Thomas Robinson | March 30^th, 2021

A recent review has highlighted that warming winters are likely to result in an expanded range for some tropical plants and animals across the United States.

Scientists have found that multiple tropical plant and animal species, such as mangrove trees and manatees, are already expanding northward resulting in what is called tropicalization.  The largest factor for northward expansion of tropical species is whether they will suffer from freezing conditions or not, and as winter’s have warmed the line where those conditions occur has moved northward.  Extreme cold events, like what happened recently in Texas, function to push back the advancement of tropical species, but these events are happening even less often than they already do which allows species that have expanded northward to become more tolerant of the cold.

Unfortunately, warmer conditions are also expected to allow invasive species such as certain tree beetles to move further north, as well as a few mosquito species.  The mosquitoes pose a threat to public health because they are known to carry diseases such as Zika and yellow fever.  Additionally, researchers are concerned about how the expansion of new species into northern habitats threatens the biodiversity of the invaded ecosystems. Insect populations have been declining across the globe, particularly in the U.S. Midwest, and it is likely that the addition of new and adaptable species will compromise existing insect populations.