Hiking up to the next plot…
Climate change is currently modifying the myriad linkages between soils, plants, animals and the atmosphere. Being able to predict these changes in advance allows us to conserve key components of natural environments and, more practically, preserve the vital services that nature provides to humans, such as clean air. Of particular concern are tipping points, where a certain linkage appears to be stable but then suddenly and dramatically shifts to another state, or collapses entirely. One way of thinking about nature is to think about the ?flow? of various chemical elements, like carbon and nitrogen, through different organisms over time. For example, a plant breathes in carbon dioxide and uses it to make a new leaf, which gets eaten by a worm, where the carbon is used for energy and is eventually breathed back out into the atmosphere. For our project, we are assessing whether mountain ecosystems are likely to reach future tipping points in these flows of carbon and nitrogen. One method of predicting the future is to use natural gradients in temperature, such as the slope of a mountain. As you walk down from the top of a mountain to the bottom, you are effectively walking through a simulation of global warming. For our project, we are walking along mountain gradients around the world, measuring how much plants are breathing and how much carbon and nitrogen is stored in leaves, wood, soils and tiny animals in the soil. In this way, we hope to predict whether the linkages between different aspects of nature will change gradually or abruptly as climate change progresses. Identifying abrupt changes will provide an important timeframe for land managers to conserve mountain environments and prevent losses of ecosystems services.