Addition of multiple limiting resources reduces grassland diversity

HARPOLE, W.S.; FIRN, J.; CHASE, J.; HILLEBRAND, H.; LIND, E.M.; WILLIAMS, R.; BORER, E.T.; CHANETON, E.J.; HAUTIER, Y.; DAVIES, K.F.; SEABLOOM, E.W.; SULLIVAN, L.L.; KNOPS, J.M.H.; ADLER, P.A.; CADOTTE, M.W.; MORGAN, J.W.; D'ANTONIO, C.M.; FAY, P.A.; SCHUETZ, M.; KIRKMAN, K.P.; MACDOUGALL, A.S.; MOORE, J.L.; BAKKER, J.D.; RISCH, A.C.; CLELAND, E.E.; WRAGG, P.D.; GRUNER, D.S.; LA PIERRE, K.J.; PROBER, S.M.; STEVENS, C.J.

NATURE

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2016 vol. 537 p. 93 - 96

0028-0836

Niche dimensionality provides a general theoretical explanation for biodiversity?more niches, defined by more limiting factors, allow for more ways that species can coexist. Because plant species compete for the same set of limiting resources, theory predictsthat addition of a limiting resource eliminates potential trade-offs, reducing the number of species that can coexist. Multiple nutrient limitation of plant production is common and therefore fertilization may reduce diversity by reducing the number or dimensionality of belowground limiting factors. At the same time, nutrient addition, by increasing biomass, should ultimately shift competition from belowground nutrients towards a one-dimensional competitive trade-off for light. Here we show that plant species diversitydecreased when a greater number of limiting nutrients were added across 45 grassland sites from a multi-continent experimental network. The number of added nutrients predicted diversity loss, even after controlling for effects of plant biomass, and evenwhere biomass production was not nutrient-limited. We found that elevated resource supply reduced niche dimensionality and diversity and increased both productivity and compositional turnover. Our results point to the importance of understanding dimensionality in ecological systems that are undergoing diversity loss in response tomultiple global change factors.