Temporal changes in the abundance, leaf growth and photosynthesis of threeco-occurring Philippine seagrasses

The analysis of the temporal changes in shoot density, areal leaf biomass, leaf growth and parameters of the photosynthesis-irradiance relationship of three tropical seagrass species (Enhalus acoroides, Thalassia hemprichii a nd Cymodocea rotundata), co-existing in a shallow subtidal meadow in Cape B olinao, Philippines, shows that species-specific traits are significant sou rces of temporal variability, and indicates that these seagrass species res pond differently to a common environmental forcing. Species-specific differ ences are much less important as source of variability of the temporal chan ge in chlorophyll concentration of seagrass leaves. The results indicate th at the temporal changes in photosynthetic performance of these seagrasses w ere driven by environmental forcing and their specific responses to it most ly, but the temporal change in their abundance and leaf growth was also con trolled by other factors. The significant contribution of species-specific factors in the temporal changes of biomass, growth and photosynthetic perfo rmance of co-occurring seagrass species in Cape Bolinao should contribute t o the maintenance of the multispecific, highly productive meadows character istic of pristine coastal ecosystems in Southeast (SE) Asia. (C) 2001 Elsev ier Science B.V. All rights reserved.