modeling the impact of hemlock woolly adelgid under several climate change scenarios
abstract
the hemlock woolly adelgid (adelges tsugae), or hwa, is a species of insect
invasive to eastern north america that has caused significant mortality amongst its
hemlock (tsuga spp.) hosts. survivorship and subsequent population expansion of the
hwa is theorized to be limited primarily by minimum winter temperatures. as climate
change reduces the severity and cold periods of winter, the potential for a northward
expansion of the hwa is introduced. this study utilized maximum entropy modeling
(maxent) in conjunction with an inaturalist citizen-science occurrence dataset via the
global biodiversity information facility (gbif) and worldclim (hadgem3)
downscaled climate projection data to model habitat suitability for the hwa throughout
eastern hemlock’s (tsuga canadensis) range. in addition to a historic conditions
baseline, species distribution models were generated using ssp 126, ssp 245, and ssp
585 emissions scenarios for mid-century (2041-2060) and late-century (2081-2100)
climate change scenarios. the results showed that under a low emissions ssp 126
scenario, the hwa will be capable of inhabiting almost the entirety of the eastern
hemlock’s current range by the end of the century. more extreme ssp 245 and ssp 585
warming scenarios resulted in a more rapid northwards shift in suitable habitat,
encompassing the entire range of eastern hemlock by the middle of the century. the
consequences for eastern hemlock are significant, with hwa infestations likely to
become more widespread and severe due to climate change.
collections
- undergraduate theses [325]