The Kenyon Pine Plantation

In honor of Earth Day 1990, Dr. Thomas Jegla arranged for the Newark Audubon Society to donate 1000 white pine seedlings (Pinus strobus) to Kenyon College. In April, ecologists Dr. Ray Heithaus and Dr. Kathy VanAlstyne supervised Kenyon students and community members in the planting of these trees on a hillside overlooking the Kokosing River Valley. The trees were planted in two grids, distinguished by 10 and 15 foot spacing. Then in the Spring of 1992 students in the Experimental Ecology class measured the surviving trees and began a large-scale experiment by fertilizing half of the individuals in each spacing. From the Fall of 1992 to 2001 students in An Introduction to Experimental Biology have continued data collection.

In 1993, Che Smith and Mila Thigpen measured the height of pines using a meter stick.	In 1998, Sara McClean used a tangent height gauge to determine tree height.

During the first few years of growth students discovered that the fertilized trees were adding less height than their unfertilized counterparts and that the trees in the 10 foot spacing were growing better than those in the 15 foot spacing. These results were counter intuitive and lead to additional investigations to try to explain these results. The role of both deer and surrounding vegetation were explored. Students discovered that trees growing under a moderate amount of thorny cover, in this case brambles like black raspberries and Rosa rugosa grew better than those in the open or heavily covered. They also speculated that fertilizer may have enhanced the growth of brambles to such a degree that growth was inhibited.

In the Fall of 1998, the pines in the 10 foot spacing are just beginning to grow into eachother.	In the Fall of 1998, the trees in the 15 foot spacing are still widely spaced.

The improved growth of the more closely spaced trees has not been fully explained. Students checked for a bias at the time of planting, but found none. As the project continues associations between individual trees and their environment continue to change. By the fall of 1998 trees in the 10 foot spacing were beginning to grow together. It is expected that increased competition for light and space should result in changes in the growth patterns in the two spacings with the closely spaced trees showing the effects first.

Figure 1. Growth of Pinus strobus at the Kenyon Pine Plantation between 1992 and 1998. Height and annual growth were determined in October of each year.

Edited: 8-29-99

Back to Kenyon

Return to BFEC home page