High elevation five needle pines are rapidly declining throughout western North America due to warming temperatures, mountain pine beetle, white pine blister rust, and alteration of the naturally occurring fire regime. The impact of climate change is especially acute in sky islands of the Great Basin as warming temperatures alter tree distribution and contribute to overstory tree mortality. Great Basin bristlecone pine forests occur as ecological islands at the highest elevations of mountain ranges separated by extensive rangeland or desert basins. Great Basin bristlecone pine ecosystems are highly fragmented and contain many biodiversity “hot spots” with a high degree of species endemism. It is the fragmentation history and the number and character of the sky islands that are key to understanding biodiversity of Great Basin bristlecone pine forests. This paper will address the effects of climate change on Great Basin bristlecone pine forests. Specifically we will discuss climate-induced changes to the fire regime through alteration of surface and canopy fuel loading, fire hazard and risk, and on predicted changes in fire behavior and severity. Secondly we will evaluate Great Basin bristlecone pine volatile organic compounds across elevation gradients to assess changes in tree biochemistry in response to climatic stress.