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Articles 121 - 134 of 134

Full-Text Articles in Forest Sciences

Manejo De Cipós Na Amazônia, Jeffrey J. Gerwing, Edson Vidal Jan 2005

Manejo De Cipós Na Amazônia, Jeffrey J. Gerwing, Edson Vidal

Environmental Science and Management Faculty Publications and Presentations

Levantamentos florestais revelam que os cipós vêm se tornando cada vez mais abundantes em toda a Amazônia, tanto em florestas intactas quanto nas afetadas por atividades humanas, como a exploração de madeira. Nessa atividade, é recomendado o corte dos cipós ligados à árvore escolhida, para reduzir os danos às demais durante a queda. Conhecer a ecologia desse grupo de plantas e seu adequado manejo é essencial para entender as conseqüências do seu corte e para cumprir as metas de conservação da biodiversidade incluídas nos projetos de manejo de florestas tropicais.


Impactos Da Exploração Madeireira E Do Fogo Em Florestas De Transição Da Amazônia Legal, André Luiz Silva Monteiro, Carlos Moreira De Souza Jr., Paulo Gonçalves Barreto, Frank Leone De Sousa Pantoja, Jeffrey J. Gerwing Jun 2004

Impactos Da Exploração Madeireira E Do Fogo Em Florestas De Transição Da Amazônia Legal, André Luiz Silva Monteiro, Carlos Moreira De Souza Jr., Paulo Gonçalves Barreto, Frank Leone De Sousa Pantoja, Jeffrey J. Gerwing

Environmental Science and Management Faculty Publications and Presentations

A exploração de madeira e os incendios têm causado severos danos a florestas na Amazonia. Faltavam estudos sobre os impactos da exploração e do fogo em florestas de transição entre a floresta ombrófila densa e florestas de cerrado. Neste estudo, foram quantificados os impactos de várias intensidades de exploração madeireira e fogo na estrutura e composição de florestas de transição -- em termos de densidade de árvores e de cipós, cobertura do dossel e perturbação do solo e da biomassa acima do solo -- na regiao de Claudia, Mato Grosso. O estudo foi conduzido em 12 propriedades, através de inventários …


Pre-Logging Liana Cutting Reduces Liana Regeneration In Logging Gaps In The Eastern Brazilian Amazon, Jeffrey J. Gerwing, Christopher Uhl Dec 2002

Pre-Logging Liana Cutting Reduces Liana Regeneration In Logging Gaps In The Eastern Brazilian Amazon, Jeffrey J. Gerwing, Christopher Uhl

Environmental Science and Management Faculty Publications and Presentations

The cutting of all lianas prior to logging is a reduced-impact logging technique that is predicted to reduce liana proliferation in logging gaps. This study compares liana abundance and species composition in gaps created during conventional and reduced-impact logging in a forest of the eastern Brazilian Amazon. Logging treatments were conducted in side-by-side plots. Shortly following logging, 50-m2 plots were located in the approximate centers of four single treefall and four multiple treefall gaps in each logging area. Six years following logging, there were ∼40% fewer climbing lianas in reduced-impact gaps than in conventional logging gaps. In both logging …


Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff Oct 2002

Understory Species Patterns And Diversity In Old-Growth And Managed Northern Hardwood Forests, Robert M. Scheller, David J. Mladenoff

Environmental Science and Management Faculty Publications and Presentations

Forest management can significantly affect both the diversity and spatial patterning of understory vegetation. However, few studies have considered both diversity and spatial patterning at a stand scale. Our objective was to evaluate the effects of forest management on understory plant communities in northern hardwood forests and assess the processes governing differences in species composition, diversity, and spatial patterns. We sampled understory vegetation (all speciestall) and percentage of light transmission levels in three forest types in 12 mesic northern hardwood stands in northern Wisconsin and the Upper Peninsula of Michigan, USA: old-growth, undisturbed forests; even-aged forests resulting from clearcut logging …


Forest Landscape Change Detection In The Meseta PuréPecha, MichoacáN, MéXico, John Malcolm Chase Apr 2002

Forest Landscape Change Detection In The Meseta PuréPecha, MichoacáN, MéXico, John Malcolm Chase

Dissertations and Theses

Social, political, economic, and environmental factors converge in developing countries to stimulate high rates of deforestation. Forest conversion reduces biodiversity, contributes to carbon loading of the atmosphere, alters the global water balance, and degrades the quality of life for rural people. Mexico is the fifth most biologically diverse country in the world and temperate and tropical forests in Mexico are rapidly disappearing with environmental and cultural repercussions for people and ecosystems.

Social, political, economic, and environmental factors converge in developing countries to stimulate high rates of deforestation. Forest conversion reduces biodiversity, contributes to carbon loading of the atmosphere, alters the …


Integrating Liana Abundance And Forest Stature Into An Estimate Of Total Aboveground Biomass For An Eastern Amazonian Forest, Jeffrey J. Gerwing, Damiao Lopes Farias May 2000

Integrating Liana Abundance And Forest Stature Into An Estimate Of Total Aboveground Biomass For An Eastern Amazonian Forest, Jeffrey J. Gerwing, Damiao Lopes Farias

Environmental Science and Management Faculty Publications and Presentations

This study provides an estimate of aboveground live biomass for an intact eastern Amazonian forest. An allometric regression biomass equation was developed to estimate the aboveground biomass of live lianas. This equation, together with a previously published equation for trees, was then used to estimate the contributions of lianas and trees to the total biomass of forest patches in four stature classes: gap (openings in the canopy of at least 25 m2 with the dominant vegetation < 3 m high), low (3±15 m canopy height), medium (15±25 m canopy height), and high (> 25 m canopy height). Total stand-level biomass was estimated as the weighted average of the stature classes. In 130 ha of surveyed forest, forest …


Acorn Foraging As A Means To Explore Human Energetics And Forge Connections To Local Forests, Jeffrey J. Gerwing, Pamela Lockwood, Christopher Uhl Apr 1999

Acorn Foraging As A Means To Explore Human Energetics And Forge Connections To Local Forests, Jeffrey J. Gerwing, Pamela Lockwood, Christopher Uhl

Environmental Science and Management Faculty Publications and Presentations

Jeffrey Gerwing, Pamela Lockwood, and Christopher Uhl describe a rather unusual ecology laboratory/field exercise that utilizes abundant oak habitats of central Pennsylvania. For those readers not blessed with an abundant supply of oaks nearby, perhaps other species could be substituted. The exercise is unusual in two ways. It offers a new undergraduate ecology activity, and it offers opportunities for students to relate other disciplines to their science course.

In "the good old days" of higher education each discipline offered its menu of courses and expected students to make appropriate connections among the courses of their major, minor, and general education. …


Reducing Waste During Logging And Log Processing: Forest Conservation In Eastern Amazonia, Jeffrey J. Gerwing, Jennifer S. Johns, Edson Vidal Jan 1996

Reducing Waste During Logging And Log Processing: Forest Conservation In Eastern Amazonia, Jeffrey J. Gerwing, Jennifer S. Johns, Edson Vidal

Environmental Science and Management Faculty Publications and Presentations

This article describes the waste associated with logging and log processing in eastern Amazonia and suggests methods for reducing both waste and forest damage as a result of logging.


Structural Analysis Of The Pacific Northwest Lumber And Plywood Industries, James G. Strathman, Anthony M. Rufolo, M. Hossein Haeri Jan 1987

Structural Analysis Of The Pacific Northwest Lumber And Plywood Industries, James G. Strathman, Anthony M. Rufolo, M. Hossein Haeri

Center for Urban Studies Publications and Reports

The lumber and plywood industries in the Pacific Northwest were particularly affected by the 1979-1982 construction recession. A subsequent recovery in output has occurred, but employment levels have remained relatively depressed. The potential for a planned reduction in the amount of timber sold from the national forests in the region also exists, giving rise to some uncertainty about the future prospects for these industries. This paper identifies the major structural factors affecting the performance of lumber and plywood producers in the region. It then proceeds to develop and simulate a set of alternative scenarios covering the 1986-1990 period to examine …


Changes In Populations Of Soil Acari During The First Year After Clearcutting, Sue Ellen Orlaske Nov 1979

Changes In Populations Of Soil Acari During The First Year After Clearcutting, Sue Ellen Orlaske

Dissertations and Theses

Soil samples taken from a clearcut and adjacent uncut site of a Douglas Fir and Western Hemlock old growth forest in the Cascade Range of southern Washington showed greatly reduced adult and juvenile population densities of macro-phytophagous, microphytophagous, and predatory soil acari in the clearcut. These effects appeared to be due to high lethal summer litter temperatures and reduced pore spaces due to scarification. Also, the number of species of acari in the clearcut was lower than in the control after clearcutting.


The Allelopathic Potential Of Rhododendron Macrophyllum In A Western Cascades Clearcut, Ivan W. Clark Jan 1979

The Allelopathic Potential Of Rhododendron Macrophyllum In A Western Cascades Clearcut, Ivan W. Clark

Dissertations and Theses

The purposes of this study were to determine if Rhododendron macrophyllum has the potential to inhibit the growth of other species through the production of water-soluble toxins which are leached out of its litter by rainfall, and to determine if this potential is realized in the field. The study was therefore composed of two part: 1) a series of bioassays to determine the presence an activity of water-soluble phytotoxins in R. macrophyllum leaf litter, and 2) a field study to describe vegetational patterns associated with R. macrophyllum in a western Cascades clearcut.


The Effect Of Declining Timber Supplies And Productivity Increases In The Forest Products Industries Upon Employment In Douglas County, Oregon, Patrick L. Burden Jan 1977

The Effect Of Declining Timber Supplies And Productivity Increases In The Forest Products Industries Upon Employment In Douglas County, Oregon, Patrick L. Burden

Dissertations and Theses

This thesis examines some of the factors that will have significant impact upon employment in Douglas County, Oregon to the year 2000.

The major question this research attempts to answer is: Given a continuation of current policies and programs, what will future employment levels in the forest product industries and total employment levels in all industries in Douglas County be to the year 2000.


Mutual Exclusion Between Salmonberry And Douglas-Fir In The Coast Range Of Oregon, Kenneth Ray Still Jun 1972

Mutual Exclusion Between Salmonberry And Douglas-Fir In The Coast Range Of Oregon, Kenneth Ray Still

Dissertations and Theses

One serious problem faced by the forest industry in the Pacific Northwest is poor regeneration of commercial trees on land which is harvested and subsequently dominated by brush species. In Coastal Oregon, salmonberry is one of these brush species. Detailed investigations of field sites indicate that light intensity in the brush stands was low but sufficient for germination and early growth of Douglas-fir seedlings and soil moisture percentages and nutrient levels were high enough to support early Douglas-fir growth. Laboratory tests demonstrated the presence of leachable phytotoxins in the leaves of salmonberry. The hypothesis resulting from this study is that …


A Taxonomic Study Of Two Nominal Subspecies Of Pikas (Ochotona Princeps) In The Cascade Mountains Of Oregon, Richard M. Coots Jan 1972

A Taxonomic Study Of Two Nominal Subspecies Of Pikas (Ochotona Princeps) In The Cascade Mountains Of Oregon, Richard M. Coots

Dissertations and Theses

Pikas from four colonies in the Cascade Mountains of Oregon were examined. Two colonies were chosen from within the geographical distribution of two nominal subspecies. A discriminate analysis of morphological measurements taken from the specimens showed that each colony could be distinguished from each other. Each colony studied showed more intra-colony similarity than inter-colony similarity regardless of distance separating the colonies or subspecies designations. The results indicate that the validity of subspecies designations for this species can be questioned.