Research Database
Displaying 81 - 98 of 98
Evidence of Enhanced Freezing Damage in Treeline Plants During Six Years of CO 2 Enrichment and Soil Warming
Year: 2012
Climate change and elevated atmospheric CO 2 levels could increase the vulnerability of plants to freezing. We analyzed tissue damage resulting from naturally occurring freezing events in plants from a longterm in situ CO 2 enrichment (+ 200 ppm, 2001-2009) and soil warming (+ 4°C since 2007) experiment at treeline in the Swiss Alps (Stillberg, Davos). Summer freezing events caused damage in several abundant subalpine and alpine plant species in four out of six years between 2005 and 2010. Most freezing damage occurred when temperatures dropped below -1.5°C two to three weeks after snow melt…
Publication Type: Journal Article
Carbon Outcomes from Fuels Treatment and Bioenergy Production in a Sierra Nevada Forest
Year: 2012
In temperate conifer forests of the Western USA, there is active debate whether fuels reduction treatments and bioenergy production result in decreased carbon emissions and increased carbon sequestration compared to a no-action alternative. To address this debate over net carbon stocks, we performed a carbon life-cycle analysis on data from a fuels reduction treatment in a temperate, dry conifer forest in the northern Sierra Nevada of California, USA. The analysis tracks the net ecosystem carbon balance over 50 years for two scenarios (1) fuels reduction treatment combined with bioenergy…
Publication Type: Journal Article
Placing Forestry in the Assisted Migration Debate
Year: 2012
Assisted migration (AM) is often presented as a strategy to save species that are imminently threatened by rapid climate change. This conception of AM, which has generated considerable controversy, typically proposes the movement of narrowly distributed, threatened species to suitable sites beyond their current range limits. However, existing North American forestry operations present an opportunity to practice AM on a larger scale, across millions of hectares, with a focus on moving populations of widely distributed, nonthreatened tree species within their current range limits. Despite these…
Publication Type: Journal Article
Fluvial Response to Abrupt Global Warming at the Palaeocene/Eocene Boundary
Year: 2012
Climate strongly affects the production of sediment from mountain catchments as well as its transport and deposition within adjacent sedimentary basins. However, identifying climatic influences on basin stratigraphy is complicated by nonlinearities, feedback loops, lag times, buffering and convergence among processes within the sediment routeing system. The Palaeocene/Eocene thermal maximum (PETM) arguably represents the most abrupt and dramatic instance of global warming in the Cenozoic era and has been proposed to be a geologic analogue for anthropogenic climate change. Here we evaluate the…
Publication Type: Journal Article
Living with Wildfire: The State of Practice in Western Communities
Year: 2012
On the order of Congress, the federal land and fire management agencies are collaboratively developing a “National Cohesive Wildfire Management Strategy” (Cohesive Strategy). In order to integrate the experience and insights of community stakeholders working on fire management issues in the west, leaders responsible for the Western Region Cohesive Strategy needed a strong understanding of current trends, needs and opportunities. This assessment was designed to provide that information and is intended to inform strategies, policies and programs emerging through the Cohesive Strategy and in…
Publication Type: Report
Using niche models with climate projections to inform conservation management decisions
Year: 2012
Conservation science strives to inform management decisions. Applying niche models in concert with future climate projections to project species vulnerability to extinction, range size loss, or distribution shifts has emerged as a potentially useful tool for informing resource management decisions. Making climate change niche modeling useful to conservation decisions requires centering studies on the types of decisions that are made regarding the focal taxa of a niche model study. Recent recommendations for climate adaptation strategies suggest four types of decision makers: policy, habitat…
Publication Type: Journal Article
Feedback from Plant Species Change Amplifies CO 2 Enhancement of Grassland Productivity
Year: 2012
Dynamic global vegetation models simulate feedbacks of vegetation change on ecosystem processes, but direct, experimental evidence for feedbacks that result from atmospheric CO 2 enrichment is rare. We hypothesized that feedbacks from species change would amplify the initial CO 2 stimulation of aboveground net primary productivity (ANPP) of tallgrass prairie communities. Communities of perennial forb and C 4 grass species were grown for 5 years along a field CO 2 gradient (250-500 microL/L) in central Texas USA on each of three soil types, including upland and lowland clay soils and a sandy…
Publication Type: Journal Article
Ecosystem Greenspots: Identifying Potential Drought, Fire, and Climate-Change Micro-Refuges
Year: 2012
In response to climate change and other threatening processes there is renewed interest in the role of refugia and refuges. In bioregions that experience drought and fire, micro-refuges can play a vital role in ensuring the persistence of species. We develop and apply an approach to identifying potential micro-refuges based on a time series of remotely sensed vegetation greenness (fraction of photosynthetically active radiation intercepted by the sunlit canopy; fPAR). The primary data for this analysis were NASA MODIS 16-day L3 Global 250 m (MOD13Q1) satellite imagery. This method draws upon…
Publication Type: Journal Article
Forest Protection and Forest Harvest as Strategies for Ecological Sustainability and Climate Change Mitigation
Year: 2012
An important consideration in forest management to mitigate climate change is the balance between forest carbon (C) storage and ecological sustainability. We explore the effects of management strategies on tradeoffs between forest C stocks and ecological sustainability under five scenarios, three of which included management and two scenarios which provide baselines emulating the natural forest. Managed forest scenarios were: (a) Protection (PROT), i.e., management by suppression of natural disturbance and harvest exclusion; (b) Harvest at a higher rate removing all sustainably available wood…
Publication Type: Journal Article
Estimating Consumption and Remaining Carbon in Burned Slash Piles
Year: 2012
Fuel reduction treatments to reduce fire risk have become commonplace in the fire adapted forests of western North America. These treatments generate significant woody debris, or slash, and burning this material in piles is a common and inexpensive approach to reducing fuel loads. Although slash pile burning is a common practice, there is little information on consumption or even a common methodology for estimating consumption. As considerations of carbon storage and emissions from forests increase, better means of quantifying burn piles are necessary. This study uses two methods, sector…
Publication Type: Journal Article
Responding to Climate Change in National Forests: A Guidebook for Developing Adaptation Options
Year: 2011
This guidebook contains science-based principles, processes, and tools necessary to assist with developing adaptation options for national forest lands. The adaptation process is based on partnerships between local resource managers and scientists who work collaboratively to understand potential climate change effects, identify important resource issues, and develop management options that can capitalize on new opportunities and reduce deleterious effects. Because management objectives and sensitivity of resources to climate change differ among national forests, appropriate processes and…
Publication Type: Report
Short- and Long-term Effects of Fire on Carbon in US Dry Temperate Forest Systems
Year: 2011
Forests sequester carbon from the atmosphere, and in so doing can mitigate the effects of climate change. Fire is a natural disturbance process in many forest systems that releases carbon back to the atmosphere. In dry temperate forests, fires historically burned with greater frequency and lower severity than they do today. Frequent fires consumed fuels on the forest floor and maintained open stand structures. Fire suppression has resulted in increased understory fuel loads and tree density; a change in structure that has caused a shift from low- to high-severity fires. More severe fires,…
Publication Type: Journal Article
Forest ecosystems, disturbance, and climatic change in Washington State, USA
Year: 2010
Climatic change is likely to affect Pacific Northwest (PNW) forests in several important ways. In this paper, we address the role of climate in four forest ecosystem processes and project the effects of future climatic change on these processes across Washington State. First, we relate Douglas-fir growth to climatic limitation and suggest that where Douglas-fir is currently water-limited, growth is likely to decline due to increased summer water deficit. Second, we use existing analyses of climatic controls on tree species biogeography to demonstrate that by the mid twenty-first century,…
Publication Type: Journal Article
Fuelwood Characteristics of Northwestern Conifers and Hardwoods (Updated)
Year: 2010
This report is an update of the original publication by Oregon State University in 1987 (Resource Bulletin 60). According to agreements, researchers at the U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station and the Juneau Economic Development Council worked with Oregon State University to update this reference concerning wood energy properties. The fuelwood characteristics were reformatted and presented in tabular form, and a literature review was conducted to check for additional information published since 1987. This report provides fuelwood values for 34…
Publication Type: Report
The Forest, the Fire and the Fungi: Studying the Effects of Prescribed Burning on Mycorrhizal Fungi in Crater Lake National Park
Year: 2009
A first-of-its-kind study, conducted in a forest of old-growth ponderosa pine and white fir in Oregon’s Crater Lake National Park, explored the relationships among seasonal prescribed burning, an array of soil attributes, and mycorrhizal fungal fruiting patterns. This three-fold approach not only made the study unique, but also enabled researchers to separate the effects of fire treatment from the effects of soil attributes on fungal fruiting patterns. The study’s site encompassed three different prescribed burn treatments—applied in the early spring, late spring, and fall of 2002—as well as…
Publication Type: Report
Four centuries of soil carbon and nitrogen change after stand-replacing fire in a forest landscape in the western Cascade range of Oregon
Year: 2008
Episodic stand-replacing wildfire is a significant disturbance in mesic and moist Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests of the Pacific Northwest. We studied 24 forest stands with known fire histories in the western Cascade Range in Oregon to evaluate long-term impacts of stand-replacing wildfire on carbon (C) and nitrogen (N) pools and dynamics within the forest floor (FF, Oe and Oa horizons) and the mineral soil (0–10 cm). Twelve of our stands burned approximately 150 years ago (“young”), and the other 12 burned approximately 550 years ago (“old”). Forest floor mean C…
Publication Type: Journal Article
Has Fire Suppression Increased the Amount of Carbon Stored in Western US Forests?
Year: 2008
Active 20th century fire suppression in western US forests, and a resulting increase in stem density, is thought to account for a significant fraction of the NorthAmerican carbon sink. We compared California forest inventories from the 1930s with inventories from the 1990s to quantify changes in aboveground biomass. Stem density in mid-montane conifer forests increased by 34%, while live aboveground carbon stocks decreased by 26%. Increased stem density reflected an increase in the number of small trees and a net loss of large trees. Large trees contain a disproportionate amount of carbon,…
Publication Type: Journal Article
Do wood-boring beetles influence the flammability of deadwood?
Year:
Global warming increases the risk of wildfire and insect outbreaks, potentially reducing the carbon storage function of coarse woody debris (CWD). There is an increasing focus on the interactive effects of wildfire and insect infestation on forest carbon, but the impact of wood-boring beetle tunnels via their effect on the flammability of deadwood remains unexplored. We hypothesized that the presence of beetle holes, at natural densities, can affect its flammability positively through increased surface area and enhanced oxygen availability in the wood. To test this, wood-boring beetle holes…
Publication Type: Journal Article