Sudden
Oak Death. Sudden Oak Death is a new and virulent disease affecting
hardwood forests in coastal California. The pathogen, Phytophthora
ramorum, has reached epidemic levels in several California forests,
killing thousands of trees. The pathogen also colonizes the foliage
of several other overstory and understory hosts without killing them.
The Kellylab is investigating the dynamics of the disease using geospatial
technologies in the following areas:
Remote
sensing of mortality. We're using digital
imagery (ADAR 5500) (Spectral Bands: Blue: 450-550 nm, Green: 520-610
nm, Red: 610-700 nm, Near Infrared (NIR): 780-920 nm), at 1-m spatial
resolution to map dead crowns, and forest structure. We are investigating
different automated classifiers, including standard MLC and ISODATA,
and comparing them to hybrid methods, object oriented methods, and
machine
learning classifiers. Mindy Syfert and former students Desheng
Liu and Qinghua Guo were involved in this research when they were grads.
Spatial
pattern of mortality. This research attempts to explore the
hypothesis that links the disease spread with presence of foliar
hosts. In other words, by using remote sensing and spatial analysis
as the primary tools, the spatial relationship between the suspected
foliar hosts and terminal hosts can be explored over a longer time
period (and into the past, prior to onset of the disease) and over
a larger area than might be allowed using field methods alone.
Former students Desheng Liu and Qinghua Guo were involved.
OakMapper webGIS: Monitoring
Sudden Oak Death in California. Maintenance of accurate
and precise spatial measurement of disease presence in the state
is imperative for regulation. The Kelly lab maintains all statewide
spatial data describing the confirmed locations of P. ramorum in
a GIS format. We produce static maps, and provide an interactive
GIS-based website for the public called the OakMapper. Karin Tuxen and Brent Pedersen are involved in this effort.
Modeling
Sudden Oak Death risk across scales. We are using numerous spatial
and Machine Learning models to estimate risk across landscape, regional
and global scales as an aid to monitoring efforts. Qinghua
Guo and
Ken-ichi Ueda have been involved in this project.
Forest
Structure. Two broad research areas examine forest structure
associated with the disease; Barbara Allen-Diaz is our colleague
on these projects. First, we are investigating the histroric forest
structure of plots with SOD and without the disease using data from
the VTM collection. Second, Tim
DeChant is examining the dynamics of gaps created by the disease across a gradient of infestation
in China Camp State Park.
Collaborators
/ Staff / Graduate Students / Post-docs who have contributed to the
effort: Barbara Allen-Diaz, Brice McPherson, David Wood, Richard Standiford, Greg Biging, Peng Gong, Qinghua Guo, Xiaobing Guo, Faith Kearns, Desheng
Liu, Ruiliang Pu, Dave Shaari, Wanxiao Sun, Kalliopi Tzivanki, Karin
Tuxen, Le Wang. This large program has been funded through the years since 2000 with funds from the USDA CSREES Program, the U.S. Forest Service, NASA and DANR.
Links:
Monitoring Sudden Oak Death
OakMapper (enter
information about trees, and view distribution maps)
California
Oak Mortality Task Force (COMTF)
2003 Geospatial Solutions article featuring OakMapper
