Tree kill:
In 1989-90, trees in this area on the south side of Mammoth Mountain volcano began dying from high concentrations of carbon dioxide gas (CO2) in the soil. High carbon dioxide concentrations in the soil kill plants by denying their roots oxygen and by interfering with nutrient uptake. In the areas of tree kill at Mammoth Mountain, carbon dioxide makes up about 20 to 95% of the gas content of the soil.