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Full-Text Articles in Life Sciences

Initial Movements Of A Dispersing Amphbian In Response To Partial Harvestion In The Acadian Forest Of Maine, Usa, Brittany Cline, Malcolm L. Hunter Jr. Jun 2016

Initial Movements Of A Dispersing Amphbian In Response To Partial Harvestion In The Acadian Forest Of Maine, Usa, Brittany Cline, Malcolm L. Hunter Jr.

Publications

Maintaining amphibian populations in managed forests requires a balance between timber extraction and retaining functional connectivity for animals that use multiple vegetation types to satisfy habitat requirements, particularly where extensive harvesting may increase fragmentation. Quantifying dispersal patterns in response to harvest, especially across high-contrast edges adjacent to unlogged forest, is critical for evaluating the effects of harvest configuration on amphibians. We tested the initial post-metamorphic orientation of juvenile wood frogs (Lithobates sylvaticus) at edges in harvests (31– 60% retention standwide) in the Acadian forest of Maine, USA, during the period when juveniles emigrate from breeding pools. We released juveniles (n …


The Effects Of Rotation And River Discharge On Net Mixing In Small-Mouth Kelvin Plumes, Kelly Cole, Robert D. Hetland May 2016

The Effects Of Rotation And River Discharge On Net Mixing In Small-Mouth Kelvin Plumes, Kelly Cole, Robert D. Hetland

Publications

Small-mouth Kelvin number plumes, or plumes with a source width smaller than the deformation radius, are characterized by near-field plume regions of rapid lateral expansion and strong vertical mixing. Net plume mixing, or the dilution of a plume by ocean water between the estuary mouth and the far-field plume, is examined using idealized numerical experiments with the Regional Ocean Modeling System (ROMS). The density anomaly of plume water entering the far field is determined from isohaline analysis of the modeled salinity field. The experiments indicate that when estuarine discharge increases, net plume mixing decreases in a rotating environment but increases …


Modeling Spatiotemporal Variability Of The Bioclimate Envelope Of Homarus Americanus In The Coastal Waters Of Maine And New Hampshire, Kisei Tananka, Yong Chen Feb 2016

Modeling Spatiotemporal Variability Of The Bioclimate Envelope Of Homarus Americanus In The Coastal Waters Of Maine And New Hampshire, Kisei Tananka, Yong Chen

Publications

A bioclimate envelope model was developed to evaluate the potential impacts of climate variability on American lobster (Homarus americanus). Bioclimate envelopes were defined by season-, sex-, and stage- specific Habitat Suitability Indices (HSI) based on (1) bottom temperature, (2) bottom salinity, and (3) depth. The species’ association to each of these three environmental attributes was expressed using Suitability Indices (SIs) calibrated by standardized lobster abundance derived from 14 years of fishery independent survey. A regional ocean model (Finite-Volume Community Ocean Model) was integrated with the HSI to hindcast spatiotemporal variability of bioclimate envelopes for American lobster in coastal waters of …


Why Rhetoric Matters For Ecology, Caroline Druschke, Bridie Mcgreavy Feb 2016

Why Rhetoric Matters For Ecology, Caroline Druschke, Bridie Mcgreavy

Publications

Increasingly, scientists and funding agencies such as the US National Science Foundation are recognizing the need for better science communication and more effective broader impacts activities. Compelled to make research more relevant to public stakeholders and policy makers, researchers look for ways to gain the necessary skillset to move their science from the field and laboratory into public forums. We suggest that the ancient discipline of rhetoric provides a useful – and underutilized – path forward. Building from the fundamental connections between ecology and rhetoric and drawing from practical examples at the intersection of these two fields, we demonstrate how …


Linking Remote Sensing And Various Site Factors For Predicting The Spatial Distribution Of Eastern Hemlock Occurrence And Relative Basal Area In Maine, Usa, Kathleen Dunckel, Aaron Weiskittel, Greg Fiske, Steven A. Sader, Erika Latty, Amy Arnett Dec 2015

Linking Remote Sensing And Various Site Factors For Predicting The Spatial Distribution Of Eastern Hemlock Occurrence And Relative Basal Area In Maine, Usa, Kathleen Dunckel, Aaron Weiskittel, Greg Fiske, Steven A. Sader, Erika Latty, Amy Arnett

Publications

Introduced invasive pests are perhaps the most important and persistent catalyst for changes in forest composition. Infestation and outbreak of the hemlock woolly adelgid (Adelges tsugae; HWA) along the eastern coast of the USA, has led to widespread loss of hemlock (Tsuga canadensis (L.) Carr.), and a shift in tree species composition toward hardwood stands. Developing an understanding of the geographic distribution of individual species can inform conservation practices that seek to maintain functional capabilities of ecosystems. Modeling is necessary for understanding changes in forest composition, and subsequent changes in biodiversity, and one that can be implemented at the species …


Evaluation Of A Waistband For Attaching External Radiotransmitters To Anurans, Luke Alexander Groff, Amber Pitt, Robert Baldwin, Aram J K Calhoun, Cynthia Loftin Jul 2015

Evaluation Of A Waistband For Attaching External Radiotransmitters To Anurans, Luke Alexander Groff, Amber Pitt, Robert Baldwin, Aram J K Calhoun, Cynthia Loftin

Publications

Radiotelemetry provides fine-scale temporal and spatial information about an individual's movements and habitat use; however, its use for monitoring amphibians has been restricted by transmitter mass and lack of suitable attachment techniques. We describe a novel waistband for attaching external radiotransmitters to anurans and evaluate the percentages of resulting abrasions, lacerations, and shed transmitters. We used radiotelemetry to monitor movements and habitat use of wood frogs (Lithobates sylvaticus) in 2006 and 2011–2013 in Maine, USA; American toads (Anaxyrus americanus) in 2012 in North Carolina, USA; and, wood frogs, southern leopard frogs (L. sphenocephalus), and green frogs (L. clamitans) in 2012 …


Understanding Social Resilience In The Maine Lobster Industry, Teresa R. Johnson, Anna M. Henry Apr 2015

Understanding Social Resilience In The Maine Lobster Industry, Teresa R. Johnson, Anna M. Henry

Publications

The Maine lobster Homarus americanus fishery is considered one of the most successful fisheries in the world due in part to its unique comanagement system, the conservation ethic of the harvesters, and the ability of the industry to respond to crises and solve collective-action problems. However, recent threats raise the question whether the industry will be able to respond to future threats as successfully as it has to ones in the past or whether it is now less resilient and can no longer adequately respond to threats. Through ethnographic research and oral histories with fishermen, we examined the current level …


Urbanization Changes The Composition And Bioavailability Of Dissolved Organic Matter In Headwater Streams, Thomas B. Parr, Christopher Cronan, Tsutomu Ohno, Stuart Findlay, Sean Smith, Kevin Simon Feb 2015

Urbanization Changes The Composition And Bioavailability Of Dissolved Organic Matter In Headwater Streams, Thomas B. Parr, Christopher Cronan, Tsutomu Ohno, Stuart Findlay, Sean Smith, Kevin Simon

Publications

Population growth in cities has resulted in the rapid expansion of urbanized land. Most research and management of stream ecosystems affected by urban expansion has focused on the maintenance and restoration of biotic communities rather than their basal resources. We examined the potential for urbanization to induce bottom-up ecosystem effects by looking at its influence on dissolved organic matter (DOM) composition and bioavailability and microbial enzyme activity. We selected 113 headwater streams across a gradient of urbanization in central and southern Maine and used elemental and optical analyses, including parallel factor analysis of excitation-emission matrices, to characterize DOM composition. Results …


Biogeochemical Hotspots In Forested Landscapes: The Role Of Vernal Pools In Denitrification And Organic Matter, Krista A. Capps, Regina L. Rancatti, Nathan Tomczyk, Aram J K Calhoun, Malcolm L. Hunter Jr. Dec 2014

Biogeochemical Hotspots In Forested Landscapes: The Role Of Vernal Pools In Denitrification And Organic Matter, Krista A. Capps, Regina L. Rancatti, Nathan Tomczyk, Aram J K Calhoun, Malcolm L. Hunter Jr.

Publications

Quantifying spatial and temporal heterogeneity in ecosystem processes presents a challenge for conserving ecosystem function across landscapes. In particular, many ecosystems contain small features that play larger roles in ecosystem processes than their size would indicate; thus, they may represent ‘‘hotspots’’ of activity relative to their surroundings. Biogeochemical hotspots are characterized as small features within a landscape that show comparatively high chemical reaction rates. In northeastern forests in North America, vernal pools are abundant, small features that typically fill in spring with snow melt and precipitation and dry by the end of summer. Ephemeral flooding alters soil moisture and the …


Pushing The Pace Of Tree Species Migration, Eli D. Lazarus, Brian Mcgill Aug 2014

Pushing The Pace Of Tree Species Migration, Eli D. Lazarus, Brian Mcgill

Publications

Plants and animals have responded to past climate changes by migrating with habitable environments, sometimes shifting the boundaries of their geographic ranges by tens of kilometers per year or more. Species migrating in response to present climate conditions, however, must contend with landscapes fragmented by anthropogenic disturbance. We consider this problem in the context of wind-dispersed tree species. Mechanisms of long-distance seed dispersal make these species capable of rapid migration rates. Models of species-front migration suggest that even tree species with the capacity for long-distance dispersal will be unable to keep pace with future spatial changes in temperature gradients, exclusive …


Managing The Middle Ground: Forests In The Transition Zone Between Cities And Remote Areas, Charles Colgan, Malcolm L. Hunter Jr., Aaron Weiskittel, Brian Mcgill Jun 2014

Managing The Middle Ground: Forests In The Transition Zone Between Cities And Remote Areas, Charles Colgan, Malcolm L. Hunter Jr., Aaron Weiskittel, Brian Mcgill

Publications

In many parts of the world there are extensive landscapes where forests and people strongly intermingle, notably in the suburbs and exurbs of cities. This landscape of transitional forest generally receives limited attention from policy makers and researchers who tend to be rooted in traditions centered on either urban planning or management of natural resources in rural areas. The transitional forest is on the periphery of both perspectives, but it is a large area that provides numerous important values (biodiversity, ecosystem function, forest products, and amenities) to the people that live in them and their neighboring cities. Here we argue …


The Complementary Niches Of Anthropocentric And Biocentric Conservationists, Malcolm L. Hunter Jr., Kent H. Redford, David Lindenmayer Apr 2014

The Complementary Niches Of Anthropocentric And Biocentric Conservationists, Malcolm L. Hunter Jr., Kent H. Redford, David Lindenmayer

Publications

A divergence of values has become apparent in recent debates between conservationists who focus on ecosystem services that can improve human well-being and those who focus on avoiding the extinction of species. These divergent points of view fall along a continuum from anthropocentric to biocentric values, but most conservationists are relatively closer to each other than to the ends of the spectrum. We have some concerns with both positions but emphasize that conservation for both people and all other species will be most effective if conservationists focus on articulating the values they all share, being respectful of divergent values, and …


Different Open-Canopy Vegetation Types Affect Matrix Permeability For A Dispersing Forest Amphibian, Brittany Cline, Malcolm L. Hunter Jr. Apr 2014

Different Open-Canopy Vegetation Types Affect Matrix Permeability For A Dispersing Forest Amphibian, Brittany Cline, Malcolm L. Hunter Jr.

Publications

Population viability often depends on conserving functional connectivity in fragmented landscapes. For pool-breeding amphibians, population connectivity is largely maintained through juvenile dispersal, often through various vegetation types that may differ as filters or conduits to movement. We quantified the relative permeability of different types of open-canopy vegetation to juvenile wood frogs Lithobates sylvaticus to determine whether this influences functional connectivity during dispersal. We conducted experimental releases of juveniles (n = 561) in ten runways representing five treatments: hayfield, moderate-cover lawn (45–85% cover), open lawn (0% cover), row crop (forage-corn) and recent clear-cut. Runways consisted of 35 × 2·5 m enclosures, …


Comparafac: A Library And Tools For Rapid And Quantitative Comparison Of Dissolved Organic Matter Components Resolved By Parallel Factor Analysis., Thomas B. Parr, Tsutomu Ohno, Kevin Simon Mar 2014

Comparafac: A Library And Tools For Rapid And Quantitative Comparison Of Dissolved Organic Matter Components Resolved By Parallel Factor Analysis., Thomas B. Parr, Tsutomu Ohno, Kevin Simon

Publications

Parallel Factor Analysis (PARAFAC) is a well-established method for characterizing dissolved organic matter (DOM). While methods for sample processing and PARAFAC analysis are well defined and robust, subsequent classification of DOM fluorescence components and comparisons of components among studies remain highly qualitative. Because these comparisons often guide the interpretation of subsequent data, it is important that quantitatively accurate comparisons be made. We developed a statistical tool, comPARAFAC, using a modified Tucker’s Congruence Coefficient (mTCC), an established method of factor comparison, to provide a quantitative basis for comparing models. To develop and test this tool we used mTCC to compare factors …


Fisheries Management In A Changing Climate: Lessons From The 2012 Ocean Heat Wave In The Northwest Atlantic., Katherine E. Mills, Andrew Pershing, Curtis J. Brown, Yong Chen, Fu-Sung Chiang, Daniel S. Holland, Sigrid Lehuta, Janet A. Nye, Jenny C. Sun, Andrew C. Thomas, Richard A. Wahle Jun 2013

Fisheries Management In A Changing Climate: Lessons From The 2012 Ocean Heat Wave In The Northwest Atlantic., Katherine E. Mills, Andrew Pershing, Curtis J. Brown, Yong Chen, Fu-Sung Chiang, Daniel S. Holland, Sigrid Lehuta, Janet A. Nye, Jenny C. Sun, Andrew C. Thomas, Richard A. Wahle

Publications

No abstract provided.


Agent-Based Modeling Of Harvest Decisions By Small Scale Forest Landowners In Maine, Usa, Jessica Leahy, Erika Reeves, Kathleen Bell, Crista L. Straub, Jeremy Wilson Jan 2013

Agent-Based Modeling Of Harvest Decisions By Small Scale Forest Landowners In Maine, Usa, Jessica Leahy, Erika Reeves, Kathleen Bell, Crista L. Straub, Jeremy Wilson

Publications

Small-scale forests are an excellent example of coupled social-ecological systems, which involve human and biophysical subsystems with complex two-way feedback interactions. The multifaceted nature of landowner decisions drives a significant need to better understand decision-making processes, reactions to policy, and combined impacts on ecosystems in a comprehensive manner. Small-scale forests require an integrated approach to modeling the social and biophysical components comprehensively. Agent-based modeling involves modeling individualistic behavior and interpreting patterns that emerge. The interaction between agents and their environments makes this a valuable tool to assess repeated decisions of individual landowners responding to changing environmental conditions. Agent-based models can …


Observations On The Expansion Of A Relict Population Of Eastern Oysters (Crassostrea Virginica) In A Maine Estuary: Implications For Climate Change And Restoration, Peter Larsen, Karen Wilson, Dana Morse Jan 2013

Observations On The Expansion Of A Relict Population Of Eastern Oysters (Crassostrea Virginica) In A Maine Estuary: Implications For Climate Change And Restoration, Peter Larsen, Karen Wilson, Dana Morse

Publications

The Gulf of Maine has undergone dramatic physiographic and oceanographic changes over the last several millenia resulting in some unusual biogeographic consequences. One is that there are pockets of Virginian species, including Crassostra virginica (Eastern Oyster), that survive in isolated warm water pockets, usually at the heads of estuaries. These small and vulnerable populations need documentation, protection, and restoration in order to preserve their genetic characteristics and ecological services. In this contribution, we describe the circumstances whereby tidal restoration made available 2.5 linear km of new habitat area to the relict oyster population of the Marsh River, ME, the northernmost …


Mercury Bioaccumulation In Wood Frogs Developing In Seasonal Pools, Cynthia Loftin, Aram J K Calhoun, Sarah J. Nelson, Adria A. Elskus, Kevin Simon Dec 2012

Mercury Bioaccumulation In Wood Frogs Developing In Seasonal Pools, Cynthia Loftin, Aram J K Calhoun, Sarah J. Nelson, Adria A. Elskus, Kevin Simon

Publications

Seasonal woodland pools contribute significant biomass to terrestrial ecosystems through production of pool-breeding amphibians. The movement of amphibian metamorphs potentially transports toxins bioaccumulated during larval development in the natal pool into the surrounding terrestrial environment. We documented total mercury (THg) in seasonal woodland pool water, sediment, litter, and Lithobates sylvaticus LeConte (Wood Frog) in Acadia National Park, ME. THg concentrations in pool water varied over the study season, increasing during April-June and remaining high in 2 of 4 pools upon October refill. Water in pools surrounded by softwoods had lower pH, greater dissolved organic carbon, and greater THg concentrations than …


Science Communication And Vernal Pool Conservation: A Study Of Local Decision Maker Attitudes In A Knowledge-Action System, Bridie Mcgreavy, Thomas Webler, Aram J K Calhoun Mar 2012

Science Communication And Vernal Pool Conservation: A Study Of Local Decision Maker Attitudes In A Knowledge-Action System, Bridie Mcgreavy, Thomas Webler, Aram J K Calhoun

Publications

designing and implementing boundary management strategies, and highlights the complexities of direct engagement between scientists and policymakers and the implications of that engagement for scientists and their academic institutions. We draw from a case study conducted in Maine to argue that there are contexts in which the need arises for scientists to manage and span the science-policy boundary. The complexities involved in preparing scientists to engage more thoroughly in policy activities and the challenges in garnering institutional support for advancing the participation of scientists in boundary spanning activities are explored.


Emergent Behavior In A Coupled Economic And Coastline Model For Beach Nourishment, Eli D. Lazarus, D E. Mcnamara, M D. Smith, S Gopalakrishnan, A B. Murray Dec 2011

Emergent Behavior In A Coupled Economic And Coastline Model For Beach Nourishment, Eli D. Lazarus, D E. Mcnamara, M D. Smith, S Gopalakrishnan, A B. Murray

Publications

Developed coastal areas often exhibit a strong systemic coupling between shoreline dynamics and economic dynamics. "Beach nourishment", a common erosion-control practice, involves mechanically depositing sediment from outside the local littoral system onto an actively eroding shoreline to alter shoreline morphology. Natural sediment-transport processes quickly rework the newly engineered beach, causing further changes to the shoreline that in turn affect subsequent beach-nourishment decisions. To the limited extent that this landscape/economic coupling has been considered, evidence suggests that towns tend to employ spatially myopic economic strategies under which individual towns make isolated decisions that do not account for their neighbors. What happens …


Clearcutting Has A Long-Lasting Effect On Habitat Connectivity For A Forest Amphibian By Decreasing Permeability To Juvenile Movements, Viorel Popescu, Malcolm L. Hunter Jr. Jun 2011

Clearcutting Has A Long-Lasting Effect On Habitat Connectivity For A Forest Amphibian By Decreasing Permeability To Juvenile Movements, Viorel Popescu, Malcolm L. Hunter Jr.

Publications

Conservation of forest amphibians is dependent on finding the right balance between management for timber production and meeting species' habitat requirements. For many pond-breeding amphibians, successful dispersal of the juvenile stage is essential for long-term population persistence. We investigated the influence of timber-harvesting practices on the movements of juvenile wood frogs (Lithobates sylvaticus). We used a chronosequence of stands produced by clear-cutting to evaluate how stand age affects habitat permeability to movements. We conducted experimental releases of juveniles in 2008 (n = 350) and 2009 (n = 528) in unidirectional runways in four treatments: mature forest, recent clearcut, …


The Cc-Bio Project: Studying The Effects Of Climate Change On Quebec Biodiversity, Dominique Berteaux, Sylvie Blois, Jean-François Angers, Joël Bonin, Nicolas Casajus, Marcel Darveau, François Fournier, Murray Humphries, Brian Mcgill, Jacques Larivée, Travis Logan, Patrick Nantel, Catherine Périé, Frédéric Poisson, David Rodrigue, Sébastien Rouleau, Rouleau Siron, Wilfred Thuiller, Luc Vescovi Nov 2010

The Cc-Bio Project: Studying The Effects Of Climate Change On Quebec Biodiversity, Dominique Berteaux, Sylvie Blois, Jean-François Angers, Joël Bonin, Nicolas Casajus, Marcel Darveau, François Fournier, Murray Humphries, Brian Mcgill, Jacques Larivée, Travis Logan, Patrick Nantel, Catherine Périé, Frédéric Poisson, David Rodrigue, Sébastien Rouleau, Rouleau Siron, Wilfred Thuiller, Luc Vescovi

Publications

Anticipating the effects of climate change on biodiversity is now critical for managing wild species and ecosystems. Climate change is a global driver and thus affects biodiversity globally. However, land-use planners and natural resource managers need regional or even local predictions. This provides scientists with formidable challenges given the poor documentation of biodiversity and its complex relationships with climate. We are approaching this problem in Quebec, Canada, through the CC-Bio Project (http://cc‑bio.uqar.ca/), using a boundary organization as a catalyst for team work involving climate modelers, biologists, naturalists, and biodiversity managers. In this paper we present the CC-Bio Project and its …


A Multi-Scale Assessment Of Amphibian Habitat Selection: Wood Frog Response To Timber Harvesting, Sean Michael Blomquist, Malcolm L. Hunter Jr. Sep 2010

A Multi-Scale Assessment Of Amphibian Habitat Selection: Wood Frog Response To Timber Harvesting, Sean Michael Blomquist, Malcolm L. Hunter Jr.

Publications

To understand changes in habitat selection in response to timber harvesting, we used radio-telemetry data from 82 adult wood frogs (Lithobates sylvaticus, formerly Rana sylvatica) and logistic regression modelling to assess habitat selection in response to an unharvested control and 3 forest management techniques: clearcutting (with removal of all merchantable timber > 10 cm diameter), clearcutting with coarse woody debris (CWD) retention, and partial harvesting with retention of ∼50% canopy cover. At the home range scale, frogs selected the partially harvested treatment in spring 2005 and avoided the CWD-retained treatment in fall 2006. Frogs spent 5 ± 2 d (mean ± …


Comparing Relative Abundance Of Amphibians In Forest Canopy Gaps Of Natural Origin Vs. Timber Harvest Origin, Carol J. Strojny, Malcolm L. Hunter Jr. Jan 2010

Comparing Relative Abundance Of Amphibians In Forest Canopy Gaps Of Natural Origin Vs. Timber Harvest Origin, Carol J. Strojny, Malcolm L. Hunter Jr.

Publications

Relative abundance of amphibians in forest canopy gaps of natural origin vs. timber harvest origin.— Small–scale canopy gaps created by logging may retain adequate habitat structure to maintain amphibian abundance. We used pitfalls with drift fences to measure relative abundance of amphibians in 44 harvested gaps, 19 natural treefall gaps, and 36 closed–canopy forest plots. Metamorphs had relatively lower capture rates in large harvest gaps for Ambystoma maculatum, Lithobates catesbeianus, L. clamitans, and L. sylvaticus but we did not detect statistically significant (p < 0.1) differences among gap types for Lithobates palustris metamorphs. L. clamitans juveniles and L. sylvaticus juveniles and adults had relatively …


Thresholds And The Mismatch Between Environmental Laws And Ecosystems, Malcolm L. Hunter Jr., Michael J. Bean, David Lindenmayer, David S. Wilcove Jul 2009

Thresholds And The Mismatch Between Environmental Laws And Ecosystems, Malcolm L. Hunter Jr., Michael J. Bean, David Lindenmayer, David S. Wilcove

Publications

No abstract provided.