AUTHORS: Benjamin W. Tjepkes, University of Missouri; Grant P. Elliott, University of Missouri; Clayton F. Blodgett, University of Missouri; Thomas W. Bonnot, U.S. Fish and Wildlife Service
ABSTRACT: Many forest communities across the central hardwoods ecoregion of the United States are experiencing shifts from oak dominance to later successional species after anthropogenic alternations to historical disturbance regimes. This transition, amidst unprecedented climatic variability, casts uncertainty on the future of resident and migratory forest passerines that depend on this region for access to high-quality breeding 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. This research explores how regional forest phenology patterns relate to demographic trends in avian communities across the Central Hardwoods Bird Conservation Region under anthropogenic climate change to assess the utility of phenology-informed models in predicting wildlife habitat suitability at regional scales. We used 40 years of Landsat multispectral imagery to model spatially explicit estimates of phenological transition dates based on gap-filled Enhanced Vegetation Index (EVI) values, gridded climate data, and Forest Inventory and Analysis (FIA) data to represent the temporal progression of passerine habitat within a season while accounting for species-specific responses. These climate-mediated phenological metrics will serve as inputs for hierarchical Bayesian avian community models using relative abundance trends from U.S. Breeding Bird Survey (BBS) point counts within the region. We will then be projecting any bird-phenology relationships through the year 2100, using a range of future climate scenarios and forest composition projections. This work will extend existing bird research in the central hardwoods to better understand climatic drivers of forest phenology and whether these patterns relate to diachronic bird abundance trends. The findings of this research will offer insights for conservation initiatives focused on preserving avian diversity by implementing resilient forest management practices informed by climate-based spatial prioritization at landscape scales.
