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Articles 1 - 13 of 13
Full-Text Articles in Physical Sciences and Mathematics
Estimating Potential Forest Npp, Biomass And Their Climatic Sensitivity In New England Using A Dynamic Ecosystem Model, Guoping Tang, Brian Beckage, Benjamin Smith, Paul A. Miller
Estimating Potential Forest Npp, Biomass And Their Climatic Sensitivity In New England Using A Dynamic Ecosystem Model, Guoping Tang, Brian Beckage, Benjamin Smith, Paul A. Miller
College of Agriculture and Life Sciences Faculty Publications
Accurate estimation of forest net primary productivity (NPP), biomass, and their sensitivity to changes in temperature and precipitation is important for understanding the fluxes and pools of terrestrial carbon resulting from anthropogenically driven climate change. The objectives of this study were to (1) estimate potential forest NPP and biomass for New England using a regional ecosystem model, (2) compare modeled forest NPP and biomass with other reported data for New England, and (3) examine the sensitivity of modeled forest NPP to historical climatic variation. We addressed these objectives using the regional ecosystem model LPJ-GUESS implemented with eight plant functional types …
The Whale Pump: Marine Mammals Enhance Primary Productivity In A Coastal Basin, Joe Roman, James J. Mccarthy
The Whale Pump: Marine Mammals Enhance Primary Productivity In A Coastal Basin, Joe Roman, James J. Mccarthy
Rubenstein School of Environment and Natural Resources Faculty Publications
It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.3x104 metric tons of N per year in the Gulf of Maine's euphotic zone, more than the input of all rivers combined. This upward ''whale pump'' played a much larger …
Null Model Analysis Of Species Associations Using Abundance Data, Werner Ulrich, Nicholas J. Gotelli
Null Model Analysis Of Species Associations Using Abundance Data, Werner Ulrich, Nicholas J. Gotelli
College of Arts and Sciences Faculty Publications
The influence of negative species interactions has dominated much of the literature on community assembly rules. Patterns of negative covariation among species are typically documented through null model analyses of binary presence/absence matrices in which rows designate species, columns designate sites, and the matrix entries indicate the presence (1) or absence (0) of a particular species in a particular site. However, the outcome of species interactions ultimately depends on population-level processes. Therefore, patterns of species segregation and aggregation might be more clearly expressed in abundance matrices, in which the matrix entries indicate the abundance or density of a species in …
A Hitchhiker's Guide To The Maritimes: Anthropogenic Transport Facilitates Long-Distance Dispersal Of An Invasive Marine Crab To Newfoundland, A. M.H. Blakeslee, C. H. Mckenzie, J. A. Darling, J. E. Byers, J. M. Pringle, J. Roman
A Hitchhiker's Guide To The Maritimes: Anthropogenic Transport Facilitates Long-Distance Dispersal Of An Invasive Marine Crab To Newfoundland, A. M.H. Blakeslee, C. H. Mckenzie, J. A. Darling, J. E. Byers, J. M. Pringle, J. Roman
Rubenstein School of Environment and Natural Resources Faculty Publications
Aim To determine timing, source and vector for the recent introduction of the European green crab, Carcinus maenas (Linnaeus, 1758), to Newfoundland using multiple lines of evidence.Location Founding populations in Placentia Bay, Newfoundland, Canada and potential source populations in the north-west Atlantic (NWA) and Europe. Methods We analysed mitochondrial and microsatellite genetic data from European and NWA populations sampled during 1999-2002 to determine probable source locations and vectors for the Placentia Bay introduction discovered in 2007. We also analysed Placentia Bay demographic data and shipping records to look for congruent patterns with genetic analyses. Results Demographic data and surveys suggested …
The Amazon Frontier Of Land-Use Change: Croplands And Consequences For Greenhouse Gas Emissions, Gillian L. Galford, Jerry Melillo, John F. Mustard, Carlos E.P. Cerri, Carlos C. Cerri
The Amazon Frontier Of Land-Use Change: Croplands And Consequences For Greenhouse Gas Emissions, Gillian L. Galford, Jerry Melillo, John F. Mustard, Carlos E.P. Cerri, Carlos C. Cerri
Rubenstein School of Environment and Natural Resources Faculty Publications
The Brazilian Amazon is one of the most rapidly developing agricultural frontiers in the world. The authors assess changes in cropland area and the intensification of cropping in the Brazilian agricultural frontier state of Mato Grosso using remote sensing and develop a greenhouse gas emissions budget. The most common type of intensification in this region is a shift from single-to double-cropping patterns and associated changes in management, including increased fertilization. Using the enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, the authors created a green-leaf phenology for 2001-06 that was temporally smoothed with a wavelet filter. …
Calibrating A Long-Term Meteoric 10Be Accumulation Rate In Soil, Lucas Reusser, Joseph Graly, Paul Bierman, Dylan Rood
Calibrating A Long-Term Meteoric 10Be Accumulation Rate In Soil, Lucas Reusser, Joseph Graly, Paul Bierman, Dylan Rood
College of Arts and Sciences Faculty Publications
Using 13 samples collected from a 4.1 meter profile in a well-dated and stable New Zealand fluvial terrace, we present the first long-term accumulation rate for meteoric 10Be in soil (1.68 to 1.72 × 106 at/(cm2yr)) integrated over the past ∼18 ka. Site-specific accumulation data, such as these, are prerequisite to the application of meteoric 10Be in surface process studies. Our data begin the process of calibrating long-term meteoric 10Be delivery rates across latitude and precipitation gradients. Our integrated rate is lower than contemporary meteoric 10Be fluxes measured in New Zealand rainfall, suggesting that long-term average precipitation, dust flux, or …
The Interplay Of Chaos Between The Terrestrial And Giant Planets, Wayne B. Hayes, Anton V. Malykh, Christopher M. Danforth
The Interplay Of Chaos Between The Terrestrial And Giant Planets, Wayne B. Hayes, Anton V. Malykh, Christopher M. Danforth
College of Engineering and Mathematical Sciences Faculty Publications
We report on some simple experiments on the nature of chaos in our planetary system. We make the following interesting observations. First, we look at the system of Sun + four Jovian planets as an isolated five-body system interacting only via Newtonian gravity. We find that if we measure the Lyapunov time of this system across thousands of initial conditions all within observational uncertainty, then the value of the Lyapunov time seems relatively smooth across some regions of initial condition space, while in other regions it fluctuates wildly on scales as small as we can reliably measure using numerical methods. …
Protecting Degraded Rainforests: Enhancement Of Forest Carbon Stocks Under Redd+, David P. Edwards, Brendan Fisher, Emily Boyd
Protecting Degraded Rainforests: Enhancement Of Forest Carbon Stocks Under Redd+, David P. Edwards, Brendan Fisher, Emily Boyd
Rubenstein School of Environment and Natural Resources Faculty Publications
The likely Reducing Emissions from Deforestation and Degradation (REDD+) mechanism includes strategies for the enhancement of forest carbon stocks. Recent concerns have been expressed that such enhancement, or restoration, of forest carbon could be counterproductive to biodiversity conservation, because forests are managed as "carbon farms" with the application of intensive silvicultural management that could homogenize diverse degraded rainforests. Restoration increases regeneration rates in degraded forest compared to naturally regenerating forest, and thus could yield significant financial returns for carbon sequestered. Here, we argue that such forest restoration projects are, in fact, likely to provide a number of benefits to biodiversity …
Temporal And Spatial Monitoring Of Mobile Nanoparticles In A Vineyard Soil: Evidence Of Nanoaggregate Formation, N. Perdrial, J. N. Perdrial, J. E. Delphin, F. Elsass, N. Liewig
Temporal And Spatial Monitoring Of Mobile Nanoparticles In A Vineyard Soil: Evidence Of Nanoaggregate Formation, N. Perdrial, J. N. Perdrial, J. E. Delphin, F. Elsass, N. Liewig
College of Arts and Sciences Faculty Publications
Mechanisms of formation, stabilization, liberation, transport and deposition of nanoparticles and their relationship to contaminant transport remain scarcely investigated in natural porous media. This study investigated nanoparticles mobilized in the pore space of a French vineyard soil by observing mobile soil-derived organic matter (SOM) and minerals in pore fluids over an 8-month monitoring period. Samples were collected in situ and investigated by transmission electron microscopy coupled to electron-dispersive spectroscopy. The main types of nanoparticles transported within the soil were clay, bacteria, SOM and nanoaggregates. Nanometric clay particles were enriched in various metals (Fe, Zn, As and Pb) and organically-derived constituents. …
Transient Social-Ecological Stability: The Effects Of Invasive Species And Ecosystem Restoration On Nutrient Management Compromise In Lake Erie, Eric D. Roy, Jay F. Martin, Elena G. Irwin, Joseph D. Conroy, David A. Culver
Transient Social-Ecological Stability: The Effects Of Invasive Species And Ecosystem Restoration On Nutrient Management Compromise In Lake Erie, Eric D. Roy, Jay F. Martin, Elena G. Irwin, Joseph D. Conroy, David A. Culver
Rubenstein School of Environment and Natural Resources Faculty Publications
Together, lake ecosystems and local human activity form complex social-ecological systems (SESs) characterized by feedback loops and discontinuous change. Researchers in diverse fields have suggested that complex systems do not have single stable equilibria in the long term because of inevitable perturbation. During this study, we sought to address the general question of whether or not stable social-ecological equilibria exist in highly stressed and managed lacustrine systems. Using an integrated human-biophysical model, we investigated the impacts of a species invasion and ecosystem restoration on SES equilibrium, defined here as a compromise in phosphorus management among opposing stakeholders, in western Lake …
Species Interactions And Thermal Constraints On Ant Community Structure, Sarah E. Wittman, Nathan J. Sanders, Aaron M. Ellison, Erik S. Jules, Jaime S. Ratchford, Nicholas J. Gotelli
Species Interactions And Thermal Constraints On Ant Community Structure, Sarah E. Wittman, Nathan J. Sanders, Aaron M. Ellison, Erik S. Jules, Jaime S. Ratchford, Nicholas J. Gotelli
College of Arts and Sciences Faculty Publications
Patterns of species occurrence and abundance are influenced by abiotic factors and biotic interactions, but these factors are difficult to disentangle without experimental manipulations. In this study, we used observational and experimental approaches to investigate the role of temperature and interspecific competition in controlling the structure of groundforaging ant communities in forests of the Siskiyou Mountains of southwestern Oregon. To assess the potential role of competition, we first used null model analyses to ask whether species partition temporal and/or spatial environments. To understand how thermal tolerances influence the structure of communities, we conducted a laboratory experiment to estimate the maximum …
Indigenous Lands, Protected Areas, And Slowing Climate Change, Taylor H. Ricketts, Britaldo Soares-Filho, Gustavo A.B. Da Fonseca, Daniel Nepstad, Alexander Pfaf, Annie Petsonk, Anthony Anderson, Doug Boucher, Andrea Cattaneo, Marc Conte, Ken Creighton, Lawrence Linden, Claudio Maretti, Paulo Moutinho, Roger Ullman, Ray Victurine
Indigenous Lands, Protected Areas, And Slowing Climate Change, Taylor H. Ricketts, Britaldo Soares-Filho, Gustavo A.B. Da Fonseca, Daniel Nepstad, Alexander Pfaf, Annie Petsonk, Anthony Anderson, Doug Boucher, Andrea Cattaneo, Marc Conte, Ken Creighton, Lawrence Linden, Claudio Maretti, Paulo Moutinho, Roger Ullman, Ray Victurine
Rubenstein School of Environment and Natural Resources Faculty Publications
No abstract provided.
Projecting The Distribution Of Forests In New England In Response To Climate Change, Guoping Tang, Brian Beckage
Projecting The Distribution Of Forests In New England In Response To Climate Change, Guoping Tang, Brian Beckage
College of Agriculture and Life Sciences Faculty Publications
Aim To project the distribution of three major forest types in the northeastern USA in response to expected climate change. Location The New England region of the United States. Methods We modelled the potential distribution of boreal conifer, northern deciduous hardwood and mixed oak-hickory forests using the process-based BIOME4 vegetation model parameterized for regional forests under historic and projected future climate conditions. Projections of future climate were derived from three general circulation models forced by three global warming scenarios that span the range of likely anthropogenic greenhouse gas emissions. Results Annual temperature in New England is projected to increase by …