frenne, Pieter and Graae, Bente J. and Brunet, J{\"o}rg and Shevtsova, Anna and De Schrijver, An and Chabrerie, Olivier and Cousins, Sara A. O. and Decocq, Guillaume and Diekmann, Martin and Hermy, Martin and Heinken, Thilo and Kolb, Annette and Nilsson, Christer and Stanton, Sharon and Verheyen, Kris}, title = {The response of forest plant regeneration to temperature variation along a latitudinal gradient}, series = {Annals of botany}, volume = {109}, journal = {Annals of botany}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0305-7364}, doi = {10.1093/aob/mcs015}, pages = {1037 -- 1046}, year = {2012}, abstract = {The response of forest herb regeneration from seed to temperature variations across latitudes was experimentally assessed in order to forecast the likely response of understorey community dynamics to climate warming. Seeds of two characteristic forest plants (Anemone nemorosa and Milium effusum) were collected in natural populations along a latitudinal gradient from northern France to northern Sweden and exposed to three temperature regimes in growth chambers (first experiment). To test the importance of local adaptation, reciprocal transplants were also made of adult individuals that originated from the same populations in three common gardens located in southern, central and northern sites along the same gradient, and the resulting seeds were germinated (second experiment). Seedling establishment was quantified by measuring the timing and percentage of seedling emergence, and seedling biomass in both experiments. Spring warming increased emergence rates and seedling growth in the early-flowering forb A. nemorosa. Seedlings of the summer-flowering grass M. effusum originating from northern populations responded more strongly in terms of biomass growth to temperature than southern populations. The above-ground biomass of the seedlings of both species decreased with increasing latitude of origin, irrespective of whether seeds were collected from natural populations or from the common gardens. The emergence percentage decreased with increasing home-away distance in seeds from the transplant experiment, suggesting that the maternal plants were locally adapted. Decreasing seedling emergence and growth were found from the centre to the northern edge of the distribution range for both species. Stronger responses to temperature variation in seedling growth of the grass M. effusum in the north may offer a way to cope with environmental change. The results further suggest that climate warming might differentially affect seedling establishment of understorey plants across their distribution range and thus alter future understorey plant dynamics.}, language = {en} }