OREGON STATE UNIVERSITY

LIDAR use expands into monitoring biodiversity, ecosystem health

09/14/2010

The journal publication this story is based on is available online: http://bit.ly/arPjpL

CORVALLIS, Ore. – Forestry researchers at Oregon State University have used LIDAR to identify with accuracy the breeding habitat of a particular migratory bird – another evolving role for this sophisticated remote sensing technology, and an important step forward for widespread ecosystem monitoring.

The increasing use of LIDAR – short for “light detecting and ranging” – has now reached the point, scientists say, that it could become a powerful tool to assess habitat loss and fragmentation, which is estimated to be responsible for most species decline and extinction, even more so than climate change.

In this case, the researchers used LIDAR to define the breeding habitat of the black-throated blue warbler, a migratory bird of hardwood forests in the northeastern U.S. The study was published recently in the journal Ecology, in work supported by NASA and the National Science Foundation.

That study, and others like it, are concluding that one of the key elements that determines what species can live and thrive in an area is “vertical structure” of trees, shrubs and other plant life.

“Many experts increasingly believe vertical structure is the primary driver of biodiversity,” said Matthew Betts, an assistant professor of forest ecosystems and society. “Researchers can often predict with considerable accuracy the diversity of birds, mammals, even insects and butterflies that will live in areas, based on what you can tell of the vertical structure of the forest.”

Previously, Betts said, evaluation of structure conditions and the species favored by them was incredibly time consuming and painstaking – it might take several hours just to measure a small plot. Now, LIDAR images taken from aircraft can provide data on entire regions in the same amount of time, and allow scientists to better evaluate what land changes are taking place and how that might affect species survival. LIDAR is also being used from satellites.

The images could be used to identify vegetation, explore forest health and gain a better understanding of disease and insect epidemics, Betts said. Data can be obtained on tree size, canopy cover, shrub size, and possibly even coarse woody debris and snags.

LIDAR images of this type can be tailored to reveal different levels of detail, down to individual branches on a tree if that’s necessary. They can be used to predict what species will live there, how successful they will be, even their chances of reproducing. Scientists say LIDAR will be used in everything from measuring carbon and biomass to managing wildfire and understanding microclimates.

The technology is based on the use of lasers to reveal land forms and the vegetation above them, if required, and its use has exploded in recent years. Researchers at OSU and elsewhere are using LIDAR to reveal ancient earthquake faults long ago hidden by vegetation. OSU engineers used LIDAR to measure and study damage and landform changes following a recent tsunami in American Samoa.

An ancient Mayan metropolis in Belize was examined with LIDAR. And now, OSU researchers are using LIDAR in wildlife studies ranging from New Hampshire to the H.J. Andrews Experimental Forest near Blue River, Ore.

“LIDAR is like any new tool – you don’t know quite what it can do for you,” said Tom Spies, a research ecologist with the Pacific Northwest Experiment Station of the USDA Forest Service. “It’s like the telescope and microscope, it opens up a whole new avenue of investigation.”