Date of Award

2026-05-01

Degree Name

Master of Science

Department

Environmental Sciences

Advisor(s)

Kelly S. Ramirez

Abstract

Global change, driven by both natural processes and human activities, has significantly transformed ecosystems. Urbanization and artificial light at night (ALAN) are key contributors, disrupting natural light cycles and influencing biological rhythms, biodiversity, and ecosystem functions. Thus far, there remains a gap in knowledge of how soil ecosystems are impacted by ALAN. This study uses a laboratory incubation to investigate the effects of ALAN on soil microbial communities and functions across urban and natural ecosystems. Briefly, soil was collected from eight sites around El Paso, Texas and neighboring New Mexico representing urban and rural light exposure. Soil was then subjected to experimental treatments simulating natural light and dark cycles (0.01, 0.1, 1.0, and 10 lux). After an 8-week incubation, we evaluated microbial community composition (diversity), microbial activity through respiration, and soil abiotic properties including pH and moisture content. Overall light intensity alone did not consistently alter microbial community composition or relative abundance across treatments. Microbial communities instead remained broadly similar across lux levels, with only modest shifts observed in the relative abundance of taxa. This work will help to build an understanding of the extent to which artificial lighting alters belowground ecosystem processes and may help inform urban planning and conservation strategies to mitigate potential ecological disruptions caused by artificial night lighting.

Language

en

Provenance

Received from ProQuest

File Size

78 p.

File Format

application/pdf

Rights Holder

Randall L. Walker

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