Download or read book Characterizing Early seral Competitive Mechanisms Influencing Douglas fir Seedling Growth Vegetation Community Development and Physiology of Selected Weedy Plant Species written by Eric J. Dinger and published by . This book was released on 2012 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. The first experiment served as the foundation for this dissertation and was designed to quantify tradeoffs associated with delaying forest establishment activities by introducing a fallow year in order to provide longer-term management of competing vegetation. A range of six operationally relevant treatments were applied over two growing seasons that included in the first (1) a no-action control, (2) a spring release only, (3) a fall site preparation without sulfometuron methyl followed by a spring release, as well as (4) a fall site preparation with sulfometuron methyl and a spring release. In the second year, there was (5) a fall site preparation without sulfometuron methyl followed by a spring release and also in the second year (6) a fall site preparation with sulfometuron methyl and a spring release. Treatments 5 and 6 were left fallow without planting during the first year. These treatments were applied in two replicated experiments within the Oregon Coast Range. After adjusting for initial seedling size, year-3 results indicated that plantation establishment and competition control immediately after harvest (i.e. no fallow period) enabled seedlings to be physically larger than those planted after a one year delay. At the Boot study site, limiting vegetation below 20% for the first growing season improved year-3 Douglas-fir seedling stem volume over 273 cm3. Delaying establishment activities one year and reducing competing vegetation below 11% enabled seedling volume after two years to be statistically the same as three year old seedlings in the no-action control, a volume range of between 148 to 166 cm3. Delaying forest establishment at Jackson Mast improved seedling survivorship over 88% when a spring heat event reduced survivorship of trees planted a year earlier to less than 69%. The combined effect of applying a fall site preparation and spring release was necessary to reduce competitive cover below 10% in the year following treatment and provided longer-lasting control of woody/semi-woody plants. Less intense control measures (i.e. no-action control and treatment 2) were not able to restrain woody/semi-woody plant cover which grew to nearly 40% at Boot and over 24% at Jackson Mast in three years. No treatment regime provided multi-year control of herbaceous species. Including sulfometuron methyl in the fall site preparation tank-mix did not have a negative effect on seedling growth or provide significant reductions in plant community abundance in the year following application when compared to similar regimes that did not include the chemical. Delaying establishment lengthened the amount of time associated with forest regeneration except on a site that accentuated a spring heat event. In the second study, horizontal distance and azimuth readings provided by a ground-based laser were used to stem map seedling locations and experimental unit features at Boot. These data were used to create a relative Cartesian coordinate system that defined spatially explicit polygons enabling, for the first time, the ability to collect positional data on competing forest vegetation within an entire experimental unit. Deemed "vixels" or vegetation pixels, these polygons were assessed for measures of total cover and cover of the top three most abundance species during the initial three years of establishment. An alternate validity check of research protocols was provided when total cover resulting from this vixel technique was compared to a more traditional survey of four randomly located subplots. The resulting linear regression equation had an adjusted R2 of 0.90 between these two techniques of assessing total cover. When compared within a treatment and year, total cover differed by less than 12 percentage points between the two techniques. Analysis of year-3 woody/semi-woody plant cover produced by the techniques led to identical treatment differences. Two treatments resulted in woody/semi-woody cover of approximately 1500 ft2 by the vixel method and nearly 40% cover by the subplot method while the remaining four treatments were grouped below 600 ft2 or 20% cover, respectively. With continued refinement, these techniques could visually present forest development through all phases and provide long-term information used to bolster growth and yield models, measures of site productivity, as well as community ecology research. The third study evaluated the season-long gas exchange and biomass partitioning of four weedy plant species capable of rapidly colonizing Pacific Northwest regenerating forests. Cirsium arvense, Cirsium vulgare, Rubus ursinus and Senecio sylvaticus were studied at two sites. A greenhouse was used to introduce two levels of irrigation (well-watered and droughty). These species were also studied while growing among a larger vegetation community at a field site. Irrigation treatments had little impact on gas exchange rates. Species achieved maximum photosynthetic rates of 30, 20, 15 and 25 [micro]mol CO2 m−2 s−1 (respectively) prior to mid-July coinciding with an active phase of vegetative growth. As the season progressed, photosynthetic rates declined in spite of well-watered conditions while transpiration rates remained relatively consistent even when soil water decreased below 0.25 m3 H2O/m3 soil. Water use efficiency was high until late-July for all study species, after which time it decreased below 5 [micro]mol CO2 · mmol H2O−1. Multi-leaf gas exchange measurements as well as biomass data provided a holistic view of plantlevel mechanisms used to shunt activity toward developing tissues. Herbaceous species had assimilation rates that differed vertically (within each species) by as much as 10 to 20 [micro]mol CO2 m−2 s−1 from July to September as lower leaves senesced in favor of those higher on study plants. Specific leaf area was greatest in June for all species then declined indicating species placed little effort into sacrificial early season leaves when compared to those higher on the plant that could continue to support flowering or vegetative growth. The study of seasonal gas exchange in the presence of declining water availability has helped to describe competitive mechanisms at work during forest regeneration as well as provide physiologic support for the application of vegetation management regimes.
Download or read book Root Ecology written by Hans de Kroon and published by Springer Science & Business Media. This book was released on 2003-05-21 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of evolution, a great variety of root systems have learned to overcome the many physical, biochemical and biological problems brought about by soil. This development has made them a fascinating object of scientific study. This volume gives an overview of how roots have adapted to the soil environment and which roles they play in the soil ecosystem. The text describes the form and function of roots, their temporal and spatial distribution, and their turnover rate in various ecosystems. Subsequently, a physiological background is provided for basic functions, such as carbon acquisition, water and solute movement, and for their responses to three major abiotic stresses, i.e. hard soil structure, drought and flooding. The volume concludes with the interactions of roots with other organisms of the complex soil ecosystem, including symbiosis, competition, and the function of roots as a food source.
Download or read book The Effects of Selected Seedling and Site Characteristics on First year Growth and Survival in a Douglas fir Plantation written by David Joseph Swanson and published by . This book was released on 1977 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Combined Effects of Vegetation Control and Seedling Size Class on Douglas fir Pseudotsuga Menziesii Mirb Franco Seedling Productivity on a Site in Oregon written by Robert F. Lefebvre and published by . This book was released on 2014 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlling competing vegetation with the application of herbicides and increased seedling size at planting has been shown to increase seedling survival and growth. These two important reforestation tools have often been studied independently of each other, limiting comparisons that can be made between them. This study utilized a factorial treatment structure to test for interactions among four different vegetation control treatments and three seedling size classes in a randomized complete block design. The first year results reported in this thesis indicate that the effects of vegetation control and seedling size are additive, and stem volume increased with vegetation control and increased seedling size. Stem volume ranged from 6.2cm3 for seedlings in the smallest size class that received a fall site preparation only to 36.2cm3 for seedlings in the largest size class that received a fall site preparation and a spring release. Seedlings that were excavated after the first growing season showed that competition negatively impacted root growth. Monthly vegetation surveys indicated that herbicide application was effective in reducing competing vegetation to below 15% in treated plots, increasing cumulative soil moisture by 21% throughout the growing season. The spring release treatment also altered the vegetation community, reducing forbs across the growing season in treated plots but had little effect on perennial species. Future measurements will continue to assist nursery and land managers in decisions regarding nursery cultural practices and vegetation control treatments.
Download or read book Allelopathy written by Manuel J. Reigosa and published by Springer Science & Business Media. This book was released on 2006-02-28 with total page 635 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are many good books in the market dealing with the subject of allelopathy. When we designed the outline of this new book, we thought that it should include as many different points of view as possible, although in an integrated general scheme. Allelopathy can be viewed from different of perspectives, ranging from the molecular to the ecosystem level, and including molecular biology, plant biochemistry, plant physiology, plant ecophysiology and ecology, with information coming also from the organic chemistry, soil sciences, microbiology and many other scientific disciplines. This book was designed to include a complete perspective of allelopathic process. The book is divided into seven major sections. The first chapter explores the international development of allelopathy as a science and next section deals with methodological aspects and it explores potential limitations of actual research. Third section is devoted to physiological aspects of allelopathy. Different specialists wrote about photosynthesis, cell cycle, detoxification processes, abiotic and biotic stress, plant secondary metabolites and respiration related to allelopathy. Chapters 13 through 16 are collectively devoted to various aspects of plant ecophysiology on a variety of levels: microorganisms, soil system and weed germination. Fundamental ecology approaches using both experimental observations and theoretical analysis of allelopathy are described in chapters 16 and 17. Those chapters deal with the possible evolutionary forces that have shaped particular strategies. In the section named “allelopathy in different environments”, authors primarily center on marine, aquatic, forest and agro ecosystems. Last section includes chapters addressing application of the knowledge of allelopathy.
Download or read book Forest Succession written by D. C. West and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Succession-nothing in plant, community, or ecosystem ecology has been so elaborated by terminology, so much reviewed, and yet so much the center of controversy. In a general sense, every ecologist uses the concept in teaching and research, but no two ecologists seem to have a unified concept of the details of succession. The word was used by Thoreau to describe, from a naturalist's point of view, the general changes observed during the transition of an old field to a forest. As data accumulated, a lengthy taxonomy of succession developed around early twentieth century ecologists such as Cooper, Clements, and Gleason. Now, nearer the end of the century, and after much discussion concerning the nature of vegetation communities, where do ecologists stand with respect to knowledge of ecological succession? The intent of this book is not to rehash classic philosophies of succession that have emerged through the past several decades of study, but to provide a forum for ecologists to present their current research and present-day interpretation of data. To this end, we brought together a group of scientists currently studying terrestrial plant succession, who represent research experience in a broad spectrum of different ecosystem types. The results of that meeting led to this book, which presents to the reader a unique summary of contemporary research on forest succession.
Download or read book First Year Survival and Growth of Planting Stock of Various Size on Adverse Sites written by Jerome J. Chetock and published by . This book was released on 1976 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: First year survival of Douglas-fir seedlings outplanted in areas characterized by intense vegetative competition is heavily dependent on available soil moisture. To test this hypothesis, five distinct classes of Douglas-fir planting stock were planted on the south slope of McCulloch Peak in McDonald Forest in February of 1975. The stocking classes represented in this study are 2-2 transplants, 2-0 seedlings, one-year-old container-grown (plug) seedlings, 3-0 seedlings, and 2-1 transplants. Four treatments were applied in two replications: (1) a combination of irrigation and herbicidal control of competing vegetation; (2) irrigation; (3) herbicidal control of competing vegetation; and (4) no cultural treatment. The Scholander pressure bomb technique was used to determine the timing of the irrigation treatment. Whenever the average pre-dawn xylem pressure potential of the seedlings fell below -20 bars, irrigation was applied. The two replications corresponded to two distinct vegetative communities: a brush-dominant community and a, grass-dominant community. To eliminate the variable of wildlife pressure, every seedling was protected by a mesh animal exclosure. Seedling mortality was tallied at intervals throughout the summer, and leader elongation was measured in October of 1975. The vegetation community in which a seedling was outplanted was of overriding importance to the seedling's potential for survival. Phenological development of the constituents of the vegetation community greatly influenced the availability of soil moisture so critical to seedling establishment. In turn, community structure determined the favorability, or lack thereof, of the microenvironment in which a seedling developed. In respect to both phenology and structure, the community dominated by grasses was more adverse to the introduction of Douglas-fir seedlings than was the community dominated by brush. The importance of the type of vegetative cover was further underscored by the response to the various cultural treatments. the brush-dominant community, irrigation, herbicides, and the combination of irrigation and herbicides proved equally effective as measures of site preparation. This was in contrast to the results in the grass-dominant community which showed that irrigation alone could not ensure acceptable seedling survival. Due to their inherent ability to disrupt the normal development of established vegetation, herbicides emerged as an especially effective means of ameliorating adverse site conditions. In both communities, little additional benefit was realized by coupling irrigation to the herbicide treatment. As was expected, seedlings which received no cultural treatment performed poorly regardless of type of vegetative cover. In regards to the performance of the various age-classes, the one-year-old container-grown seedlings showed a survival rate of nearly 90% in the grass community. Unable to match this performance, the 2-0, 2-1, 3-0, and 2-2 bare-rooted stock survived at the following rates: 45%, 44%, 36%, and 33%, respectively. The container-grown seedlings were not, however, superior in the brush community. Both the 2-1 and 3-0 planting stock had higher survival, 76 and 71%, respectively, than the container-grown seedlings (70%) and the 2-2 transplants (68%). The 2-0 seedlings (56% survival) performed poorly in the brushy area; although they had the highest survival of the bare-rooted stock in the grass community. Seedling morphological characteristics were meaningful to survival in the case of the 3-0 seedlings in the grass community and the container-grown seedlings in the brush community. In terms of height, diameter, and weight, the smaller 3-0 seedlings adapted to their new environment better than did larger 3-0 seedlings. For the container-grown seedlings, larger stem diameters were correlated with increasingly better survival. As a check on the various seedlings control of stomatal aperture, leaf water conductance was measured with a null balance diffusion porometer. Small seedlings tended to have higher rates of transpiration than large seedlings, but total transpirational loss under given environmental conditions was judged to be equivalent regardless of seedling size.
Download or read book Bibliography of Agriculture written by and published by . This book was released on 1998 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fire Effects Guide written by and published by . This book was released on 1994 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecology written by Charles J. Krebs and published by Benjamin-Cummings Publishing Company. This book was released on 2001 with total page 695 pages. Available in PDF, EPUB and Kindle. Book excerpt: This best-selling majors ecology book continues to present ecology as a series of problems for readers to critically analyze. No other text presents analytical, quantitative, and statistical ecological information in an equally accessible style. Reflecting the way ecologists actually practice, the book emphasizes the role of experiments in testing ecological ideas and discusses many contemporary and controversial problems related to distribution and abundance. Throughout the book, Krebs thoroughly explains the application of mathematical concepts in ecology while reinforcing these concepts with research references, examples, and interesting end-of-chapter review questions. Thoroughly updated with new examples and references, the book now features a new full-color design and is accompanied by an art CD-ROM for instructors. The field package also includes The Ecology Action Guide, a guide that encourages readers to be environmentally responsible citizens, and a subscription to The Ecology Place (www.ecologyplace.com), a web site and CD-ROM that enables users to become virtual field ecologists by performing experiments such as estimating the number of mice on an imaginary island or restoring prairie land in Iowa. For college instructors and students.
Download or read book The Supporting Roots of Trees and Woody Plants Form Function and Physiology written by A. Stokes and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication comprises the proceedings of the first International Conference devoted to the structural roots of trees and woody plants. 'The Supporting Roots - Structure and Function,' 20-24 July 1998, Bordeaux, France. The meeting was held under the auspices ofIUFRO WPS 2. 01. 13 'Root Physiology and Symbiosis,' and its aim was to bring together scientific researchers, foresters and arboriculturalists, to discuss current problems in structural root research and disseminate knowledge to an audience from a wide disciplinary background. For the first time in an international conference, emphasis was placed on presenting recent reseach in the field of tree anchorage mechanics and root biomechanics. The way in which tree stability can be affected by root system symmetry and architecture was addressed, as well as how movement during wind sway can influence the development and shape of woody roots. The role of different nursery and planting techniques was discussed, in relation to effects on root system form and development. Root response to different environmental stresses, including water, temperature, nutrient and mechanical stress was addressed in detail. The structure and function of woody roots was also considered at different levels, from coarse to fine roots, with several papers discussing the interaction between roots and the rhizosphere. One of the conference highlights was the presentation of new methods in root research, by a series of workshops held at LRBB-INRA, Pierroton, on the northern border of the Gascony forest.
Download or read book The Physiological Ecology of Woody Plants written by Theodore T. Kozlowski and published by Academic Press. This book was released on 2012-12-02 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: The efficient management of trees and other woody plants can be improved given an understanding of the physiological processes that control growth, the complex environmental factors that influence those processes, and our ability to regulate and maintain environmental conditions that facilitate growth. Emphasizes genetic and environmental interactions that influence woody plant growth Outlines responses of individual trees and tree communities to environmental stress Explores cultural practices useful for efficient management of shade, forest, and fruit trees, woody vines, and shrubs
Download or read book Global Climate Change Impacts in the United States written by U.S. Global Change Research Program and published by Cambridge University Press. This book was released on 2009-08-24 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes the science of climate change and impacts on the United States, for the public and policymakers.
Download or read book Restoration of Boreal and Temperate Forests written by John A. Stanturf and published by CRC Press. This book was released on 2015-08-14 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humans have influenced the landscapes and forests throughout the temperate and boreal zones for millennia. Restoration of Boreal and Temperate Forests, Second Edition focuses on the negative impact of human activity, and explains the importance of forest restoration as a way to repair habitat, restore forest structure and function, and counteract t
Download or read book Coronado National Forest Plan written by and published by . This book was released on 1986 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Attributes of Trees as Crop Plants written by Melvin G. R. Cannell and published by . This book was released on 1985 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Domestication. Perspectives on the evolutionary history of tree crops. The basis of selection, management and evaluation of multipurpose trees - an overview. Forest tree breeding and fruit tree breeding: strategies, achievements and constraints. Strategies for optimizing the yield of tree crops in suboptimal environments. Tree growth at cool temperaturea and prospects for improvement by breeding. The ideotype concept applied to forest trees. Definition and exploitation of forest tree ideotypes in Finland. The capacity for vegetative propagation in trees. The vegetative structure. Biometrical, structural and physiological relationships among tree parts. Dry matter partitioning in tree crops. Forest productivity in relation to carbon partitioning and nutrient cycling: a mathematical model. Prospects for manipulating vascular-cambium productivity and xylem-cell differentiation. Branching, crown structure and the control of timber production. Trees as producers of exudates and extractives. Trees as producers of fuel. Trees as fodder crops. Roots, symbionts and soils. Roots as a component of tree productivity. Improving tree crops using micro-organisms in designed systems. Trees as soil improvers in the humid tropics?. Exploiting tree crop-symbiont specificity. Flowering and fruiting. Promotion of flowering in the crops: different mechanisms and techniques, with special reference to conifers. Variability in flower initiation in forest trees. Reproduction behaviour of fruit tree crops and its implications for the manipulation of fruit set. Some attributes of nut-bearing trees of temperate forest origin. Trees in stands. Future fruit orchard design: economics and biology. Transpiration and assimilation of tree and agricultural crops: the 'omega factor'. The competition process in forest stands. Forest canopy design: biological models and management implications. Future forest design: economic aspects. Wood properties, and future requirements for wood products.
Download or read book Silvics of Forest Trees of the United States written by and published by . This book was released on 1965 with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:
