The latest in the Ecological Reviews series is Grasslands and Climate Change. Kathryn Yurkonis, co-author with Will Harris of the chapter ‘Keeping up: climate-driven evolutionary change, dispersal and migration‘, tells us more about their contribution to the book below.
Can our grassland species keep up with climate change? Can we predict which species are more at risk to be negatively affected by climate change?
These are fundamental questions at the heart of grassland conservation and the future of the grassland habitats and landscapes we depend on. Even in settings where it can be unattractive to show outward concern over climate change, people that live, work, and play in America’s grasslands wonder about future trends in the populations of plants and animals they love and depend on. If not because they are passionate about their preservation, then because their livelihoods and familial identities depend on them.
What is happening with the deer populations? When will the ducks come this year? Will my grandkids still be able to raise cattle on these pastures? Managing our world grasslands depends on us doing our best to address these questions.
In leading a discussion on the rise of the world’s grasslands to a small and very astute group of Geology capstone students, one asked at the end of the conversation: knowing this, is there a way for us to predict how grassland organisms will respond to future climate change? That is a good question, and, as always in biology, has a complicated answer.
In a way, the answer is yes. We know that plants and animals vary in how well they can tolerate environmental changes and some will be more successful under changing environmental conditions than others. It’s remarkable how quickly this selection can take place. Recent work on the genetic changes seen in plant populations within restored grasslands is a great example. Even after a few years the genetic composition of plant populations can change to reflect their new environment. This is even more striking when considering that it’s not only the sequence of letters in the genetic code than can be selected upon and passed from generation to generation, the environment can imprint changes on DNA as well. Instructions for plants and animals on how to use their DNA to handle their new environments that are heritable in ways that we are only beginning to understand. Certainly, plants and animals around the world have the capacity to interact with their environment and emerging genetic and molecular technologies are allowing us to see that in real time.
But in a way, the answer to this student’s question is no. While grassland plants and animals have the capacity to respond to climate change, there are some big wild cards that affect how climate change would affect the world’s plants and animals. Sure, alongside changes that occur in place, organisms have the capacity to disperse into new areas, to find a new home when conditions become inappropriate. But this only works if the organisms have the capacity and pathways to do so. We know all too well that many species face insurmountable barriers to their dispersal in our fragmented grassland landscapes. Only the most mobile species are likely to make it through the filters we’ve placed to inhibit their movement on our grassland landscapes. But the real wild card is how fast these generational and distributional changes can occur relative to the speed of climate change. If the environmental extremes that push species to change and disperse occur too rapidly, only a select few from our original species pools will make it through the filter of human-induced climate change.
So yes, species have the most amazing capacity to keep up with climate change and there are fantastic examples of species that have not only done it in the past, but are doing it now. But their ability to do so is limited by their ability to move and interact and reorganize on our human dominated landscapes in environments that are changing at an unprecedented rate.
In Grasslands and Climate Change, Will Harris and I review the current literature on species evolutionary and distributional responses to climate change and the methods that exist for screening species for vulnerability as we incorporate climate change into conservation planning.
Kathryn A. Yurkonis, University of North Dakota, USA
Grasslands and Climate Change is part of the Ecological Reviews series. BES members get 25% off all titles in the series when buying directly from Cambridge University Press. See also, David Gibson’s blog post: Grasslands and Climate Change