Ingrid Burke, professor and Carl W. Knobloch, Jr. Dean of Forestry and Environmental Studies at Yale University, conducts research on grasslands, rangelands and some agricultural systems, looking specifically at how land use management — such as grazing or row-crop agricultural management — and climate change influence the storage and cycling of both carbon and nitrogen in those systems.

Members of the UD community will have a chance to hear how her research sheds light on impacts from climate change and other human-induced changes in this very different environment when Burke travels to UD to give the John R. Mather Visiting Scholars Lecture on at 6 p.m. on Thursday, Nov. 8 in Mitchell Hall. The focus of Burke’s lecture will be on “Temperate Drylands and Human Impacts.”

She said in an interview that dryland ecosystems are interesting for two reasons: they store most of their carbon below ground, and biology happens at a slow rate in those ecosystems due to their water limitations.

“When you look at a grassland or a shrubland, you do not see much vegetation above ground,” Burke said. “Because they’re so limited by water, the plants are excavating below ground. They’ve got their roots everywhere so that they can gather as much moisture as possible — it’s like a forest turned upside down. As a result, most of the carbon is stored down there and most of the biological action occurs below ground.”

In addition, because of their lack of water, the ecosystems are vulnerable to change.

Burke noted that when hurricanes hit or deforestation occurs in places like Puerto Rico, which has a tropical forest habitat, those forests are able to grow back quickly. This is not the case with dryland ecosystems.

“Anything that influences the soils can cause some dramatic change in the system, and they’re very slow to recover,” said Burke. “Over-grazing, for instance, which can lead to erosion, can be extremely damaging. Cultivation management to turn those dryland systems into dryland cropping can be very damaging as well.”

These systems are sensitive and vulnerable to indirect human impact in the case of climate change, as well. Climate change impacts the ecosystems indirectly by causing higher temperatures, more evaporation and less available water for plant growth. With human activity changing temperate drylands both directly and indirectly, it is important to stay up to date on the causes and consequences of those changes on a global scale.

About the Mather Lecture

The John R. Mather Visiting Scholars Lecture honors the memory of John (Russ) Mather, who served as a professor of geography at UD from 1963-2003, and as chair of the Department of Geography from 1966-89. 

Sandra F. Mather established the lectureship to honor her late husband by enabling the department to host well-known scholars for the active exchange of ideas related to Mather's broad interests in climatology and geography.

The lecture is hosted by the Department of Geography, which is housed in UD’s College of Earth, Ocean, and Environment.

The event is free and open to the public but registration is required. To register, visit the John R. Mather Visiting Scholars Lecture page.