Treesearch

The American pika, Ochotona princeps, has been referred to as a 'canary in the coal mine' when it comes to climate change. This small rabbit relative inhabits cool alpine and subalpine mountain areas and has been shown to be sensitive to higher temperatures from both physiological experiments (Smith 1974) and from past climate transitions in the late Quaternary (Grayson 2005). Two studies in the Sierra Nevada and Great Basin showed recently abandoned pika habitats possibly due to global warming and associated heat stress (Beever et al. 2010, Millar et al. 2010). A more indirect influence...

We refer to fire as a natural disturbance, but unlike other disturbances such as forest insects and diseases, fire has had an intimate relationship with humans. Fire facilitated human evolution over two million years ago when our ancestors began to use fire to cook. Fire empowered our furbearers to adapt to cold climates, allowing humans to disperse and settle into North America when they migrated over the land bridge on the Bering Strait. American Indians used fire throughout North America because it was an ideal tool to chase away predators, clear land, facilitate travel, and increase...

On 17 May and 27 June 2011 severe cyclonic storms damaged several hundred hectares of spruce forest (Picea schrenkiana) in the Tian Shan Mountains. Bark beetle populations increased rapidly in dead and damaged trees, particularly Ips hauseri, I. typographus, I. sexdentatus, and Piiyogenesperfossus (all Coleoptera: Curculionidae), and there is concern about the likelihood of a catastrophic bark beetle outbreak. Little is known about the frequency, extent, or severity of either large storm events or bark beetle outbreaks in the Tian Shan Mountains. The ecology and outbreak dynamics of I....

For species with irruptive population behavior, dispersal is an important component of outbreak dynamics. We developed and parameterized a mechanistic model describing mountain pine beetle (Dendroctonus ponderosae Hopkins) population demographics and dispersal across a landscape. Model components include temperature-dependent phenology, host tree colonization determined by an Allee effect, and random-walk dispersal with motility conditioned by host tree density. The model was parameterized at a study site in central Idaho, United States (US), and evaluated at an independent site in...

Limitations inherent to airborne laser scanning (ALS) technology and the complex sorting and packing relationships of forests complicate accurate remote sensing of mid- and understory trees, especially in denser forest stands. Self-similarities in rank-sized individual tree distributions (ITD), e.g. bole diameter or height, are a well-understood property of natural, non-plantation, forests undergoing density dependent self-thinning and thus offer an approach to solving this problem. Alternately, semi-arid conifer forests of the southwestern USA that experience episodic wildfires and...

On February 2, 1912, Aldo Leopold (1887-1948) wrote to his fiancee, Estella Bergere, in Santa Fe that the Forest Service had appropriated $650 to build a new supervisor's quarters he had designed at Tres Piedras, New Mexico, northwest of Taos. At the time, Leopold was about to become the new Forest Supervisor of the Carson National Forest in Tres Piedras. Later that year, he built the house, which the newly married couple decided to call "Mi Casita."

Armillaria species have a global distribution and play variable ecological roles, including causing root disease of diverse forest, ornamental and horticultural trees. Accurate identification of Armillaria species is critical to understand their distribution and ecological roles. This work focused on characterizing an unidentified Armillaria isolate from a Serbian forest using pairing, sequencing of the partial large subunit and intergenic spacer-1 regions of rDNA (LSU-IGS1) and the translation elongation factor-1 alpha gene (tef-1a) genes, and phylogenetic analyses. Despite previously...

National law and policy direct the management of the National Forests, with restoring resilient forest conditions being an overarching theme. Climate is a major driver of disturbances that affect ecosystems, especially those with vegetation that show large departures from historical conditions. Drought, fire, insects, and diseases are common forest stressors whose impacts are being exacerbated by climate change. These stressors are threatening the ecosystem services that people value in the forests of the northern Rocky Mountains. The forests of most concern are the dry ponderosa pine and...

The 1910 fires, which burned more than 1.3 million ha of northern Rocky Mountain forests, provided a mission and management objectives for the newly created Forest Service. By 1911, the Priest River Experimental Station (Forest- PREF) was established in northern Idaho to help meet the needs of the Forest Service. Harry T. Gisborne, whose work was centered at PREF, proved to be one, if not the most influential and far-seeing fire researcher in the history of the Forest Service. Examples of his contributions include the fire danger rating system, fuel moisture sticks, short- and long-term...

Ash (Fraxinus, Oleaceae) species occur on most continents, within a wide range of forest tree communities. Emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), introduced into the U.S. from Asia in the late twentieth century, has caused widespread mortality, primarily in green ash, Fraxinus pennsylvanica Marsh. (Section: Melioides) and now impacts other North American ash species. The development and successful reintroduction of resistant trees requires genetic tools to evaluate population dynamics and aid in species identification. Here, we report 15 novel EST-SSR...