Effect of rainfall characteristics on performance of ten annual species

Köchy, M., and F. Jeltsch (2004)

We have examined the effect of rainfall characteristics on performance of ten annual species from Mediterranean and arid regions in Israel using a spatially explicit, rule-based model. The model simulates germination and growth of individual plants on a 1-m2 area. Using the model, we tested which single rainfall characteristics (annual rain volume, annual rain volume of days with >10 mm rain, number of days with >5, 10, 15, or 20 mm rain, or number of days with >10, 15, or 20 mm rain during the early growing season) best predicted total aboveground biomass. For six species, the number of days with >15 mm rain, for the others, the number of days >20 mm rain were the best predictors in linearized regressions. This indicates that plant performance would be affected by changes to rainfall patterns in two ways: changes to annual rain volume and changes to volume per rainstorm. Examination of long-term precipitation records suggests that changes to the volume per rainstorm would have the strongest impact on biomass in regions with <600 mm annual precipitation.


89. Annual Meeting of the Ecological Society of America. 1.-6. August 2004, Portland, Oregon (USA).