Seeing the Forest for the Trees
UMaine researcher works with NASA to help save Central American
About the Photo:
"Deforestation can only be understood holistically, with its links
social, political and environmental forces operating at regional and
levels." — Steve Sader
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Steve Sader knows the importance of
seeing the forest for the trees. The "big picture" of the world's
forests shows their connectedness and health — and the effect that human
actions are having on them.
From Sader's perspective, forests are inextricably linked to political,
economic, social and environmental issues around the globe.
"It is well documented in the literature that through tropical
deforestation, we're losing plants and animals that are important to the
world. We all can be affected by deforestation, habitat reduction and
subsequent environmental deterioration in ways that we don't usually
think about. Even civil wars can happen because of political unrest and
economic instability that is directly linked to resource depletion and
lack of rural development alternatives."
For almost 25 years, Sader has monitored the condition and extent of
temperate forests in the United States and tropical forests in Central
America using data collected by remote sensing satellites — space-age
technology that provides researchers with detailed pictures of large
land areas by recording reflected light, heat and microwave signals.
Sader, director of the Maine Image Analysis Laboratory at The University
of Maine, and his students translate the computerized data into
color-coded maps of the Earth, detailing land use, vegetation, habitat
diversity, and forest type, density and canopy structure.
Views provided from Earth's orbiting satellites have many down-to-earth
applications – better management of natural resources, heightened public
awareness about the environment, and development of conservation
policies and strategies. They also can be used to contribute to greater
understanding of global climate change.
"Whether talking about the Maine woods or the Central American
rainforests, it's important that a sustainable production of goods and
services be maintained through time," says Sader.
A UMaine professor of forest resources, Sader has been conducting remote
sensing research in Central America since 1978 and in Maine since
joining the University's Department of Forest Management in 1987. Much
of his work throughout his career has been in cooperation with NASA's
Office of Earth Science, which is doing remote sensing all over the
world in an effort to understand the effects of natural and human
changes on the global environment.
NASA is particularly interested in Central America because it is a
region for which, until recently, there was little regional inventory or
monitoring of the natural resource base. Central America has some of the
closest tropical forests to the United States.
"As a region, Central America continues to have one the highest
deforestation rates in the world," says Sader, formerly a NASA research
forester responsible for temperate and tropical forest research projects
conducted at NASA's Stennis Space Center in Mississippi. "It is not that
the Central American forest constitutes a big area (say, compared to the
Brazilian Amazon) but that the region is losing forests at a rapid rate
— around 1.5 percent annually for the past two decades, mostly due to
population pressure and lack of alternatives for poor people who clear
Currently, Sader is the principal investigator on a $1 million,
three-year contract with NASA to create regional satellite databases to
monitor forest condition and environmental change throughout Central
America. UMaine has been working with Conservation International and
NASA research laboratories to look at land use change in Central
America's Mesoamerican Biological Corridor, a chain of protected and
proposed conservation areas linking natural habitats from the borders of
northern Colombia to southern Mexico.
In 1998, NASA signed a Memorandum of Understanding with the Central
American Commission on the Environment and Development supporting
research cooperation focused on monitoring the biological corridor. As
part of the cooperation, NASA is developing the region's first detailed
land-use maps using satellite data.
Creation of the corridor is a "political ideal" based on the premise
that conservation of forest cover equates to protection of soils,
biodiversity and habitat, Sader says. Although this is an important
goal, the reality is its success depends on the stakeholders — primarily
the poor — who live on or near these areas.
"If people don't have economically viable alternatives to deforestation
for their sustainability, the best laid plans of the government will
fail to achieve this goal," Sader says. "That's why deforestation can
only be understood holistically, with its links to economic, social,
political and environmental forces on regional and international
Now in the third year of the project, Sader and a team of international
researchers are developing large regional databases and natural resource
maps to create an environmental data information system. In addition,
Central Americans are trained to process and use the data and remote
sensing technology, and become research cooperators.
On campus, the Maine Image Analysis Lab, designated a National Center of
Excellence in Remote Sensing Applications by NASA, is now analyzing new
satellite data from throughout the region that will be used to document
how the corridor has changed since the late 1980s.
"We want to know how much forest remains in the corridor and how much
was lost in the past 10 years. We can see that certain areas have higher
deforestation rates than others. We can monitor the fragmentation of the
forests with continued conversion for pasture and agricultural uses,
including those areas that were once remote and inaccessible. But we
also have good news in that there is more forest still in the protected
zones, compared to the unprotected areas.
"A major goal of the project is to bring the science community together
in the region," Sader says. "The hope is that it will grow into better
cooperation and lead to better science that can be used to conserve and
manage the natural resources."
by Margaret Nagle
December, 2001/January, 2002
for more stories from this issue of UMaine Today Magazine.