Date of Award

2023

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Natural Resources

First Advisor

Anthony W. D'Amato

Abstract

Forests are increasingly being managed for their carbon sequestration potential. As such, an understanding of the factors controlling carbon dynamics across and within sites is becoming increasingly important for guiding carbon management strategies. Given that much of a forest’s carbon is stored in soils, identifying the factors that control how much carbon is stored in soils is critical. This study used detailed vegetation and soil measurements across a rich northern hardwood forest in Corinth, Vermont to identify factors that drive soil carbon storage in a northern hardwood forest, a common type in New England, and investigated how multiple non-native species might impact these factors. These forests have a large component of white ash (Fraxinus americana), a species threatened by the invasive emerald ash borer (Agrilus planipennis), creating an urgency to assess how ash trees influence soil organic carbon sequestration, as well as how their mortality may impact future carbon dynamics. Furthermore, non-native earthworms, which have a large impact of forest floor and soil carbon, are impacting these systems. This work quantified how these stressors are affecting carbon storage and tree regeneration. Analysis of organic litter material and mineral soil samples from these areas indicate both earthworms and overstory ash basal area significantly impact leaf litter nitrogen content and leaf litter carbon to nitrogen ratio (C:N); however, there was no interaction between the two factors. Earthworms also significantly decreased soil pH, however it is difficult to disentangle if earthworms are drawn to higher pH areas or if they create these conditions. Conversely, basal area of white ash had a significant, increasing effect on leaf litter pH. Soil pH was the best predictor of soil carbon in the upper soil horizons, and carbon to nitrogen ratio (C:N) in the forest floor was best explained by the interaction of litter pH and earthworm prevalence. Collectively, these results suggest both earthworm and emerald ash borer may alter soil carbon and nutrient dynamics in rich northern hardwood forests and the pathways by which carbon is stored.

Language

en

Number of Pages

39 p.

Download

Share

COinS