Hemlock Hill: an ecosystem study for BPS fifth grade students
Recent outreach to Boston Public Schools resulted in a collaboration to enhance its fifth grade life science curriculum on ecosystems. Hemlock Hill was chosen as a small ecosystem for study because it is a local forest undergoing significant ecological change that students can visibly observe. The site of an impressive stand of native hemlocks, the area has been affected by a small, non-native insect: the hemlock woolly adelgid (HWA). HWA devastated the hemlock population on the hill, sending a majority of the plants into severe decline. However, recent applications of soil-injected pesticide have almost eliminated the adelgid and brought back a healthy canopy to most of the hemlocks.
Students can observe the phenomena of ecological change:
- The lower limbs of the hemlock trees are broken and defoliated, representing the years of adelgid predation. Additionally, several dead hemlock trees are scattered on the forest floor in a state of early decomposition.
- The resulting defoliation allowed light to penetrate down to the forest floor, creating the conditions for new plant life to emerge and thrive.
- The hemlock canopy has rejuvenated, resulting in increased shade.
Students are able to closely examine a forest in transition, search for and categorize the organisms that populate this site, and explore how each organism finds the energy it needs to survive.
An Arboretum educator visits the classroom prior to the field trip to talk with the students about what they will see on Hemlock Hill. The Arboretum provides bus transportation to the schools and regularly consults with teachers about the effectiveness of the program. In the 2011-12 school year, 238 Boston fifth graders from nine schools participated in ecosystem studies on Hemlock Hill.