Treesearch

A national survey was conducted in the United States to learn more about public preferences and perceptions regarding forest and vegetation planning and management in urban freeway roadsides. In response to images depicting a visual continuum of landscape management treatments, drivers most preferred settings having tree plantings that screen adjacent commercial land uses. Preference results suggest solutions for landscape practices that create visual quality for drivers and provide visibility for commercial properties adjacent to freeway roadsides. The research also investigated public...

Translocation of animals to re-establish extirpated populations or to maintain declining ones has often been carried out without genetic information on source or target opulations, or adequate consideration of the potential effects of mixing genetic stocks. We consider the conservation status of the fisher (Martes pennanti) and evaluate the potential genetic consequences of past and future translocations on this medium-sized carnivore by examining population variation in mitochondrial control-region sequences. We sampled populations throughout the fisher's range in North America including...

Single-species conservation and natural reserves seem insufficient for protecting biodiversity to scientists, and conventional forestry seems suspect in sustainability to much of the public. In northwestern USA, comparisons of natural and managed coniferous forests support the idea that both single-species conservation and conventional forestry are unlikely to be successful because biocomplexity is more important than individual habitat elements in maintaining the diversity of forest ecosystems and their capacity to produce useful goods and services. Experiments in inducing heterogeneity...

Recent harvest declines in the Western United States have focused attention on the question of economic impacts at the community level. The impact of changing timber-related economic activity in a given community on other local activity and the general economic health of the community at large has been a persistent and often contentious issue in debates surrounding forest policy decisions. The economic base hypothesis, in which changes in local export-related economic activity are assumed to cause changes in economic activity serving local demand, is a common framework for understanding...

Overall hunter demand for deer on Prince of Wales Island, Alaska, has not changed significantly in the last 10 years, although demand has increased in five communities on the island. These five communities each experienced a decline in household median income between 1989 and 1999. In communities with a smaller percentage of Native Alaskans, deer was a larger component of their subsistence harvest. The cash-based market economy on Prince of Wales Island is in transition as the dependence on logging and commercial fishing declines. The subsistence economy in Alaska has traditionally...

Image-to-image registration requires identification of common points in both images (image tie-points: ITPs). Here we describe software implementing an automated, area-based technique for identifying ITPs. The ITP software was designed to follow two strategies: ( I ) capitalize on human knowledge and pattern recognition strengths, and (2) favour robustness in many situations over optimal performance in any one situation. We tested the software under several confounding conditions, representing image distortions, inaccurate user input, and changes between images. The software was robust to...

We report hydraulic lift in the sawmlia vegetation of central Brazil (Cerrado). Both heat-pulse measurements and isotopic (deuterium) labelling were used to determine whether hydraulic lift occurred in two common species, and whether neighbouring small shrubs and trees were utilizing this water.Both techniques showed water uptake by tap-roots and reverse flow of water in lateral roots. Roots transferred hydraulically lifted water to the soil, and small shrubs and trees neighbouring the labelled individuals were labelled by deuterated water.Isotopic mass-balance equations and sap-flow...

Wood density, moisture content, tracheld width and cell wall size were examined in trees from plots that were sprayed for 5 years with chlorothalonil (Bravo ®) fungicide to reduce the impact of Swiss needle-cast (SNC) and from trees in adjacent unsprayed plots. The unsprayed (more heavily diseased) trees had significantly narrower sapwood, narrower growth tings, lower sapwood moisture content, and narrower tracheid cell wall thickness than did the sprayed (less heavily diseased) trees. Moreover, unsprayed trees had altered earlywood denslty—earlywood width, relationshlps, higher...

Rural areas of the Pacific Northwest experienced a dramatic growth in population during the late 1980s to early 1990s. This growth was fueled by both push and pull factors, including environmental and natural resource based amenities. Such growth has not only stressed the capacity of rural counties and communities to cope with change but also has raised important questions about interactions between people and natural resources. This paper, explores four fundamental components of this interaction: (1) the drivers of population growth; (2) the consequences of population growth, primarily...

Bulk density and soil resistance to penetration were measured in ten, 3- to 11-ha operational units in overstocked, mixed-conifer stands in northeast Washington. Resistance was measured with a recording penetrometer to the 33-cm depth (13 in) at 10 stations on each of 8 to 17, 30.5-m-long, randomly located transects in each unit. Subsequently, different combinations of felling and yarding equipment were used to thin eight units; no combination was replicated. Two units remained as nonharvested controls. Soil measurements were repeated after harvest. Most trails were designated, others were...