Download or read book Effects of Forest Management on Understory and Overstory Vegetation written by David R. Thysell and published by . This book was released on 2000 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Forest Management on Understory and Overstory Vegetation written by David R. Thysell and published by . This book was released on 2000 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Forest Management Impacts on Understory and Overstory Vegetation Cover Runoff and Sediment Yield in a Northern New Mexico Forest written by Onur Beyazoglu and published by . This book was released on 2015 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fire suppression techniques over the last century have increased tree densities and altered the ecological processes of montane forests within New Mexico. Alternative forest silviculture treatments might reduce wildfire risk and improve water yield and herbaceous cover. This study's goals were to 1) determine how forest silvicultural thinning treatments affect understory and overstory vegetation cover and 2) determine how forest silvicultural treatments affect runoff and sediment yield. Thinning treatments were a control, pile, innerspace (space between piles), and lop-scatter. The effect of treatments on herbaceous and overstory cover were assessed with a fixed-plot layout at treatment sites, where 2014 post-treatment results were compared to 2008 post-treatment measurements. Runoff and sediment yield were measured utilizing one-hour rainfall simulations at the runoff ring scale (1 m2). Results showed forest thinning treatments significantly impacted herbaceous vegetation cover, litter cover, bare cover, and canopy cover. In lop-scatter treatments, vegetation cover and canopy cover were higher in 2014 than in 2008. Inner-space plots showed higher bare ground cover percent than in pile and in lop-scatter areas. Litter cover from the control plots resulted in higher cover than both lop-scatter and pile plots on the gentle slopes, while on the steep slopes the cover was only higher than the pile plots. Data suggest that all thinning treatments promote increased vegetative understory cover promote increased vegetative understory cover. There was no significant difference in runoff ratio among the treatments during the dry runs; however, control sites had lower runoff ratios than inner-space, lop-scatter, and pile treatments during the wet runs. During both dry and wet runs, time to runoff initiation was greater on the pile treatments and scatter treatments compared to the control treatments. There were no differences in time to peak runoff among silvicultural treatments during simulated rainfall. During wet runs, sediment yield did not differ by treatment; however, on steep slope sites, sediment yield was higher than on gentle slopes. This study suggests that the combination of thinning and burning silvicultural treatments promotes increased vegetative understory cover; the treatments appear to delay runoff when compared to control plots.

Download or read book Demographic Patterns and Disturbance Responses of Understory Vegetation in a Managed Forest of Southern New England Implications for Sustainable Forestry and Biodiversity Maintenance written by David S. Ellum and published by . This book was released on 2007 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current interest in sustainable forestry is generating a need for an increased understanding of the effects of forest management practices on floristic diversity patterns. For U.S. forests, it is the herbaceous understory plants as a group that must be better understood physiologically and demographically if forest managers are to successfully maintain or increase biological diversity within vegetative communities. This dissertation describes a study that (1) investigates understory floristic patterns in a southern New England mixed-hardwood forest and (2) tests the ability of understory plants to adapt to full sun conditions that would accompany canopy removing disturbances.

Download or read book Effects of Variable density Thinning on Understory Diversity and Heterogeneity in Young Douglas fir Forests written by Juliann E. Aukema and published by . This book was released on 2008 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nine years after variable-density thinning (VDT) on the Forest Ecosystem Study, we examined low understory vegetation in 60 plots of eight stands (four pairs of VDT and control). We compared native, exotic, ruderal, and nonforest species richness among the stands. We used clustering, ordination, and indicator species analysis to look for distinctive patches of plant associations. Native, exotic, ruderal, and nonforest plant species diversity were higher in VDT stands compared to control stands for both forests. Differentiation of the understory into multiple distinct vegetation patches was not definitive, but there were trends toward greater heterogeneity in VDT stands.

Download or read book Understory overstory Vegetation Relationships written by Peter F. Ffolliott and published by . This book was released on 1982 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Overstory Thinning on Understory Vegetation and Stand Regeneration in a P i n u s P o n d e r o s a Forest on the Turnbull National Wildlife Refuge written by Mark John Patrick Royan and published by . This book was released on 1981 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This study ws a comparative vegetational analysis of two stands of pondrerosa pine (Pinus ponderosa) located naar the south boundary of the Turnbull National Wildlife Refuge. One stand (experimental) was thinned to approximately 6.1 meter spacing between trees during the spring and summer of 1971. Adjacent to the experimental site, a portion of the same forest was left undisturbed as a control. The objective of this study was to assess the impact of thinning on overstory, understory, and pine seedling germination and establishment according to land management policies set forth by the refuge. In the thinned site, overstory canopy as reduced 90%, species richness in the understory increased by 42%, and species diversity in the understory increased by 15% compared to the undisturbed control site. The thinned site has established juvenile pines every year since 1973, while no establishment since 1971 was observed for the control site. The most striking understory change observed in the experimental site was the increase in the native bunch- grass; Festuca idahoesis (Idaho fescue). This species was found to be approximately 25 times more abundant in the experimental site than in the control"--Document.

Download or read book Plantation Forests and Biodiversity Oxymoron or Opportunity written by Eckehard G. Brockerhoff and published by Springer Science & Business Media. This book was released on 2010-07-23 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1 Plantation forests and biodiversity: Oxymoron or opportunity? Forests form the natural vegetation over much of the Earth’s land, and they are critical for the survival of innumerable organisms. The ongoing loss of natural forests, which in some regions may have taken many millennia to develop, is one of the main reasons for the decline of biodiversity. Preventing the further destruction of forests and protecting species and ecosystems within forests have become central issues for environmental agencies, forest managers, and gove- ments. In this di?cult task science has an important role in informing policy and management as to how to go about this. So how do industrial and other pl- tation forests ?t into this? Plantation forests, comprised of rows of planted trees that may be destined for pulp or sawmills after only a few years of growth, appear to have little to c- tribute to the conservation of biodiversity. Yet there is more to this than meets the eye (of the casual observer), and there are indeed numerous opportunities, and often untapped potential, for biodiversity conservation in plantation forestry. With plantation forests expanding at a rate of approximately three million hectares per year, it is crucial to understand how plantations can make a positive contribution to biodiversity conservation and how the potentially negative impacts of this land use can be minimised. That is the topic of this book.

Download or read book Visual Impacts of Forest Management Activities written by Robert Earl Benson and published by . This book was released on 1981 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Silvicultural Treatment Impacts on Understory Trees and 20 Year Understory Vegetation Dynamics in Mature Douglas Fir Forests written by Jim E. Priebe and published by . This book was released on 2016 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Policy regarding the management of public forests has undergone a drastic shift over the past couple of decades due to the loss old-growth forests in the Pacific Northwest (PNW) of the United States. For much of the 20th century, forest management on public lands emphasized timber production through the use of even-aged management practices. There has been increasing recognition, however, that traditional even-aged management approaches are unable to support species that rely on the complex, heterogeneous structures provided by old-growth forests. In response, public forest managers have redirected their focus to developing more ecologically sustainable forests capable of meeting a broad array of objectives including an increasing emphasis on the development of late-seral and old-growth characteristics. Thinning has been identified as a promising method for promoting late-seral characteristics in managed stands. Recent long-term studies have shown that thinning stands does indeed accelerate the development of at least some late-seral structure characteristics, particularly when varying levels of thinning intensity and non-uniform retention patterns are incorporated into silvicultural prescriptions. Likewise, thinning has also shown some ability to increase the abundance of late-seral associated plant species in the understory. The impacts of thinning on vegetation dynamics are complicated by external factors such as natural disturbance events and the influence of pre-treatment vegetation on post-treatment communities. Within the context of managing for late-seral attributes, thinning is used to imitate natural disturbance processes. However, this does not preclude the occurrence of natural disturbances, which may either disrupt or compound treatment effects. Initial site conditions create another potential complication for the development of late-seral attributes by limiting the potential for change in understory communities. While some studies have shown that thinning improves late-seral plant abundance, others have found that the legacy of pre-treatment vegetation has a stronger impact on post-treatment communities. This study focused on the impacts of ice storm disturbance and pre-treatment vegetation on the understory of mature Douglas-fir forests using the ongoing Mature Forest Study (MFS), a long-term silvicultural experiment evaluating the effects of thinning and understory vegetation management treatments, as a framework. The first study examined the impact of an ice storm (glaze disturbance) on planted understory trees. Specifically, I looked at the effect of understory tree species, tree size, and overstory neighborhood environment on the type (bending, crown loss), source (ice loading, falling debris), and severity of damage experienced by planted understory trees at one of the MFS sites. Tree species, size, and overstory environment all affected the amount of understory glaze damage. Frequency and severity of damage both varied among underplanted tree species. In general, smaller trees were more prone to being bent, while larger trees were more susceptible to crown loss. The Douglas-fir component of the overstory provided enough additional sheltering that the increased risk to understory trees from falling debris was balanced by a corresponding decrease in the odds of damage by ice loading. This was not the case for the hardwood component; increasing risk of damage to understory trees from falling debris with increasing hardwood basal area drove an overall increase in the risk of understory damage as hardwood basal area increased. This study suggests that species, tree size, and overstory environment all need to be considered by managers hoping to reduce glaze damage risk to younger cohorts in multi-aged stands. The second study investigated the impacts of thinning intensity and herbicide application on the long-term (20-year post-treatment) development of understory vegetation communities on both of the MFS sites. Trends were examined with a focus on the ability of herbicide application, in concert with thinning treatments, to reduce the legacy of common pre-treatment species and promote the abundance of late-seral associates. Results indicated that both thinning intensity and herbicide application affected 20-year changes in understory plant community composition. Herbicide application was associated with a decrease in the abundance of common pre-treatment species, suggesting that it did reduce the legacy effect. However, this was not associated with any change in the abundance of late-seral species. While light thinning showed some ability to mitigate decline in late-seral species relative to higher intensity thinnings, there was no evidence of treatment interaction with herbicide application. These results suggest that while managers may be able to reduce the influence of initial site conditions on post-treatment vegetation communities, the use of herbicides offers little control over the successional trajectory of the understory. Light thinning appears to be the most effective means of increasing late-seral species abundance, although the use of herbicides to meet other management objectives is not contraindicated by the results of this study. Overall, these results suggest that the best options available to managers to both reduce glaze disturbance impacts to understory trees and hasten the development of late-seral plant communities are heavy thinning with unmanaged leave patches to provide late-seral refugia, or light thinning with gaps to provide growing space for better tree regeneration.

Download or read book Effects of Greentree Reservoir Management on Understory and Overstory Vegetation written by Robert E. Martin and published by . This book was released on 1983 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Patterns in Understory Vegetation Communities Across Canopy Gaps in Young Douglas fir Forests of Western Oregon written by Robert T. Fahey and published by . This book was released on 2005 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Canopy gap formation is a major factor contributing to maintenance of overstory species diversity and stand structure in forests and may be integral to development of understory shrub and herb layers as well. Acknowledgement of gap formation as a fundamental feature of natural forests has led to consideration of gaps as an option in forest management regimes. This study examined understory vegetation communities across canopy gaps created as a part of the Density Management Study (DMS), which investigates the effectiveness of a thinning regime in promoting late-successional habitat development in young Douglas-fir forests of western Oregon. Patterns in understory vegetation community composition in and around 0.1 and 0.4ha gaps created as a part of the DMS treatment were investigated. The primary goal of this research was to investigate the potential role of canopy gap creation in fostering heterogeneity in understory vegetation communities, and to examine the extent of gap influence on the surrounding thinned forest matrix. Tree species distributions have been shown to partition across gaps in tropical forest systems through differential responses of species to gradients in resource availability, a pattern known as gap partitioning. In temperate forests, understory vegetation communities are much more diverse than the overstories, and display a greater array of habitat requirements. Therefore, understory communities may be more likely than overstories to exhibit gap partitioning in these forests. Patterns in understory community composition across gaps suggest that gap partitioning has occurred. The strength of this partitioning effect appears to differ between gap sizes, as smaller gaps showed a less powerful effect. Abundance of ruderal species was strongly related to gap partitioning in larger gaps, while smaller gaps were dominated by competitor species. Partitioning may be related to an interactive relationship between harvest-related ground disturbance and resource gradients. Therefore, considerations of gap partitioning processes should take into account intensity and spatial distribution of ground disturbance in relation to resource gradients. In addition, conditions necessary for the expression of gap partitioning in understory vegetation communities may be rare in natural gaps in this region. The influence of gaps on understory vegetation communities in the surrounding forest appears to be relatively small. This small influence extent may help explain the lack of a stand level response to gap formation in these stands. Larger gaps exhibit a slight influence on the understory plant community in the surrounding forest to the north of the gap. In small gaps, there seemed to be an influence of the surrounding forest on gap interiors, resulting in an area of influence smaller than the physical gap area. This relationship may indicate that the area of gap influence on understory vegetation may not scale linearly with physical gap size. Species diversity was higher in gap interiors than in surrounding thinned forests. However this effect was partially due to the presence of exotic species, which showed an affinity for gap interiors. Late successional associated species were negatively related to gap interiors, but only in the larger gap size. Gap creation appears to be promoting small scale species diversity in these stands, but creation of large gaps may also promote the establishment of exotic species and may have a negative effect on late successional associated species. However, any and all of these effects may be transient, as understory communities will be strongly affected by overstory re-establishment, and related changes in resource availability. In general, gap formation may influence small-scale stand heterogeneity as evidenced by understory plant communities, but this effect may rely strongly on the nature of gap formation and intensity of disturbance related to this formation.

Download or read book Principles of Soil Physics written by Rattan Lal and published by CRC Press. This book was released on 2004-05-28 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Soil Physics examines the impact of the physical, mechanical, and hydrological properties and processes of soil on agricultural production, the environment, and sustainable use of natural resources. The text incorporates valuable assessment methods, graphs, problem sets, and tables from recent studies performed around the globe and offers an abundance of tables, photographs, and easy-to-follow equations in every chapter. The book discusses the consequences of soil degradation, such as erosion, inhibited root development, and poor aeration. It begins by defining soil physics, soil mechanics, textural properties, and packing arrangements . The text continues to discuss the theoretical and practical aspects of soil structure and explain the significance and measurement of bulk density, porosity, and compaction. The authors proceed to clarify soil hydrology topics including hydrologic cycle, water movement, infiltration, modeling, soil evaporation, and solute transport processes. They address the impact of soil temperature on crop growth, soil aeration, and the processes that lead to the emission of greenhouse gases. The final chapters examine the physical properties of gravelly soils and water movement in frozen, saline, and water-repellant soils. Reader-friendly and up-to-date, Principles of Soil Physics provides unparalleled coverage of issues related to soil physics, structure, hydrology, aeration, temperature, and analysis and presents practical techniques for maintaining soil quality to ultimately preserve its sustainability.

Download or read book Relationships Between Overstory and Understory Density and Composition in a Mixed Conifer Forest Following Thinning on the Eastern Slope written by Rita Daniels and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: [Abstract quoted from thesis]

Download or read book Plant Disturbance Ecology written by Edward A. Johnson and published by Academic Press. This book was released on 2020-10-21 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Disturbance ecology continues to be an active area of research, having undergone advances in many areas in recent years. One emerging direction is the increased coupling of physical and ecological processes, in which disturbances are increasingly traced back to mechanisms that cause the disturbances themselves, such as earth surface processes, mesoscale, and larger meteorological processes, and the ecological effects of interest are increasingly physiological. Plant Disturbance Ecology, 2nd Edition encourages movement away from the informal, conceptual approach traditionally used in defining natural disturbances and clearly presents how scientists can use a multitude of approaches in plant disturbance ecology. This edition includes nine revised chapters from the first edition, as well new, more comprehensive chapters on fire disturbance and beaver disturbance. Edited by leading experts in the field, Plant Disturbance Ecology, 2nd Edition is an essential resource for scientists interested in understanding plant disturbance and ecological processes. - Advances understanding of natural disturbances by combining geophysical and ecological processes - Provides a framework for collaboration between geophysical scientists and ecologists studying natural disturbances - Includes fully updated research with 5 new chapters and revision of 11 chapters from the first edition

Download or read book Forests Water Guidelines written by Great Britain. Forestry Commission and published by . This book was released on 1993 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work advises owners and managers how woodlands and forests influence the freshwater ecosystem, and gives guidance on how operations should be carried out in order to protect and enhance the water environment. The guidelines apply equally to forest enterprises and the private sector.

Download or read book Forest Canopies written by Margaret Lowman and published by Academic Press. This book was released on 2004-09 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: The treetops of the world's forests are where discovery and opportunity abound, however they have been relatively inaccessible until recently. This book represents an authoritative synthesis of data, anecdotes, case studies, observations, and recommendations from researchers and educators who have risked life and limb in their advocacy of the High Frontier. With innovative rope techniques, cranes, walkways, dirigibles, and towers, they finally gained access to the rich biodiversity that lives far above the forest floor and the emerging science of canopy ecology. In this new edition of Forest Canopies, nearly 60 scientists and educators from around the world look at the biodiversity, ecology, evolution, and conservation of forest canopy ecosystems. Comprehensive literature list State-of-the-art results and data sets from current field work Foremost scientists in the field of canopy ecology Expanded collaboration of researchers and international projects User-friendly format with sidebars and case studies Keywords and outlines for each chapter