Tropical trees have shorter life spans than trees in other parts of the world, living, for example, just over half as long as temperate trees. A new analysis suggests that, as the world warms up, tropical trees will live even shorter lives, spelling trouble for global biodiversity and carbon stocks. A new study published in the journal Proceedings of the National Academy of Sciences (PNAS) suggests that in warm tropical lowlands, tree longevity decreases when forests become drier and when the mean annual temperatures is greater than 25.4° Celsius (77.7° Fahrenheit). “Our findings — which are the first to demonstrate that there is a temperature threshold — suggests that for trees in these regions, their longevity is likely to be negatively affected,” study co-author Manuel Gloor from the University of Leeds, U.K., said in a statement. The researchers examined tree-ring data from more than 100,000 trees belonging to 438 species from more than 3,300 sites around the world. Growth rings, found within tree trunks, represent one year of growth, allowing researchers to estimate the age of trees and speed of growth. Each tree rings, shown here in a temperate tree, represents one year of growth. Photo by Arnoldius via Wikimedia Commons (CC-BY-SA-2.5) The authors used statistical modeling to assess how tree growth and longevity were related to climate in the tropics, taking into account factors that may influence the results, such as seasonal temperature, soil moisture, soil type, cloud cover, and human influence. “Tropical forests may be more vulnerable to increasing heat than has been…This article was originally published on Mongabay Läs mer