Treesearch

Wildfire risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of wildfire risk could benefit from recognizing and accounting for these interactions in terms of socioecological systems, also known as coupled natural and human systems (CNHS). We characterize the primary social and ecological dimensions of the wildfire risk pathology, paying particular attention to the...

Wildfires pose complex challenges to policymakers and fire agencies. Fuel break networks and area-wide fuel treatments are risk-management options to reduce losses from large fires. Two fuel management scenarios covering 3% of the fire-prone Algarve region of Portugal and differing in the intensity of treatment in 120-m wide fuel breaks were examined and compared with the no-treatment option. We used the minimum travel time algorithm to simulate the growth of 150 000 fires under the weather conditions historically associated with large fires. Fuel break passive effects on burn probability,...

The surface air warming over the Arctic has been almost twice as much as the global average in recent decades. In this region, unprecedented amounts of smoldering peat fires have been identified as a major emission source of climate-warming agents. While much is known about greenhouse gas emissions from these fires, there is a knowledge gap on the nature of particulate emissions and their potential role in atmospheric warming. Here, we show that aerosols emitted from burning of Alaskan and Siberian peatlands are predominantly brown carbon (BrC) – a class of visible lightabsorbing organic...

Effectively addressing wildfire risk to communities on large multi-owner landscapes requires an understanding of the biophysical factors that influence risk, such as fuel loads, topography, and weather, and social factors such as the capacity and willingness for communities to engage in fire-mitigation activities. Biophysical and social processes often are disconnected in wildfire mitigation planning frameworks because of mismatches in scale. The different spatial and temporal scales of these processes usually are not recognized in the planning process. Forest Service scientists Alan Ager,...

We examined the dynamics of aboveground forest woody carbon pools — live trees, standing dead trees, and down wood—during the first 6 years following wildfire across a wide range of conditions, which are characteristic of California forest fires. From repeated measurements of the same plots, we estimated change in woody carbon pools as a function of crown fire severity as indicated by a post-fire index, years since fire, pre-fire woody carbon, forest type group (hardwood vs. softwood), elevation, and climate attributes. Our analysis relied on 130 U.S. national forest inventory plots...

Research has shown there is a positive relationship between urban greenness and the well-being of cityresidents. But greenness is often unevenly distributed across a city, raising environmental justice issues.In 2011 and 2012 the USDA Forest Service, Forest Inventory and Analysis program installed ground plotsin the urbanized areas of Oregon and Washington. We analyze these data for the urban areas west of theCascade Mountains, linking it with demographic data from the U.S. Census to examine the relationshipbetween greenness and socioeconomic status at a sub-regional scale. To explore some...

Water and carbon cycles are strongly coordinated and water availability is a primary limiting factor in many terrestrial ecosystems. Photosynthesis requires sufficient water supply to leaves and constraints on delivery at any point in the hydraulic continuum can lead to stomatal closure and reduced photosynthesis. Thus, maximizing water transport enhances assimilation and can provide plants with a competitive advantage. Unregulated water transport, however, can lead to excessive gradients in xylem tension that result in the development of air or vapor bubbles (i.e. embolisms) that block...

Forest resilience to climate change is a topic of national concern as our standing assets and future forestsare important to our livelihood. Many tree species are predicted to decline or disappear while othersmay be able to adapt or migrate. Efforts to quantify and disseminate the current condition of forests areurgently needed to guide management and policy. Here, we develop a new indicator to summarize rawdensity-independent mortality of forested stands by species from the last decade of the 20th century tothe first decade of the 21st century using forest inventory data. We define...

MCFire is a computer program that simulates the occurrence and effects of wildfire on natural vegetation, as a submodel within the MC1 dynamic global vegetation model. This report is a technical description of the algorithms and parameter values used in MCFire, intended to encapsulate its design and features a higher level that is more conceptual than the level provided by the computer source code, so that programmers and users can better understand its features and limitations. Two primary sources of the MCFire algorithms are the National Fire-Danger Rating System and CONSUME 3.0. MC1...

This annotated bibliography contains all citations that we could find on tree voles (Arborimus longicaudus, A. pomo) and white-footed voles (A. albipes), including many unpublished sources in museum archives, court proceedings, and agency documents. Some documents not readily available in published form or museum archives are available upon request from the compilers.