You are here
Harvard Forest REU Symposium Abstract 2022
- Title: Examining the relationship between negative density-dependent factors and seedling mortality in Tsuga canadensis in a North American research forest
- Author: Jordan O'Hare Gibson (University of Massachusetts - Amherst )
- Abstract:
Tsuga canadensis, Eastern Hemlock, is a coniferous tree native to North America. T. canadensis is also experiencing population decline due to a host-specific, negative density dependent factor — Hemlock Wooly Adelgid. This makes it a good model organism for examining the Janzen-Connell hypothesis in northeastern NA temperate forests. This presentation details a study in which the density of conspecific and heterospecific trees surrounding T. canadensis seedlings is examined in relation to seedling mortality rates throughout time and space on the Harvard ForestGEO megaplot. This study took place in the Harvard Forest in the northeastern United States, with data collection occurring in the summer months using 1x1m research plots set up along N-S transects. Results are consistent with the Janzen-Connell hypothesis, showing a statistically significant negative correlation between T. canadensis seedling establishment and the density of nearby mature conspecific trees. This relationship is likely due to Hemlock Wooly Adelgid spreading from mature trees to seedlings, thus inhibiting survivability. These findings may help inform the future of Eastern Hemlock at Harvard Forest.
- Research Category: Conservation and Management; Ecological Informatics and Modelling; Large Experiments and Permanent Plot Studies; Physiological Ecology, Population Dynamics, and Species Interactions
