Date of Completion

2024

Document Type

Honors College Thesis

Department

Biology

Thesis Type

Honors College, College of Arts and Science Honors

First Advisor

Pablo E. Gutiérrez-Fonseca

Second Advisor

Alison K. Brody

Keywords

Macroinvertebrates, Organic Matter Processing, Urbanization, leaf litter decomposition

Abstract

Anthropogenic activities, including land use changes, exert a significant impact on the physical and chemical characteristics of streams as well as the assemblage of organisms living in and around the stream. Urban streams are especially vulnerable to alterations in nutrient loads, hydrological regimes, and physiochemical variables, which can lead to reduced biodiversity and negative impacts on ecosystem processes (e.g., leaf litter decomposition). This study aimed to assess the health of four streams in Vermont using metrics for macroinvertebrate community health and organic matter processing. Streams were selected to represent different land use practices: two streams were in an urban catchment area (>10% of the catchment area was covered in human development), and two streams were in a forested catchment area (85% of the catchment area was covered by natural vegetation). Stream health was evaluated based on the stream’s respective macroinvertebrate species biomass, diversity, abundance, functional feeding group proportions, and organic matter processing. We predicted that streams with higher water quality (expected to be the forested streams) would harbor healthier macroinvertebrate communities (reQlected by greater abundance, diversity, and biomass) leading to more organic matter processing compared to streams of lower water quality (expected to be urban streams). Data were gathered by collecting macroinvertebrate samples from the streams through the use of leaf litter bags. Measures of stream physiochemical variables (temperature, conductivity, and pH) were also taken in each stream. The results displayed differences between urban and forested streams in some physiochemical variables, such as higher temperature and conductivity in urban streams compared to the forested streams (PERMANOVA: p<0.05). There was no difference between urban and forested streams in terms of macroinvertebrate abundance, richness, biomass, or functional feeding group relative abundance (ANOVA: p>0.05). Consequently, no significant differences were observed in remaining litter between land uses or streams (ANOVA: p>0.05). Overall, these results suggest that, in the streams studied, different land use practices do not significantly affect their macroinvertebrate communities. The goal of this study was to act as a baseline of stream health in Vermont by exploring the effects of local urbanization on some Vermont streams and their macroinvertebrate assemblages.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Download

Share

COinS