Treesearch

Trees successfully and unsuccessfully attacked by mountain pine beetles have several symptoms in common, so that proper diagnosis is not always easy. Guidelines presented here enable the observer to correctly distinguish nearly all attacked trees.

To facilitate debris management, procedures for inventorying downed woody material are presented. Instructions show how to estimate weights and volumes of downed woody material, fuel depth, and duff depth. Using the planar intersect technique, downed material is inventoried by 0- to 0.25-inch, 0.25- to 1-inch, and 1- to 3-inch diameter classes; and by 1-inch classes for sound and rotten pieces over 3 inches. The method is rapid and easy to use and can be applied to naturally fallen debris and to slash. The method involves counting downed woody pieces that intersect vertical sampling planes...

Logged and unlogged stands of Engelmann spruce-subalpine fir were evaluated in spruce beetle outbreak areas infested about 15, 25, 50, and 100 years ago. Seedling regeneration was generally adequate except in heavily logged areas, although seedlings were often damaged, apparently by animals. Species composition was dramatically altered in favor of fir in the unlogged spruce-fir type. In the overstory, fir may predominate for many years but eventually the spruce will replace it. When the forest reaches a basal area of 150 to 200+ ft2 per acre in predominantly large spruce, the potential for...

A negative exponential equation containing three parameters was derived to describe time trends in surface erosion on severely disturbed soils. Data from four different studies of surface erosion on roads constructed from the granitic materials found in the Idaho Batholith were used to develop equation parameters. The evidence suggests that surface "armoring" was the dominant factor causing the time trends in surface erosion. The significance of time trends in surface erosion is discussed.

This pictorial describes how western spruce budworm larvae feed on young western larch and the trees' responses to this damage. Larvae feed not only on the current year's foliage-their usual diet on most coniferous hosts-but also sever stems of current year's shoots. Multiple-topped, bushlike trees develop in direct response to the amount and type of damage. As a result, trees cannot maintain straight boles and good form. Sustained budworm damage could conceivably influence the management of western larch-one of the more important conifers in the northern Rockies.

An electronic capacitance meter was used to estimate herbage yield from sown ranges in western USA. On an area in Arizona where the grass stand had been sown broadcast, ^a r2 of 0-47 was obtained between the meter value and oven-dry weight estimate. Excluding those plots with very large amounts of standing dead organic matter (OM), or very succulent plants which bad not been sown, improved yield estimates. Tests on pastures in Colorado in which seed had been drilled and the meter tested to evaluate performance in relation to drill rows showed that a common regression could be used for...

First-year Engelmann spruce seedlings have an average rooting depth of 3.4 inches, 11 branch roots, and a total root length of 5 inches. Seedlings were field-grown on scarified shaded seedbeds in the central Rocky Mountains, Colorado.

Abscisic acid (ABA) inhibited sucker development and promoted callus formation from cambium exposed at cut ends of excised roots from two clones of trembling aspen, Populus tremuloides Michx. Clonal differences in response to ABA inhibition of sucker outgrowth appeared to be related to the developmental stage of the preexisting shoot primordia. When ABA treatment was followed about a month later by gibberellic acid, ABA inhibition was partially reversed. This is one of few investigations in which both promotive and inhibitory effects of ABA have been demonstrated simultaneously on the same...

In the United States game management objectives traditionally have focused on the maximization of game numbers using such programs as transplanting and habitat improvement (ORRRC 1962). This was a logical orientation, based on the assumption that success (game bagged) was the principal source of hunter satisfaction. The concept that sport hunting provides a wide range of human satisfactions and benefits that are independent of or only indirectly linked to success has received only limited attention (Crissey 1971).

Pulling of plants by grazing animals has been a common problem on ‘Sherman’ big bluegrass (Poa ampla Merr.) pastures in Colorado. Fertilizers were applied to individual plants in a greenhouse study to evaluate their influence on plant resistance to pullup. The fertilizer treatments were 56 kg/ha N, 56 kg/ha P, or 56 kg/ha of each element as an N+P combination. Fertilizer treatments were applied to vernalized and nonvernalized plants grown in two soils. Tensions required for pullup in the greenhouse were correlated with total root weight (r = .75**) and significantly increased with N...