Tropical montane cloud forests are globally rare ecosystems which rely on fog inputs at least seasonally, support a highly endemic species community and are key to the hydrological regulation of downstream watersheds that are critical resources for both people and natural ecosystems. Mean cloud altitudes are expected to increase with climate warming, which may increase the frequency of water stress in these ecosystems, where soils are often shallow and precipitation is highly seasonal.
Studying the integrated effects of drought in forest ecosystems requires intensive, long-term field experiments. To investigate the relative importance of rain vs. fog inputs in supporting tropical cloud forest ecosystem processes, and to simulate a potential future climate, our lab is collaborating with Lund University and others on a unique paired experiment, reducing fog inputs to one plot using a 30-meter high curtain, while reducing throughfall in another plot.
This work is being conducted at Wayqecha Cloud Forest Biological Station, at 3,000 m elevation. The station is located in the headwaters of the Kosñipata catchment of the Rio Madre de Dios watershed, 60 km NE of Cusco, Peru.
Ongoing measurements being made and analyzed by our lab in these experiments include:
- Sapflow (heat-ratio method)
- Tree growth (point dendrometers)
- Sapwood water content
- Soil moisture
- Stable C isotope ratios
To date, our participation in this project has been funded by NASA IDS (NNX14AD31G), and a Fulbright Fellowship to Heidi Asbjornsen.
More information about this experiment can be found at cloudcurtain.org