Treesearch

The effect of a single application of ammonium nitrate fertilizer on diameter, height, and volume growth of a Site IV plantation of Pseudotsuga menziesii was measured repeatedly during a 15-year period. Fertilizer dosages of 157, 314, and 471 kg N/ha increased gross volume growth during the 15-year period by an average of 5 I, 88, and 111 percent, respectively (67, 116, and 146 m~/ha). Quadratic equations best described the relationship between fertilizer dosage and gross and net volume growth during the entire period and during three intermediate periods. Volume growth on fertilized plots...

Responses following the application of six precommercial thinning treatments to a 27-year-old Douglas-fir plantation (2.4-m spacing, height at age 100 = 24 m) have been monitored for 25 years. Spacing after thinning ranged from 3.4 m to 8.1 m. Immediately following thinning, trees exhibited thinning shock; that is, substantial height growth reductions. The severity and duration of the shock effect were partially related to the severity of thinning. From 15 to 25 years following thinning, however, height growth was positively related to growing space with the best height growth at the wider...

Chemical characteristics of mineral soil beneath red alder (Alnus rubra Bong.) stands of various ages were studied. Total nitrogen (N) of the 0-to 20-centimeter (0- to 8-inch) soil layer increased with stand age, and pH of both the 0- to 20-centimeter and 20- to 50-centimeter (8- to 20-inch) layers decreased with stand age. Contents of some mineral nutrients accumulated with N in one or the other soil layers. Conversely, exchangeable calcium and magnesium decreased substantially in the 0- to 20-centimeter layeras total N increased and pH decreased. Authors suggest monitoring base status of...

This report is a comprehensive compilation of information on western redcedar (Thuja plicata Donn) - its occurrence and abundance; associated plant species; morphology and anatomy; products; medical aspects; diseases; insect, bird, and mammal. pests; genetics; horticulture; physiology; ecology; mensuration; and silviculture. Management recommendations and an extensive list of references are included.

This paper reviews procedures for establishing and maintaining permanent plots for silvicultural and yield research; discusses purposes, sampling, and plot design; points out common errors; and makes recommendations for research plot designs and procedures for measuring and recording data.

Regression equations are presented for estimating biomass of five western hardwoods: red alder (Alnus rubra Bong.), giant chinkapin (Castanopsis chrysophylla (Dougl.) A. DC.), bigleaf maple (Acer macrophyllum Pursh), Pacific madrone (Arbutus menziesii Pursh), and tanoak (Lithocarpus densiflorus (Hook. & Arn.) Rehd.). Estimators are given for total crown biomass, cumulative proportions for separating crown weight into foliage and four timelag fuel diameter classes, bark weight, and bole volume (inside bark) to any specified top diameter. With one exception, the equations use diameter at...

A survey in the Blue Mountains of north-eastern Oregon and southeastern Washington showed that, on the average, partial cuts in the grand fir/big huckleberry community were well stocked with a mixture of advance, natural post-harvest, and planted reproduction of a number of species. Partial cuts in the mixed conifer/pinegrass community had considerably fewer seedlings; some plots were understocked. Much of the understocking appeared to be related to low and irregular overstory density, lack of advance reproduction, reproduction destroyed by logging, and heavy grass cover.

Twenty-two forages from Admiralty Island, southeastern Alaska, were monitored bimonthly for one year to assess seasonal changes in their chemical composition: neutral detergent fiber, acid detergent fiber, cellulose, lignin/cutin, invitro dry-matter digestibility, total nitrogen, phosphorus, potassium, calcium, magnesium, sodium, copper, manganese, iron, and zinc. Seasonal fluctuations were pronounced but generally paralleled the pulse of plant growth in spring-summer. Only minor differences were found in chemical composition of forages from two study areas and results of this study did...

Logging-damage surveys and tree-dissection studies were made in commercially thinned, naturally established young-growth true fir stands in the Lassen National Forest in northern California. Significant damage occurred to residual trees in stands logged by conventional methods. Logging damage was substantially lower in stands thinned using techniques designed to reduce injuries from felling and skidding. A total of 243 wounded white and red firs in 11 stands were felled, dissected, and analyzed for decay. All wounds were infected by decay fungi. Decay losses associated with wounds were 6.8...

A growth-simulation model for central Oregon lodgepole pine (Pinus contorta Dougl.) has been constructed by combining data from temporary and permanent sample plots. The model is similar to a conventional yield table with the added capacity for dealing with the stand-density variable. The simulator runs on a desk-top computer.