Does biodiversity self limit?

Pollination of endemic and non-endemic species in highly diverse plant communities


Modern conservation biology seeks to understand natural ecological system well enough to maintain their diversity at all ecological organization levels, from genetic variability within a species to biodiversity of organism whithin and between ecosystems on Earth.

Provided that species diversity is highly heterogeneous among regions World wide, the hotspot approach focuses on species diversity as a way to protect as many species as possible with the least cost. However, species richness is a poor indicator of differences among biological communities in the degree to which they retain significant interactions and we should devote more effort to understand community structure and function if we want to preserve the complex ecosystem dynamics. Unfortunately, very little is known about the structure and functioning of highly diverse communities and the importance of rare species for ecosystem functioning. In this project we seek to contribute filling up this gap.

Recent bibliographic analyses reveal a significant positive relationship between pollen limitation and regional plant species richness at the global scale. Analyzing the causes of such pattern is urgent from Conservation purposes too because many endemic and endangered species inhabit the most species-rich areas on Earth and they could may be particularly sensitive to current pollinators decline associated to climate change, habitat fragmentation and species invasions.
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Two are the ultimate objetives of this collaborative project among researches at Estación Biológica de Doñana-CSIC in Spain (see here), the Universidad Autónoma de Yucatán in México (see here) and the University of Pittsburg in USA (see here). First, we test the hypothesis that endemism affects pollen limitation by comparing pollen limitation and reproductive success of coexisting endemic and non-endemic species at different plant communities and explore which other species specific features might modulate such effect. Second, we determine whether there is a universal response of pollination and pollen limitation of plant reproduction to increasing diversity across plant communities, or whether this relationship depends on specific community composition by conducting the study at three highly diverse communities of flowering plants, the Mediterranean regions of Iberia and California and the sub-tropical Peninsula of Yucatán, all characterized by high levels of endemism.

Within the Spanish region we study the plant communities of the Baetic dolomite outcrops within the Natural Park of Sierras de Cazorla, Segura y las Villas, a large protected mountainus area with more than 2000 native plants species and around 17% endemism, in California we focus on plant communities at serpentine seeps within the Donald and Sylvia McLaughlin Natural Reserve (Northern California) and in the northern coast of the Yucatan state on the sub-tropical coastal scrublands. (read more)