PARENT SESSION
Wednesday, August 9, 1:30-5:00 pm
COS 60 - Climate and global change II: impacts on ecosystems at varying scales
L-12, Lobby Level, Cook Convention Center
Presiders: L Hidinger and J Schedlbauer
Soil seed banks and climate change: an experimental approach along a climatic gradient in Israel.
Sternberg, Marcelo *,1, Holzapfel, Claus2, Parag, Hadas, Konsens, Irit 1, Harel, Danny1, 1 Tel Aviv University, Tel Aviv, Tel Aviv, Israel2 Rutgers University, Newark, New Jersey, USA
ABSTRACT- Soil seed banks are of crucial importance in highly variable and unpredictable environ-ments. They play a determinant role in plant community dynamics, as differential plant germination strategies buffer against inter-annual variability in growing conditions. Thus, understanding the role of soil seed banks in determining the composition and structure of plant communities under future climatic scenarios becomes an important task in order to understand future global changes. Natural climatic gradients, which are represented by changes in environmental conditions provides an excellent framework for studying the ef-fects of climate change on the factors that regulate the structure and dynamics of soil seed banks. Particularly, the strong climatic gradient in Israel, provides an excellent opportunity to test predictions regarding the effects of global climate change on plant community dy-namics. This climatic gradient runs from mesic Mediterranean ecosystems in the North to arid desert ecosystems in the South. Climate change scenarios are experimentally tested with manipulations of rainfall amount using rainout shelters and irrigation systems. The re-sults showed important differences in the germinable seed bank along the gradient between years. A clear relation between the number of seeds in the soil seed bank and total rainfall of the previous year was found due to year-specific seed production. Significant differ-ences in abundance were found between sites along the gradient. The net effect of shrubs on seed densities in the soil and litter changed from positive effects in the arid site to in-creasingly negative effects in the moist part of the gradient. It is predicted that in case of a reduction in rainfall in the region we may expect important reduction on seed densities at the transitional sites (particularly at the semiarid ecosystem) as the proportion of change may be higher.
Key words: Climate change, Seed bank, Aridity