College of Agriculture & Natural Resources

From MSU AgBioResearch, Summer 2012, Vol. 2, No. 2

A Michigan State University (MSU) AgBioResearch scientist has helped to advance the university’s “Be Spartan Green” environmental stewardship initiatives with groundbreaking research on urban treed spaces. He is using his knowledge and expertise to help people in Kenya manage their forests.

“We have to pay more attention to how we utilize trees because the planet is becoming more urbanized and more deforested, so trees are becoming more of a precious resource,” said David MacFarlane, an associate professor in the MSU Department of Forestry, who specializes in forest measurements and modeling.

The research began with an urban timber inventory in Michigan cities, something no one had done.  In a 13-county area in southeastern Michigan, MacFarlane and several students employed the same procedure used for commercial forest inventories to measure the level and quality of wood in urban trees.

Results of the inventory showed that the quality of wood in urban trees was better than expected and that annual tree removals in the study area could yield lumber equivalent to 5,500 homes per year, or an energy equivalent of 97 megawatts annually — that’s enough to run the MSU power plant for a year.

MacFarlane pointed out that this is a nonpoint resource.

“These are all little bits and pieces at various locations, so it seems logistically difficult to try to bring it all together,” he said. “That was an early argument against curbside recycling and now we routinely do that, however, so maybe wood could be added to the materials recycled at curbside.”

The results of the research sparked the interest of MSU officials. They asked what could be done to obtain renewable fuels to substitute for coal in the campus power plant. One of MacFarlane’s students worked with MSU foresters in the summer of 2011 to figure out how much useable wood might be in the thousands of acres of off-campus forests that MSU owns. Some of that wood is now being used to fuel the power plant, and MacFarlane credits the urban wood research with sparking the idea.

The other part of MacFarlane’s recent research relates to the carbon storage capacity of trees and its role in helping to offset carbon dioxide (CO2) emissions into the environment. In 2009, he undertook a project to quantify the carbon sequestered by trees on the main campus.

Using information from the MSU Office of Campus Planning Administration, which  keeps detailed information on most trees on campus, including GPS coordinates, species, date planted and what happens to the tree during its life, MacFarlane determined that in 2009, about 66 tons of CO2 equivalents were offset by about 5,000 planted trees. MSU then claimed the first urban forest CO2 emissions offset credits registered with the Chicago Climate Exchange, a voluntary carbon market in April 2010. The offsets were subtracted from emissions reported from the campus power plant.

Now MacFarlane is using insights from his research in Kenya. He received a Fulbright Scholarship and has been on a six-month sabbatical in Kenya since January.

“Kenya needs to plant more trees and protect its forests, but it also needs to increase its capacity to implement such projects scientifically,” MacFarlane said. “Through new research, workshops and lectures, I hope that I can help increase what the country can do.”

He is based with the Kenya Forestry Research Institute on the Kenya coast. 

“This is an excellent place to study connections between forest ecosystems and human well-being,” MacFarlane said.  “The mangrove forests I have been studying, for example, filter water, protect and enhance the adjacent coral reef ecosystem and marine fisheries, host a very high diversity of birds and other organisms, and are widely used by everyone from farmers to eco-tourists.  So they are very important economically, but they are also very sensitive to climate change, such as rises in sea level.”

The mountain cloud forests in Kenya, sometimes called the “water towers,” such as the one MacFarlane recently surveyed in the Taita Hills, collect much of the rainfall that is used to generate hydroelectric power and feed the rivers that provide water for drinking and irrigation. 

“The clearing of these forests can change and has changed the hydrological cycles, which, through apparent feedbacks via global warming, appears to have contributed to increasing forest fires, releasing yet more carbon into the atmosphere.” 

MacFarlane points out that more research is needed to understand these effects but to preserve these forests in the wake of a growing Kenyan population, there needs to be a mechanism to create additional economic value associated with maintaining forestland. 

“The research I’m doing is helping to get a better handle on the potential for carbon stored in these forests to offset climate change and to develop monitoring systems to help assure that investment funds are actually translating into increased carbon sequestration and better forest management.”