Treesearch

It’s late fall in the high mountains of western North America and the whitebark pine (Pinus albicaulis) forests are alive with activity. Birds and mammals are feasting on the pine’s copious amounts of large seeds. When the cones ripen, the competition for the fatty, nutritious seeds - which contain “more energy than chocolate per unit of weight” according to the Cornell Laboratory of Ornithology - is a sight to see.

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of...

We used spatial optimization to allocate and prioritize prescribed fire treatments in the fire-prone Bages County, central Catalonia (northeastern Spain). The goal of this study was to identify suitable strategic locations on forest lands for fuel treatments in order to: 1) disrupt major fire movements, 2) reduce ember emissions, and 3) reduce the likelihood of large fires burning into residential communities.We first modeled fire spread, hazard and exposure metrics under historical extreme fire weather conditions, including node influence grid for surface fire pathways, crown fraction...

Sustainable fire management has eluded all industrial societies. Given the growing number and magnitude of wildfire events, prescribed fire is being increasingly promoted as the key to reducing wildfire risk. However, smoke from prescribed fires can adversely affect public health. We propose that the application of air quality standards can lead to the development and adoption of sustainable fire management approaches that lower the risk of economically and ecologically damaging wildfires while improving air quality and reducing climate-forcing emissions. For example, green fire breaks at...

Alpine treelines are expected to move upward in a warming climate, but downward in response to increases in wildfire. We studied the effects of fire on vegetation structure and composition across four alpine treeline ecotones extending from Abies lasiocarpa/Picea engelmannii forests at lower elevations, through Pinus albicaulis/Larix lyallii parkland, to alpine tundra. We estimated the probabilities of burning and transitions between states following fire among four canopy-cover (structural) classes: nonforest (0% tree cover), sparse woodland (<10% tree cover), open forest (10-40% tree...

In this analysis we introduce a broad-scale long-term overview of the US West’s costliest wildfires in relation to the natural distribution of ponderosa pine (Pinus ponderosa). The species is dependent on frequent, low-intensity burning, but in absence of this function, it has become one of the region’s most altered ecosystems (U.S. Government Accounting Office, 1999; U.S.D.A. Forest Service, 2000; Arno and Allison-Bunnell, 2002; Fiedler and Arno, 2015). This analysis illuminates the relationship between deteriorated forest conditions over very large scales and the potential for severe,...

Understanding the impacts of climate change is critical for improving the conservation and management of ecosystems worldwide. Ecosystems vary along a precipitation and temperature gradient, ranging from tropical jungles to arid deserts. The Great Basin is a semi-arid eco-region that is found within the western United States. Plant communities within the Great Basin range from sagebrush valleys to sub-alpine conifer forests found at high elevation areas. It is predicted that the Great Basin will experience prolonged periods of drought, more intense fires, and greater variability in average...

The use of bio-based fuels for energy generation can have positive or negative impacts on water and resources. To best understand these impacts, the effects of bioenergy systems on water and soil resources should be assessed as part of an integrated analysis considering environmental, social and economic dimensions. Bioenergy production systems that are strategically integrated in the landscape to address soil and water problems should be promoted where their establishment does not cause other negative impacts that outweigh these benefits. While standardized metrics, such as footprints and...

American Three-toed Woodpeckers Picoides dorsalis are considered a sensitive species by the United States Bureau of Land Management and are on the United States Fish and Wildlife Service’s Watch List. In Idaho, Oregon and Washington, they are of conservation concern due to low abundance and an apparent reliance on disturbed, old-growth forests. This species is strongly associated with Spruce Beetle Dendroctonous rufipennis epidemics, yet their occupancy relation with epidemic conditions have not been described. We studied Three-toed Woodpecker occupancy patterns in spruce–fir forests...

Limber pine (Pinus flexilis James) co-evolved with the mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) and is now also challenged by the non-native pathogen Cronartium ribicola (J.C. Fisch.) that causes the lethal disease white pine blister rust (WPBR). Previous research suggests that trees infected with WPBR can be preferred hosts for MPB. Using resin duct traits associated with MPB resistance, we tested for a relationship between resistance to MPB and WPBR in limber pine, in the absence of either biological agent. These analyses will help evaluate if MPB historically may have...