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Filters: Types: Citation (X) > Tags: {"type":"Science Themes"} (X) > partyWithName: Northeast CSC (X)

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Abstract (from http://www.tandfonline.com/doi/full/10.1080/00028487.2016.1150879): Long-term sampling of fisheries data is an important source of information for making inferences about the temporal dynamics of populations that support ecologically and economically important fisheries. For example, time series of catch-per-effort data are often examined for the presence of long-term trends. However, it is also of interest to know whether certain sampled locations are exhibiting temporal patterns that deviate from the overall pattern exhibited across all sampled locations. Patterns at these “unusual” sites may be the result of site-specific abiotic (e.g., habitat) or biotic (e.g., the presence of an invasive species)...
Concern over global environmental change and associated uncertainty has given rise to greater emphasis on fostering resilience through forest management. We examined the impact of standard silvicultural systems (including clearcutting, shelterwood, and selection) compared with unharvested controls on tree functional identity and functional diversity in three forest types distributed across the northeastern United States. Sites included the Argonne, Bartlett, and Penobscot Experimental Forests located in Wisconsin, New Hampshire, and Maine, respectively. We quantified functional trait means for leaf mass per area, specific gravity, maximum height, height achieved at 20 years, seed mass, drought tolerance, shade tolerance,...
Abstract (from Wiley Online Library): Annual distributions of waterfowl during the nonbreeding period can influence ecological, cultural, and economic relationships. We used previously developed Weather Severity Indices (WSI) that explained migration by dabbling ducks in eastern North America and weather data from the North American Regional Reanalysis to develop an open-access internet-based tool (i.e., WSI web app) to visualize and query WSI data. We used data generated by the WSI web app to determine whether the weather known to elicit southerly migration by dabbling ducks had changed, from October to April 1979 to 2013. We detected that the amount of area in the Mississippi and Atlantic Flyways with weather...
Floodplains pose challenges to managers of conservation lands because of constantly changing interactions with their rivers. Although scientific knowledge and understanding of the dynamics and drivers of river-floodplain systems can provide guidance to floodplain managers, the scientific process often occurs in isolation from management. Further, communication barriers between scientists and managers can be obstacles to appropriate application of scientific knowledge. With the coproduction of science in mind, our objectives were the following: (1) to document management priorities of floodplain conservation lands, and (2) identify science needs required to better manage the identified management priorities under...
Abstract (from http://www.sciencedirect.com/science/article/pii/S0272771416302724): Salt marshes buffer coastlines and provide critical ecosystem services from storm protection to food provision. Worldwide, these ecosystems are in danger of disappearing if they cannot increase elevation at rates that match sea-level rise. However, the magnitude of loss to be expected is not known. A synthesis of existing records of salt marsh elevation change was conducted in order to consider the likelihood of their future persistence. This analysis indicates that many salt marshes did not keep pace with sea-level rise in the past century and kept pace even less well over the past two decades. Salt marshes experiencing higher local...
We developed high-resolution climate projections for the mid- and late 21st century across the Great Lakes region, including the Midwest and Northeast United States and southern Canada. We applied a regional climate model that addresses future changes in Great Lakes’ water temperatures, ice cover, and evaporation, which critically impact lake-effect snowfall. This new dataset is highly valuable, given that most global climate models applied in the reports of the Intergovernmental Panel on Climate Change and National Climate Assessment either completely lack the Great Lakes or largely under-represent their coverage and impacts. After quantifying projected changes in weather severity based on air temperature and snow...
Abstract (from https://link.springer.com/article/10.1007/s10980-017-0540-9): Context Quantitative models of forest dynamics have followed a progression toward methods with increased detail, complexity, and spatial extent. Objectives We highlight milestones in the development of forest dynamics models and identify future research and application opportunities. Methods We reviewed milestones in the evolution of forest dynamics models from the 1930s to the present with emphasis on forest growth and yield models and forest landscape models We combined past trends with emerging issues to identify future needs. Results Historically, capacity to model forest dynamics at tree, stand, and landscape scales was constrained...
Categories: Publication; Types: Citation; Tags: Forests, Landscapes, Northeast CASC
Abstract (from http://link.springer.com/article/10.1007%2Fs10980-015-0294-1): Context Tree species distribution and abundance are affected by forces operating at multiple scales. Niche and biophysical process models have been commonly used to predict climate change effects at regional scales, however, these models have limited capability to include site-scale population dynamics and landscape-scale disturbance and dispersal. We applied a landscape modeling approach that incorporated three levels of spatial hierarchy (pixel, landtype, and ecological subsection) to model regional-scale shifts in forest composition under climate change. Objective To determine (1) how importance value of individual species will...
The Northeast United States and Atlantic Canada share many of the same types of forests, wetlands, and natural communities, and from a wildlife perspective the region is one contiguous forest. However, resources are classified and mapped differently on the two sides of the border, creating challenges for habitat evaluation, species modeling, and predicting the effects of climate change. To remedy this, ecologists from The Nature Conservancy collaborated with a committee of scientists from various Canadian institutions to produce the first international map of terrestrial habitats for northeast North America. The project used extensive spatial data on geology, soils, landforms, wetlands, elevation and climate. Additionally,...
This study set out to answer the question: “What data and modeling frameworks are needed to provide scientists reliable, climate-informed, water temperature estimates for freshwater ecosystems that can assist watershed management decision making?” To accomplish this, researchers gathered existing stream temperature data, identified data gaps, deployed stream temperature monitoring devices, and developed and tested a stream temperature model that could be regionalized across the Northeast Climate Science Center (NE CSC) domain. Polebitski and colleagues partnered with another NE CSC funded project team, NorEaST-Stream Temperature Web Portal Demonstration and Application, led by Jana Stewart (USGS Wisconsin Water...
Abstract (from: http://link.springer.com/article/10.1007/s00442-014-2881-2): Forest biomass growth is almost universally assumed to peak early in stand development, near canopy closure, after which it will plateau or decline. The chronosequence and plot remeasurement approaches used to establish the decline pattern suffer from limitations and coarse temporal detail. We combined annual tree ring measurements and mortality models to address two questions: first, how do assumptions about tree growth and mortality influence reconstructions of biomass growth? Second, under what circumstances does biomass production follow the model that peaks early, then declines? We integrated three stochastic mortality models with...
There is growing evidence that headwater stream ecosystems are vulnerable to changing climate and land use, but their conservation is challenged by the need to address the threats at a landscape scale, often through coordination with multiple management agencies and landowners. A decision faced by managers of headwater systems is how to best manage stream habitats to maximize their suitability for multiple species of conservation concern, including stream salamanders and brook trout, which occur in different parts of a stream network, are affected by both the terrestrial landscape and each other, and are likely influenced by future climate change. Because streams and terrestrial habitats are linked, decisions relating...
Headwater stream ecosystems are vulnerable to numerous threats associated with climate and land use change. In the northeastern US, many headwater stream species (e.g., brook trout and stream salamanders) are of special conservation concern and may be vulnerable to climate change influences, such as changes in stream temperature and streamflow. Federal land management agencies (e.g., US Fish and Wildlife Service, National Park Service, USDA Forest Service, Bureau of Land Management and Department of Defense) are required to adopt policies that respond to climate change and may have longer-term institutional support to enforce such policies compared to state, local, non-governmental, or private land managers. However,...
Montane regions support distinct animal and plant communities that are widely viewed as communities of high conservation concern due to their significant contribution to regional biodiversity. These communities are also thought to be particularly vulnerable to anthropogenically caused stressors such as climate change, which is generally expected to cause upward shifts and potential range restrictions in montane plant and animal distributions. In the northern Appalachian Mountains of North America, not only is it becoming warmer at mid-elevations but the ecotone between the northern hardwood and the montane coniferous forests is also shifting. Therefore, species that are limited by climate or habitat along the elevational...
Abstract: We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater...
Eastern spruce-fir forest ecosystems are among the most vulnerable to climate change within the conterminous US. The goal of this project was to develop tools to identify refugia sites most likely to support spruce-fir forest and its associated high-priority obligate spruce-fir bird species over the long-term under projected climate change scenarios. Specific research objectives included: (1) producing high-resolution (temporal and spatial) projections of spruce-fir forests, including stand characteristics like structure and composition; (2) estimating future changes in the distribution, productivity, and stand characteristics of the spruce-fir forest type due to potential changes in climate; (3) comparing the distribution...
Abstract (from http://link.springer.com/article/10.1007%2Fs10980-015-0217-1): Context Tree species distribution and abundance are affected by forces operating across a hierarchy of ecological scales. Process and species distribution models have been developed emphasizing forces at different scales. Understanding model agreement across hierarchical scales provides perspective on prediction uncertainty and ultimately enables policy makers and managers to make better decisions. Objective Our objective was to test the hypothesis that agreement between process and species distribution models varies by hierarchical level. Due to the top-down approach of species distribution models and the bottom-up approach of process...
White-tailed deer (Odocoileus virginianus) in Michigan’s Upper Peninsula exist on the edge of their climate tolerance for cold temperatures and deep snow, especially in the lake effect snow zones of the north half of the peninsula. Each year, deer migrate to conifer swamps to escape the deep snow. Many of these swamps are managed by the Michigan Department of Natural Resources (DNR) as critical deer wintering complexes (DWC), and there has been an effort to acquire and protect additional acres of DWC as deer habitat. Conifer swamps are also managed for many other values, including timber products, which are difficult or impossible to access during mild winters. Recent warming trends have resulted in a 71% decrease...
Forests in the Eastern United States are changing in response to ecological succession, tree harvest and other disturbances and climate change has the potential to further change these forests. We predicted the distribution and abundance of common tree species across portions of the Eastern U.S. under alternative climate scenarios that varied in the amount of warming by the end of the century from 1.1 to 4.2 degrees C. We used a forest landscape change model to forecast changes in tree abundances and distribution in the North Atlantic region of the U.S. while accounting for climate change, succession, and harvest. We then considered a broader region of the U.S. and combined our results with results from previous...
Abstract (from http://www.sciencedirect.com/science/article/pii/S1146609X15300059): Woody species are increasing in density, causing transition to more densely wooded vegetation states, and encroaching across ecotonal borders into non-forested ecosystems. We examined USDA Forest Service Forest Inventory and Analysis data to identify tree species that have expanded longitudinally in range, particularly into the central United States. We analyzed compositional differences within ecological regions (i.e., subsections) in eastern and western ranges of species using repeated measures ANOVA. We considered differences in outer ranges to indicate range expansion or contraction. We also estimated the shift in forest area...