The remaining wildlands in the north central U.S. include varying proportions of public, private, and tribal lands across water balance ecotones. These wildlands may be highly vulnerable to continuous climate change impacting their ability to sustain biodiversity and ecosystem functioning. For their effective conservation, the degree of wildlands’ exposure to climate change should be quantified. We compared 2071-2099 to 1980-2005, and examined the changes in growing season climate (temperature) and water balance metric (moisture index) among land allocation types (public, private, and tribal lands) within nine Greater Wildland Ecosystems (GWEs) across Central Plains, Western Plains, and Western Mountains ecoregions of north central U.S. Our goal was also to test the evidence of any systematic climatic bias on distribution of tribal lands, which are often claimed to be placed non-randomly. We used growing season average precipitation, temperature, and potential evapotranspiration under CCSM4 GCM at 4 km spatial resolution from biased corrected and spatially downscaled Multivariate Adaptive Constructive Analogs (MACA) products. The moisture index was estimated as the ratio of precipitation and potential evapotranspiration.
Results/Conclusions
The climate model projected an increase in temperature and decrease in MI across all GWEs with a narrow range of difference in spatial pattern of increased temperature (4.6 to 5.5 °C). The projected moisture index illustrated the highest decrease for Central Plains GWE (-28%) and the least in Western Plains GWEs (-17%). However, both historic and projected temperature and MI are similar among three land allocation types within a GWE. Our findings revealed that the placement of tribal lands is not systematically biased as the spatial patterns of historic and projected moisture index are similar among land allocation types within each GWE. We conclude that the placement of tribal and public lands is not climatically biased in the historic period and the projected rates of change in climate are similar among land allocation types within GWEs. All GWEs, however are projected to warm and undergo increasing aridity, which may challenge management to sustain ecological health and human wellbeing across all land allocation types.