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Full-Text Articles in Life Sciences

First Stewards: Ecological Outcomes Of Forest And Wildlife Stewardship By Indigenous Peoples Of Wisconsin, Usa, Donald M. Waller, Nicholas J. Reo Jan 2018

First Stewards: Ecological Outcomes Of Forest And Wildlife Stewardship By Indigenous Peoples Of Wisconsin, Usa, Donald M. Waller, Nicholas J. Reo

Dartmouth Scholarship

Indigenous peoples manage forestlands and wildlife differently than public and private forestland managers. To evaluate ecological outcomes from these differences, we compared the structure, composition, and diversity of Ojibwe and Menominee tribal forests to nearby nontribal forestlands in northern Wisconsin. These indigenous peoples seek to manage forests for mature conditions, accommodate wolves and other predators, and hunt deer to sustain traditional livelihood values. Their forests are often more mature with higher tree volume, higher rates of tree regeneration, more plant diversity, and fewer invasive species than nearby nontribal forestlands. In contrast, nontribal forestlands lost appreciable plant diversity in the 20th …


Nonnative Forest Insects And Pathogens In The United States: Impacts And Policy Options, Gary M. Lovett, Marissa Weiss, Andrew M. Liebhold, Thomas P. Holmes, Brian Leung, Kathy F. Lambert, David A. Orwig, Faith T. Campbell, Jonathan Rosenthal, Deborah G. Mccullough, Radka Wildova, Matthew P. Ayres May 2016

Nonnative Forest Insects And Pathogens In The United States: Impacts And Policy Options, Gary M. Lovett, Marissa Weiss, Andrew M. Liebhold, Thomas P. Holmes, Brian Leung, Kathy F. Lambert, David A. Orwig, Faith T. Campbell, Jonathan Rosenthal, Deborah G. Mccullough, Radka Wildova, Matthew P. Ayres

Dartmouth Scholarship

We review and synthesize information on invasions of nonnative forest insects and diseases in the United States, including their ecological and economic impacts, pathways of arrival, distribution within the United States, and policy options for reducing future invasions. Nonnative insects have accumulated in United States forests at a rate of ~2.5 per yr over the last 150 yr. Currently the two major pathways of introduction are importation of live plants and wood packing material such as pallets and crates. Introduced insects and diseases occur in forests and cities throughout the United States, and the problem is particularly severe in the …


The Price Of Snow: Albedo Valuation And A Case Study For Forest Management, David A. Lutz, Richard B. Howarth Jun 2015

The Price Of Snow: Albedo Valuation And A Case Study For Forest Management, David A. Lutz, Richard B. Howarth

Dartmouth Scholarship

Several climate frameworks have included the role of carbon storage in natural landscapes as a potential mechanism for climate change mitigation. This has resulted in an incentive to grow and maintain intact long-lived forest ecosystems. However, recent research has suggested that the influence of albedo-related radiative forcing can impart equal and in some cases greater magnitudes of climate mitigation compared to carbon storage in forests where snowfall is common and biomass is slow-growing. While several methodologies exist for relating albedo-associated radiative forcing to carbon storage for the analysis of the tradeoffs of these ecosystem services, they are varied, and they …


Unintended Outcomes Of Farmers' Adaptation To Climate Variability: Deforestation And Conservation In Calakmul And Maya Biosphere Reserves, Claudia Rodriguez-Solorzano Jan 2014

Unintended Outcomes Of Farmers' Adaptation To Climate Variability: Deforestation And Conservation In Calakmul And Maya Biosphere Reserves, Claudia Rodriguez-Solorzano

Dartmouth Scholarship

Minimizing the impact of climate change on farmer livelihoods is crucial, but adaptation efforts may have unintended consequences for ecosystems, with potential impacts on farmers’ welfare. Unintended outcomes of climate adaptation strategies have been widely discussed, however, empirical exploration has been neglected. Grounded in scholarship on climate adaptation, environmental governance, social–ecological systems, and land-use change, this paper studies whether farmers’ climate adaptation contributes to deforestation or forest conservation. The paper draws on interviews with 353 farmers from 46 communities in Calakmul Biosphere Reserve in Mexico and Maya Biosphere Reserve in Guatemala. Farmers in the area of study have implemented adaptation …


Interactive Effects Of Defoliation And Climate Change On Compensatory Growth Of Silver Birch Seedlings, Liisa Huttunen, Matthew P. Ayres, Pekka Niemelä, Susanne Heiska, Riitta Tegelberg, Matti Rousi, Seppo Kellomaki Jun 2013

Interactive Effects Of Defoliation And Climate Change On Compensatory Growth Of Silver Birch Seedlings, Liisa Huttunen, Matthew P. Ayres, Pekka Niemelä, Susanne Heiska, Riitta Tegelberg, Matti Rousi, Seppo Kellomaki

Dartmouth Scholarship

Atmospheric warming increases the abundance of insect herbivores and intensifies the risk of defoliation, especially in high latitude forests. At the same time, the effects of increasing temperature and CO2 on plant responses to foliage damage are poorly understood. We examined if previous-year defoliation, varying between 0 and 75% of total leaf area, and different combinations of elevated temperature, CO2 and nutrient availability alter the growth of two-year old silver birch (Betula pendula Roth) seedlings. We measured the greatest height growth in seedlings that were fertilized and defoliated twice at the level of 50% of total leaf area, and subjected …


Low Mortality In Tall Tropical Trees, R. Q. Thomas, J. R. Kellner, D. B. Clark, D. R. Peart Apr 2013

Low Mortality In Tall Tropical Trees, R. Q. Thomas, J. R. Kellner, D. B. Clark, D. R. Peart

Dartmouth Scholarship

The dynamics of the tallest trees in tropical forests are of special interest due to their carbon content, canopy dominance, and the large canopy gaps created when they die. Known ecological mechanisms that may influence tall tree survival lead to conflicting predictions. Hydraulic stress and exposure to high winds and desiccation should increase death rates, yet the tallest trees have the greatest access to light and escape damage caused by falling boles and branches. The uncertainty in tall tree mortality rates has been difficult to address due to their low density, which makes mortality rates challenging to estimate accurately. Here, …


Changes In Nitrogen Cycling During The Past Century In A Northern Hardwood Forest, Kendra K. Mclauchlan, Joseph M. Craine, W. Wyatt Oswald, Peter R. Leavitt, Gene E. Likens May 2007

Changes In Nitrogen Cycling During The Past Century In A Northern Hardwood Forest, Kendra K. Mclauchlan, Joseph M. Craine, W. Wyatt Oswald, Peter R. Leavitt, Gene E. Likens

Dartmouth Scholarship

Nitrogen (N) availability, defined here as the supply of N to terrestrial plants and soil microorganisms relative to their N demands, limits the productivity of many temperate zone forests and in part determines ecosystem carbon (C) content. Despite multidecadal monitoring of N in streams, the long-term record of N availability in forests of the northeastern United States is largely unknown. Therefore, although these forests have been receiving anthropogenic N deposition for the past few decades, it is still uncertain whether terrestrial N availability has changed during this time and, subsequently, whether forest ecosystems have responded to increased N deposition. Here, …


Competitive Interactions Among Symbiotic Fungi Of The Southern Pine Beetle, Kier D. Klepzig, Richard T. Wilkens Nov 1997

Competitive Interactions Among Symbiotic Fungi Of The Southern Pine Beetle, Kier D. Klepzig, Richard T. Wilkens

Dartmouth Scholarship

The southern pine beetle, a damaging pest of conifers, is intimately linked to three symbiotic fungi. Two fungi, Ceratocystiopsis ranaculosus and Entomocorticium sp. A, are transported within specialized structures (mycangia) in the beetle exoskeleton and are mutualists of the beetle. A third fungus, Ophiostoma minus, is transported externally on the beetle exoskeleton (phoretically) and is an antagonist of the beetle. This study examined competitive interactions among these three fungi. The results of de Wit replacement series and primary and secondary resource capture assays with these fungi provide strong evidence for differential competition between the phoretic and mycangial fungi. O. minus …


A Comparative Analysis Of Potential Nitrification And Nitrate Mobility In Forest Ecosystems, Peter M. Vitousek, James R. Gosz, Charles C. Grier, Jerry M. Melillo, William A. Reiners Jan 1982

A Comparative Analysis Of Potential Nitrification And Nitrate Mobility In Forest Ecosystems, Peter M. Vitousek, James R. Gosz, Charles C. Grier, Jerry M. Melillo, William A. Reiners

Dartmouth Scholarship

Mobilization in a wide range of forest ecosystems were investigated through a combination of field and laboratory experiments.Trenched plot experiments were performed in 17 forests, and laboratory incubation studies of potential ammonium and nitrate production were made on soils from 14ofthese sites.