W. Keith Moser

Combining satellite imagery with forest inventory data to assess damage severity following a major blowdown event in northern Minnesota, USA

Effects of a catastrophic blowdown event in northern Minnesota, USA were assessed using field inventory data, aerial sketch maps and satellite image data processed through the North American Forest Dynamics programme. Estimates were produced for forest area and net volume per unit area of live trees pre- and post-disturbance, and for changes in volume per unit area and total volume resulting from disturbance. Satellite image-based estimates of blowdown area were similar to estimates derived from inventory plots and aerial sketch maps. Overall accuracy of the image-based damage classification was over 90%. Compared to field inventory estimates, image-based estimates of post-blowdown mean volume per unit area were similar, but estimates of total volume loss were substantially larger, although inaccessibility of the most severely damaged inventory plots may have depressed the inventory-based estimate. This represents the first application of state model differencing to storm damage assessment. The image-based procedure can be applied to historical archives of satellite imagery and does not require pre-disturbance field inventory data.

Maine's forests 2008

The second annual inventory of Maines forests was completed in 2008 after more than 3,160 forested plots were measured. Forest land occupies almost 17.7 million acres, which represents 82 percent of the total land area of Maine. The dominant forest-type groups are maple/beech/yellow birch, spruce/fir, white/red/jack pine, and aspen/white birch. Statewide volume equals 25.5 billion ft3, resulting from nearly 590 million ft3 of live-tree volume grown each year. The report also contains additional information on sustainability, biomass, carbon, forest health, land-use change, and timber products. The DVD includes detailed information on forest inventory methods, quality of estimates found, and tables forest statistics.

Farmers’ objectives toward their woodlands in the upper Midwest of the United States: implications for woodland volumes and diversity

This paper reports the results of a study that explores the relationship between farm woodland owners’ stated intentions for owning woodland, and the structure and composition of these woodlands in the states of Illinois, Indiana and Iowa in the upper Midwest of the United States. Data from two sample-based inventories conducted by the USDA Forest Service, Forest Inventory and Analysis (FIA) program were combined for this analysis—the FIA forest resources inventory and the National Woodland Owner Survey (NWOS). We looked for relationships between product value and investment in woodlands, as reflected in volumes and tree quality. We also examined whether measures of diversity reflected specific management focus. Our results partially supported our hypotheses. Woodland-focused ownership reasons were found to have larger volumes and individual tree sizes. We found that a passive woodland ownership reason—that woods were “part of the farm”—generally had lower volumes per hectare. Although we were not able to differentiate between different forest product classes and measures of volume, we did find that those landowners who harvested veneer had more volume than those who harvested for firewood. Woodland owners who salvage-harvested their woodlands—a harvesting reason that is more reactive than proactive—exhibited lower volumes per hectare than those who harvested for more proactive, product-focused reasons. Biodiversity was also found to be related to the ownership focus and harvest intent. Generally, there was lower diversity in overstory species when the woodland was viewed merely as “part of the farm,” when the product harvested was fence posts and when timber was harvested for salvage or land clearing. The small sample size limits our analysis, but we can conclude that focusing the woodland owners on management of their woodlands—regardless of what the specific management goals might be—should increase productivity and biodiversity of those woodlands.

South Dakota's forests 2005

The first completed annual inventory of South Dakotas forests reports almost 1.7 million acres of forest land. Softwood forests make up 74 percent of the total forest land area; the ponderosa pine forest type by itself accounts for 69 percent of the total.

Iowa's Forests 2008

The second full annual inventory of Iowas forests (2004-2008) reports more than 3 million acres of forest land, almost all of which is timberland (98 percent), with an average volume of more than 1,000 cubic feet of growing stock per acre. American elm and eastern hophornbeam are the most numerous tree species, but silver maple and bur oak predominate in terms of live tree volume. Iowas forest land is comprised of 65 percent sawtimber, 19 percent poletimber, and 16 percent sapling/seedling or nonstocked size classes. Average annual net growth of growing-stock trees on Iowas timberland increased during the past decade to the current estimate of nearly 105 million cubic feet. This report includes additional information on forest attributes, land use change, carbon, timber products, and forest health. A DVD included in this report includes 1) descriptive information on methods, statistics, and quality assurance of data collection, 2) a glossary of terms, 3) tables that summarize quality assurance, 4) a core set of tabular estimates for a variety of forest resources, and 5) a Microsoft Access database that represents an archive of data used in this report, with tools that allow users to produce customized estimates.

North Dakota's forests 2005

The second annual inventory of North Dakotas forests reports more than 772,000 acres of forest land with an average volume of more than 921 cubic feet per acre. Forest land is dominated by the bur oak forest type, which occupies more than a third of the total forest land area. The poletimber stand-size class represents 39 percent of forest land, followed by sawtimber (32 percent) and saplings/seedlings (28 percent). The volume of growing stock currently totals more than 341 million cubic feet. The average annual net growth of growing stock on forest land from 2006 to 2010 was approximately 6.8 million cubic feet per year. This report includes additional information on forest attributes, land use change, carbon stocks, timber products, forest health, and statistics, methods, and quality assurance of data collection. Detailed information on forest inventory methods and data quality estimates is included in a DVD at the back of this report. Tables of population estimates and a glossary are also included.

Vermont's Forests 2007

The first full annual inventory of Vermonts forests reports more than 4.5 million acres of forest land with an average volume of more than 2,200 cubic feet per acre. Forest land is dominated by the maple/beech/birch forest-type group, which occupies 70 percent of total forest land area. Sixty-three percent of forest land consists of large-diameter trees, 27 percent contains medium-diameter trees, and 9 percent contains small-diameter trees. The volume of growing stock on timberland has been rising since the 1980s and currently totals nearly 9 billion cubic feet. The average annual net growth of growing stock on timberland from 1997 to 2007 is approximately 180 million cubic feet per year. Additional information is presented on forest attributes, land use change, carbon, timber products, and forest health. Detailed information on forest inventory methods and data quality estimates is included in a DVD at the back of the report. Tables of population estimates and a glossary are also included.