NUK - logo
E-viri
Recenzirano Odprti dostop
  • Prototype campaign assessme...
    Villegas, Juan Camilo; Law, Darin J.; Stark, Scott C.; Minor, David M.; Breshears, David D.; Saleska, Scott R.; Swann, Abigail L. S.; Garcia, Elizabeth S.; Bella, Elizabeth M.; Morton, John M.; Cobb, Neil S.; Barron‐Gafford, Greg A.; Litvak, Marcy E.; Kolb, Thomas E.

    Ecosphere, March 2017, 2017-03-00, 20170301, Letnik: 8, Številka: 3
    Journal Article

    Changes in large‐scale vegetation structure triggered by processes such as deforestation, wildfires, and tree die‐off alter surface structure, energy balance, and associated albedo—all critical for land surface models. Characterizing these properties usually requires long‐term data, precluding characterization of rapid vegetation changes such as those increasingly occurring in the Anthropocene. Consequently, the characterization of rapid events is limited and only possible in a few specific areas. We use a campaign approach to characterize surface properties associated with vegetation structure. In our approach, a profiling LiDAR and hemispherical image analyses quantify vegetation structure and a portable mast instrumented with a net radiometer, wind–humidity–temperature stations in a vertical profile, and soil temperature–heat flux characterize surface properties. We illustrate the application of our approach in two forest types (boreal and semiarid) with disturbance‐induced tree loss. Our prototype characterizes major structural changes associated with tree loss, changes in vertical wind profiles, surface roughness energy balance partitioning, a proxy for NDVI (Normalized Differential Vegetation Index), and albedo. Multi‐day albedo estimates, which differed between control and disturbed areas, were similar to tower‐based multi‐year characterizations, highlighting the utility and potential of the campaign approach. Our prototype provides general characterization of surface and boundary‐layer properties relevant for land surface models, strategically enabling preliminary characterization of rapid vegetation disturbance events.