Date of Award

2023-08-01

Degree Name

Doctor of Philosophy

Department

Biological Sciences

Advisor(s)

Jennie McLaren

Abstract

Shrub encroachment is a worldwide phenomenon that affects multiple biomes at different ecological and anthropogenic levels. In dryland ecosystems, shrub encroachment is a noted concern amongst land managers, as it can lead to a loss of soil resources and biodiversity. To mitigate the negative effects of shrub encroachment in Drylands, land managers can implement large-scale shrub removal practices. These land restoration practices can shift landscapes to novel ecosystems, where resulting plant communities can vary following treatments. Grass recovery or increasing herbaceous cover is often a primary goal of these treatments, however predicting which sites may show higher grass responses to treatments is challenging. There is also still much unknown on how these shrub removal practices will affect valuable soil resources such as soil carbon, or whether these effects will vary with the age of treatment. The overarching goal of this dissertation is to address these gaps in knowledge by exploring the importance of soil properties and resources (like soil carbon) in large-scale shrub removal practices in the Chihuahuan Desert of southwestern New Mexico. Our aims are to explore if soil and site-level properties can help support desert grassland restoration planning, as well as determine how these large-scale shrub removal practices affect soil resources like soil carbon. We present here three chapters that address each of these research aims. In Chapter 2, we identify accessible site-level and soil properties that can be used to help select ideal areas for desert grassland restoration (via shrub removal). In Chapter 3, we determine if large-scale shrub removal practices affect soil organic and inorganic carbon (8 years after shrubs were removed). In Chapter 4, we explore whether the effects of large-scale shrub removal on soil carbon vary at different time points (ages) of restoration. This dissertation furthers our understanding on how soil carbon (inorganic and organic) could change with shrub removal (at different time points of restoration) and identifies site and soil properties that could provide support for future desert grassland restoration planning.

Language

en

Provenance

Recieved from ProQuest

File Size

p.

File Format

application/pdf

Rights Holder

Kathleen Schaeffer

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