Project Title: Valley Fog and Forest Function in Central Appalachia
Valley fog is an iconic feature of Central Appalachia that occurs when cool air masses drain and condense into low elevation areas. This phenomenon may occur throughout the year but in Eastern Kentucky, it is most common during the morning hours of the growing season. A growing body of research from other ecosystems has found that fog or low-lying clouds can have a large impact on the way water moves through environments. In addition, cloud or fog water that is intercepted by leaves can help plants increase productivity, recover from drought and decouple tree physiology from soil moisture. While valley fog is a ubiquitous feature of the Central Appalachian landscape, its importance for forest health and the hydrology of the region are not well known.
The objective of this year's field season is to begin to quantify the frequency and duration of valley fog and link the presence of this phenomenon with canopy water cycling and tree health. This project is taking place at the University of Kentucky’s, Robinson Forest, a 14,000 acre experimental forest in the Cumberland Plateau. This beautiful and rugged landscape is one of the last remaining examples of the oldest and most biologically diverse ecosystems in North America—the mixed mesophytic forest.
As a first step towards our objective, we have installed microclimate sensor arrays and sap flow probes along a transect in one watershed on both the north and south-facing slopes from valley bottom to ridge top. Trail cameras and modified tipping-bucket gauges have also been installed along the transect to document fog presence. In addition to these continuous measures, monthly measurements of photosynthesis and leaf water potential will be made throughout the growing season to evaluate the impact of this water source on tree health and productivity.
Stay tuned for updates on this project. Below are some photos from our first weeks in the field!