Humans have played major role in loss of biodiersity

EcoWatch - One of the largest studies ever conducted on biodiversity loss worldwide has revealed that humans are having a severely detrimental impact on global wildlife.  The number of species is declining, as well as the composition of populations....

A team of scientists from UZH and the Swiss Federal Institute of Aquatic Science and Technology (Eawag) collected data from roughly 2,100 studies comparing biodiversity at nearly 50,000 sites that had been impacted by humans with an equal number of reference locations that remained unaffected...

The findings, “The global human impact on biodiversity,” were published in the journal Nature and leave no doubt as to the devastation humans are imposing on global biodiversity.

“We analyzed the effects of the five main human impacts on biodiversity: habitat changes, direct exploitation such as hunting or fishing, climate change, pollution and invasive species,” said lead author François Keck, a postdoctoral researcher at Eawag, in the press release. “Our findings show that all five factors have a strong impact on biodiversity worldwide, in all groups of organisms and in all ecosystems.”

The average number of species at affected sites was nearly one-fifth lower than at those that were unaffected. Vertebrates such as amphibians, reptiles and mammals were found that have experienced especially dramatic species loss across all biogeographic regions. These populations have a tendency to be significantly smaller than those of invertebrates, which makes them more vulnerable to extinction.

“Biodiversity change poses a critical threat to human societies from local to global scales, highlighting the urgent need for understanding the complex relationship between human pressures and their effects on ecosystems,” the authors wrote in the findings. “Human pressures, broadly classified in five main types — land-use change, resource exploitation, pollution, climate change and invasive species — can enhance or reduce species diversity locally. Crucially, by impacting biodiversity at local scales, effects of human pressures can similarly impact biodiversity patterns among communities at broader spatial scales.”