The loss of the planet's biological diversity is increasingly threatening Mother Nature's ability to provide humans with goods and services like food, water, fodder, fertile soils, and protection from pests and disease, according to a sweeping review of 20 years of research by an international team of ecologists, including biologists from the University of British Columbia and McGill.

The 17 researchers present their findings in the journal Nature in a scientific consensus statement that summarizes evidence that has emerged from more than 1,000 ecological studies conducted since the 1992 Earth Summit in Rio de Janeiro, Brazil.

"We've reached a point where efforts to preserve species and biological diversity might no longer be an act of altruism," says Diane Srivastava, Professor with the Department of Zoology and the Biodiversity Research Centre at University of British Columbia and author on the paper.

"This research review dramatically underscores the importance of strengthening--not weakening or curtailing--environmental assessment processes in order to stem the tide of the loss of species and diversity that so many humans benefit from and depend on. This is particularly true in economies heavily reliant on natural resources,like British Columbia's."

The balance of evidence reviewed in the study shows that genetic diversity increases the yield of commercial crops, enhances the production of wood in tree plantations, improves the production of fodder in grasslands, and increases the stability of yields in fisheries.

Plant diversity also contributes to greater resistance to invasion by exotic plants, inhibits plant pathogens such as fungal and viral infections, increases above-ground carbon sequestration through enhanced biomass, and increases nutrient remineralization and soil organic matter.

"Much as the consensus statements by doctors led to public warnings that tobacco use is harmful to your health, this is a consensus statement by experts who agree that loss of Earth's wild species will be harmful to the world's ecosystems and may harm society by reducing ecosystem services that are essential to human health and prosperity," said Bradley Cardinale, Associate Professor at the University of Michigan and leader of the research effort.

"We need to take biodiversity loss far more seriously - from individuals to international governing bodies - and take greater action to prevent further losses of species."

The call to action comes as international leaders prepare to gather in Rio de Janeiro on June 20 for the United Nations Conference on Sustainable Development, known as the Rio+20 Conference.

The upcoming conference marks the 20th anniversary of 1992 Earth Summit in Rio, which resulted in 193 nations supporting the Convention on Biological Diversity's goals of biodiversity conservation and the sustainable use of natural resources.

"We believe that ongoing loss of biological diversity is diminishing the ability of ecosystems to sustain human societies," says Andrew Gonzalez, Associate Professor with the Department of Biology and the Quebec Centre for Biodiversity Science at McGill University and author on the paper.

In addition to Cardinale, Gonzalez and Srivastava, co-authors of the Nature paper are: J. Emmett Duffy of The College of William and Mary; Charles Perrings and Ann P. Kinzig of Arizona State University; Patrick Venail and Anita Narwani of U-M's School of Natural Resources and Environment; Georgina M. Mace of Imperial College London; David Tilman of the University of Minnesota; David A. Wardle of the Swedish University of Agricultural Sciences; Gretchen C. Daily of Stanford University; Michel Loreau of Centre National de la Recherche Scientifique in Moulis, France; James B. Grace of the U.S. Geological Survey; Anne Larigauderie of the Museum National d'Histoire Naturelle in Paris, France.