Treesearch

Logs are an important structural feature of forest ecosystems, and their abundance affects many resources and forest processes, including fire regimes, soil productivity, silviculture, carbon cycling, and wildlife habitat. Consequently, logs are often sampled to estimate their frequency, percent cover, volume, and weight. The line-intersect method (LIM) is one of the most widely used methods to obtain these estimates and has been shown to produce unbiased estimates of log characteristics. With the traditional LIM the diameters of each log at the point of its intersection with the sampling...

In this study we investigated the capacity of Andean alder (Alnus acuminata Kunth), inoculated with Frankia and two ectomycorrhizal fungi (Alpova austroalnicola Dominguez and Alpova diplophloeus [Zeller and Dodge] Trappe and Smith), for nodulation and growth in pots of a soilless medium that contained vermiculite or a mixture of ground basalt rock and vermiculite. The seedlings were inoculated with Frankia suspensions prepared from root nodules of A. acuminata, followed by inoculation with spores of either one of the two Alpova species. The seedlings were grown in a greenhouse for 12...

Climate modeling based on a variety of scenarios for the Pacific Northwest suggests that over the next century temperatures may increase and that the abundance of summer precipitation may decline. Historically, climate changes at the century scale have been accompanied by adjustments in species population sizes and the composition of vegetation communities. Silvicultural practices may be employed to assist in forest adaptation to climate changes, principally by influencing stand structure and species composition throughout stand development. Forest managers might consider a primary...

Establishing a long-term ecological research program and research collaborations in northwestern Patagonia. A workshop in San Carlos de Bariloche, Argentina, January 2009. The relict flora of Gondwanda, the mystic nature of the windswept Patagonian steppe, the Andes mountains and the southern beech forests, all combined, made San Carlos de Bariloche the perfect setting for gathering researchers from North and South America to discuss a common goal: establishing a program of research and scientific interaction focused on long-term ecological questions in northern Patagonia. The meeting...

Dimensions, volume, and biomass were measured for 121 hand-constructed piles composed primarily of coniferous (n = 63) and shrub/hardwood (n = 58) material at sites in Washington and California. Equations using pile dimensions, shape, and type allow users to accurately estimate the biomass of hand piles. Equations for estimating true pile volume from simple geometric shapes and measurements of pile dimensions were also developed for users who require estimates of pile volume for regulatory reporting. Biomass and volume estimation equations were developed to allow users to estimate either...

Subsampling and subsequent imputation of tree heights can improve the predictive performance of stand volume estimation but may also introduce biases. Using coastal Douglas-fir data from southwest Oregon, USA, the predictive performance of several height imputation strategies for estimating stand volume was evaluated. A subsample of 1 to 15 trees was randomly selected per stand, and missing heights were imputed using a regional Chapman-Richards function with diameter only and diameter plus stand density measures, fitted using a nonlinear least-squares model (NFEM) and a nonlinear mixed-effe...

Information on current forest condition is essential to assess and characterize resources and to support resource management and policy decisions. The 1998 Farm Bill mandates the U.S. Forest Service to conduct annual inventories to provide annual updates of each state's forest. In annual inventories, the sample size of 1 year (panel) is only a portion of the full sample, and therefore the precision of the estimations for any given year is low. To achieve higher precision, the Forest Inventory and Analysis program uses a moving average (MA), which combines the data of multiple panels, as...

Boundary-line release criteria are increasingly applied to evaluate forest disturbance histories from tree-ring data. However, a number of important properties central to the technique have not been evaluated, including: (i) the ability of boundary-line release criteria to standardize releases across various sites, species, and tree life stages (ii) the minimum sample sizes necessary for developing boundary lines, and (iii) the degree to which the criteria can resolve the degree of crown exposure following a disturbance event. In an analysis of 11 North American tree species, boundary-line...

Downed wood provides important faunal microhabitat in forests for numerous invertebrate taxa, small mammals and amphibians. Habitat suitability of downed wood as refugia is an increasing concern in managed Pacific Northwest forests, where overstory reduction may result in both reduced downed wood recruitment and increased temperatures within logs. We examined temperature profiles in western Oregon to assess differences in thermal regimes of logs and soil relative to summer air temperature extremes and their implications with respect to habitat suitability for plethodontid salamanders....

The ecosystem service concept has been proposed as a meaningful framework for natural resource management. In theory, it holds concomitant benefit and consequence for the forest product sector. However, numerous barriers impede practitioners from developing concrete and enduring responses to emerging ecosystem service markets, policies, and initiatives. Principal among these barriers is that the ecosystem service concept has a complex history, numerous definitions in use, and an astounding diversity in rationale and application. This article provides a conceptual review of ecosystem...