Download or read book The Influence of Dense Understory Shrubs on the Ecology of Canopy Tree Recruitment in Southern Appalachian Forests written by Colin Mitchell Beier and published by . This book was released on 2002 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Suppression of canopy tree recruitment beneath rapidly spreading thickets of Rhododendron maximum L. (Ericaceae) in southern Appalachian forests is an issue of major concern because of the potential impacts on forest productivity, hydrology and wildlife habitat. Many studies have investigated the causes of seedling inhibition beneath dense shrub understories, but few have uncovered specific mechanisms leading to seedling decline. In this study, I have examined the influence of the evergreen understory (R. maximum and Kalmia latifolia L.) on tree recruitment processes at multiple stages - seed rain, seed bank, and post-establishment seedling growth and survivorship. Effects of dense shrub cover on seed rain and seed bank density and composition were examined using a paired treatment design in which samples were collected beneath shrub-influenced and open understories. A second experiment investigated the influence of R. maximum and K. latifolia density on the growth and survivorship of Quercus seedlings, resource availability, and the rates/causes of seedling damage. I found that neither seed rain, nor seed bank density or species richness was inhibited by the presence of R. maximum or K. latifolia. Forest seed banks were dominated by sweet birch (Betula lenta L.), and were compositionally disparate from the overstory. Analysis of resource competition between shrubs and seedlings indicated that seedling performance and survivorship was a negative function of R. maximum density. Open-canopy light availability, nitrogen content in the organic horizon (litter and humus), and soil nutrient availability were potential resource-related mechanisms. Further, I found that the rates of insect herbivory on Quercus seedlings were positively correlated with R. maximum density. Kalmia latifolia had little influence on resource availability, seedling performance or herbivory rates, and does not appear to have a suppressive effect on tree seedlings. Overall, this research indicates that resource competition is the primary mechanism by which seedling suppression occurs beneath R. maximum, and that increased herbivory on seedlings may be an additional mechanism that demands further study.
Download or read book Proceedings of the Biennial Southern Silvicultural Research Conference written by and published by . This book was released on 2001 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book General Technical Report Southern Research Station written by and published by . This book was released on 2004 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book General Technical Report SRS written by and published by . This book was released on 2004 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Practice of Silviculture written by Mark S. Ashton and published by John Wiley & Sons. This book was released on 2018-03-19 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most up-to-date, comprehensive resource on silviculture that covers the range of topics and issues facing today’s foresters and resource professionals The tenth edition of the classic work, The Practice of Silviculture: Applied Forest Ecology, includes the most current information and the results of research on the many issues that are relevant to forests and forestry. The text covers such timely topics as biofuels and intensive timber production, ecosystem and landscape scale management of public lands, ecosystem services, surface drinking water supplies, urban and community greenspace, forest carbon, fire and climate, and much more. In recent years, silvicultural systems have become more sophisticated and complex in application, particularly with a focus on multi-aged silviculture. There have been paradigm shifts toward managing for more complex structures and age-classes for integrated and complementary values including wildlife, water and open space recreation. Extensively revised and updated, this new edition covers a wide range of topics and challenges relevant to the forester or resource professional today. This full-color text offers the most expansive book on silviculture and: Includes a revised and expanded text with clear language and explanations Covers the many cutting-edge resource issues that are relevant to forests and forestry Contains boxes within each chapter to provide greater detail on particular silvicultural treatments and examples of their use Features a completely updated bibliography plus new photographs, tables and figures The Practice of Silviculture: Applied Forest Ecology, Tenth Edition is an invaluable resource for students and professionals in forestry and natural resource management.
Download or read book The Herbaceous Layer in Forests of Eastern North America written by Frank Gilliam and published by Oxford University Press. This book was released on 2014-04 with total page 689 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive existing volume of multidisciplinary research by top ecologists on the herbaceous layer of forests.
Download or read book Influence of Land use Change on the Long term Persistence of Forest Understory Herbs in the Southern Appalachian Highlands written by Jennifer M. Fraterrigo and published by . This book was released on 2005 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Eleventh Biennial Southern Silvicultural Research Conference written by Kenneth W. Outcalt and published by . This book was released on 2002 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 2005-03 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understory Herb and Shrub Responses to Root Trenching Pre commercial Thinning and Canopy Closure in Douglas fir Forest of the Western Cascades Oregon written by Briana C. Lindh and published by . This book was released on 2003 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines factors limiting understory herb presence and flowering in young second-growth Douglas-fir (Pseudotsuga menziesii) forests on the west side of the Cascade Mountains, Oregon, USA. I studied the belowground effects of canopy trees on understory herbs and shrubs in old-growth forests using trenched plots from which tree roots were excluded. Effects of tree density and stand age were tested by comparing the understory community composition of old-growth stands and pre-commercially thinned and unthinned young second-growth stands. I also examined the effect of conifer basal area on understory herb presence and flowering within one young second-growth watershed. In young stands, I focused on three groups of understory herb species: disturbance-responsive (release), forest generalist and old-growth associated. The effects of root trenching on vegetation and soil moisture were tested in closed-canopy and gap locations in two old-growth Douglas-fir (Pseudotsuga menziesii) forests. Ten years after installation, trenched plots averaged 92% total understory cover while untrenched plots averaged 47% cover. Trenched plots under closed canopies were moister than control plots throughout the growing season; the trenching effect on soil moisture became apparent in the generally wetter gaps only at the end of the growing season. Vegetation responses to trenching were concomitantly larger under closed canopies than in gaps. Stands that had been pre-commercially thinned 20 years earlier exhibited understory composition more similar to old growth than did unthinned stands. Thinned stands exhibited higher frequencies, abundances and density of flowering of old-growth associated herbs than did unthinned stands, but lower than did old-growth stands. Forest generalist and release species showed mixed responses to thinning. I used both general linear models and classification and regression tree models to explore the association of herb species presence and flowering with conifer basal area and abiotic variables. Both modeling approaches yielded similar biological insights. Flowering was more sensitive than presence to current stand basal area. Flowering of old-growth associated and release species was negatively correlated with conifer basal area. Linear models allowed clearer hypothesis tests, while tree-based models had greater explanatory power and provided information about interactions between variables.
Download or read book Long Term Response of a Forest Watershed Ecosystem written by Wayne T. Swank and published by Oxford University Press. This book was released on 2014-04 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: A long-term study of the effects of clearcutting on forest and stream ecosystems.
Download or read book The Influence of Tree Cover and Shade Pattern Upon the Distribution of Understory Plants in Ponderosa Pine Stands of Central Oregon written by Andrew Frederick Robinson (jr) and published by . This book was released on 1967 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven sites of uniform topography and soil were selected within a self perpetuating ponderosa pine forest found on the eastern flank of the central Oregon Cascades. These plots were located along a vegetational gradient caused mainly by an orographic rain shadow. Data gathered included density, frequency, and cover for all understory species, amount of direct overhead tree cover, and amount of shade cast by the tree canopy. An attempt was made to relate the distributional pattern of understory species to influences caused by shade, overhead tree cover, and shrub cover within each pIot. The Dfd index and Cole's index were statistical methods used to correlate the herbaceous species pattern to overhead tree cover, shrub cover, and shade. Of the two, Cole's index appeared to be a more sensitive tool for this study. All the shrub species with the exception of Purshia tridentata showed a consistent distributional pattern to insolation. The position along the vegetational gradient appeared to be related with the shrub's affinity for an insolation class. Those shrubs restricted to the mesic end of the gradient showed an affinity for Iow insolation or deep shade. Conversely, those shrubs occurring on the xeric end showed an affinity for higher insolation. Those shrubs found in the center of the gradient showed an affinity for moderate insolation. Ten herbaceous species out of a total of 16 observed showed apparent affinities for a certain microhabitat within the stand. Plot location, shade, overhead vertical crown cover, and shrub cover influenced the distribution of herbaceous species within the plot. Species found within mesic plots showed a weak affinity for cover, but those on xeric plots showed a strong affinity for cover. A weak indication of the spatial ecological niche was gained for 15 herbaceous species, but a strong indication was observed for Trientalis latifolia. Similarly, some insight into the ecological performance of the species was gained in regard to insolation. Usually the plot location coincided with the species' affinity for an insolation class. If the species occurred mainly on the mesic end of the gradient, it showed an affinity, for deep shade (Lupinus caudatus, Fragaria virginiana, Trientalis latifolia, and Pteridium aquilinum). If the species occurred mainly on the xeric end of the gradient, it showed an affinity for high insolation (Viola purpurea, Carex inops, and Madia minirna). Five species showed some affinity for moderate insolation (Clarkia rhornboidea, Eriogonurn urnbellaturn, Kelloggia galioides, Mimulus nanus, and Stipa occidentalis), but the correlation with plot location was less clear. Four species (Festuca idahoensis, Sitanion hvstrix, Achillea rnillefoliurn, and Lathvrus lanswertii) were not restricted to any part of the gradient. These species showed preference to insolation with the plot, but this preference was not usually the same throughout the gradient. Indications of the limits of ecological potential were found for some of these species, in particular Achillea millefolium which did not occur on any plot where insolation was less than 10%.
Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 2005 with total page 788 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Deciduous Tree Representation on Understory Plant Communities in Pacific Northwest Forests written by Dano Holt and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: While broadleaf deciduous trees are historically a consistent component of forest canopy composition, the ecological importance of these trees has been understudied, in particular their impact on understory plant communities. Broadleaf deciduous trees are a unique source of functional diversity in the Pacific Northwest's conifer dominated forests, and have been shown to alter soil nutrients, precipitation reaching the forest floor, epiphytic communities and provide critical habitat for a number of dependent wildlife species. However, their impact on understory plant communities has remained understudied. In particular, as one of the key functional differences in coniferous and broadleaf trees in the Pacific Northwest is a deciduous leaf habit which increases light transmission in the fall through winter, their impact on light availability to the understory has remained under investigated. It was hypothesized that understory plants growing beneath deciduous trees would be exposed to more light. This study investigated understory plant communities growing under overstory canopies of highly coniferous, low deciduous or highly deciduous compositions. Hypotheses were that 1) understory plant communities will differ significantly from communities under stands with differing overstory percent deciduousness, and that there would be changes to understory plant community diversity and 2) commonly occurring generalist species be acclimated to higher light availability in terms of functional traits, including specific leaf area (SLA), leaf area (LA), rachis angle (in Polystichum munitum), light compensation point (LCP), light response curves, saturation point (K) and intrinsic water use efficiency (iWUE). Understory community composition sampling indicated that canopy composition type had a significant effect on understory community, as indicated by a PERMANOVA test. Additionally, there were a number of species that only occurred under either highly coniferous or highly deciduous canopies. Results from functional trait sampling indicated that for the majority of traits generalist species including Acer circinatum, Berberis nervosa and Polystichum munitum exhibited changes to functional traits indicating that highly deciduous plots were higher light plots. Not only were understory communities growing under highly deciduous canopies significantly differ from those growing beneath low deciduous or highly coniferous canopies, but there were changes to morphology and physiology of plants under differing canopy types. These results suggest that broadleaf deciduous trees in the Pacific Northwest have a functional impact on heterogeneity of the understory environment and consequently the understory plant communities. These results imply that broadleaf deciduous trees play an important role in structuring forests in the Pacific Northwest, and their impact should be assessed in both forest management and conservation purposes.
Download or read book Ecology written by and published by . This book was released on 1989 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publishes essays and articles that report and interpret the results of original scientific research in basic and applied ecology.
Download or read book A Field Guide to the Trees and Shrubs of the Southern Appalachians written by Robert E. Swanson and published by JHU Press. This book was released on 1994-03 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the title suggests this is a guide to plants in a limited geographic range, the plants here are found in many areas of eastern North America, and the book can therefore be used as a guide for this larger area. But for naturalists visiting the beautiful area of the Southern Appalachians, it is a detailed and useful guide to the amazing variety of trees, shrubs, and woody vines growing there. "For naturalists visiting the beautiful area of the Southern Appalachians, it is a detailed and useful guide to the amazing variety of trees, shrubs, and woody vines growing there."-American Reference Books Annual
Download or read book COVER written by Melinda Moeur and published by . This book was released on 1985 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The COVER extension to the Stand Prognosis Model predicts tree canopy closure, crown volume, crown profile area, and foliage biomass within vertical height classes, and the probability of occurrence, height, and cover of shrubs in forest stands. The model may be used to produce a descriptive summary of a stand at the time of inventory, or to project overstory and understory characteristics through time for natural and managed stands. This paper documents use of the COVER program, an adjunct to Version 5.0 of the Prognosis Model. Preparation of input, interpretation of output, program control, and model characteristics are described. Potential applications of COVER estimates to wildlife, hydrology, and insect pest modeling are presented.
