On one hillside outside of RMBL are set of sophisticated sensors and instruments. These sample the air (measuring moisture, temperature, etc.) and calculate continual changes in the atmosphere. A set of infrared lights then warm the plots to simulate the amount of heat that would be present if carbon dioxide levels were double what they currently are. This translates to a conservative estimate of 2 degrees Celsius increase.
The heaters have been continuously operating since the experiment started, and they keep the warming plots always 2 degrees Celsius higher than non-heated control plots. Predictably, snow melts sooner and the moisture content of the soil is lower in the warming plots.
What is amazing is that even with this seemingly small change in temperature, the plant communities in the Warming Meadow have been drastically altered. The alpine wildflowers that you would normally see are less abundant, and in their place you see a lot more sage brush and other dry-adapted vegetation. The difference is like having wet grassy meadows of the Colorado Rockies replaced with the dry chaparral of the California high desert. Since I am a native Californian, my allergies immediately peaked in response to the familiar plant antigens of my home state.
Unfortunately, what is happening in the Warming Meadows may soon be reflected in the rest of the Rocky Mountains. As global temperatures continue to rise, we may see a shift in local plant communities and a loss of the alpine wildflower meadows. What we are interested in is how this shift may also impact microbial communities.