Treesearch

A symposium held September 15-18,1997, in Provo, UT, and Sanpete County, UT, provided information on the ecology, management, resource values, and restoration of pinyon-juniper communities in the Interior Western United States. The conference was hosted by the USDA Forest Service, Rocky Mountain Research Station and the Utah Division of Wildlife Resources in cooperation with personnel from other agencies and organizations. Oral and poster presentations were given by scientists, land managers, and educators. Also included was a field tour to observe distribution and areas of occurrence of...

Fire history investigations were carried out in three widely separated Great Basin pinyon-juniper woodlands in east-central Nevada, southeastern Oregon and northwestern Nevada, and western Nevada. Study results suggested frequent fires on deep soils that produced an abundance of fine fuels and infrequent fires on shallow soils and rocky sites where fuels were sparse. Decades of intensive livestock grazing and successful fire suppression in pinyon-juniper woodlands have resulted in a shift from low intensity fires to high intensity fires. This shift has been the result of large increases in...

Research in the vegetation types of the Central Arizona Highlands has evolved, for the most part, from single resource evaluations (increased water yield) to evaluations that consider the multiple benefits of vegetation management treatments. The papers presented in this publication have demonstrated that vegetation can be managed to increase water yields, while providing timber, forage, recreation, wildlife, and other amenities. One question that should be asked is to what extent can the established research framework and available databases be used to meet future management-oriented...

The Salt-Verde River Basin, covering about 8.4 million acres of the Central Arizona Highlands, supplies most of the water for the Salt River Valley in addition to providing other multiple use values. Mixed conifer, ponderosa pine forests, and a portion of the pinyon-juniper woodlands predominantly occupy the higher-elevation watersheds. Chaparral shrublands occupy a wide range of elevations, experience varied annual precipitation amounts, and overlap major portions of the pinyon-juniper woodland and semidesert grassland types (figure 2). Management of these shrublands for increased forage...

Newspaper accounts of avalanche accidents from the 1860s through 1950 have been compiled, summarized, and discussed. Many of the avalanches that caused fatalities came down rather small, innocuous-looking paths. Land use planners can use historical avalanche information as a reminder of the power of snow avalanches and to assure rational development in the future.

Ten-year diameter and basal area growth were determined for partially cut stands at 4 locations. Average diameters in the partially cut plots generally increased by 1 inch or more, while average diameter in the uncut controls increased by 0.9 inches or less. Individual tree growth is discussed in relation to potential susceptibility to mountain pine beetle infestation. Basal area increases ranged from 0.9 to 1.9 ft2/acre/ yr in partially cut plots, while basal area increases in the control plots ranged from 0.4 to 1.4 ft2/acre/yr. Endemic mountain pine beetle infestations and snow breakage...

Field observations made in 1993 suggested that rodents were preying on spotted knapweed (Centaurea maculosa) seedheads, possibly targeting the gall fly larvae (Urophora spp.) which overwinter within them. I conducted a brief study to determine the cause of seedhead predation and quantify gall fly predation. Stomachs were examined from 19 deer mice (Peromyscus maniculatus) captured in the fall of 1993 and winter of 1997. All individuals had preyed upon gall fly larvae. The mean number of gall fly larvae found in 10 deer mouse stomachs in the winter of 1997 was 212.8. The minimum number of...

One of the three largest metapopulations of the western prairie fringed orchid (Platanthera praeclara) occurs on the Sheyenne National Grassland, in southeastern North Dakota. Our study was initiated in 1993 to quantify the effect of flooding on individual orchid plants. In 1993, 66 plants (33 flowering and 33 vegetative) growing in standing water were permanently marked; their status was checked at the end of the growing season in 1993 and in subsequent growing seasons (1994-1996). Most (70%) of the flowering plants persisted through the 1993 growing season. Those that did not were...

Recent reintroduction of the black-footed ferret (Mustela nigripes) in west-central South Dakota has focused new attention on black-tailed prairie dogs (Cynomys ludovicanus), because prairie dog colonies provide essential habitat for ferrets. Currently, management agencies are assessing prairie dog populations by counting active burrows, a technique that is attracting criticism. We correlated active and total burrow counts with prairie dog mark-recapture population estimates from 12 colonies located in Badlands National Park and adjacent Buffalo Gap National Grassland. We also correlated...

Forty-two white-tailed deer fawns (Odocoileus virginianus dakotensis) were captured and fitted with radio transmitters and observed from June through September 1991 and 1992 to determine diurnal bed site use in the Black Hills of South Dakota. Fawns were monitored biweekly during daylight hours and 259 bed sites were located. In addition, 301 random sites were measured for comparison. Of 31 habitat variables measured, 8 were significant to determine use by fawns for a bed site when compared with random sites. Sites used by fawns were in relatively open stands of ponderosa pine (Pinus...