Download or read book Edge Effects of Clearcut Harvesting on Ground Arthropod Species Composition and Predator Community Structure in Old growth Douglas fir Forests written by Timothy Theron Work and published by . This book was released on 2000 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edge effects resulting from forest fragmentation are likely to alter the distributions and interactions of resident species. I evaluated changes in species composition, species turnover, and relative abundance of ground arthropods across replicated transects extending from regenerating clearcuts into old-growth Douglas-fir forests. Arthropods were collected from 3-August to 14-September in 1997 and 23-May 1998 to 31-July 1998 using pitfall traps. Pitfall traps were positioned at 75 m (in the clearcut), -25, 0 (forest edge), 50, 100 and 200 m into the forest in 1997. In 1998, traps were repositioned at 25, 0, 25, 50,lOO, and 200 m into the forest. Changes in species composition and relative abundance were compared using non-metric multidimensional scaling ordination. Two-hundred, five species representing 24,178 individuals were collected. Edge effects on species composition and relative abundance were apparent up to 100 m into old-growth forests. Species were characterized as edge-phobic (interior forest associates), edge-philic, edge-insensitive or as edge-input (clearcut associates). The majority of species were characterized as either edge-phobic or edge-input species. Seasonal patterns in activity are also reported. To further address the impacts of edges on community structure, changes in species abundance of predator taxa across the edge-forest gradient were compared to four models of resource partitioning. Observed patterns of species abundance did not differ across the edge-forest gradients and were consistent with a model of random assortment (or non-equilibrium) where an individual predator species utilizes resources independently of other predators. This pattern was consistent whether species abundance was expressed as numerical abundance or biomass. This study suggests that edge effects resulting from forest fragmentation alter species composition and may negatively affect interior forest species. Furthermore, although species composition changes across forest edges, this study suggests that resource partitioning by a trophic group such as predators remains unaffected by forest edges.

Download or read book Rogue River Siskiyou National Forest N F Ashland Forest Resiliency written by and published by . This book was released on 2008 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2000 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1999 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Correlation Between Structural Heterogeneity and Arthropod Biodiversity written by Stephanie Lee Madson and published by . This book was released on 1998 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The "old-growth controversy" in the Pacific Northwest recognized thinning as the primary silvicultural practice for land managers to produce wildlife habitat while continuing to produce timber. For the foreseeable future, forest stands will be harvested to produce forest gaps and a patchwork of trees of different ages. In order to evaluate the effect of thinning on biodiversity, nine 15-year-old harvests of this type (age=70 years) were paired with adjacent old-growth and even-aged, unthinned "pole" stands. Since soil is the crucible of terrestrial biodiversity, it is critical to contrast the effects upon the forest floor of this future practice with current management. Soil and litter fauna were monitored along 250 meter transects (pitfall and Berlese sampling at ten-meter intervals) to meet the following objectives: 1) to determine biological diversity on public lands, per federal mandate, and use diversity as a management tool; 2) compare levels of biodiversity between three management strategies; 3) determine best methods to assay arthropod diversity; and 4) identify structural and environmental determinants of arthropod diversity and abundance. The study's hypotheses were: 1) old-growth forests will have greater arthropod diversity than thinned stands; 2) thinned stands will have greater arthropod diversity than unthinned stands; and 3) species found within old-growth stands, but not within unthinned pole stands, will also be found in thinned stands. This study contrasted nine Western Hemlock/Douglas-fir sites each with contrasting old-growth, thinned and unthinned pole management stands. Sites were equally blocked in Southern Oregon, the Coast Range, and the Cascade Mountains. No segment of the arthropod fauna. (i.e., pitfall-trapped epigeic macroarthropods, Berlese-extracted litter-dwelling meso- and microarthropods, or soil-dwelling microarthropods) exhibited a management (treatment) effect throughout the entire region. When the regional blocking was removed, within-region analysis generally revealed that old-growth was most distinct. Old-growth stands had the highest abundance of individuals, but were comprised of the fewest species. Thinned stands were characterized by the highest species richness. Within-region analysis revealed an interaction of management effects and specific locale effects; locale effects dominated for soil microarthropods and epigeic macroarthropods, while management options dominated for litter arthropods. Within the Southern Oregon region, I attempted to correlate arthropod community structure (canonical correspondence analysis (CCA) of within-stand samples) with a suite of soil chemical and microbiological descriptors. Full analysis of twelve variables within one exemplary stand revealed several potential trends (negative: dissolved organic carbon, soil moisture, distance from the beginning of the transect; positive: total CO2 field respiration, mineralizable nitrogen, water-induced respiration, substrate-induced respiration). Relatively shallow slopes and very low r-value coefficients of correlation characterized all statistical tests. Few of the trends apparent at one site were paralleled at more than one other site; at all sites potential correlates had very low r-values. No community revealed separate clouds in CCA analysis, indicating distinct "micro-communities" of arthropods inhabiting distinct micro-habitats. Lack of distinctive species assemblages and lack of correlation with microhabitat variables indicated that arthropods respond on different temporal and/or spatial scales then the microbial-oriented variables, and that each taxon is responding in an individual manner.

Download or read book Relations of Native and Exotic Species 5 Years After Clearcutting with and Without Herbicide and Logging Debris Treatments written by David Peter and published by . This book was released on 2012 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: To increase timber production and manage other forest resource values, some land managers have undertaken logging debris and vegetation control treatments after forest harvest. We explored the roles of clearcutting on plant community composition and structure at three sites where logging debris was dispersed, piled, or removed and vegetation was annually treated or not treated with herbicides for 5 years. Without vegetation control, a competitive relation was identified between exotic and native ruderal (i.e., disturbance-associated) species. When exotic ruderal cover changed by 4 percent, native ruderal cover changed by 10 percent in the opposite direction. This relation was independent of site, but site was important in determining the overall dominance of ruderals. Five annual vegetation control treatments increased Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) growth, but decreased richness and cover of other species at the rate of one species per 10 percent reduction in cover. Debris treatment effects were small and found on only one site.

Download or read book Effects of Silviculture Systems on Arthropod Community Structure written by B Lindgren (Staffan) and published by . This book was released on 1999 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Relations of native and exotic species 5 years after clearcutting with and without herbicide and logging debris treatments written by David Peter and published by . This book was released on 2012 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: To increase timber production and manage other forest resource values, some land managers have undertaken logging debris and vegetation control treatments after forest harvest. We explored the roles of clearcutting on plant community composition and structure at three sites where logging debris was dispersed, piled, or removed and vegetation was annually treated or not treated with herbicides for 5 years. Without vegetation control, a competitive relation was identified between exotic and native ruderal (i.e., disturbance-associated) species. When exotic ruderal cover changed by 4 percent, native ruderal cover changed by 10 percent in the opposite direction. This relation was independent of site, but site was important in determining the overall dominance of ruderals. Five annual vegetation control treatments increased Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) growth, but decreased richness and cover of other species at the rate of one species per 10 percent reduction in cover. Debris treatment effects were small and found on only one site.

Download or read book Forest Macro arthropods as Potential Indicators of Ecosystem Conditions in Western Idaho written by Margaret E. Ruby and published by . This book was released on 2001 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adaptive ecosystem management is a new paradigm for managing federal forests which requires regular monitoring of ecosystem function and diversity to measure the effects of management. Managers need new strategies and tools to help them assess their progress in maintaining healthy, productive and biologically diverse forests. Biomonitoring of select forest macro-arthropod species can provide useful information on the effects of management on forest biodiversity and ecosystem function. The purpose of this study was threefold: (1) to inventory the macro-arthropod community and important environmental variables in the Bear Creek and Indian Creek study area within the Payette National Forest (PNF) in Western Idaho; (2) to compare measures of community composition, diversity, and structure in forest macro-arthropod communities between patches of different sizes and treatment; and (3) to assist PNF managers in their ecosystem management efforts by providing principles to guide the use of macro-arthropods as indicators of changing forest conditions. Transects with pitfall traps were used to collect macro-arthropods at 22 sites in the Bear Creek and Indian Creek study area during the summer of 1994. Five forest patch types in Abies grandis habitat types were sampled. Intact forest patches of 100 or more hectares, and large patches of 50-100 hectares, ranged in age between 50 and 250 years old with multistoried structure. Small patches up to 10 hectares were remnants or fragments of formerly intact forest isolated by logging. A plantation patch was 15 years old with patchy understory and forb cover. Clearcut patches had little or no overstory, and variable understory, and forb layers. At each transect, soil samples were collected and six environmental descriptor variables were analyzed according to patch treatment and patch size. These site descriptors were: basal area (ft2/acre); percent canopy cover for the overstory, understory; and forb layers; litter depth (cm), and percent soil moisture content. Differences detected using an ANOVA and T-tests are discussed in the Results section. Arthropod community composition, diversity, and structure were described according to relative abundance, and four measures of diversity. They were also described by membership in seventeen orders and/or super-families; ten functional groups; two disperser classes (long or short distance); and three species indicator classes. A total of 5455 macro-arthropod individuals, representing 17 orders and/or super-families and 219 species were collected in the Bear Creek and Indian Creek study area. While macro-arthropod fauna relative abundance did not vary significantly by treatment (ANOVA p

Download or read book Changes in Macromoth Community Structure Following Deforestation in Western Washington State written by Matthew R. Fisher and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timber management, especially clear-cut logging, dramatically alters forest ecosystems. In temperate conifer forests of the Pacific Northwest, succession following deforestation is a slow process, lasting several decades for early and mid-successional stages and several hundred years for late maturity and old growth stages. Despite the history of logging in the region and the importance of these forests to wildlife, it is not well understood how animal communities respond to forest disturbance, particularly over successional gradients. In this study, I examined the response of macromoth communities to habitat change in western Washington State by sampling moths along a chronosequence of previously-logged sites and by making comparisons to moth communities in old growth areas. Based on previous research on moths in a variety of forest ecosystems, I expected to find that abundance, species richness, and diversity would all be lowest in recently-logged sites but would increase with stand age. I also predicted that the proportion of rare and unique species (species occurring at only one site) would increase with stand age, as would the number of specialist feeders, but I expected the relative abundance of pests and non-natives to decrease with increasing stand age. I found that moth abundance increased with stand age among previously-logged sites, while average species richness and diversity (measured by the alpha index) were greater in old growth areas for both observed and sample size-corrected values. Based on rarefaction curves, it was evident that sample sizes were not large enough to attain a firm measure of total species richness at each site, but a modest increase in sampling effort may be sufficient to achieve this in some sites. Shifts in community structure were detected by analyzing proportions of species and individuals within functional groups. For example, the relative abundance of generalist feeders and pest species decreased with increasing stand age, while the proportion of oligophagous and conifer-feeding individuals increased with stand age. In old growth sites, the average proportion of specialist feeding species was greater than in previously-logged sites. The effects of deforestation were most pronounced in stands less than 10 years old. Moth communities at these sites had distinct community structure and species assemblages. Despite the large differences among very young sites, moth communities in previously-logged stands increasingly resembled those in old growth forests as stand age increased for many of the community variables examined, and this similarity was generally most pronounced for the oldest previously-logged sites. The community-wide responses following deforestation suggest that moths are potentially useful indicators of habitat disturbance and quality. The geometrid subfamily Larentiinae and noctuid subfamily Xyleninae closely represented overall patterns in moth community dynamics and would likely serve well as indicators of macromoth species richness and diversity in forest stands of different ages within this region and elevation range. Specifically identifying which factors associated with stand history were responsible for the observed shifts in moth community structure was not an objective of this study. Given the important relationship between moths and their larval host plants, it is nonetheless likely that changes in plant community structure and canopy complexity during secondary succession influence macromoth communities. Further studies should address if changes to forestry practices, such as shifting from clear-cut to selective harvesting, might improve moth biodiversity by retaining aspects of plant diversity and forest structure. Based on my results, simply increasing the length of harvest rotations in these forests could result in important changes to moth biodiversity, which may have important ecological consequences for the numerous species utilizing moths as a food source. However, it appears that even after 85 - 95 years, moth communities in previously-logged sites do not fully resemble communities in old growth sites.

Download or read book Long term Effects of Clearcutting and Post harvest Herbicide Treatment on Species Composition and Stand Structure in an Upland Quercus Carya Forest in the Illinois Ozarks written by Jessica A. Yeagle and published by . This book was released on 2005 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wildlife Habitats in Managed Forests written by Jack Ward Thomas and published by . This book was released on 1979 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: That is what this book is about. It is a framework for planning, in which habitat is the key to managing wildlife and making forest managers accountable for their actions. This book is based on the collective knowledge of one group of resource professionals and their understanding about how wildlife relate to forest habitats. And it provides a longoverdue system for considering the impacts of changes in forest structure on all resident wildlife.

Download or read book The Effects of Clearcut Harvesting on Forest Soils written by American Forest Institute and published by . This book was released on 1972* with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Arthropod Communities on Understory Plants in Thinned and Unthinned Douglas fir Forests in the Oregon Coast Range written by Alyssa M. Doolittle and published by . This book was released on 2000 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study assessed the effects of thinning on arthropod communities on understory plants in the Central Oregon Coast Range. Arthropods were sampled from five understory plants in five pairs of thinned and unthinned, young (50-80 yrs), managed Douglas-fir stands, from late May to mid-July of 1998. Vine maple (Acer circinatum), salal (Gaultheria shallon), understory hemlock (Tsuga heterophylla), bracken fern (Pteridium aquilinum), and sword fern (Polystichum munitum) were sampled for arthropods using beating sheet and aspirators. Arthropod taxa were sorted and identified to family, species where possible. Intensities and diversity indices were calculated both for all arthropods (including spider taxa) and for spiders separately. Arthropods were placed into functional groups based on trophic level/feeding habits. Spiders were placed in guilds based on prey capture strategies. Collembolans, psocopterans, aphids and linyphiid spiders together made up 50% of total arthropod abundance. Spiders made up 23% of the total arthropod abundance. Functional groups overall were not found in different intensities between thinned and unthinned stands. Relative representation of spider guilds was different between thinned and unthinned stands. Cobweb weavers and nocturnal hunters had higher intensities in thinned stands. Sheetweb weavers, orbweb weavers and agile hunters had higher intensities in unthinned stands. Sap-suckers on vine maple were more abundant in unthinned stands. Parasitoids on vine maple were more abundant in thinned stands. Agile hunters on salal were more abundant in unthinned stands. Salal, especially in unthinned stands, provided important structure for spider communities. Salal supported high spider diversity. Hemlock had the highest species richness, for both arthropod and spider communities. Communities on vine maple were diverse, despite low overall arthropod abundance. The arthropod communities showed significant segregation by plant species and treatment condition. Shrub cover, shrub diversity, patch size, light levels, tree density and stand age explained arthropod community differences. Each one of the understory plants I studied supported a unique portion of the overall understory arthropod community and should be maintained in managed forests to support this important element of diversity. Differences in species distribution and structure of understory vegetation between treatments, resulting in arthropod community differences, suggests that maintenance of both treatment conditions across a landscape is important for maintaining diversity of understory arthropod communities.

Download or read book Herbaceous layer Species Composition and Dynamics in Leave Patches Before and After Clearcut Harvesting of Surrounding Forest written by Megan F. de Graaf and published by . This book was released on 2008 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecology and Conservation of Forest Birds written by Grzegorz Mikusiński and published by Cambridge University Press. This book was released on 2018-03-29 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative review of the ecology of forest birds and their conservation issues throughout the Northern Hemisphere.

Download or read book Structural and Microclimatic Edge Effects Associated with Clearcutting in a Rocky Mountain Forest written by David A. Vaillancourt and published by . This book was released on 1995 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: