Life Sciences Commons^™

Influence Of Forest-To-Silvopasture Conversion And Drought On Components Of Evapotranspiration, Adam P. Coble, Alexandra R. Contosta, Richard G. Smith, Nathan W. Siegert, Matthew A. Vadeboncoeur, Katie A. Jennings, Anthony J. Stewart, Heidi Asbjornsen

Natural Resources & the Environment

The northeastern U.S. is projected to experience more frequent short-term (1-2 month) droughts interspersed among larger precipitation events. Agroforestry practices such as silvopasture may mitigate these impacts of climate change while maintaining economic benefits of both agricultural and forestry practices. This study evaluated the effects of forest-to-silvopasture (i.e., 50% thinning) conversion on the components of evapotranspiration (transpiration, rainfall interception, and soil evaporation) during the growing season of 2016. The study coincided with a late-summer drought throughout the northeastern U.S., which allowed us to also evaluate the effects of forest-to-silvopasture conversion on drought responses of multiple tree species, including Pinus strobus, …

Modelling Associations Between Public Understanding, Engagement And Forest Conditions In The Inland Northwest, Usa., Joel N. Hartter, Forrest R. Stevens, Lawrence C. Hamilton, Russell G. Congalton, Mark J. Ducey, Paul T. Oester

Natural Resources & the Environment

Abstract Opinions about public lands and the actions of private non-industrial forest owners in the western United States play important roles in forested landscape management as both public and private forests face increasing risks from large wildfires, pests and disease. This work presents the responses from two surveys, a random-sample telephone survey of more than 1500 residents and a mail survey targeting owners of parcels with 10 or more acres of forest. These surveys were conducted in three counties (Wallowa, Union, and Baker) in northeast Oregon, USA. We analyze these survey data using structural equation models in order to assess …

Optimal Land Cover Mapping And Change Analysis In Northeastern Oregon Using Landsat Imagery., Michael J. Campbell, Russell G. Congalton, Joel N. Hartter

Natural Resources & the Environment

Abstract The necessity for the development of repeatable, efficient, and accurate monitoring of land cover change is paramount to successful management of our planet’s natural resources. This study evaluated a number of remote sensing methods for classifying land cover and land cover change throughout a two-county area in northeastern Oregon (1986 to 2011). In the past three decades, this region has seen significant changes in forest management that have affected land use and land cover. This study employed an accuracy assessment-based empirical approach to test the optimality of a number of advanced digital image processing techniques that have recently emerged …

Maximum Likelihood Parametric Reconstruction Of Forest Vertical Structure From Inclined Laser Quadrat Sampling., Mark J. Ducey

Natural Resources & the Environment

Abstract

Forest vertical structure is critical to ecological function, and provides a crucial link to air- and spaceborne remote sensing (including LiDAR), but is difficult to measure from the ground. Laser point quadrat sampling has been suggested as one alternative, but previous statistical approaches to modeling forest structure using such data have required impractical sample sizes. Here, I develop the theory for maximum likelihood estimation of a parametric model of forest vertical structure, and illustrate it using inclined point quadrat sampling with a handheld laser. Results from three forest stands in arctic Norway suggest excellent qualitative agreement with structure derived …

Effects Of Invasive Winter Moth Defoliation On Tree Radial Growth In Eastern Massachusetts, Usa., Michael J. Simmons, Thomas D. Lee, Mark J. Ducey, Joseph S. Elkinton, George H. Boettner, Kevin J. Dodds

Natural Resources & the Environment

Abstract

Winter moth, Operophtera brumata L. (Lepidoptera: Geometridae), has been defoliating hardwood trees in eastern Massachusetts since the 1990s. Native to Europe, winter moth has also been detected in Rhode Island, Connecticut, eastern Long Island (NY), New Hampshire, and Maine. Individual tree impacts of winter moth defoliation in New England are currently unknown. Using dendroecological techniques, this study related annual radial growth of individual host (Quercus spp. and Acer spp.) trees to detailed defoliation estimates. Winter moth defoliation was associated with up to a 47% reduction in annual radial growth of Quercus trees. Latewood production of Quercus was reduced by …

Invasion Of Winter Moth In New England: Effects Of Defoliation And Site Quality On Tree Mortality., Michael J. Simmons, Thomas D. Lee, Mark J. Ducey, Kevin J. Dodds

Natural Resources & the Environment

Abstract

Widespread and prolonged defoliation by the European winter moth, Operophtera brumata L., has occurred in forests of eastern Massachusetts for more than a decade and populations of winter moth continue to invade new areas of New England. This study characterized the forests of eastern Massachusetts invaded by winter moth and related the duration of winter moth defoliation estimated using dendrochronology to observed levels of tree mortality and understory woody plant density. Quercus basal area mortality in mixed Quercus and mixed Quercus-Pinus strobus forests in eastern Massachusetts ranged from 0-30%; mortality of Quercus in these forests was related to site …

Carbon Benefits From Protected Areas In The Conterminous United States, Daolan Zheng, Linda S. Heath, Mark J. Ducey

Natural Resources & the Environment

Background

Conversion of forests to other land cover or land use releases the carbon stored in the forests and reduces carbon sequestration potential of the land. The rate of forest conversion could be reduced by establishing protected areas for biological diversity and other conservation goals. The purpose of this study is to quantify the efficiency and potential of forest land protection for mitigating GHG emissions.

Results

The analysis of related national-level datasets shows that during the period of 1992–2001 net forest losses in protected areas were small as compared to those in unprotected areas: -0.74% and −4.07%, respectively. If forest …

Plant Community Structure Mediates Potential Methane Production And Potential Iron Reduction In Wetland Mesocosms., Sarah E. Andrews, R Schultz, Serita D. Frey, V Bouchard, R Varner, Mark J. Ducey

Natural Resources & the Environment

Abstract

Wetlands are the largest natural source of methane to the atmosphere, but factors controlling methane emissions from wetlands are a major source of uncertainty in greenhouse gas budgets and projections of future climate change. We conducted a controlled outdoor mesocosm experiment to assess the effects of plant community structure (functional group richness and composition) on potential methane production and potential iron reduction in freshwater emergent marshes. Four plant functional groups (facultative annuals, obligate annuals, reeds, and tussocks) were arranged in a full-factorial design and additional mesocosms were assigned as no-plant controls. Soil samples from the top 10 cm were …

Carbon Benefits From Protected Areas In The Conterminous United States., Daolan Zheng, Linda S. Heath, Mark J. Ducey

Natural Resources & the Environment

Abstract

Background: Conversion of forests to other land cover or land use releases the carbon stored in the forests and reduces carbon sequestration potential of the land. The rate of forest conversion could be reduced by establishing protected areas for biological diversity and other conservation goals. The purpose of this study is to quantify the efficiency and potential of forest land protection for mitigating GHG emissions.Results: The analysis of related national-level datasets shows that during the period of 1992-2001 net forest losses in protected areas were small as compared to those in unprotected areas: -0.74% and -4.07%, respectively. If forest …

Comparison Of Forest Attributes Derived From Two Terrestrial Lidar Systems., Mark J. Ducey, Rasmus Astrup, Stefan Seifart, Hans Pretzsch, Bruce C. Larson, K David Coates

Natural Resources & the Environment

Terrestrial lidar (TLS) is an emerging technology for deriving forest attributes, including conventional inventory and canopy characterizations. However, little is known about the influence of scanner specifications on derived forest parameters. We compared two TLS systems at two sites in British Columbia. Common scanning benchmarks and identical algorithms were used to obtain estimates of tree diameter, position, and canopy characteristics. Visualization of range images and point clouds showed clear differences, even though both scanners were relatively high-resolution instruments. These translated into quantifiable differences in impulse penetration, characterization of stems and crowns far from the scan location, and gap fraction. Differences …

Late-Successional And Old-Growth Forests In The Northeastern United States: Structure, Dynamics, And Prospects For Restoration., Mark J. Ducey, John S. Gunn, Andrew A. Whitman

Natural Resources & the Environment

Abstract

Restoration of old-growth forest structure is an emerging silvicultural goal, especially in those regions where old-growth abundance falls below the historic range of variability. However, longitudinal studies of old-growth dynamics that can inform silvicultural and policy options are few. We analyzed the change in structure, including stand density, diameter distribution, and the abundance of large live, standing dead, and downed dead trees on 58 late-successional and old-growth plots in Maine, USA, and compared these to regional data from the U.S. Forest Inventory and Analysis program. Structural dynamics on the late-successional plots reflected orderly change associated with density-dependent growth and …

Carbon Changes In Conterminous Us Forests Associated With Growth And Major Disturbances., Daolan Zheng, Linda S. Heath, Mark J. Ducey, James E. Smith

Natural Resources & the Environment

Abstract

We estimated forest area and carbon changes in the conterminous United States using a remote sensing based land cover change map, forest fire data from the Monitoring Trends in Burn Severity program, and forest growth and harvest data from the USDA Forest Service, Forest Inventory and Analysis Program. Natural and human-associated disturbances reduced the forest ecosystems' carbon sink by 36% from 1992 to 2001, compared to that without disturbances in the 48 states. Among the three identified disturbances, forest-related land cover change contributed 33% of the total effect in reducing the forest carbon potential sink, while harvests and fires …

Use Of Waveform Lidar And Hyperspectral Sensors To Assess Selected Spatial And Structural Patterns Associated With Recent And Repeat Disturbance And The Abundance Of Sugar Maple (Acer Saccharum Marsh.) In A Temperate Mixed Hardwood And Conifer Forest., Jeanne E. Anderson, Mark J. Ducey, Andrew J. Fast, Mary E. Martin, Lucie C. Lepine, Marie-Louise Smith, Thomas D. Lee, Ralph O. Dubayah, Michelle A. Hofton, Peter Hyde, Birgit E. Peterson, J. Bryan Blair

Natural Resources & the Environment

Abstract

Waveform lidar imagery was acquired on September 26, 1999 over the Bartlett Experimental Forest (BEF) in New Hampshire (USA) using NASA's Laser Vegetation Imaging Sensor (LVIS). This flight occurred 20 months after an ice storm damaged millions of hectares of forestland in northeastern North America. Lidar measurements of the amplitude and intensity of ground energy returns appeared to readily detect areas of moderate to severe ice storm damage associated with the worst damage. Southern through eastern aspects on side slopes were particularly susceptible to higher levels of damage, in large part overlapping tracts of forest that had suffered the …

Potential Applications Of Randomised Graph Sampling To Invasive Species Surveillance And Monitoring., Mark J. Ducey, Kathleen M. O'Brien

Natural Resources & the Environment

Abstract

Many invasive plants and animals disperse preferentially through linear networks in the landscape, including road networks, riparian corridors, and power transmission lines. Unless the network of interest is small, or the budget for surveillance is large, it may be necessary to draw inferences from a sample rather than a complete census on the network. Desired features of a surveillance system to detect and quantify invasion include: (1) the ability to make unbiased statements about the spatial extent of invasion, the abundance of the invading organism, and the degree of impact; (2) the ability to quantify the uncertainty associated with …

Spatial Distribution Of Forest Aboveground Biomass Estimated From Remote Sensing And Forest Inventory Data In New England, Usa., Daolan Zheng, Linda S. Heath, Mark J. Ducey

Natural Resources & the Environment

Abstract

We combined satellite (Landsat 7 and Moderate Resolution Imaging Spectrometer) and U.S. Department of Agriculture forest inventory and analysis (FIA) data to estimate forest aboveground biomass (AGB) across New England, USA. This is practical for large-scale carbon studies and may reduce uncertainty of AGB estimates. We estimate that total regional forest AGB was 1,867 teragram (1012, dry weight) in 2001, with a mean AGB density of 120 Mg/ha (Standard deviation = 54 Mg/ha) ranging from 15 to 240 Mg/ha within a 95% percentile. The majority of regional AGB density was in the range of 80 to 160 Mg/ha (58.2%). …