How Climate Change is Impacting Global Forests: Trees Reveal New Changes

As our climate changes, forest ecosystems around the world are also changing. Now, 107 collaborators have taken a look at trees around the world in order to examine how 59 forests from 24 countries are changing.

Measuring and understanding the effects of changes occurring in forests isn't easy. In this case, the scientists collected information from CTFS-ForestGEO, the only network of standardized forest-monitoring sites spanning the globe. This network revealed that since the census first began in 1981, atmospheric carbon dioxide has increased by about 16 percent. In addition, the forest sites in the network have warmed by an average of over 1 degree Fahrenheit and experience up to 30 percent changes in precipitation.

That's not all the researchers found. They discovered that permafrost thaw is driving forest loss in Canada while drought is killing trees in Panama, southern India and Borneo. In the U.S., deer in Virginia are eating trees before they reach maturity while nitrogen pollution is changing soil chemistry in Canada and Panama.

In addition to monitoring trees, the researchers described the relatedness of trees, tracked flower and seed production, collected insects, surveyed mammals, quantified carbon stocks and flows within the ecosystem, took soil samples and measured climate variables. This shows not only how forests are changing, but also why.

In the end, the scientists found that many of the changes occurring in forests worldwide can be attributed to human impacts on climate, atmospheric chemistry, land use and animal populations. In fact, these changes are so pervasive that they warrant classification of a new geologic period in Earth's history, the Anthropocene.

The findings reveal a bit more about how climate and humans are changing forest ecosystems across the globe. This shows that the rate of change is almost unprecedented and that we're entering a new era when it comes to climate.

The findings are published in the journal Global Change Biology.