Projected Future Distribution of Tsuga canadensis across Alternative Climate Scenarios in Maine, U.S

Abstract

Climate change is having an impact on forest ecosystems around the world and is expected to alter the suitable habitat of individual tree species. Forest managers require resources about potential impacts of climate change at the regional scale to aid in climate mitigation efforts. By understanding the geographic distribution of changes in suitable habitat, migration corridors can be identified for conservation and active management. With the increased availability of climate projection data, ancillary Geographic Information Systems data, and field observations, modeling efforts at the regional scale are now possible. Here, we modeled and mapped the continuous distribution of Tsuga canadensis throughout the state of Maine at the regional scale(30 m) with high precision (89% of pixels had a coefficient of variation ≤ 4.0%). The random forest algorithm was used to create a strong prediction of suitable habitat for the years 2050 and 2100 from both high and low emission climate projections. The results clearly suggest a significant gain in suitable habitat for Tsuga canadensis range with a general northwest expansion.

Possible Increases in Flood Frequency Due to the Loss of Eastern Hemlock in the Northeastern United States: Observational Insights and Predicted Impacts

“…Giuntoli et al (2018) review hydrologic land surface models for operational flood forecasts and demonstrate high variability in the complexity of plant dynamics. It is therefore not surprising that recent projections of future riverine flooding risk have focused so heavily on shifts in atmospheric forcing with simplified or static numerical representations of vegetation (e.g., Chen et al, 2018 ;Hirabayashi et al, 2013 ;Stryker et al, 2018) despite clear evidence for climate-driven changes in the density and composition of temperate forests (Boulanger et al, 2018;Dunckel et al, 2017).…”

“…Estimates of eastern USA forest composition response to climate change are similarly uncertain but possibly less controversial (Boulanger et al, ; Dunckel et al, ; Swanston et al, ) though they have received limited attention in flood frequency analysis. Trees exert a fundamental control on the hydrologic cycle through soil shading, canopy interception and storage, root water uptake of soil and groundwater, partitioning of latent heat losses between evaporation and transpiration, and root modification of soil pore size distributions (Brantley et al, ; Knighton et al, ; Sprenger et al, ).…”

Mortality and Recovery of Hemlock Woolly Adelgid (Adelges tsugae) in Response to Winter Temperatures and Predictions for the Future

“…The effect of climate change on the host of HWAs, T. canadensis, should also be considered. Prasad and Potter [72] reported that future eastern hemlock habitats will decline and colonization beyond its current distribution will be very limited due to increases in aridity and temperature, while Dunckel [73] found that eastern hemlock will increase in range within Maine in a northwest expansion. Eastern hemlock may alter its distribution, but is unlikely to expand farther north of its current range.…”

Climate change in the human environment: Indicators and impacts from the Fourth National Climate Assessment

“…HWAs drain trees of their stored sugars, causing needle loss and branch death. An increase in winter minimum temperatures has facilitated a northward expansion of its habitat in the Northeast (Dunckel et al 2017), as well as a habitat expansion of the mountain pine beetle in high-elevation forests of the West (Vose et al 2018). Studies project continued northward expansion of the HWA into the full range of hemlock in New England and southern Canada, with the potential to eliminate the species in the coming decades (Boucher et al 2020).…”