Fig. 1. The Unorganized townships of Maine. They are called “unorganized” because too few people live here to form any local government. Most of this 10-million-acre area is managed for timber and forest products.
Fig. 2. LiDAR (Light Detection and Ranging). A laser mounted in an airplane fires thousands of laser pulses at the ground per second. The laser reflected back to the plane sensor results in a massive 3-dimensional digital “point cloud” that represents the forest it is “seeing.”
Fig. 3. The image below is a “Canopy Height Model” generated from LiDAR data. The different colors represent differnt heights of trees. The oranges and yellows are shorter forest, harvested in the last 20 years or so. The blue/magenta color represents tall forest. The magenta “flecks” represent trees over 22 meters (72′) tall. Our ground truthing of this “blue/magenta LiDAR signature” in 2023 showed us that over 95% of the time, this signature indicates late-successional or old-growth forest. We got the same result all across the unorganized townships of Maine. One limitation is that this method does not reveal short, stunted old forest that you might find at high elevations or in low, black spruce bogs. But those areas are not as much at risk of harvesting. So, the LiDAR signature works well where it needs to work most– in the majority of the landscape where harvesting is likely to occur. The large square grid in the diagram represents 100-hectare units (247 acres).
Fig. 4. This is the exact same scene as Fig. 3., except the “blue/magenta signature” for LSOG forest has been converted to a more user-friendly map. Below, we generated a simple polgyon “LSOG Yes/No” map below. Whereever there is a magenta polygon, there is a tree at least 22 m tall. Small magenta polygons represent a single tall tree. Larger polygons represent LSOG stands. As you can see, the large blue/magenta stand on the north side of the Golden Road (the black wavy line across the center of Fig. 3) shows up as solid magenta on this map. Our ground truthing of this stand verified that it is a late-successional stand, with some parts even being closer to old-growth. One spruce we cored was 253 years old– it was a seedling when the first shot of the Revolutionary War was fired. For scale, the large square grid in the diagram represents 100-hectare units (247 acres).
Fig. 5. Below is an “LSOG magenta polyon map” we generated for a 1.2-million-acre area of interest to the Rangeley Lakes Land Trust. The magenta polygons indicate likely LSOG stands at least 10 acres in extent. We can easily screen large landscapes like this for LSOG with incredible precision. Ground truthing is always recommended, but our own field work indiciates the map will be accurate at least 95% of the time. With further tweaking of our models, we expect to improve the accuracy even more.
Project Team
John Hagan, Ph.D., Our Climate Common
Ben Shamgochian, Our Climate Common
Molly Lynch, Tufts University
Michael Reed, Ph.D., Tufts University
Dave Sandilands, U. Maine Wheatland Geospatial Lab
Andy Whitman, Maine Forest Service
LSOG Working Group
Kyle Burdick, Baskahegan Co.
Shawn Fraver, University of Maine
Jake Metzler, Forest Society of Maine
Shelby Perry, Northeast Wildnerness Trust
Justin Schlawin, Maine Inland Fisheries and Wildlife
Forest Landowner Partners
Seven Islands Land Co.
Landvest
Huber Forest Resources
Weyerhaeuser
Appalachian Mountain Club
The Nature Conservancy
Baskahegan Co.
Irving Woodlands
Acadian Timber Corp.
Funders
The Dorr Foundation
Cooperative Forest Research Unit, U. Maine
Maine Timberlands Charitable Trust
EJK Foundation
The Betterment Fund
The Arboretum Fund of the Maine Community Foundation
An anonymous donor