IT expected to simplify tracking of forest health.

New technology will allow forest companies to view satellite images of the forests they harvest

In the very near future, forest companies will be able to track the year-by-year health of the trees they harvest by simply logging onto a Web site and downloading spectral images from a satellite.

We're on the edge of a great explosion in potential information sources for forest companies from satellite sources," says Thomas Noland; a tree biochemist with the Ontario Forest Research Institute (OFRI) in Sault Ste. Marie.

He has been overseeing an ongoing joint research project, involving York University, that uses remote sensing devices at both the airborne and satellite level to provide biological indicators of forest health.

For a number of years, OFRI have been studying sugar maples on test plots north of the Sault on Lake Superior's east shore. The area, which stretches from the Batchawana River northward towards Montreal River and into Lake Superior Provincial Park, has a wide range of both healthy and stressed trees to fully test the application of their technology.

Since the late 1990s, they have been experimenting with a spectrometer known as a CASI (Compact Airborne Spectrographic Imager) provided by their research partners at York, to measure the reflectance of light off the leaves of sugar maples.

Through the spectral imagery produced they can analyse the chlorophyll concentrations in the leaves the green pigment in trees that drives photosynthesis by absorbing light and look for any signs of chemical or biological stress.

Noland says the images produced from these airborne surveys is akin to taking a very detailed photograph of a stand of trees including the infrared light reflected off the leaves. The measurement of light given off is an indicator of how well photosynthesis is functioning in the trees. When there is less chlorophyll, Noland says, the "red edge" shifts to a deeper red, almost blue.

"Basically, the redder it is, the more stressed it is."

Though it is difficult to tell what causes forests to be stressed, it is usually a problem associated with the soil either being too shallow, dry or losing nutrients.

To drop a crew of biologists on the ground to take leaf and soil samples can be an expensive and laborious process, especially in remote areas with no roads and the only float plane access.

Upgrading to an airborne spectrometer is an improvement, Noland says; but quite a bit of planning is required, and weather conditions can hamper regular fly-overs.

In this next round of research, they are adding satellite hyper spectral imaging and are mixing in more species of commercial interest such as jack pine, black spruce, white birch and aspen.

A satellite can cover a larger swath of bush with a regular pass every two weeks to 16 days and "the availability and frequency of the data is much better," says Noland.

Starting this summer, they will be taking four comparative collections in June, July, August and early September using a satellite, the CASI and researchers on the ground.

The satellite involved in the campaign is National Aeronautics Space Administration's (NASA) new Earth Observing One (EO-1) equipped with the first hyper spectral sensor in orbit, the Hyperion. Normally, one transect is about $16,000 a pass; but NASA is donating this data to the project.

"NASA is just as interested in looking at commercial forestry applications for their satellites as we are for-developing the technologies for doing that."

Noland says their campaign results will be shared with Domtar, whose holdings make up the research area.

"If (forest companies) can find a way of doing it cheaper and easier than the traditional on-the-ground physical measurements of trees through remote sensing, they'll have a powerful new tool."

Potentially, all of the satellite data can be archived on a year-by-year basis to identify trends and conditions of a particular site. A forest products company could conceivably request data from NASA, or a private satellite company, buy the information and download it.

Satellites in the past have been used exclusively as a research tool. Now more and more private satellites are being launched for commercial uses such as mapping, charting city changes and vegetation cover.

Noland predicts in the next five to 10 years, forestry companies should be able to pick and choose between a number of satellite systems.