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Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

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 …


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 …


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 …


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 …


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 …


The Role Of Forest Harvesting And Subsequent Vegetative Regrowth, Viorel D. Popsedu, David A. Patrick, Malcolm L. Hunter Jr., Aram J K Calhoun Jan 2012

The Role Of Forest Harvesting And Subsequent Vegetative Regrowth, Viorel D. Popsedu, David A. Patrick, Malcolm L. Hunter Jr., Aram J K Calhoun

Publications

Conservation of forest-dependent amphibians is dependent on finding a balance between timber management and species’ habitat requirements. To examine the effect of short-term vegetative regrowth post-harvesting on amphibian habitat use, we studied the response of eight species (four forest specialists and four habitat generalists) to four forestry treatments (partial harvest, clearcut with coarse woody debris [CWD] removed, clearcut with CWD retained, and uncut control) over a 6-year period, using replicated experimental treatments in Maine, USA. Forest amphibians showed a strong negative response to clearcutting through the duration of the study, regardless of the presence of CWD, but only during the …


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, …


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 …