Treesearch

Enhanced sets of compatible stem profile equations were used with data collected from felled and standing pine trees to calculate tree volumes to various top merchantability limits. Standing trees were measured with the Criterion 400 Laser, Tele-Relaskop, and Wheeler Pentaprism. These measurements were used to compare accuracies of the optical dendrometers for the measurement of tree dbh and height and the prediction of tree volume from stem profile equations.

A digital camera was used to measure diameters at various heights along the stem on 20 red oak trees. Diameter at breast height ranged from 16 to over 60 cm, and height to a 10-cm top ranged from 12 to 20 m. The chi-square maximum anticipated error of geometric mean diameter estimates at the 95 percent confidence level was within ±4 cm for all heights when obtained at a distance of 12 m or greater. Error increased with increased stem height from ±3 to ±7 cm for heights from 1 to 20 m. In general, the error is equivalent to three times the instrument precision, which varies with distance....

Forest survey analysts usually are interested in tables of values rather than single point estimates. A common error is to include only plots on which nonzero values of the attribute were observed when computing the variance of a mean. Similarly, analysts often exclude nonforest plots from the analysis. The development of the correct estimates of forest area, attribute totals, and their means over the area of interest is described. Program TabGen was written to perform these calculations correctly assuming simple random sampling, stratified random sampling, or double sampling for stratifica...

Ecological aspects are increasingly influencing silvicultural management. Estimating forest biodiversity has become one often major tools for evaluating management strategies. A stand-scale forest biodiversity index is developed, based on available data from the state forest inventory. The index combines aspects of forest structure, woody and herbal layer composition, and deadwood, as biodiversity indicators. The index is calculated by means of a score system following a standard procedure. It reflects the variability of forests in Flanders in a logical way and is sensitive enough to...

A multivariate decision tree model was used to quantify the relative importance of complex hierarchical relationships between biophysical variables and the occurrence of tropical forest fires. The study site is the Huai Kha Kbaeng wildlife sanctuary, a World Heritage Site in northwestern Thailand where annual fires are common and particularly destructive. Thematic layers of several biophysical variables were combined in a GIS with field measurements of fuel loading and stand physiognomy. Canopy vegetation (NDVI), rainfall, geology, elevation, and forest type explain most of the variation...

Assortment structure analysis of tree trunks is a characteristic and proper problem that can be solved by using mathematical modeling and standard computer programs. Mathematical form model of tree trunks consists of tapering curve equations and their parameters. Parameters for nine species were obtained by processing measurements of 2,794 model trees and studying the variability of 53,000 relative diameters.

The Forest Health Monitoring (FHM) Program was initiated in 1990 as a cooperative effort between the USDA Forest Service and the National Association of State Foresters. Program efforts include detecting changes in tree health from a national grid of one-sixth acre permanent sample plots. Tree data have been collected in various states since 1991, and include species, diameter at breast height (dbh), status (live, dead, or cut), and various ratings of crown condition and damage.

When available information is scarce, the Maximum-Entropy Principle can estimate the distributions of parameters. In our case study, we estimated the distributions of the parameters of the forest self-thinning process based on literature information, and we derived the conditional distribution functions and estimated the 95 percent confidence interval (CI) of the self-thinning process for several tree species. The 95 percent CI indicated that the slope parameter of the so-called self-thinning law can be considered a random variable with a mean value of -3/2.

Forests occupy 80-90 percent of the Sikhote-Alin mountain forest region. Cenotic and species diversity of its forest vegetation is the highest in Russia. In the Sikhote-Alin forests, about 200 species of trees and shrubs and 6 species of lianas grow; about 1,000-1,100 species of grassy plants and more than 450 species of mosses and lichens are registered.

New Zealand's timber harvest is rapidly increasing and will continue to do so over the next 20 years. This increase provides opportunities for adding value and increasing profitability, but to achieve the full potential of the harvest, the best management decisions at strategic, tactical, and operational levels are required. The key to market-driven harvest planning in New Zealand is a greatly improved knowledge of the quantity, quality, and condition of the standing trees. Industry is demanding that pre-harvest inventory be intensified with more detail about the quality of the stems, more...