Kiley Chen

Document Type

Honors Thesis

Major

Wildlife Ecology

Advisor(s)

Sydne Record

Committee Members

Noah Charney, Lindsay Seward

Graduation Year

May, 2025

Publication Date

2025

Abstract

Seedling dynamics are a significant bottleneck to forest populations and can provide information on how forests will respond to change over time. Studies have shown that parameters such as height, light availability, heterospecific density, and conspecific density can influence both seedling growth and survival. In this study, I investigated the impacts of these parameters on Acer rubrum seedlings in a temperate forest currently impacted by the invasive Adelges tsugae in central Massachusetts from 2017 to 2018 and 2018 to 2019. I then fitted survival and growth kernels of an integral projection model for each year period to explore the seedling survival rates and most critical age class transitions. I predicted that A. rubrum seedling survival and growth are higher with greater initial seedling height, light exposure, and lower seedling density; however, the effect size of conspecific presence on survival and growth is more positive than for heterospecifics. I found that height was positively correlated with seedling growth for both years and survival from 2018 to 2019, light was positively correlated with height and survival for both years, heterospecific density was negatively correlated with growth from 2018 to 2019, and conspecific density was negatively correlated with growth from 2018 to 2019. I also found that the most critical size transition class was larger (150mm-250mm) from 2017 to 2018 and smaller (50mm-100mm) from 2018 to 2019. This indicates that A. rubrum seedlings are susceptible to changes with temporal variation but could benefit from hemlock canopy decline. Further investigations should incorporate fecundity and adult tree data for a complete population analysis.

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