No abstract

We investigated soil compaction and hydrologic responses from mechanically shredding Utah juniper (Juniperus ostesperma [Torr.] Little) to control fuels in a sagebrush/bunchgrass plant community (Artemisia nova A. Nelson, Artemisia tridentata Nutt. subsp. wyomingensis Beetle & Young/Pseudoroegneria spicata [Pursh] A. Lö ve, Poa secunda J. Presl) on a gravelly loam soil with a 15% slope in the Onaqui Mountains of Utah. Rain simulations were applied on 0.5-m 2 runoff plots at 64 mm ? h 21 (dry run: soil initially dry) and 102 mm ? h 21 (wet run: soil initially wet). Runoff and sediment were collected from runoff plots placed in five blocks, each containing four microsites (juniper mound, shrub mound, vegetation-free or bare interspace, and grass interspace) with undisturbed or tracked treatments for each microsite type and a residue-covered treatment for grass and bare interspace microsites. Soil penetration resistance was measured at the hill slope scale, and canopy and ground cover were measured at the hill slope and runoff plot scale. Although shredding trees at a density of 453 trees ? ha 21 reduced perennial foliar cover by 20.5%, shredded tree residue covered 40% of the ground surface and reduced non-foliar-covered bare ground and rock by 17%. Tire tracks from the shredding operation covered 15% of the hill slope and increased penetration resistance. For the wet run, infiltration rates of grass interspaces were significantly decreased (39.8 vs. 66.1 mm ? h 21) by tire tracks, but infiltration rates on juniper mounds and bare interspaces were unchanged. Bare interspace plots covered with residue had significantly higher infiltration rates (81.9 vs. 26.7 mm ? h 21) and lower sediment yields (38.6 vs. 313 g ? m 22) than those without residue. Because hydrologic responses to treatments are site-and scale-dependent, determination of shredding effects on other sites and at hill slope or larger scales will best guide management actions.

PositionThe Intermountain Society of American Foresters promotes management of PinyonJuniper 1 (PJ) forests and woodlands for a variety of resource benefits. In some cases it will mean managing pinyon and juniper ecosystems for sustained woodland habitat and products where these species are the persistent and dominant vegetation type. In some cases this will mean removal of pinyon and juniper to favor other vegetation types where PJ has expanded into other ecotypes. In many cases it will mean managing for a mosaic of vegetation types and stand densities within the same watershed.Appropriate forest management and sound silvicultural tools should be used in PJ ecosystems to manage and sustain such systems in a healthy ecological condition while providing many values and benefits.Management goals for PJ forests and woodlands vary and are determined through a variety of land management planning processes for private, state and federally owned lands.Land managers are responsible for selecting appropriate, site-specific practices to accomplish the desired conditions. Professional foresters have experience and research to support effective use of silvicultural practices in PJ ecosystems. Skillful use of silvicultural practices, carefully attuned to the desires and needs of the landowner and to the ecology of the site, can more rapidly achieve and better maintain desired resource conditions with greater assurance of success than will acceptance of un-managed processes of change.Foresters must have the support of decision-makers to use silvicultural practices to improve ecological conditions and to manage vegetation for a variety of goals, including when hazardous fuel build-up poses risks to landscapes. Land managers are expected and encouraged to use professional knowledge, experience, and judgment to improve the health, productivity, and condition of PJ ecosystems for the benefit of humans, wildlife, and the health of the land for today and for future generations. 1 The PJ cover type, its distribution, and the species that compose it are described by Larson, Forest Cover Type 239, Pinyon-Juniper, pages 116-117 in Eyre, 1980.

No abstract

No abstract