Soil scientist joins CABNR faculty after DRI stint

Assistant Professor Paul Verburg has joined CABNR as a soil scientistStory by Anne Conway

Assistant Professor Paul Verburg has joined CABNR as a soil scientist after 15 years at the Desert Research Institute.

"My main focus at DRI was research, but I did a little bit of teaching and found that I really enjoyed that, "

Verburg said. "So I became interested in a position that would allow me to interact more with students. That was an important reason for this move over to CABNR." Verburg grew up in the Netherlands and earned his degrees in soil science and environmental science at Wageningen Agricultural University.

"I was trained as a traditional soil scientist, but when I was getting my Ph.D I got interested in the interactions between plants and soils, so, although lot of my research is based on soil science, I try to take a broader view."

At DRI, Verburg focused on effects of large-scale environmental changes brought on by climate change and acid rain on nutrient cycling. He applies his understanding of soil processes to ecosystem-wide issues, and he has collaborated with a broad variety of scientists, from plant physiologists to atmospheric chemists.

In CABNR he is looking at continuing some of the research he started while still at DRI. One of those research projects was examining how forest management practices, such as thinning and controlled burns, may affect water and air quality at Lake Tahoe. The forests of the Tahoe Basin are in many places overgrown due to fire suppression efforts, and environmental regulators have encouraged thinning as a way to reduce the threat of devastating wildfires, such as the Angora Fire of several years ago.

In this project, on which he collaborated with two DRI colleagues, he looked at the impacts of prescribed fire on nutrient emissions from soils to aquatic environments and the atmosphere. That research has found that the effects of management practices vary depending on a site's characteristics, such as soil type, slope and the time of year. He and his fellow researchers have found that at his study site there isn't a lot of nutrient-rich sediment flowing into streams from forest management but that there is evidence of less nitrogen - a key nutrient affect algae growth in the lake - volatilizing into the atmosphere when wet fuels are burned in the spring as opposed to dry fuels being burned in the fall. In addition, chemical speciation and thus reactivity of volatile N components is highly dependent on fuel moisture.
Dr's Paul Verburg and Dale Johnson collecting soil samples prior to a controlled burn near Lake Tahoe.Verburg and colleagues have also studied the potential of using pinyon-juniper forests as a feedstock for biofuels as well as the environmental impacts associated with harvesting. This is a key management issue because pinyon-juniper forests are expanding in Nevada and encroaching on grazing land and wildlife habitat, particularly areas used by sage grouse, which is a candidate for the Endangered Species List. Verburg has found that harvesting pinyon-juniper may not currently be economically feasible but that the situation could change. In addition, currently not many studies have taken a close look at the short and long-term environmental impacts of pinyon-juniper harvesting so there is still a lot of opportunity for research in that area.

"If you take into account the infrastructure, elevation, slope steepness and those kinds of things, from an economical standpoint it often doesn't make a lot of sense," he said. "But people are getting better at preprocessing materials on site and converting it to a form that's easier to transport. The way I look at it, there is this management objective of reducing fuels at the same time that people are looking for alternative fuels. So I'd like to find a way to combine those two objectives while minimizing environmental impacts of harvesting pinyon-juniper."