Undergraduate Honors Theses

Thesis Defended

Spring 2016

Document Type


Type of Thesis

Departmental Honors


Ecology and Evolutionary Biology

First Advisor

Nichole Barger

Second Advisor

Pieter Johnson

Third Advisor

Daniel Jones


Increased infilling and expansion of shrubby woodlands into grasslands has been observed worldwide since European settlement, which has led to serious fuel loads and the risk of severe fire. Under the National Fire Plan in the U.S., fuel reduction treatments have been implemented in order to reduce risk of hazardous wildfire and restore ecosystem structure and function in these woodlands. Piñon-juniper (“P-J”) woodlands are often the most spatially extensive vegetation type and are often targeted for fuel reduction and restoration. In this study, we evaluated soil responses in an upland P-J woodland on the Colorado Plateau to three fuel reduction treatments: 1) mechanical shredding (“mastication”), 2) hand thinned debris burned in piles (“pile burn”), and 3) hand thinned debris scattered across the land then burned (“broadcast burn”), one (2010), two (2011), and six (2015) growing seasons post-treatment. We quantified biocrust presence, soil aggregate stability, and percent cover of woody debris and litter as indicators of soil response to tree removal treatments. If land management goals are to implement fuel reduction treatments while promoting soil health, our results indicate the mastication treatments are best in terms of soil structure and function.