Treesearch

The immature stages, feeding and oviposition behaviors, patterns of larval abundance, and associated arthropod fauna of Dasypyga alternosquarnella Ragonot (Pyralidae) on Arceuthobiurn vaginatum susp. cryptopodum (Hawks.), the Southwestern dwarf mistletoe, are described and illustrated. The study was conducted at the Manitou Experimental Forest, U.S.D.A. Rocky Mountain Research Station, Woodland Park, Colorado, where the Southwestern dwarf mistletoe parasitizes Pinus ponderosa (Laws.) scopulorum.

Fuel treatment silviculture and the resulting long-term flow of biomass were examined using data from selected western stands. An uneven-aged management regime with reserve trees was modeled, using a canopy closure of 40 percent for the dominant trees as a target and a harvest cutting cycle of 20 years. Fuel reduction treatments in currently overstocked stands resulted in an initial peak of removal for the first and second cutting cycles. Yields stabilized in subsequent cutting cycles. Removal of some large reserve trees was crucial for maintaining stand structure and fire resilience.

Detection and quantification of temporal change in spatial objects is the subject of a growing number of studies. Much of the change shown in such studies may be an artifact of location error and classification error. The basic units of these two measures are different (distance units for location error and pixel counts for classification error). The lack of a single index summarizing both error sources poses a constraint on assessing and interpreting the apparent change. We present an error model that addresses location and classification error jointly. Our approach quantifies location...

During the past 50 years the moist forests of northern Idaho changed from being dominated by western white pine (Pinus monticola), an early sera! species, to ones dominated by late serial species, grand fir (Abies grandis) and western hemlock (Tsuga heterophylla). Variable fire regimes, successional processes and endemic insects and pathogens worked in concert to produce the stable and resilient forests of the past. This conversion to late seral species would take 200 to 300 years depending on fire regime but because of the destabilizing impacts primarily from white pine blister rust...

The Interior West Resource Inventory, Monitoring, and Evaluation (IWRIME) Program of the USDA Forest Service, Rocky Mountain Research Station (formerly the Intermountain Research Station), as part of its national Forest Inventory and Analysis (FIA) duties, entered into a cooperative agreement with the Northern Region (Region 1) for the inventory of its National Forests. This report presents the highlights of the Beaverhead-Deerlodge National Forest 1997 inventory, using commonly requested variables and summaries. The data could be summarized in other ways for different purposes (see “For...

Partial cambial mortality is a growth form that is characteristic of Pinus aristata trees. To better elucidate their cambial death pattern, tree size and aspect of cambial death data were gathered from three Pinus aristata forests in central Colorado, USA. Stripping frequency tended to be higher for larger diameter classes. Partial cambial mortality exhibits significant directionality within each stand. Furthermore, cambial death was measured to be most frequent on the wind-exposed side of stripped trees in two of the three study sites and appeared to be at the third. Data presented here...

Limber pine (Pinus flexilis James) ranges in latitude from 33°N to 51°N and in elevation from 870 m above sea level (asl) in North Dakota to ~3400 m asl in Colorado (Burns and Honkala 1990). In the central Rocky Mountains, limber pine co-occurs with many tree species due to its broad elevational range (Peet 1981). Limber pine seeds are large, generally wingless, and dispersed by birds (Lanner and Vander Wall 1980). While it is known that seeds of limber pine in Colorado are eaten by animals such as Clark’s Nutcrackers (Nucifraga columbiana Wilson), black bears (Ursus americanus; McCutchen...

ECO-Report is an annual Rocky Mountain Research Station (RMRS) publication which contains a set of articles showcasing the Bitterroot Ecosystem Management Research Project (BEMRP) research projects and activities. The articles are concise, user-friendly, and designed to inform a broad range of audiences interested in ecosystem management. Articles featured in this issue: One Ranger's Experience in Summer 2000 "You couldn’t train for the scale of fires we had this year."; 2000 Southwestern Montana Wildfires The BEMRP Response; Aftermath of the Fire Storm Insights on Structure Protection;...

The use of indices to evaluate small-mammal populations has been heavily criticized, yet a review of small-mammal studies published from 1996 through 2000 indicated that indices are still the primary methods employed for measuring populations. The literature review also found that 98% of the samples collected in these studies were too small for reliable selection among population-estimation models. Researchers therefore generally have a choice between using a default estimator or an index, a choice for which the consequences have not been critically evaluated. We examined the use of a...

The western skink (Eumeces skiltonianus) was recently classified as a Montana Species of Special Concern due to its restricted range in the state (D. P. Hendricks, Montana Natural Heritage Program, Helena, MT, pers. comm.). Records of the western skink in Montana are limited to a few, scattered locations on the western edge of the state (Tanner 1988; Reichel and Flath 1995). Skinks have been documented in the Bitterroot Valley in Ravalli County (Rodgers and Jellison 1942) and on the Kootenai National Forest in Lincoln County (Werner and others 1998). In addition, there have been unconfirmed...