Forest Sciences Commons^™

Snowpack Properties Vary In Response To Burn Severity Gradients In Montane Forests, Jordan Maxwell, Samuel B. St. Clair

Aspen Bibliography

Wildfires are altering ecosystems globally as they change in frequency, size, and severity. As wildfires change vegetation structure, they also alter moisture inputs and energy fluxes which influence snowpack and hydrology. In unburned forests, snow has been shown to accumulate more in small clearings or in stands with low to moderate forest densities. Here we investigate whether peak snowpack varies with burn severity or percent overstory tree mortality post-fire in a mid-latitude, subalpine forest. We found that peak snowpack across the burn severity gradients increased 15% in snow-water equivalence (SWE) and 17% in depth for every 20% increase in overstory …

Future Climate Change Will Have A Positive Effect On Populus Davidiana In China, Jie Li, Guan Liu, Qi Lu, Yanru Zhang, Guoqing Li, Sheng Du

Aspen Bibliography

Since climate change significantly affects global biodiversity, a reasonable assessment of the vulnerability of species in response to climate change is crucial for conservation. Most existing methods estimate the impact of climate change on the vulnerability of species by projecting the change of a species’ distribution range. This single-component evaluation ignores the impact of other components on vulnerability. In this study, Populus davidiana (David’s aspen), a tree species widely used in afforestation projects, was selected as the research subject under four future climate change scenarios (representative concentration pathway (RCP)2.6, RCP4.5, RCP6.0, and RCP8.5). Exposure components of range change as well …

Everyone In: A Road Map For Science-Based, Collaborative Restoration Of Western Quaking Aspen, Sue Miller

Aspen Bibliography

With concern over the health of aspen in the Intermountain West, public and private land managers need better guidance for evaluating aspen condition and selecting and implementing actions that will be effective in restoring aspen health. The Utah Forest Restoration Group collaboratively synthesized a step-by-step approach for aspen restoration that was applicable to western U.S. forests. In a successful case study in shared stewardship, these restoration guidelines were applied to a challenging real-world setting.The Monroe Mountain Aspen Ecosystem Restoration Project, addressed diverse public and private lands needs and interests using an “All Hands, All Lands” strategy. The Monroe Mountain Working …

Importance Of Tree-And Species-Level Interactions With Wildfire, Climate, And Soils In Interior Alaska: Implications For Forest Change Under A Warming Climate, Adrianna C. Foster, Amanda H. Armstrong, Jacquelyn K. Shuman, Herman H. Shugart, Brendan M. Rogers, Michelle C. Mack, Scott J. Goetz, K. Jon Ranson

Aspen Bibliography

The boreal zone of Alaska is dominated by interactions between disturbances, vegetation, and soils. These interactions are likely to change in the future through increasing permafrost thaw, more frequent and intense wildfires, and vegetation change from drought and competition. We utilize an individual tree-based vegetation model, the University of Virginia Forest Model Enhanced (UVAFME), to estimate current and future forest conditions across sites within interior Alaska. We updated UVAFME for application within interior Alaska, including improved simulation of permafrost dynamics, litter decay, nutrient dynamics, fire mortality, and postfire regrowth. Following these updates, UVAFME output on species-specific biomass and stem density …

Remote Sensing Of Ploidy Level In Quaking Aspen (Populus Tremuloides Michx.), Benjamin Blonder, Bente J. Graae, Burke Greer, Marja Haagsma, Kenny Helsen, Rozália E. Kapás, Henry Pai, Jolanta Rieksta, Dillon Sapena, Christopher J. Still, Richard Strimbeck

Aspen Bibliography

1. Ploidy level in plants may influence ecological functioning, demography and response to climate change. However, measuring ploidy level typically requires intensive cell or molecular methods.
2. We map ploidy level variation in quaking aspen, a dominant North American tree species that can be diploid or triploid and that grows in spatially extensive clones. We identify the predictors and spatial scale of ploidy level variation using a combination of genetic and ground‐based and airborne remote sensing methods.
3. We show that ground‐based leaf spectra and airborne canopy spectra can both classify aspen by ploidy level with a precision‐recall harmonic mean of 0.75–0.95 and …

Pleasantview Hills Aspen Stand Diversity Project: Environmental Assessment, Pocatello Field Office

Aspen Bibliography

The Bureau of Land Management (BLM) Pocatello Field Office (PFO) has prepared this Environmental Assessment (EA) to analyze the environmental impacts of implementing treatments on aspen stands in the Pleasantview Hills area. This EA discloses the direct, indirect, and cumulative environmental effects that would result from implementation of this proposal as required by the National Environmental Policy Act (NEPA) of 1969. This EA will determine whether to prepare an Environmental Impact Statement (EIS) or a Finding of No Significant Impact (FONSI) based on environmental impact context and intensity, thereby informing agency decision making. Guidance for EA organization is determined by …

Sudden Aspen Decline: A Review Of Pattern And Process In A Changing Climate, Jack A. Singer, Rob Turnbull, Mark Foster, Charles Bettigole, Brent R. Frey, Michelle C. Downey, Kristofer R. Covey, Mark S. Ashton

Aspen Bibliography

The American quaking aspen (Populus tremuloides Michx.) and its close relative, the Eurasian quaking aspen (Populus tremula L.), cover a realm that is perhaps the most expansive of all tree species in the world. In North America, sudden aspen decline (SAD) is a growing concern that marks the rapid decline of quaking aspen trees leading to mortality at the stand and landscape scale. Research suggests that drought and water stress are the primary causes of SAD. Predisposing factors (age, structure, and landscape position), as well as associated stressors (i.e., pests and pathogens), have been linked to mortality in affected stands. …

Impacts Of Climate And Insect Herbivory On Productivity And Physiology Of Trembling Aspen (Populus Tremuloides) In Alaskan Boreal Forests, Melissa A. Boyd, Logan T. Berner, Patricia Doak, Scott J. Goetz, Brendan M. Rogers, Diane Wagner, Xanthe J. Walker, Michelle C. Mack

Aspen Bibliography

Climate change is impacting forested ecosystems worldwide, particularly in the Northern Hemisphere where warming has increased at a faster rate than the rest of the globe. As climate warms, trembling aspen (Populus tremuloides) is expected to become more successful in northern boreal forests because of its current presence in drier areas of North America. However, large-scale productivity decline of aspen has recently been documented throughout the United States and Canada as a result of drought and insect outbreaks. We used tree ring measurements (basal area increment (BAI) and stable carbon isotopes (δ 13C)) and remote sensing indices …

Guidelines For Aspen Restoration In Utah With Applicability To The Intermountain West, Stanley G. Kitchen, Patrick N. Behrens, Sherel K. Goodrich, Ashley Green, John Guyon, Mary O'Brien, David Tart

Aspen Bibliography

As highly productive and biologically diverse communities, healthy quaking aspen (Populus tremuloides; hereafter aspen) forests provide a wide range of ecosystem services across western North America. Western aspen decline during the last century has been attributed to several causes and their interactions, including altered fire regimes, drought, excessive use by domestic and wild ungulates, and conifer encroachment. Today’s managers need science-based guidance to develop and implement strategies and practices to restore structure, processes, and resilience to the full range of aspen functional types across multiple spatial scales. In these guidelines, we detail a process for making step-by-step decisions …

Drought And Freezing Vulnerability Of The Isolated Hybrid Aspen Populus X Smithii Relative To Its Parental Species, P. Tremuloides And P. Grandidentata, Nicholas J. Deacon, Jake J. Grossman, Jeannine Cavender-Bares

Aspen Bibliography

Aim

We assessed the vulnerability of an isolated, relictual Pleistocene hybrid aspen population of conservation interest (Populus x. smithii ) and the nearest populations of its parent species (Populus grandidentata and Populus tremuloides ) to springtime post‐bud break freezing and growing season drought stress. Response to these stressors in the three taxa was compared in terms of avoidance and tolerance.

Location

North American Midwest; USA.

Methods

Unique genets from the hybrid Niobrara River population and from the two parental populations were propagated in a common garden from rhizome cuttings. We tracked their phenology before and after bud break …

Biodiversity Within Aspen Forests, Paul C. Rogers

Aspen Bibliography

Aspen have long been known for supporting lush vegetation and rich wildlife habitat. These features, alongside brilliant green and gold seasonal coloration, accompany a broadly appreciated aesthetic for aspen forests by the public-at-large. However, in earlier times timber producers in many locales considered aspen to have low value and actively eliminated them. More recent research has pointed out that relative moisture held within aspen communities facilitates a wide array of species – collectively, biodiversity – compared to surrounding vegetation types. Aspen groves in the Intermountain West, for example, are known to be second only to riparian forests is supporting the …

Beaver And Aspen: Synergy Among Keystone Species, Stephen N. Bennett, Nicolaas Bouwes, Paul C. Rogers

Aspen Bibliography

In the West, climate change is likely to increase the frequency, intensity, and duration of drought. Restoration of soils and water storage capacity can help create resilient uplands and riverscapes (i.e., streams and the valley bottoms). Over the past two centuries, common land uses, the removal of beaver and wood, straightening of streams, and damage to riparian areas have created simplified, structurally starved, riverscapes. Degraded streams are very efficient at transporting water, sediment, and nutrients downstream. Aspen forests are also biological hotspots that have been degraded by past land uses such as overbrowsing ungulates, land clearing, fire suppression, and outright …

Burn Severity And Fire History In The Northwestern Canadian Boreal Forest: Drivers And Ecological Outcomes, Ellen Whitman

Aspen Bibliography

Wildfire is the dominant stand-renewing disturbance in the northwestern Canadian boreal forest. Fires burn extensive areas in Canada, disturbing an average of 1.96 Mha yr−1, primarily in the boreal zone. Fires generally occur every ~30 – > 200 years in this region, due in part to a lack of fuel that allows young stands to resist reburning. Boreal understory plants and trees are adapted to stand-renewing wildfire through mechanisms such as serotiny, seed banking, and resprouting from roots and rhizomes of top-killed individuals. Such adaptations confer resilience to boreal forests, and post-fire vegetation communities generally resemble the pre-fire ones, following a …

Role Of Wildfire And Topography In Shaping Aspen Regeneration After The Hayman Fire, Co, Usa, Arianna A. B. Porter

Aspen Bibliography

Unusually rapid and widespread mortality in Quaking aspen (Populus tremuloides) has been documented throughout the 21st century primarily as a result of warm, dry weather conditions. Although aspen are not drought-adapted, aspen are well adapted to wildfire. Increases in wildfire severity and extent as a result of climate change may provide opportunities for aspen regeneration, especially at mid- and high-elevation sites. Aspen's sensitivity to drought suggests that regeneration following fire might be constrained to cooler and wetter topographic locations on the landscape which reduce drought stress on vegetation. While aspen mortality is demonstrated to occur at low elevation sites, aspen …

The Role Of Disease & Insects In Aspen Ecology, John C. Guyon Ii

Aspen Bibliography

Aspen is a keystone species in montane forests, and enhances a number of key resource values including wildlife habitat, water resources, and fire behavior. Recently, aspen forests have experienced episodes of dieback and decline across western North America (Worrall et al. 2010, Guyon and Hoffman 2011). A large proportion of the dieback and decline has been linked to drought stress or drought-prone locations (Hanna and Kulakowski 2012). However, insects and diseases are commonly found in declining aspen stands, leading to confusion about the role of insects and diseases in aspen ecology. Additionally, aspen has a reputation for being susceptible to …

Surface Fire To Crown Fire: Fire History In The Taos Valley Watersheds, New Mexico, Usa, Lane B. Johnson, Ellis Q. Margolis

Aspen Bibliography

Tree-ring fire scars, tree ages, historical photographs, and historical surveys indicate that, for centuries, fire played different ecological roles across gradients of elevation, forest, and fire regimes in the Taos Valley Watersheds. Historical fire regimes collapsed across the three watersheds by 1899, leaving all sites without fire for at least 119 years. Historical photographs and quaking aspen (Populus tremuloides Michx.) ages indicate that a high-severity fire historically burned at multiple high-elevation subalpine plots in today’s Village of Taos Ski Valley, with large high-severity patches (>640 ha). Low-severity, frequent (9–29-year median interval) surface fires burned on the south aspects …

Climate Change, Woodpeckers, And Forests: Current Trends And Future Modeling Needs, Eric S. Walsh, Kerri T. Vierling, Eva Strand, Kristina Bartowitz, Tara W. Hudiburg

Aspen Bibliography

The structure and composition of forest ecosystems are expected to shift with climate‐induced changes in precipitation, temperature, fire, carbon mitigation strategies, and biological disturbance. These factors are likely to have biodiversity implications. However, climate‐driven forest ecosystem models used to predict changes to forest structure and composition are not coupled to models used to predict changes to biodiversity. We proposed integrating woodpecker response (biodiversity indicator) with forest ecosystem models. Woodpeckers are a good indicator species of forest ecosystem dynamics, because they are ecologically constrained by landscape‐scale forest components, such as composition, structure, disturbance regimes, and management activities. In addition, they are …

Predatory Hymenopteran Assemblages In Boreal Alaska: Associations With Forest Composition And Post-Fire Succession, Alexandria Wenninger, Teresa Hollingsworth, Diane Wagner

Aspen Bibliography

Changes to the fire regime in boreal Alaska are shifting the ratio of coniferous to deciduous dominance on the landscape. The increase in aspen and birch may have important effects on predatory hymenopteran assemblages by providing a source of extrafloral nectar and increasing prey availability. Furthermore, fire-induced changes in successional age alter habitat structure and microclimate in ways that may favor ants. This study is the first to characterize the influence of fire-related vegetation changes on boreal predatory hymenopteran assemblages. We compare the abundance, species richness, and composition of predatory hymenopteran assemblages among forests at different stages of succession and …