– To those who deny climate change, all we can say is that nature seems to be of a different opinion. American trees have had enough and they are now heading North and West to escape threats. Scientists say it’s a result of climate change. Can trees really migrate to escape climate change?
Scientists have collected data from 86 tree species in the eastern United States, and discovered that over the past 30 years, most trees have been moving westward or northward in response to climate change.
During the past 30 years, the period covered by the research, the mean annual temperature in the eastern United States, where data was collected, increased by about 0.16 degree Celsius on average. The northern areas of that region had among the highest temperature increases.
“Trees are shifting partially because of climate change, but their responses are species specific,” Professor Songlin Fei at the Purdue University said.
“Deciduous trees like oak and maple are primarily moving westward. Evergreens are responding in a different way. They’re moving northwards.”
Many climate change studies have generally shown a strong correlation between changes in temperature and tree shifting.
The study revealed that precipitation was a significant factor when considering the impact climate change can have on biodiversity and the sustainability of ecosystems.
According to Professor Fei, precipitation has a stronger near term impact on species shift than temperature.
As a result, most trees in the study were shifting westward to follow changes in moisture. Fei said the westward shift was one of the most surprising findings of the study.
“Yes, we did see some northward shift as we had anticipated,” he said. “But we also found many trees have been moving westward because of changing climate. When analyzing the impact of climate change, precipitation had a much stronger near-term impacts on forests instead of temperatures.”
Professor Fei said the research shows the clear impact of climate change based on big data, not just modeling.
“It is not future predictions,” he said. “Empirical data reveals the impact of climate change is happening on the ground now. It’s in action.”
The study also led the researchers to conclude that fluctuations in average precipitation and temperature are leading to changes in forest composition. As a result, climate change is putting “the resilience and sustainability of various forest ecosystems across eastern United States in question.”
The research, based on the analysis of 30 years of data gathered by the U.S. Forest Service, was published in Science Advances.