Joshua trees are threatened by the changing climate, and may be locally extinct from places like Joshua Tree National Park within a human lifetime - it is likely getting too hot too fast for the trees to adapt. To understand how the yucca moth - the Joshua trees only pollinator - may be impacted by the changing climate, and how impacts on the moth populations could affect Joshua tree populations, Juniper Harrower studied Joshua tree and moth interactions across a climate gradient in Joshua Tree National Park. She found that climate change impacts species distributions both directly and indirectly through species interactions. She also found no moths at the hottest and coldest locations, and no seed set for Joshua trees. Any young trees at those locations were the result of clonal (underground vegetative) reproduction, suggesting that the areas are too stressful for Joshua trees and their dependent pollinators to sexually reproduce. a lack of sexual reproduction will make it difficult for Joshua trees to migrate into suitable habitats to track the rapidly changing climate.
National Geographic feature on Juniper's research here.
You can read the full science article here:
https://esajournals.onlinelibrary.wiley.com/doi/epdf/10.1002/ecs2.2439