Treesearch

Stand structure, tree height growth, and understory plant diversity were assessed in five mixed alder-conifer stands after logging in southeast Alaska. Tree species composition ranged from 7- to 91-percent alder, and basal area ranged from 30 to 55 m2/ha. The alder exhibited rapid early height growth, but recent growth has slowed considerably. Some conifers have been suppressed, but some spruce are now nearly as tall as the overstory alders. The four stands with the most alder had high species richness of shrubs, herbs, ferns, and mosses, but the predominantly spruce stand had slightly...

For forests to be sustainable, viable populations of rare plants should be maintained. Where habitat management alone cannot conserve species threatened by human activity, micropropagation may advance species recovery. Micropropagation protocols were developed for Pacific Northwest endemics; Hackelia venusta, Douglasia idahoensis, Astragalus species, and Cornus nuttallii. Microshoots and seed were multiplied and rooted on nutrient media containning minimal levels of cytokinin and auxin growth regulators to maintain stable gene expression in plantlets. Acclimatized plantlets were reintroduce...

This proceedings is a compilation of 27 papers that were presented at the regional meetings of the forest and conservation nursery associations in the United States in 1997. The Northeastern Forest Nursery Association Conference was held in Bemidji, Minnesota, on August 11-14, 1997; and the Western Forest and Conservation Nursery Association meeting was held in Boise, Idaho, on August 19-21, 1997. The subject matter ranges from seed collection and processing; through nursery cultural practices; to harvesting, storage and outplanting.

Rangelands in the western United States provide habitat for >3,000 species of mammals, birds, reptiles, fish, and amphibians. They are also shared with most of the cattle produced in the 11 western states. Managing livestock and wildlife on public lands in the western United States is one of the most challenging issues for managers of rangelands and answers do not come easily. To complicate issues further, the influences of livestock on flora and fauna are intuitively considered to be detrimental, but these relationships are not well understood. In part, this text was developed to improve...

Elk (Cervus elaphus) are an important herbivore on North American rangelands . Their large size, herding behavior, pioneering habits , and high mobility make them an especially conspicuous herbivore in s uch open areas. Moreover, the potential for elk to compete with livestock makes them an obvious source of controversy between stockgrowers and wildlife advocates. In this chapter, we describe the history of elk on rangelands. We discu ss the competitive interactions between elk and livestock, and identify methods of stocking allocation between both. We also provide concepts, prescriptions,...

We measured soil density and tree growth after wet-season, ground-based yarding on fine-textured soils at three clear-cut sites. Four treatment conditions were sampled on or near four skid trails (replicates): nontilled and tilled primary skid trails, and adjacent slash-treated areas; the fourth treatment was secondary skid trails at two locations and a logged-only control at the third location. The 16 treatment plots were split into 4 subplots, each randomly assigned to a species — stock type and planted with 30 seedlings. Tree data through year 8 after planting were analyzed as a...

We examined the physiological response of foliage in the upper third of the canopy of 125-year-old giant sequoia (Sequoiadendron giganteum Buchholz.) trees to a 61-day exposure to 0.25x, 1x, 2x or 3x ambient ozone concentration. Four branch exposure chambers, one per ozone treatment, were installed on 1-m long secondary branches of each tree at a height of 34 m. No visible symptoms of foliar ozone damage were apparent throughout the 61-day exposure period and none of the ozone treatments affected branch growth. Despite the similarity in ozone concentrations in the branch chambers within a...

Emergence, establishment and growth of Abies amabilis, Pseudotsuga menziesii and Tsuga heterophylla were studied for 2 years in variously sized canopy gaps created in four stands on the west slope of the Cascade Range in central Oregon and southern Washington, USA. Seedlings originating from seeds sown on controlled microsites were compared with natural seed rain.

Insect and disease epidemics have created unhealthy and overstocked conditions in national forests of the Blue Mountains. Two of the most important management tools for reducing fuel loads and restoring forest health are prescribed fire and mechanical thinning practices. Accurate information about public support for these practices is essential for implementing effective long-term management policies. By assessing public attitudes, we improve our understanding of the often contentious environment in which resource management decisions are made. This report presents a summary of findings...

A framework for ecosystem management is proposed. This framework assumes the purpose of ecosystem management is to maintain the integrity of ecosystems over time and space. It is based on four ecosystem principles: ecosystems are dynamic, can be viewed as hierarchies with temporal and spatial dimensions, have limits, and are relatively unpredictable. This approach recognizes that people are part of ecosystems and that stewardship must be able to resolve tough challenges including how to meet multiple demands with finite resources. The framework describes a general planning model for...