Research and Publications
Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms – including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The various BSC organismal groups demonstrate several common characteristics including – desiccation and extreme temperature tolerance, production of various soil binding chemistries, a near exclusive dependency on asexual reproduction, a pattern of aerial dispersal over impressive distances, and a universal vulnerability to a wide range of human-related perturbations. With this publication, we provide literature-based insights as to how each organismal group contributes to the formation and maintenance of the structural and functional attributes of BSCs, how they reproduce, and how they are dispersed. We also emphasize the importance of effective application of molecular and microenvironment sampling and assessment tools in order to provide cogent and essential answers that will allow scientists and land managers to better understand and manage the biodiversity and functional relationships of soil crust communities.
In an empirical analysis of shaded fuelbreaks that burned during the 2014 Bald Fire (15,950 ha on the Lassen National Forest, California), we found that overall fire severity was reduced in the treated areas relative to untreated. A non-linear mixed effects model estimates that the reduction was detected more than 400 m into the treated area, greater than the standard width of the prescribed fuelbreak. Both pre- and post-fire species composition differed between treated and untreated forest, with few living stems remaining in the measured untreated areas. In the post-fire treated area, we documented a mixed conifer forest dominated by larger diameter Pinus, implying that the fuelbreak did result in a more resilient post-fire structure and composition. These results indicate that fuelbreak design may need to be wider than generally prescribed and that even during extreme fire conditions fuel treatments can result in resilient forest structures.
This study identified 16 plant communities based on plant cover from the Assessment, Inventory, and Monitoring Strategy data from the BLM (5,200 plots). We found that abundance of lichens and mosses varies among communities, but that both components of biocrusts are present in all plant communities. Biocrusts are indicators of two of these communities: one that is defined by high cover of mosses and basin big sagebrush and one that is defined by high cover of lichens and shadscale saltbush. Using non-parametric multiplicative regression, we evaluated a suite of abiotic and disturbance variables to assess the degree to which climate and soils are associated with the abundance of lichens and mosses at the regional scale. At the regional scale, soil depth and maximum vapor pressure deficit were found to be strongly associated with the abundance of lichens and January minimum temperature dictated the abundance of mosses. At the scale of plant communities, community specific metrics of soils and climate were better able to explain the abundance of biocrusts. Our demonstration of the presence of biocrusts across the western US suggests that studies on ecosystem function could include these organisms because they are present in all plant communities, maintain arguably stronger associations with climatic variation, are directly associated with soils, and contribute to ecosystem functions that are not solely maintained by vascular plants.
This study compared trends of sagebrush-obligate songbirds from the Breeding Bird Survey and sage-grouse lek counts in 2 sage-grouse populations in Wyoming from 1996–2013. Our evaluation was focused on similarities among population performance of the umbrella species and the species under that umbrella. Sagebrush-obligate songbird and both sage-grouse populations occupied habitat within and outside of protected core areas. Trends of sagebrush-obligate songbirds were not parallel or consistently similar in trajectory to sage-grouse in either core or non-core areas. Our results indicated core areas were successful at maintaining higher sage-grouse trends compared to areas not protected under the core area policy. However, sagebrush-obligate songbird trends did not follow the same pattern. This suggests that protection of only the best sage-grouse habitat may not be a sufficient conservation strategy for other sagebrush-obligate birds.
Using data collected as part of the Sagebrush Steppe Treatment Evaluation Project (SageSTEP), this guide summarizes fuel loads, vegetation cover by functional group, and shrub and tree stem density 10 years after sagebrush and pinyon-juniper reduction treatments. The data was collected at 16 study sites in Washington, Oregon, California, Nevada, and Utah, and is summarized by treatment type, region, and roups or woodland development phases based on pre-treatment vegetation. These summarized data an be used by land managers and fire behavior specialists to quickly estimate fuel loads in older treatments or to predict fuel loads 10 years after a potential treatment. These fuel loading data can be used to create custom fuel beds to model fire behavior and effects.
In this issue:
- Fuels Guide for Sagebrush and Pinyon-Juniper Reduction Treatments: 10 years post-treatment
- Biological soil crusts as restoration targets in sagebrush steppe and woodland communities
Keys to greater sage-grouse management are maintenance of expansive stands of sagebrush, especially varieties of big sagebrush with abundant forbs in the understory, particularly during spring; undisturbed and somewhat open sites for leks; and healthy perennial grass and forb stands intermixed with sagebrush for brood rearing. Within suitable habitats, areas should have 15–25% canopy cover of sagebrush 30–80 cm tall for nesting and 10–25% canopy cover 40–80 cm tall for brood rearing. In winter habitats, shrubs should be exposed 25–35 cm above snow and have 10–30% canopy cover exposed above snow. In nesting and brood-rearing habitats, the understory should have at least 15 percent cover of grasses and at least 10 percent cover of forbs greater than or equal to 18 cm tall. Greater sage-grouse have been reported to use habitats with 5–110 cm average vegetation height, 5–160 cm visual obstruction reading, 3–51% grass cover, 3–20% forb cover, 3–69 percent shrub cover, 7–63% sagebrush cover, 14–51% bare ground, and 0–18% litter cover. Unless otherwise noted, this account refers to habitat requirements and environmental factors affecting greater sage-grouse but not Gunnison sage-grouse. Habitats used by Gunnison sage-grouse are generally similar to habitats used by Greater Sage-Grouse, but some differences have been reported. The greater sage-grouse is a game bird and is hunted throughout most of its current range. This account does not address harvest or its effects on populations; rather, this account focuses on the effects of habitat management.
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Abstracts of Recent Papers on Range Management in the West. Prepared by Charlie Clements, Rangeland Scientist, USDA Agricultural Research Service, Reno, NV
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This example features development of a post-fire assessment field guide to aid treatment and management planning in burned areas.
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This example features a training program that has extended beyond one student and classroom to involve a team of learners and multiple classrooms.