4/21/2004 Linfield students to investigate Forest Park tree health
McMINNVILLE ? Local high school and Linfield College students will investigate the health of Portland?s Forest Park trees thanks to a grant from a state agency.
The $4,960 grant was awarded to Linfield College by the Oregon Department of Forestry under the Community Forestry Assistance program. The funds will support a project in which the Science Department on Linfield?s Portland Campus will partner with the Portland Parks and Recreation Department?s Ivy Removal Project and Stewardship Program to conduct field investigations of threats to conifer seedlings in Portland?s renowned Forest Park. The field work will be carried out by college and high school student interns under the guidance of Nancy Broshot, an assistant professor of biology at Linfield.
Funding for the Community Forestry Assistance program is provided by the Oregon Department of Forestry and the USDA Forest Service.
Forest Park, an urban forest of more than 5,000 acres, is a rare example of a large forested living laboratory in an urban environment. There is a natural progression in the life of a Northwest forest in which aging hardwoods are gradually replaced by conifers. In earlier investigations in Forest Park, Broshot noticed that there were far fewer conifer seedlings growing up among the hardwoods than would normally be expected.
Possible causes of the low survival rate include seed source, disease and predation ? i.e., consumption of the seedlings by wildlife.
"The parks people had been planting conifer seedlings in the park," Broshot said, "and they noticed that these were showing a similarly low survival rate. This was especially true in the areas closest to human habitation ? which led me to suspect rodents."
This study will focus on predation, developing evidence on its relative significance in the high seedling mortality rate. A team of two Linfield students and four high school students will build and place two kinds of exclusion enclosures, one keeping both deer and rodents out and the other excluding only deer. Under Broshot?s supervision, the students will develop a research protocol, select test and control sites, plant conifers at the sites, collect and analyze data and prepare a report of the results. The Linfield students will receive an honorarium and academic credit and will publish a paper on the project. The high school students will also receive credit and an honorarium and will be credited as investigators in the published paper.
Later studies will focus on the other two suspects in this case, seed source and disease. Knowledge gained from the studies will help parks officials understand how best to help nature keep Forest Park healthy.