Date of Submission
7-2025
Document Type
Thesis
Degree Name
Master of Science in Environmental Science
Department
Biology and Environmental Sciences
Advisor
Sharon Kahara, Ph.D.
Committee Member
Buddhika Madurapperuma, Ph.D.
Committee Member
Matthew Fulda
Keywords
California’s Rangelands, Light Rotational Grazing, Unmanned Aerial Systems, NDVI/GCC Values, Data-Driven Adaptive Management, Sustainable Grazing Practices
LCSH
Rangelands, Rotational grazing, Drone aircraft
Abstract
California's rangelands, vital for biodiversity and cattle production, face threats from land use changes and climate changes, necessitating robust management strategies. While overgrazing has been studied extensively, the effects of light rotational grazing on vegetation have seldom been assessed. This study used Unmanned Aerial Systems (UASs) and multispectral imagery to assess the seasonal impacts of light rotational grazing on vegetation health and coverage in wetland mitigation areas near Willits, California. Data were collected in May (spring) and November (fall) 2024 using a DJI M3M drone and MicaSense camera capturing RGB and Near-Infrared (NIR) bands. Green Chromatic Coordinate (GCC) and Normalized Difference Vegetation Index (NDVI) values were calculated for grazed and non-grazed experimental plots. Results indicate that grazed plots consistently exhibited significantly higher mean GCC values than non-grazed plots in both spring (0.45 vs. 0.42, p=0.008) and fall (0.38 vs. 0.34, p=0.001), suggesting enhanced vegetation greenness and photosynthetic activity. For NDVI, grazed plots showed significantly higher values in spring (0.41 vs. 0.35, p=0.043), implying greater initial productivity. While this difference diminished by fall (p=0.904), pixel distribution analysis revealed that grazed areas maintained higher proportions of vigorous vegetation and greater heterogeneity (58% vs. 47.9% high NDVI in fall). These findings suggest that light, managed grazing can positively influence rangeland vegetation, promoting sustained greenness, vigor, and structural diversity, particularly extending into the fall dormant period. This research also demonstrates the effectiveness of UAV-based remote sensing as a scalable tool for data-driven adaptive management, supporting sustainable grazing practices that balance ecological health with agricultural productivity in rangeland ecosystems.
Recommended Citation
Khanal, Pramil, "Unmanned Aerial Systems (Uass) in Rangeland Ecosystem Management: Assessing Grazing Impacts at Willits, California" (2025). Master's Theses. 262.
https://digitalcommons.newhaven.edu/masterstheses/262