While the loss of biodiversity is accelerating throughout the world, little is known about its impact on mankind. To find out more, a group of 17 ecology researchers, including Michel Loreau, from the CNRS Station d’écologie expérimentale in Moulis, took stock of two decades of scientific research worldwide. Their objective was to define points of interest to the scientific community as a whole, and to identify areas where research remains insufficient.
The team analyzed the impact of biodiversity loss on the functioning and stability of ecosystems, and performed new analysis of its effect on the ecological services that benefit mankind. This article was published on June 7 2012 in Nature, two weeks before the start of the Rio+20 Earth Summit conference. It should help decision-makers implement appropriate policies to slow this alarming trend.
Along the same lines as the IPCC1 reports on climate change, the consortium of researchers used the Nature article to identify a scientific consensus based on the analysis of some 2000 papers published over the last 20 years. At a time when human activities are destroying entire ecosystems, the researchers have defined six points of concern to the scientific community. One of these is that the loss of biodiversity adversely affects the functioning and stability of ecosystems. This loss significantly reduces the efficiency with which ecosystems find vital resources, produce biomass, and decompose and recycle essential nutrients.
The researchers also present preliminary results which, should they be confirmed by further research, could change our understanding of biodiversity. For example, the effects of species extinction and gene loss are greater when the temporal or spatial scale considered is larger. In other words, while a small number of species could make up an ecosystem that would seem stable enough over a short period of time, larger ecosystems—subjected to changing conditions over time—require a greater number of species to function. Another item put forward by the researchers is that the impact of biodiversity loss in the world is comparable to that of other global changes such as climate warming and excess of nitrogen from agriculture.
The article also provides new insight into the impact of biodiversity loss on the many ecological services essential to the well-being of society. The general opinion among scientists is that diversity—of both species and genes—is necessary to increase yields from agriculture, fisheries and tree plantations. However, the role of biodiversity is less clear in other services like insect pollination or water purification by wetlands. This should be an incentive for scientists to undertake further research.
One of the main objectives of the researchers is to fuel the debate at the Rio+20 Earth Summit international conference this month. This study will also serve as a working basis for the future Intergovernmental science-policy Platform on Biodiversity and Ecosystem Services (IPBES), the equivalent of the IPCC for biodiversity, due to be set up this year. Furthermore, by highlighting gaps in scientific knowledge, this work could be used to design research programs to fill them. Finally, it should help decision-makers to implement appropriate policies to slow down the tragic loss of biodiversity. (1) IPCC: Intergovernmental Panel on Climate Chnage. Laureate of the Nobel Peace Prize in 2007, it includes several CNRS researchers.