Diversity-productivity relationships: initial effects, long-term patterns, and underlying mechanisms

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 102; no. 3; pp. 695 - 700
• Main Authors: Ruijven, J. van, Berendse, F
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 18.01.2005; National Acad Sciences
• Subjects: Aboveground biomass; Biodiversity; biodiversity experiments; Biological Sciences; Biomass; community ecology; competition; complementarity; different rooting depths; Ecological function; Ecology; Ecosystem; ecosystem productivity; Ecosystems; elevated co2; Environment; european grasslands; experimental plant-communities; Flowers & plants; Food; grasses; grassland communities; Grasslands; Growing season; Legumes; Magnoliopsida; Netherlands; Nitrogen; Nitrogen fixation; Nutrient uptake; Nutrient use efficiency; Plant communities; Plant Development; Plant diversity; plant ecology; plant growth; plant nutrition; Plant species; Plants; Productivity; Species; Species diversity; Species richness; Time; Netherlands
• DOI: 10.1073/pnas.0407524102
• ISSN: 0027-8424

A common pattern emerging from studies on the relationship between plant diversity and ecosystem functioning is that productivity increases with diversity. Most of these studies have been carried out in perennial grasslands, but many lasted only two growing seasons or reported data from a single year. Especially for perennial plant communities, however, the long-term effects of diversity are important. The question whether interactions between few species or among many species lead to increased productivity remained largely unanswered. So far, the main mechanism addressed is the increased input of nitrogen by nitrogen-fixing legumes. We report that other mechanisms can also generate strong increases of productivity with diversity. Results from 4 consecutive years of a plant diversity experiment without legumes show that a positive relationship between plant species richness and productivity emerged in the second year and strengthened with time. We show that increased nutrient use efficiency at high species richness is an important underlying mechanism. This mechanism had not been discussed in earlier studies. Furthermore, our results suggest that complementary nutrient uptake in space and time is important. Together, these mechanisms sustain consistently high productivity at high diversity.