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Forest Inventory and Analysis

September 2014: Forest Inventory and Analysis

For close to eight decades, the USDA Forest Service’s Forest Inventory and Analysis program has conducted a census of America’s forests. From the species, size, and health of trees to growth, mortality, and removals by harvest, the Northern Research Station’s FIA program knows the region’s trees.
Inventory and analysis tools and techniques have evolved, and so have the questions that FIA data is helping answer. For example, how much carbon forests store and where it’s stored are critical factors in forest management today. The Station’s FIA program is developing methods of estimating forest carbon, and FIA is also helping other nations design and implement forest inventories that will increase knowledge of how forests are storing carbon worldwide.
This month, we feature a scientist, research, a product and a partnership that demonstrate how FIA counts.

Environmental Education Link

Get a snapshot of forest land and landowners in your state at the Northern Forest Futures Project website


Educators: Project Learning Tree’s Exploring Environmental Issues: Focus on Forests module will help you walk your students through an inventory of a local forest or woodlot and explore forest health, ecology and management issues. You have to attend a PLT workshop to receive the full module,  but you can browse the activities and student pages here for more information

Featured Scientist

Patrick Miles

Patrick MilesHis father was a forester with the University of Minnesota, his uncle was a forester, and he began inventorying forest plots at the age of 17, but Research Forester Pat Miles describes his career with the Northern Research Station’s FIA program as serendipity rather than destiny.

Jobs were scarce when he completed his Master’s program in Forestry, but his background in computers helped Miles land his first job with the Forest Service in Missoula, Montana, a test center for the Forest Service’s first nationwide computing network. Thirty years later, he is the FIA’s Resource Planning Act (RPA) national database manager; his responsibilities include supplying U.S. data for the Global Forest Resource Assessment, a product of the Food and Agriculture Organization of the United Nations. Miles’ work includes development of FIA’s “Evalidator,” an online tool that allows users to produce a variety of population estimates and their sampling errors based on the current FIA database, as well as the FIA DataMart, which provides raw data to users. Miles provided inputs that were used to create the Data Dashboard for the Northern Research Station’s Northern Forest Futures Project.

Miles understands what forest analysts need from databases in part because as the FIA state analyst for Minnesota, he needs the same information. “I ask myself what I need to do my job, and then I try to build those tools and share them,” Miles said.

In addition to helping foresters in the United States get more out of existing databases, Miles is currently part of a Forest Service effort to help Peru develop a national forest inventory.

More Information on Pat Miles >>

Featured Product

Net Change In Forest Density, 1873-2001: Using Historical Maps to Monitor Long-term Forest Trends

RMAP-NRS-4 shows net change in forest density over 128 years.If a picture is worth a thousand words, maps are worth at least an essay. To demonstrate that historical maps can yield valuable information about forest change over time at regional and national scales, researchers with the Northern Research Station’s FIA Program turned to a map created in 1873 by botanist William H. Brewer. 

They started with a scanned copy of the map which provides a snapshot in time of the forest resources in the lower 48 states based on information collected for the ninth U.S. Census. Researchers used specialized software to assign real-world coordinates to the map image (a process referred to as georeferencing). Next, they created a present-day map of forest resources replicating the same woodland density categories used in the 1873 map. The modern map was based on thousands of on-the-ground observations from the FIA program combined with satellite imagery. This process enabled researchers to calculate the change between historical and current times.

The resulting map, “Net Change in Forest Density, 1873-2001,” is 128 years of forest history at a glance. That history includes Yellowstone National Park, which was established 2 years prior to the Brewer map and stands out clearly as an unchanged area in the final product. The map held some surprises. Greg Liknes, the lead author of the study, initially thought a distinct oval on the map showing “major decrease” of forest resources in northwestern Ohio was likely an error, but he discovered that it is an accurate representation of the Great Black Swamp, which remained forested until the land was drained and cleared for agricultural use much later than the surrounding areas.

“Our goal was to determine if we could extract information from historical maps that enhances our understanding of past conditions, particularly the spatial arrangement of forests,” Liknes said. “Today mapping is a critical way we communicate information because the reader can infer so much so quickly.”

More Information >>

Featured Research

If a tree falls in a forest how long does it lie there?

Forester measures downed woody material.When trees fall or shed branches, they become “downed and dead woody material,” or “DWM” to foresters, but they remain a vital part of the forest ecosystem. Dead wood is critical to nutrient cycling, carbon dynamics, tree regeneration, wildlife habitat, and wildfire behavior. The decay rate of wood – or how long wood lies on the forest floor – has become increasingly important in forest management.

In one of the first large-scale studies of DWM decay rates, FIA scientists developed a new technique that matches measured DWM pieces over short periods of time.  Instead of waiting potentially more than 100 years for a piece of dead wood to decay, land managers can use the model to predict the probability of a DWM piece moving from one stage of decay to the next advanced stage of decay. 

When the model was applied to a DWM inventory across forests of the eastern United States, it demonstrated that decay rates depend on the species, size of the piece, and its surrounding climate. For hardwood species, especially for small pieces in warm/humid climates, over half of the downed wood material biomass is lost to the atmosphere or other carbon pools within 10 years.  In contrast, for coniferous downed wood material in cold/dry climates, it may easily take more than 100 years for almost all of the carbon to be emitted or transferred to other pools.

More Information >>

Featured Partnership

SilvaCarbon Enhancing Forest Inventory, Carbon Monitoring Worldwide

Congressional delegation and partner respresentatives gather at restoration site.

When it began in the 1930s, FIA (Forest Inventory and Analysis) in the United States focused on answering questions about timber production. Today, there is worldwide interest in inventory and monitoring of forests to better understand carbon dynamics. The Forest Service’s FIA program is working to share forest inventory experiences, methods and tools with many countries around the world.
For example, the USDA Forest Service is a key member of the SilvaCarbon program, a federal partnership that works to enhance capacity worldwide for monitoring and managing forest carbon. The Northern Research Station’s FIA program leads the Forest Service’s contribution to SilvaCarbon by helping develop inventory methods and tools, participating as science partners, and building capacity. Other SilvaCarbon partners include NASA, the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Agency for International Development (USAID), and the Smithsonian Institution. FIA has worked with SilvaCarbon partners in Colombia, Vietnam, the Democratic Republic of Congo, Cameroon, Gabon, the Republic of the Congo and other nations.

“Collaboration with federal partners allows us to share a tremendous amount of expertise and deliver a very complete package to the countries we’re working with,” according to Chip Scott, FIA’s SilvaCarbon program coordinator. “The immediate benefit is that nations that have not been able to monitor their forests now have the tools they need. In the long run, all countries will benefit from increased information on forests and carbon.”


More Information on SilvaCarbon>>

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