Treesearch

The boundary plot problem is encountered when a forest inventory plot includes two or more forest conditions. Depending on the correction method used, the resulting estimates can be biased. The various correction alternatives are reviewed. No correction, area correction, half sweep, and toss-back methods are evaluated using simulation on an actual data set. Based on the simulation results, no correction is recommended when the boundary between forest conditions is gradual. For abrupt boundaries, either the area correction or toss-back methods should be used.

Fragmentation of forest area plays an important role in the ongoing discussion of forest dynamics and biological and ecosystem diversity. Among its contributing factors are size, shape, number, and spatial arrangement of forest patches. Several metrics and indexes are in use, predominantly in quantitative landscape ecology. An important area of interest is the assessment of diversity from sample data. This paper presents a sample-based approach to analyzing standard cluster sample data from forest inventories and applying basic considerations of geometrical probabilities. The number and...

The setting of objectives for monitoring schemes for landscape-size areas should be a complex task in today's regulatory and sociopolitical atmosphere. The technology available today, the regulatory environment, and the sociopolitical considerations require multiresource inventory and monitoring schemes, whether tile ownership is industrial or for preservation. Monitoring is essential so that we know if we are meeting our management objectives,

A proposed national forest inventory for Canada is to report on the state and trends of resource attributes gathered mainly from aerial photos of sample plots located on a national grid. A pilot project in New Brunswick indicates it takes about 2,800 square 400-ha plots (10 percent inventoried) to achieve a relative standard error of 10 percent or less on 14 out of 17 estimates of forest strata (cover type) proportions; it takes about 3,300 plots of similar size to achieve the same precision target on 68 of 85 strata type x age proportions. Minimum cost solutions for fixed targets of...

The Forest Inventory and Analysis (FIA) program of the USDA Forest Service has adopted a new sampling unit for the national forest inventory of the U.S. We compared this new sampling unit with five other sampling units. Data from natural loblolly pine (Pinus taeda L.) stands in the Georgia piedmont show that all sample units produce reasonable estimates for the pine overstory in this stand type. However, plot clusters typically used by FIA to sample trees in the 1.0 to 4.9 inch dbh range can produce seriously biased estimates. Use of a single, subjectively chosen "site" tree, as done by...

Integrating such disparate topics as are covered by this conference is daunting, because to do it well requires in-depth expertise of many complex technical methodologies. Based on experiences in Asia and Australia, it is suggested that there can never be one inventory design or one planning system, it will increasingly be necessary to implement specialized inventories and projects that are oriented towards meeting specific short-term and longer term objectives. Each separate study must be designed to enable all the information to be integrated in order to answer the various alternative...

Red spruce (Picea rubens Sarg.) growing in northern montane forests of eastern North America appears to be distinctive with respect to at least two aspects of winter physiology. First, red spruce attains only a modest level of midwinter cold tolerance compared to other north temperate conifers and appears barely capable of avoiding freezing injury at commonly occurring ambient winter temperatures (DeHayes, 1992). Second, red spruce is capable of net photosynthesis during winter in response to relatively brief exposure to mild temperatures (Schaberg et al., 1995). Despite considerable...

We examined the effects and potential interactions of acid mist and soil solution Ca and Al treatments on foliar cation concentrations, membrane-associated Ca (mCa), ion leaching, growth, carbon exchange, and cold tolerance of red spruce (Picea rubens Sarg.) saplings. Soil solution Ca additions increased foliar Ca and Zn concentrations, and increased rates of respiration early in the growing season (July). Soil Al treatment had a broad impact, reducing foliar concentrations of Ca, Mg, Mn, P and Zn, and resulting in smaller stem diameters, sapling heights and shoot lengths compared with...

We studied seasonal dynamics of carbohydrate storage in red spruce (Picea rubens Sarg.) seedlings by measuring starch and sugar concentrations of old needles (≥one year old), new needles (< one year old), stems, and roots in two stands in the Green Mountains of Vermont. Although the two stands differed in many site characteristics including percent slope, aspect, soil type, drainage, and 564 m in elevation, concentrations and seasonal patterns of carbohydrates were similar for the two stands. For all tissues, starch concentrations peaked in late spring, declined through summer, and reached...

Extensive forest inventories of forested lands in the United States were begun in the early part of the 20th century, but widespread, frequent use was not common until after WWII. Throughout the development of inventory techniques and their application to assess the status of the nation's forests, most of the work has been done by the USDA Forest Service through regional centers. Various sampling designs have been tried: some have proved efficient for estimation of certain parameters but not others. Some designs, though efficient in many respects, have been abandoned due to the complexity...