EFFECTS OF MECHANICALLY GENERATED SLASH PARTICLE SIZE ON PRESCRIBED FIRE BEHAVIOR AND SUBSEQUENT VEGETATION EFFECTS

Forest managers have begun to restore ecosystem structure and function in fire-prone ecosystems that have experienced fire exclusion, commodity based resource extraction, and extensive grazing during much of the 20th century. Mechanical thinning and prescribed burning are the primary tools for thinning dense stands and restoring pre-settlement forest structure, reducing the likelihood of devastating crown fires. Mechanical thinning can be costly when trees are nonmerchantable and prescribed burning can be risky unless fuel loadings are first reduced. Furthermore, stands that remain dense after commercial thinning can produce undesirable wildland fire- or even prescribed fire- effects on vegetation and soils. Land managers are interested in using mastication equipment (Fig. 1) for thinning nonmerchantable trees as a means of restoring structure and function to dry forest ecosystems. However, it is unknown how the addition of mechanically derived slash influences potential fire behavior and fire effects. The objectives of this project were to test the effectiveness of mastication effort (defined as time needed to break fuels into smaller pieces) to 1) thin dense stands of dry coniferous forest within historically frequent, low-severity fire regimes (Fig. 1) and 2) create surface fuel beds that produce prescribed fire behavior with positive effects on residual trees, understory vegetation, and soils. Specifically, we asked the following questions: (1) How does slash particle size and fuel bed depth affect fire intensity and severity? (2) How do different mastication efforts and subsequent prescribed fire affect overstory vegetation? (3) Does soil heating change from burning different types of masticated slash? and (4) What are the differences in production costs among levels of mastication effort

The National Fire and Fire Surrogate Study: Effects of Fuel Reduction Methods on Forest Vegetation Structure and Fuels

Changes in vegetation and fuels were evaluated from measurements taken before and after fuel reduction treatments (prescribed. re, mechanical treatments, and the combination of the two) at 12 Fire and Fire Surrogate (FFS) sites located in forests with a surface. re regime across the conterminous United States. To test the relative effectiveness of fuel reduction treatments and their effect on ecological parameters we used an information-theoretic approach on a suite of 12 variables representing the overstory (basal area and live tree, sapling, and snag density), the understory (seedling density, shrub cover, and native and alien herbaceous species richness), and the most relevant fuel parameters for wild. re damage (height to live crown, total fuel bed mass, forest floor mass, and woody fuel mass). In the short term (one year after treatment), mechanical treatments were more effective at reducing overstory tree density and basal area and at increasing quadratic mean tree diameter. Prescribed. re treatments were more effective at creating snags, killing seedlings, elevating height to live crown, and reducing surface woody fuels. Overall, the response to fuel reduction treatments of the ecological variables presented in this paper was generally maximized by the combined mechanical plus burning treatment. If the management goal is to quickly produce stands with fewer and larger diameter trees, less surface fuel mass, and greater herbaceous species richness, the combined treatment gave the most desirable results. However, because mechanical plus burning treatments also favored alien species invasion at some sites, monitoring and control need to be part of the prescription when using this treatment

The effect of invasive and noxious plants on land management in Eastern Oregon and Washington

A key issue for forest and rangeland health and productivity in eastern Oregon and Washington, USA is invasive species. Although some exotic plant introductions were accidental, many were intentional for wildlife habitat improvement, ornamental purposes, wood or fibre production, soil conservation, livestock forage production, or other crop uses. Exotic species, or weeds, can be a significant component of global environmental change because of their potential to alter primary productivity, decomposition, hydrology, nutrient cycling, and natural disturbance regimes. At smaller scales, they alter the structure, composition, and successional pathways of ecosystems. They lower diversity by out-competing native plants. Disturbance caused by forest restoration activities (thinning and prescribed fire) can promote weed spread, but ultimately will improve native plant diversity and productivity, improving ecosystem resistance to weed invasion. Restoration strategies need to include consideration of weed prevention and control and restoration of natives. Prevention includes restoring ecosystem processes; control includes biological, manual, mechanical, herbicidal, and prescribed burning methods; restoration involves returning native plants to a site. Monitoring is important to provide managers with information that will allow them to evaluate restoration activities and modify ineffective restoration approaches

Reproduction and pollination biology of Centaurea and Acroptilon species, with emphasis on C. diffusa

Reproduction and pollination biology of Centaurea and Acroptilon species, with emphasis on C. diffus

EVALUATING THE EFFICACY AND ECOLOGICAL IMPACTS OF BAER SLOPE STABILIZATION TREATMENTS ON THE POT PEAK/DEEP HARBOR WILDFIRE COMPLEX

Post-fire slope stabilization treatments are often prescribed for severely burned areas of a wildfire, through burned area emergency response (BAER), to reduce erosion, maintain soil productivity, protect water quality, and reduce risks to human life and property. Prescribed slope stabilization treatments can include seeding of cereal grains or grasses, fertilization, mulching, and installation of physical barriers across slope contours (e.g., contour-felled logs and straw wattles). Seeding and fertilization treatments have been proposed following several high severity wildfires in the Pacific Northwest. These treatments are designed to reduce erosion by supplementing native vegetation recovery with additional populations of fast-growing species (seeding) and increasing productivity (fertilizing). Despite the widespread use of post-fire slope stabilization treatments, and rapidly increasing costs of treatment with more frequent large and severe wildfires, there is little data establishing the general effectiveness of many commonly used treatments, especially in coniferous forests (Robichaud 2000, Beyers 2004). Effectiveness monitoring is often informal and the results are not widely reported. Additionally, some treatments may interfere with natural vegetation recovery or introduce exotic species (Beyers 2004, Keeley 2004, Kruse et al. 2004). Experimental and observational studies are needed for testing the effectiveness of new, innovative treatments, while science-based effectiveness monitoring plans are needed to assess the variability in treatment effectiveness across time and space. In response to Joint Fire Sciences AFP 2005-1, Task 2, we undertook a two-year study of BAER soil stabilization treatments that assessed 1) the relative efficacy of seeding and fertilizing treatments for providing protective soil cover (live plant and litter cover), and 2) the effects of soil stabilization treatments on post-fire vegetation dynamics, including native vegetation recovery and weed population dynamics

Isozyme variation in showy stickseed, a Washington endemic plant, and relatives

Hackelia venusta, a rare plant endemic to Chelan County, Washington, USA, consists of two entities that differ most notably by flower colour and geographic location. We evaluated the hypothesis that these entities are separate species using a phenotypic analysis of isoenzyme variation to compare both forms of H. venusta with sympatric and allopatric populations of the closely related H. diffusa var. arida, and with the allopatric taxa H. diffusa var. cottonii and H. diffusa var. diffusa. Enzyme band phenotypes revealed that all populations were variable, with 60 to 80% polymorphic enzyme systems. Most variation was within population, with only 32% among population variation detected. The level of variation was moderate to high in H. venusta populations compared to other Hackelia populations. Enzyme band pattern data support the separation of H. venusta from H. diffusa. However, data do not provide evidence for the taxonomic separation of the two colour forms of H. venusta at the species level. Regardless of the taxonomic recognition of H. venusta colour forms, they should be conserved as rare extremes of Hackelia morphology and habitat preference

THE REPRODUCTIVE BIOLOGY AND HOST SPECIFICITY OF OROBANCHE PINORUM GEYER (OROBANCHACEAE)

Volume: 46Start Page: 7End Page: 1

HACKELIA TAYLORI (BORAGINACEAE), A NEW SPECIES FROM NORTH CENTRAL WASHINGTON STATE (U.S.A.)

Volume: 7Start Page: 649End Page: 65

Monitoring Biodiversity: Quantification and Interpretation

Monitoring is necessary for an adaptive management approach and the successful implementation of ecosystem management. In this document, we present an approach to monitoring biological diversity at different levels of ecological organization: landscape, community or ecosystem, population or species, and genetic. Our approach involves identifying monitoring questions derived from regional, provincial, or watershed assessments; identifying monitoring methods; and analyzing and interpreting data to integrate into management strategies. Examples of monitoring methods, data analysis, and interpretation are provided for each level of ecological organization, beginning with the most inclusive level, the landscape. Our objective is to provide land manager

Landscape Evaluation for Restoration Planning on the Okanogan-Wenatchee National Forest, USA

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