Aspen for Trouble

photo by Griffin Cronk

photo by Griffin Cronk

Dispatch by Griffin Cronk

Second only to riparian areas in terms of ecological value in the Western United States, aspen stands make up crucial biologically diverse habitats. As a clonal species, the trees that pierce the ground are the stems of a vast subterranean organism. The largest known aspen clone grows next to Utah’s Fish Lake and was dubbed Pando, meaning ‘I spread’ in Latin. The single aspen organism has over 40,000 trunks spanning a 106 acre parcel of land and is the heaviest and oldest organism on Earth. Many important aspen organisms like Pando are in National Forests which gives them more visibility but doesn’t necessarily protect them from browsing (meaning denuding of tree starts). While they regrow quickly, aspen aren’t completely resilient in the face of cattle. If browsed, aspen will only send up stems for two seasons before they desist to recruit. In the Manti LaSal National Forest, aspen have not grown to six feet, the height necessary to elevate them out of the reach of cattle, for 80 to 100 hundred years. Conservationists blame ungulates that were introduced during this period. Aspen, it seems, have little chance of survival in the presence of cattle and today’s prevailing ranching techniques.

Climate change poses another threat. Aspen have been called ‘the canary in the coal mine’ for mountain ecosystems because they die when water availability is reduced significantly. Loss of water kills aspen trees through cavitation which occurs when a lack of groundwater allows air bubbles to infiltrate the tree’s arteries. Climate change is generating more intense and more frequent droughts that create the scenario in which trees are infected with air. Cattle put even more strain on the mountain water sources that aspen depend on. These heavy creatures tend to gather around springs and slurp until a green oasis is degraded into dry trodden earth. Here, at the intersection of public lands management and climate change the future of aspen looks bleak.