Treesearch

Recognition of the value of forest vegetation data has increased in recent years, especially when it is collected using consistent methods over many forest types. Because the cost of collecting large datasets is substantial, managers must balance the cost of collection with the utility of the conclusions that may be drawn from the data analyses. There is no single standard for collecting vegetation data; sampling protocols should be developed to address clearly defined analysis objectives. We compare the utility of the established Phase 3 Vegetation Diversity and Structure Indicator data...

The Forest Inventory and Analysis program (FIA) of the US Forest Service conducts a nationwide annual inventory. One panel (20% or 10% of all plots in the eastern and western United States, respectively) is measured each year. The precision of the estimates for any given year from one panel is low, and the moving average (MA), which is considered to be the default estimator, can result in biased estimates of current conditions. An alternative to the MA is sought, and studies comparing different alternatives to the MA approach for estimating current forest attributes in the Pacific Northwest...

The Forest Inventory and Analysis (FIA) Program of the Forest Service, Department of Agriculture, is an annual monitoring system for the entire United States. Each year, an independent "panel" of FIA field plots is measured. To improve accuracy, FIA uses the "Moving Average" or "Temporally Indifferent" method to combine estimates from multiple panels that were measured during recent years. However, timeseries estimators better serve monitoring objectives than temporally indifferent methods.This paper reviews the Kalman filter, which is a linear, minimum variance, sequential, model-based,...

The consumers of data derived from extensive forest inventories often seek annual estimates at a finer spatial scale than that which the inventory was designed to provide. This paper discusses a few model-based and model-assisted estimators to consider for county level attributes that can be applied when the sample would otherwise be inadequate for producing low-variance estimates in the smaller counties. I present and demonstrate simple spatial and/or temporal estimators that draw strength from neighboring counties and/or years in order to increase confidence in the county level annual...

As members of the forest products industry continue to reduce their landholdings, monitoring reliable future timber supplies becomes an increasingly important issue. This issue requires both spatial and forest inventory information to meet the strategic planning needs of these entities. Increased depth in the archival span of imagery available from the Landsat program in conjunction with timber estimates from FIA data have been used by Larson and McGowin, Inc. to fill this information gap in the southern U.S. by further refining timber supply projections.In generating this information for...

The forested ecosystems of the southern Appalachians are some of the most diverse in North America due to the variability in climate, soils, and geologic parent material coupled with the complex topography found throughout the region. These same characteristics cause stands of upland hardwoods to be extremely variable with regard to site quality and productivity. Site index has been the tool most commonly used to measure existing site quality and productivity, but measured site index may not accurately quantify potential site quality and productivity, largely due to ubiquitous disturbance...

Ecoregions are large mapped areas of hypothesized ecological uniformity that are delineated subjectively based on multiple physical and biological components. Ecoregion maps are seldom evaluated because suitable data sets are often lacking. Landsat imagery is a readily available, low-cost source of archived data that can be used to calculate the normalized difference vegetation index (NDVI), which is associated with seasonal and annual vegetation conditions. This paper reports on a study designed to test the use of NDVI as an integrating variable for detecting differences among mapped...

Resources have been developed in the literature to enable landowners to estimate the carbon sequestration timeline of forest products derived from their land. These tools were used here to estimate sequestration and emissions related to harvests carried out in Ravalli County from 1945 to 2007. This county-level accounting of product carbon release can later be combined with county-level estimates of growth and emissions from fire and other sources to provide landscape-level insights into relationships between forest carbon exchange and processes like harvest and fire.

Areas burned annually in 29 Canadian forest fire regions show a patchy and irregular correlation structure that significantly influences the distribution of annual totals for Canada and for groups of regions. A binary Monte Carlo Markov Chain (MCMC) is constructed for the purpose of joint simulation of regional areas burned in forest fires. For each year the MCMC prediction is a binary vector with regions classified to a large fire year (LF) or a small fire year (SF). The regional area burned is then obtained from empirical quantile functions; separately for LF and SF years. The MCMC...

These proceedings report invited presentations and contributions to the 2008 Biennial Forest Inventory and Analysis (FIA) Symposia, which was hosted by the Research and Development branch of the U.S. Forest Service. As the only comprehensive and continuous census of the forests in the USA, FIA provides strategic information needed to evaluate sustainability of current forest management practices across all ownerships. Symposium papers cover high priority and timely issue-based topics, including climate change, wildlife, fire, bio-energy, geo-spatial extensions, monitoring over time,...