Advancing understanding of the interactions between land, plants, water and air
There’s an inspiring vitality to the environment all around us. Take a hike in any natural region, and you’ll witness interesting combinations of trees, plants, and animals. Breathe the air in the forest, and you will sense something different in the atmosphere. Graduate students in ESS start with these observations, and dig deeper to fully understand the science of the Earth as a system. The Jenkins Graduate Fellowship enables research focused on the interactions between land, plants, water and air. Generous support from Mr. Greg and Brad Jenkins will fund four fellows as they explore the ecology, biogeochemistry and hydrology of the Earth’s ecosystem.
As temperatures rise, forests are affected both by a change in the water cycle, and in the climate conditions that enable growth. Anne Kelly studies these dynamics in the Sierra Nevada Mountains. Her research includes questions of how temperature and water availability determine the upper and lower tree line, how sequoias can grow in such a cold, dry environment, and how much water trees use. The Jenkins Fellowship allows Anne to access experimental plots arrayed from the Central Valley to locations near the Sierra Crest to maintain instruments and make measurements. Harsh weather makes these sites difficult to access in the winter. “Without the Jenkins Fellowship,” indicates Anne, “I would be missing key mid-winter data on forest growth and water use.”
George Azzari is developing an innovative method to measure ecosystem energy dynamics with the Microsoft Kinect Sensor. An important factor in determining surface energy budgets is the vegetation structure (plant height, crown diameter, shape, volume). To get this information, researchers collect three-dimensional measurements of vegetation (often called “point clouds”); however, current instruments are extremely expensive. The market for videogames and digital entertainment has decreased the cost of many advanced technologies. George discovered the Microsoft Kinect sensor – an infrared time of flight camera designed to track body position and movement – could be used as a low cost system for 3D imaging of vegetation. He is currently working to adapt the Kinect sensor to acquire 3D point clouds of vegetation directly from the field. These 3D maps will help George understand the controls on vegetation temperatures and how much climate change may impact plant ecosystems.
The movement of water through ecosystems is dramatically affected by climate change. Liza Litvak’s work focuses on the interchange of water between plants, soil, and the atmosphere (evapotransportation). She is working on the calibration of a portable chamber, which characterizes the evapotranspiration of turf grass. Measurements are still underway, but preliminary results are striking. Liza has found that evapotransportation from irrigated landscapes that only contain grass is considerably higher than plots that contain both grass and trees. The Jenkins Fellowship will enable Liza to collect and interpret data about this surprising phenomenon.
Forest fires have dramatic effects in the biogeochemical cycles of the Earth. Brendan Rogers studies the ways boreal fires interact with high latitude climate. North American boreal forests are subject to severe wildfires that emit climate-altering gases and aerosols, and change the landscape composition and energy budgets for decades. Brendan uses satellite data to characterize the extent of boreal forests, patterns of vegetation and land surface recovery after fires. This information, together with estimates of fire emissions, is entered into a computer model to simulate the effects of historical and future fire regimes on regional and global climate. This research represents an important advancement in our understanding of potential 21st century climate change impacts.
By supporting a variety of research projects in ESS, the Jenkins Graduate Fellowship is advancing understanding of the global environment and the possible impacts of changing climate on ecosystems.