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Full-Text Articles in Life Sciences

Log Proximity And Moss As Indicators Of Conifer Seedling Abundance In Old-Growth Douglas-Fir/ Hemlock Forests, Isabella Wetzler Dec 2021

Log Proximity And Moss As Indicators Of Conifer Seedling Abundance In Old-Growth Douglas-Fir/ Hemlock Forests, Isabella Wetzler

Fall Student Research Symposium 2021

It is increasingly essential to develop a comprehensive understanding of forest processes so that we may better conserve and maintain our old-growth forests in the face of climate change. In the Pacific Northwest, logs might elevate and remove conifer seedlings from light competition with moss and herbs, but seedlings growing on the forest floor may benefit from log shade. Moss can retain moisture which may result in higher water availability for seedlings, but in droughty conditions the desiccated moss might leave seedlings ‘high and dry’. Logs increase mircrosite heterogeneity, providing cool, moist microclimates for seedlings and protecting them from droughty …


Vulnerability Of Street Trees In Upper Midwest Cities To Climate Change, Leslie A. Brandt, Gary R. Johnson, Eric A. North, Jack Faje, Annamarie Rutledge Sep 2021

Vulnerability Of Street Trees In Upper Midwest Cities To Climate Change, Leslie A. Brandt, Gary R. Johnson, Eric A. North, Jack Faje, Annamarie Rutledge

Michigan Tech Publications

Urban trees play an important role in helping cities adapt to climate change, but also are vulnerable to changes in climate themselves. We developed an approach for assessing vulnerability of urban tree species and cultivars commonly planted in cities in the United States Upper Midwest to current and projected climate change through the end of the 21st century. One hundred seventy-eight tree species were evaluated for their adaptive capacity to a suite of current and future-projected climate and urban stressors using a weighted scoring system based on an extensive literature review. These scores were then evaluated and adjusted by leading …


Tree Responses To Moderate And Extreme Drought In The Northeastern United States, Ruth A. Van Kampen Aug 2021

Tree Responses To Moderate And Extreme Drought In The Northeastern United States, Ruth A. Van Kampen

Electronic Theses and Dissertations

Climate change is expected to lead to novel drought conditions in the Northeastern United States. Therefore, experimental studies that mimic these conditions are crucial to understand the potential impact on forests. Further, recent large scale dendrochronological studies suggest that spring and summer droughts may immediately impact tree growth while fall droughts may cause delayed impacts on growth the following growing season. Therefore, in this study, we investigated the impacts of six-week-long spring, summer, and fall droughts on the physiology and intra-annual growth on 288 saplings of six tree species native to the Northeastern United States. These species (deciduous broadleaf angiosperms, …


Beyond Planning Tools: Experiential Learning In Climate Adaptation Planning And Practices, Kristen M. Schmitt, Todd A. Ontl, Stephen D. Handler, Maria K. Janowiak, Leslie A. Brandt, Patricia Butler-Leopold, P. Danielle Shannon, Courtney L. Peterson, Christopher W. Swanston May 2021

Beyond Planning Tools: Experiential Learning In Climate Adaptation Planning And Practices, Kristen M. Schmitt, Todd A. Ontl, Stephen D. Handler, Maria K. Janowiak, Leslie A. Brandt, Patricia Butler-Leopold, P. Danielle Shannon, Courtney L. Peterson, Christopher W. Swanston

Michigan Tech Publications

In the past decade, several dedicated tools have been developed to help natural resources professionals integrate climate science into their planning and implementation; however, it is unclear how often these tools lead to on-the-ground climate adaptation. Here, we describe a training approach that we developed to help managers effectively plan to execute intentional, climate-informed actions. This training approach was developed through the Climate Change Response Framework (CCRF) and uses active and focused work time and peer-to-peer interaction to overcome observed barriers to using adaptation planning tools. We evaluate the effectiveness of this approach by examining participant evaluations and outlining the …


Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang May 2021

Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang

Dissertations

Changes in climate and atmospheric acidic deposition alter biogeochemical cycles in forested ecosystems. I investigated the responses of vegetation, soil, and hydro-related processes to changes in climate and acidic deposition at five high-elevation forests in the southeastern U.S. using a biogeochemical model - PnET-BGC model. I focused on change-points and thresholds concepts that were less studied in forest ecosystems as well as seasonal variability of responses and extreme events. I applied principal component analysis (PCA) to reduce the dimensionality of data. I developed a Bayesian multi-level model to derive key biogeochemical variables response to temperature and precipitation (local) and latitude …


Pheonolgy And Climate Change In The Tw Daniel Experimental Forest Meadow, Elise Riley Apr 2021

Pheonolgy And Climate Change In The Tw Daniel Experimental Forest Meadow, Elise Riley

Student Research Symposium

As the earth’s climate warms many plant species are experiencing phenological stages (the timing of their seasonal life cycle events) earlier than they previously have. Dangers of phenological stages occurring earlier in the year include a greater risk of frost kill and the possibility of the speciation of already small populations, both of which could make species more susceptible to extinction. This research focused on determining if meadow forb species within Utah State University’s TW Daniel Experimental Forest (TWDEF) have experienced earlier phenology -specifically, earlier flowering dates- over the past 52 years. Historical phenological data was obtained from journals kept …


Historic Declines In Growth Portend Trembling Aspen Death During A Contemporary Leaf Miner Outbreak In Alaska, Melissa A. Boyd, Logan T. Berner, Adrianna C. Foster, Scott J. Goetz, Brendan M. Rogers, Xanthe J. Walker, Michelle C. Mack Apr 2021

Historic Declines In Growth Portend Trembling Aspen Death During A Contemporary Leaf Miner Outbreak In Alaska, Melissa A. Boyd, Logan T. Berner, Adrianna C. Foster, Scott J. Goetz, Brendan M. Rogers, Xanthe J. Walker, Michelle C. Mack

Aspen Bibliography

Climate change-driven droughts and insect outbreaks are becoming more frequent and widespread, increasing forest vulnerability to mortality. By addressing the impacts of climate and insects on tree growth preceding death, we can better understand tree mortality risk under a changing climate. Here, we used tree stature and interannual growth (basal area increment; BAI) to assess processes leading to trembling aspen (Populus tremuloides) survival or mortality during an unprecedented leaf miner (Phyllocnistis populiella) outbreak in boreal North America. We identified eight sites (22 plots) in the longest running forest monitoring network in Alaska, spanning ~350 km of …


Consequences Of Increased Variation In Peatland Hydrology For Carbon Storage: Legacy Effects Of Drought And Flood In A Boreal Fen Ecosystem, Evan Kane, Catherine M. Dieleman, Danielle L. Rupp, Kevin H. Wyatt Feb 2021

Consequences Of Increased Variation In Peatland Hydrology For Carbon Storage: Legacy Effects Of Drought And Flood In A Boreal Fen Ecosystem, Evan Kane, Catherine M. Dieleman, Danielle L. Rupp, Kevin H. Wyatt

Michigan Tech Publications

Globally important carbon (C) stores in boreal peatlands are vulnerable to altered hydrology through changes in precipitation and runoff patterns, groundwater inputs, and a changing cryosphere. These changes can affect the extent of boreal wetlands and their ability to sequester and transform C and other nutrients. Variation in precipitation patterns has also been increasing, with greater occurrences of both flooding and drought periods. Recent work has pointed to the increasing role of algal production in regulating C cycling during flooded periods in fen peatlands, but exactly how this affects the C sink-strength of these ecosystems is poorly understood. We evaluated …


The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann Jan 2021

The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann

Electronic Theses and Dissertations

Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …


Effects Of Prescribed Fire On Drought Resistance And Recovery In Mixed Conifer Forests Of Lassen Volcanic National Park, California, Zachary J. Wenderott Jan 2021

Effects Of Prescribed Fire On Drought Resistance And Recovery In Mixed Conifer Forests Of Lassen Volcanic National Park, California, Zachary J. Wenderott

Cal Poly Humboldt theses and projects

Forests throughout much of the western United States are experiencing increasing climatic variability, often resulting in decreased forest productivity and elevated likelihood of tree mortality. Severe drought, such California’s recent 2012-2015 drought, are projected to increase in intensity, frequency, and severity throughout much of this region in coming years. Forest management has long relied on prescribed fire and mechanical thinning to reduce fuel loads and ameliorate potential fire hazards. These treatments may also have the ability to reduce stand density, alleviate competitive pressures, and allow residual trees access to critical resources during periods of extreme stress. Utilizing a long-term National …


Forest Development And Regeneration Dynamics In The Context Of Global Change And Associated Adaptation Strategies, Peter Clark Jan 2021

Forest Development And Regeneration Dynamics In The Context Of Global Change And Associated Adaptation Strategies, Peter Clark

Graduate College Dissertations and Theses

Over the past century, forested ecosystems in northeastern North America have undergone significant changes characterized by the recovery from intensive land use and impacts from the introduction of invasive insects and disease. These changes, coupled with emerging threats posed by a changing climate present challenges to the maintenance and conservation of biodiversity, ecological functions, and delivery of critical forest ecosystem services. While management strategies to increase forest resilience and mitigate impacts from climate change have been broadly proposed, there are nascent empirical evaluations of their effectiveness. To address this uncertainty, this dissertation couples field manipulations with long-term measurements to examine …


The Impacts Of Asian Longhorned Beetle On Forests In Southern New England, Olivia Fay Box Jan 2021

The Impacts Of Asian Longhorned Beetle On Forests In Southern New England, Olivia Fay Box

Graduate College Dissertations and Theses

Over the past several decades, the United States has been experiencing an influx of nonnative pests due to increased globalization, and many of these pests have the potential to permanently alter the composition, structure, and function of forests. Asian longhorned beetle (ALB) is an invasive pest that came into Worcester county, MA in 2008, where the first instance of this species invading both urban and natural forested areas was documented. Within the quarantine area for this novel invasion, 30,000 trees were removed over the course of 10 years as part of management efforts focused on harvesting all host species, primarily …