Long-term dynamics of forest phenology across the central hardwoods
No Thumbnail Available
Authors
Meeting name
Sponsors
Date
Journal Title
Format
Thesis
Subject
Abstract
Many forest communities across the central hardwoods region of the United States are experiencing shifts from oak dominance to later successional species after anthropogenic alterations to historical disturbance regimes. This transition, amidst unprecedented climatic variability, casts uncertainty about the future of wildlife depending on these forests for access to high-quality habitat. Land surface phenology, the timing of annual growth cycles measured from remote sensing platforms, offers a potential proxy for forest ecosystem response to changing bioclimatic conditions that can be used for landscape-based wildlife conservation planning. However, many prior assessments are restricted to recent satellite sensors and cannot reliably distinguish forested areas from mixed land cover due to their spatial resolution, limiting their ecological applicability. In this project, I used 40 years of Enhanced Vegetation Index (EVI) values from Landsat multispectral imagery to model spatially explicit estimates of phenological transition dates under a Bayesian hierarchical framework. From these estimates, I additionally measured long-term trends and used machine learning models to understand how these metrics were changing over time and what factors might be driving those responses. My analysis revealed spatially heterogeneous trends in phenology across the central hardwoods. Spring green-up has advanced and accelerated in many areas, especially in the eastern portion of the region. Patterns of autumn senescence were more variable, but most samples in the western portion of the region exhibited longer transitions from late spring until dormancy. Strong associations were found between phenological shifts and cumulative growing degree days, April temperatures, and topographic variability. Phenology in the central hardwoods is changing in complex, spatially distinct ways in response to climate variability and local landscape context. Altered phenological timing may disrupt ecological synchrony, particularly for migratory bird species whose breeding cycles are linked to vegetation development. These findings provide critical insight into where and how phenological mismatches may emerge, offering a foundation for proactive, climate-informed conservation planning.
Table of Contents
DOI
PubMed ID
Degree
M.A.