Functional trade-offs increase species diversity in experimental plant communities.
Functional trade-offs have long been recognised as important mechanisms of species coexistence, but direct experimental evidence for such mechanisms is extremely rare. Here, we test the effect of one classical trade-off - a negative correlation between seed size and seed number - by establishing microcosm plant communities with positive, negative and no correlation between seed size and seed number and analysing the effect of the seed size/number correlation on species richness. Consistent with theory, a negative correlation between seed size and seed number led to a higher number of species in the communities and a corresponding wider range of seed size (a measure of functional richness) by promoting coexistence of large- and small-seeded species. Our study provides the first direct evidence that a seed size/number trade-off may contribute to species coexistence, and at a wider context, demonstrates the potential role of functional trade-offs in maintaining species diversity.
Department of Ecology, Evolution & Behavior, Institute of Life Sciences, Campus Edmond J. Safra, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 91904, Israel.
Eyal
E
Ben-Hur
Jerusalem Botanical Gardens, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 91904, Israel.
Ori
O
Fragman-Sapir
Israel Plant Gene Bank, Institute of Plant Sciences, Agricultural Research Organization - Volcani Center, P.O. Box 6, Bet-Dagan, 50250, Israel.
Rivka
R
Hadas
Israel Plant Gene Bank, Institute of Plant Sciences, Agricultural Research Organization - Volcani Center, P.O. Box 6, Bet-Dagan, 50250, Israel.
Alon
A
Singer
Department of Ecology, Evolution & Behavior, Institute of Life Sciences, Campus Edmond J. Safra, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 91904, Israel.
Ronen
R
Kadmon
D044822:Biodiversity; D017753:Ecosystem; D056084:Genetic Fitness; D063245:Plant Development; D010944:Plants / Q000235:genetics; D011157:Population Dynamics; D012098:Reproduction; D012639:Seeds