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Category :
Languages : en
Pages : 0
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Book Description
An understanding of trajectories in long-term forest development is essential for examining several fundamental issues in forest ecology and management. Long-term forest development has important implications for issues as diverse as forest productivity, carbon storage, biological diversity, and ecological forestry methods. While much has been learned from studies of old-growth forests, a limitation is that these have necessarily been brief snapshots of species composition and forest structure at one point in time from which accurate trends are difficult to infer. The overarching themes of this dissertation are the long-term trajectory of forest development and the impact of the historic natural disturbance regime on that trajectory. Specific objectives were: (1) to quantify long-term trends in above-ground tree biomass and stand structure in northern hardwood forests, and effects of the natural disturbance regime, (2) to estimate the frequency of structural stand stages, along with residence times and transition rates among stages, under several disturbance regimes, and (3) to develop a quantitative approach to evaluating demographic sustainability of tree populations under several conditions, including those of restricted recruitment. Computer simulation with the CANOPY model was used to clarify long-term trends. However, to the extent possible, these model predictions were verified against available field data, including an extensive field survey and a 30-year record of change on permanent plots in the Porcupine Mountains Wilderness State Park. Major conclusions from this work were: (1) The Bormann-Likens hypothesis of a peak in biomass followed by a decline to a lower level was largely supported by both simulation and field data. The asymptotic biomass trend documented in recent chronosequences may be a consequence of using maximum tree age to estimate stand age. (2) The majority of landscapes of old-growth northern hardwoods is occupied by non-equilibrium stands, but nearly 1/3 was also structurally indistinguishable from steady state. Individual stands were highly dynamic, spending only a few decades in any structural stage. (3) Minimum sustainable tree populations had a variable slope in their size distribution. Enforcing a shallow fixed slope in understory trees typical of those used in uneven-aged management for larger trees rendered the stand unsustainable.
Author: Brian J. Palik
Publisher: Waveland Press
ISBN: 1478645237
Category : Technology & Engineering
Languages : en
Pages : 343
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Book Description
Classical silviculture has often emphasized timber models, fundamentally based in production agriculture. This books presents silvicultural methods based in natural forest models—models that emulate natural disturbances and development processes, sustain biological legacies, and allow time to take its course in shaping stands. These methods, dubbed “ecological forestry,” have been successfully implemented by foresters for decades managing a wide variety of forestlands. Ecological silvicultural strategies protect threatened and rare species, sustain biological diversity, and provide habitat for game and non-game species, all while providing timber in profitable ways.
Author: Paul E. Sendak
Publisher:
ISBN:
Category : Forest thinning
Languages : en
Pages : 20
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Book Description
In 1959 a study of crop-tree release and species cleaning was established in a 25-year-old northern hardwood stand growing on an above-average hardwood site that resulted from a silvicultural clearcut in the White Mountains of New Hampshire. Three treatmentslight crop-tree release, heavy release, and species cleaningwere randomly assigned to quarter-acre plots, five plots per treatment, including five untreated plots. The stand was followed for 5 years and based on the results, treatment effects were projected to a stand age of 45 years. These projections were subjected to a financial analysis. The treatment plots were tallied at stand ages 56 (1990) and 69 (2003) years. We summarize the results of the early crop-tree release and species cleaning and provide a long-term financial perspective based on the new tallies. Our goal was to repeat the financial analysis and re-examine the results and conclusions of the original study. We found that the return on investment at stand ages 56 and 69 years was not as good as originally reported. The least expensive treatment, a light crop-tree release, gave the greatest return on investment. An opportunity for a commercial thinning between stand age 45 and 56 was missed and most likely would have improved the financial outcome of the treatments. Approximately 400 crop trees per acre were selected for release in 1959 but 200 crop trees per acre would have been more than sufficient and would have improved the financial outcome of the treatments by lowering initial cost. On a similarly good hardwood site, with an equally well stocked young stand, and good markets for small diameter roundwood, we only can speculate that releasing 200 or preferably fewer dominant or codominant trees per acre at stand age 25 followed by a commercial thinning when feasible after stand age 45 could be a good investment for a landowner.
Author: Julio J. Diez
Publisher: BoD – Books on Demand
ISBN: 953510621X
Category : Technology & Engineering
Languages : en
Pages : 472
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Book Description
Sustainable forest management (SFM) is not a new concept. However, its popularity has increased in the last few decades because of public concern about the dramatic decrease in forest resources. The implementation of SFM is generally achieved using criteria and indicators (C
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 310
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Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 720
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Author: Dale S. Solomon
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 20
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Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 404
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Author:
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ISBN:
Category : Forest management
Languages : en
Pages : 406
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Book Description
Balancing Ecosystem Values: Innovative Experiments for Sustainable Forestry is a compendium of more than 40 contributions from Asia, Europe, and North America. The theme encompasses experiments implemented at an operational scale to test ecological, social, or economic responses to silvicultural treatments designed to balance the complex set of objectives currently targeted in sustainable forest management. Several invited and plenary papers emphasize the variety of outcomes demanded by the public, as well as the essential role that these long-term studies will play in allowing natural resource managers to make better-informed, science-based decisions. A broad spectrum of silvicultural treatments and systems are covered, as are simulation runs with different types of models and discussion about design challenges for scaling up from stands to landscapes. Diverse forest ecosystems, stand structures and plant, animal, and fungal species are also considered. The conference included 2 days in the field where participants saw several types of the comprehensive field experiments firsthand. The conference concluded with a critique from state, private, and public land managers.
Author: Deborah C. Hayes
Publisher: Springer
ISBN: 1461418186
Category : Science
Languages : en
Pages : 666
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Book Description
USDA Forest Service Experimental Forests and Ranges (EFRs) are scientific treasures, providing secure, protected research sites where complex and diverse ecological processes are studied over the long term. This book offers several examples of the dynamic interactions among questions of public concern or policy, EFR research, and natural resource management practices and policies. Often, trends observed – or expected -- in the early years of a research program are contradicted or confounded as the research record extends over decades. The EFRs are among the few areas in the US where such long-term research has been carried out by teams of scientists. Changes in society’s needs and values can also redirect research programs. Each chapter of this book reflects the interplay between the ecological results that emerge from a long-term research project and the social forces that influence questions asked and resources invested in ecological research. While these stories include summaries and syntheses of traditional research results, they offer a distinctly new perspective, a larger and more complete picture than that provided by a more typical 5-year study. They also provide examples of long-term research on EFRs that have provided answers for questions not even imagined at the time the study was installed.
