Treesearch

During the past decade, research on large in-stream wood has expanded beyond North America's Pacific Northwest to diverse environments and has shifted toward increasingly holistic perspectives that incorporate processes of wood recruitment, retention, and loss at scales from channel segments to entire watersheds. Syntheses of this rapidly expanding literature can be facilitated by agreement on primary variables and methods of measurement. In this paper we address these issues by listing the variables that we consider fundamental to studies of in-stream wood, discussing the sources of...

In a world where populations and resource demands continue to grow, there is a long history of concern about the "capacity" of the environment to support human uses, including timber, rangelands, fish and wildlife, and recreation. Work on visitor capacities has evolved considerably since the late 1960s as a result of environmental planning, court proceedings, recreation management practice, and recreation research. This monograph documents the "state-of-knowledge" understanding of capacity among our group of long-term professionals, who represent a wide range of experience and perspectives....

The new micro-dolichopodid genus Hurleyella and two new species, H. cumberlandensis and H. brooksi are described from the Nearctic. Hurleyella resembles the subfamily Medeterinae in having the legs bare of major setae, a depressed posterior mesonotum, and concave dorsal postcranium, but the complex male genitalia is unlike the relatively simple structure of traditional Medeterinae (e.g., Medetera, Thrypyicus, Corindia, etc.). Until the relationship of Hurleyella to other genera can be determined, and the limits of dolichopodid subfamilies refined, it should be considered as incertae sedis.

Approximately 185,000 forest inventory and ecological plots from both USA and Canada were used to predict the contemporary distribution of western larch (Larix occidentalis Nutt.) from climate variables. The random forests algorithm, using an 8-variable model, produced an overall error rate of about 2.9 %, nearly all of which consisted of predicting presence at locations where the species was absent. Genetic variation among 143 populations within western larch's natural distribution was predicted from multiple regression models using variables describing the climate of the seed source as...

This manual is based on the best current knowledge of container nursery management and should be used as a general reference. Recommendations were made using the best information available at the time and are, therefore, subject to revision as more knowledge becomes available. Much of the information in this manual was primarily developed from information on growing western and southern conifer seedlings in the United States. Because of the wide variation in individual species responses, container nursery managers will need to adapt these principles and procedures to their own crop...

Wildfire is a critical land management issue in the western United States. Efforts to mitigate the effects of altered fire regimes have led to debate over ecological restoration versus species conservation framed at the conjuncture of terrestrial and aquatic ecosystems and their respective management regimes. Fire-related management activities may disrupt watershed processes and degrade habitats of sensitive fishes. However, the restoration of forest structure, process, and functionality, including more natural fire regimes, might also benefit longer-term habitat complexity and the...

Coarse woody debris (CWD) provides important ecosystem services in forests and affects fire behavior, yet information on amounts and types of CWD typically is limited. To provide such information, we sampled logs and stumps in mixed-conifer and ponderosa pine (Pinus ponderosa) forests in north-central Arizona. Spatial variability was prominent for all CWD parameters. Correlations between amounts of CWD and current forest structure (tree density and basal area) were relatively weak. Most plots in mixed-conifer forest exceeded current USFS guidelines for retention of large logs. In contrast,...

Mill residues from forest industries are the source for most of the current wood-based energy in the US, approximately 2.1% of the nation's energy use in 2007. Forest residues from silvicultural treatments, which include limbs, tops, and small non-commercial trees removed for various forest management objectives, represent an additional source of woody biomass for energy. We spatially analyzed collecting, grinding, and hauling forest residue biomass on a 515,900 ha area in western Montana, US, to compare the total emissions of burning forest residues in a boiler for thermal energy with the...

A common challenge when comparing forest canopy cover and similar metrics across different ecosystems is that there are many field- and landscape-level measurement methods. This research conducts a cross-comparison and evaluation of forest canopy cover metrics produced using unmixing of reflective spectral satellite data, light detection and ranging (lidar) data, and data collected in the field with spherical densiometers. The coincident data were collected across a ~25 000 ha mixed conifer forest in northern Idaho. The primary objective is to evaluate whether the spectral and lidar canopy...

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number of recent studies have provided evidence that water limitation in the upper canopy can constrain foliar morphological adaptations to higher light levels. We measured height, light, and LMA of all species encountered along 45...