Predicting climate change-related impacts to species is of foremost importance for natural resources management. In the southwestern US, climate change is already causing shifts in where species occur and reproduce on the landscape. At Joshua Tree National Park, in southern California, 14 perennial plant species, have been assessed in a prior study for vulnerability to climate change in the park using vulnerability assessments (VAs) that included species distribution modeling. To assess whether projected range shifts have begun to occur, we measured these plants in a network of macroplots spanning the transition from the Colorado to the Mojave Deserts. We assessed cover, density and condition assessments for individuals within replicated transects within each macroplot and full demographic sweeps for large tree-like species (including single-leaf pinyon pine (Pinus monophylla), California Juniper (Juniperus californica) and Joshua trees (Yucca brevifolia).
Results/Conclusions
Comparing the current area of live and dead cover across the elevation gradient, and assessing density and estimated condition of individuals, we found differing evidence of possible climate-related impacts between species. These results, together with community composition data, are aimed at helping land managers predict impacts and take climate-adaptive conservation actions.