Steven Sader is a retired professor of forest resources and former director of the Maine Image Analysis Laboratory at the University of Maine in Orono, where he joined the faculty in 1987. The laboratory is a research facility for application of satellite remote sensing and geographic information systems (GIS) to natural resource management.
"As Maine's forest landscape continues to change in response to economic and societal expectations, it has become critical for researchers and natural resource managers to have access to the most advanced information and technologies to plan for the future," Steve maintains. "Landscape change over the next decade and beyond will impact Maine's natural resources and environment in a number of ways."
For 25 years, Steve managed over 80 research projects in the lab primarily funded by the USDA Forest Service, the National Aeronautics and Space Administration (NASA), the Maine Department of Conservation, and conservation organizations such as The Nature Conservancy and the New England Forestry Foundation. Each year, Steve supervised four to six graduate students in the lab and an occasional postdoctoral or research associate, as well as undergraduate students who performed field work in the summer.
Prior to his faculty appointment, Steve was the principal investigator for projects involving remote sensing of temperate and tropical forests at NASA's Stennis Space Center in Mississippi. As a scientist for the Bureau of Land Management's Branch of Remote Sensing in Denver, Colorado, Steve mapped forest and rangeland vegetation communities and wildlife habitat in eight western states.
"My research helped to develop remote sensing and large landscape monitoring and modeling methods applicable to Maine, the New England region, the nation, and the international forestry community," explains Steve. "My lab used satellite imagery, Lidar, and aerial imagery combined with field or inventory data to address forest landscape change, forest biomass estimation, spruce budworm outbreak vulnerability, conservation easement monitoring, and forest harvest and regeneration patterns in Maine and other northern New England forests."
Steve received several awards from the Northeastern States Research Cooperative (NSRC) to help support his research program. “NSRC funding has increased interdisciplinary research cooperation among several investigators in the [University of Maine] School of Forest Resources, including Kasey Legaard, Erin Simons, Jeremy Wilson, and Aaron Weiskittel, and with other scientists at different institutions," acknowledges Steve. "These researchers possess a range of complementary skills in remote sensing and spatial analysis, modeling, forest inventory, and biometrics to address complex large landscape and regional forest management questions and issues.”
In his NSRC-funded project that developed methods for monitoring forest sustainability across large landscapes, Steve and his colleagues analyzed Landsat satellite imagery from the mid-1970s to 2007 for a 1.8 million hectare study area in northern Maine. They observed trends in forest landscape patterns that included a decrease in the extent and aggregation of large patches of intact mature forest.
They found that land owned by timber investment management organizations and real estate investment trusts had the highest harvest rates in the 2000s, whereas parcels managed under a Working Forest Conservation Easement tended to have more extensive and connected mature forest. Large patches of tree regeneration that were common during the spruce budworm salvage logging of the 1970s and 1980s decreased during the 1990s and 2000s with implementation of the Maine Forest Practices Act when clearcutting declined and partial harvesting became prevalent.
In a second project supported by NSRC, Steve used Landsat imagery to investigate the effects of partial harvesting on forest stands owned by stable and changing landowners in the same 1.8 million hectare study area. Results revealed how partial harvesting influences the condition of residual forest stands and can be used to predict future wood supply and biomass/carbon stock estimates under changing ownership scenarios. These methods can be applied statewide and elsewhere in the Northern Forest region.
NSRC funding also supported Steve and his colleagues from the University of Maine, the USDA Forest Service, and the University of New Brunswick as they used Landsat imagery and field data to develop methods to predict and map the vulnerability of forests across 10 million acres in northern Maine to spruce budworm defoliation.
"Periodic infestations by spruce budworm have caused widespread defoliation, growth reduction, and mortality of balsam fir and spruce trees throughout the northeastern U.S. and eastern Canada," explains Steve. "With the next anticipated outbreak approaching, it is timely to examine the vulnerability of the Northern Forest to this pest. Budworm vulnerability maps can be used to evaluate alternative management strategies on forest structure, timber supply, and multi-use objectives."
"Research by [Steve] and his graduate students through the Maine Image Analysis Laboratory have revolutionized the way we see and understand Maine's incredible forest resource," states Robert Wagner, director of the University of Maine's School of Forest Resources and Center for Research on Sustainable Forests. "By developing new methods of analyzing and interpreting satellite imagery, we can now detect very small changes in forest conditions at fine scales anywhere in the state. This work has allowed us to better understand the impact of harvesting and other forest disturbances on forest structure and composition, wildlife habitat, and other important ecological features."
Steve lives in Orono with his wife Kris, a printmaker and former printmaking instructor at the University. Steve enjoys the Northern Forest of Maine for kayak fishing, hiking, gardening, and tree and shrub identification. He is on the Board of Directors for the Orono Land Trust which maintains trails on several forest conservation easements in the Orono area. For part of the summer, Steve leaves the Northern Forest to enjoy his cabin at Twin Lakes in the Toyabi National Forest of California.