Date Thesis Awarded

5-2021

Access Type

Honors Thesis -- Open Access

Degree Name

Bachelors of Science (BS)

Department

Geology

Advisor

Nicholas Balascio

Committee Members

Abigail Buffington

James Kaste

Abstract

The College Woods, west of William & Mary’s campus, consists of ~900 acres of protected southern mixed hardwood forest. The woods surround Lake Matoaka, a former millpond established in ~1700. Despite the rich history of the area, little is known about how the dominant vegetative landcover has shifted over the last 300 years. This study set out to quantify the modern vegetation within the College Woods via the phytolith assemblages within the soil and identify shifts in the assemblages since the creation of Lake Matoaka and whether these changes are distinct from the vegetation that existed in the area before the lake. To accomplish this, I studied the composition and preservation of phytoliths – silica bodies generated within and between plant cells. The study focused on the two questions: do the modern phytolith assemblages in the soil of the College Woods reflect the vegetation present and can phytoliths within the sediments of Lake Matoaka be used to identify the dominant vegetative communities over the last ~300 years? I addressed these questions with three approaches: 1) Identify the primary phytolith producing taxa within the College Woods; 2) Identify the modern phytolith assemblages within the soil of the College Woods; 3) Identify the differences between phytolith assemblages from the lake sediment core samples. I found the following: 1) The production of phytoliths varies heavily between and within different common taxa of the College Woods, with species of oaks (Quercus spp.) unpredictably producing phytoliths and beeches (Fagus grandifolia) likely contributing the majority of dicot phytoliths; 2) The modern phytolith assemblages of the College Woods reflect a low phytolith producing environment, and the vegetative homogeneity is reflected in the phytolith record; 3) The phytolith density between 1700 and 1810 indicates an increased presence of grasses likely due to a major shift away from forested landcover. Before the lake, the landcover was distinct from all vegetation post-1700 indicating the natural vegetative community of the pre-lake has not returned to the area despite being protected for nearly a century.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

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