Researchers have found clear evidence that biological communities rich in species are substantially healthier and more productive than those depleted of species.
Using new scientific techniques, U.S. Geological Survey (USGS) research ecologist Jim Grace and a group of international scientists have resolved a long-standing debate about whether species diversity is necessary for a healthy ecosystem.
Scientists have long hypothesized that biodiversity is of critical importance to the stability of natural ecosystems and their abilities to provide ecosystem services. In fact, because this assumption is intuitively true to the general public, many of the efforts of conservation agencies around the world are driven by the assumption that this hypothesis is scientifically proven. Although theoretical studies have supported this claim, scientists have struggled for the past half-century to clearly isolate such an effect in the real world. This new study does just that. The findings have been published online on 13 January in the journal Nature.
The scientists used data collected for this research by a global consortium, the Nutrient Network, from more than a thousand grassland plots spanning five continents. Using recent advances in analytical methods, the group was able to isolate the biodiversity effect from the effects of other processes, including processes that can reduce diversity. Using these data with “integrative modelling” — integrating the predictions from multiple theories into a single model — scientists detected the clear signals of numerous underlying mechanisms linking the health and productivity of ecosystems with species richness.
“The ability to explain the diversity in the number of species is tremendously important for potential conservation applications,” said Grace. “The new type of analysis we developed can predict how both specific management actions (such as reduction of plant material through mowing or increase in soil fertility through fertilization), as well as shifts in climate conditions, may alter both productivity and the number of species.”
According to Debra Willard, Coordinator for the USGS Climate Research & Development Program, “These results suggest that if climate change leads to reduced species or genetic diversity, which is a real possibility, that then could lead to a reduced capacity for ecosystems to respond to additional stresses.”
As an indication of the global awareness of this issue, the Intergovernmental Platform on Biodiversity and Ecosystem Services was recently created to help policy-makers understand and address problems stemming from the global loss of biodiversity and degradation of ecosystems.
Another study recently published in Nature showed that greater biodiversity makes ecosystems more resilient to climate change, which supports the theory of biodiversity being critical to ecosystem health. While in 2013 researchers from the University of East Anglia, UK, said more than half of common plants and one third of the animals could see a dramatic decline this century due to climate change (more here). This makes it all the more important to follow up on the historic agreement to combat climate change and unleash actions and investment towards a low carbon, resilient and sustainable future that was agreed by 195 nations in Paris in December last year [Moos].
(Source: USGS news release, 15.01.2016)