In this issue of Keystone Wild! Notes, we hear what the state’s leading conservationists think are the biggest challenges facing our native species, and not surprisingly, climate change is near the top of the list. Our climate is changing faster than anyone expected. Predictions vary, but models using realistic assumptions about future greenhouse gas emissions point to a 3.5° C rise in the next 50 years, which would dramatically change species and their distribution across North America.
While the impact will vary, most places will see a trend toward higher temperatures and more sporadic, but intense, bouts of precipitation. This means Pennsylvania will probably see a lot less snow; have drier, hotter summers; and will have a climate more like southern Georgia by the end of the century. While that may sound appealing, it means significant changes for our native species and habitats.
Unfortunately, it seems inevitable that we’re going to lose some species, especially those with narrow tolerance ranges and specific habitat requirements. While it’s possible we could lose as many as one in four species by 2050, most species will survive. As temperatures increase, habitats will shift to the north and to higher elevations, and many species will move along with them. As long as they are mobile, have a place to go and a path to get there, moving is a viable response to climate change. This strategy even works for plants through the process of seed dispersal.
Unfortunately, changing climate conditions will also benefit invasive species. Invasives such as kudzu and the gypsy moth will be spreading further into ecosystems already stressed by the effects of climate change.
Even though we’re already seeing some of the effects of climate change, including earlier blooming in some plants and earlier migration by some birds, the truth is we aren’t sure how climate change will affect many of Pennsylvania’s native plants and animals.
Knowing which species and habitats are likely to decline or shift is critical to developing a strategy to help species cope with climate change. WRCP has taken the first step to answering this question by providing funds to Pennsylvania Natural Heritage Program scientists at the Western Pennsylvania Conservancy to develop and apply a climate change susceptibility index.
The index will be based on criteria that evaluate a species’ sensitivity to climate change, including dispersal ability, how specific their habitat requirements are, and their current population size and distribution. This information will allow scientists to rank species and identify those most likely to be significantly impacted by changing climate conditions.
Once we know which species are most at risk, we can begin taking the steps necessary to conserve them. These will include monitoring populations and their movement; identifying and protecting large, undisturbed tracts of habitat that can act as refuges for emigrating species; and identifying and conserving habitat corridors they can use to make the journey. Supporting and participating in projects like these will be among WRCP’s top priorities in the coming years.