Treesearch

Decades of research have brought increasing focus to the biotic and abiotic factors associated with bark beetle infestation of North American conifers. Information is lacking, however, regarding beetle-caused mortality for ponderosa pine of the Colorado Plateau. From 1995 to 2019, we installed and periodically remeasured permanent plots in this forest type with a goal of identifying factors related to infestation probability including tree and stand characters, and abiotic factors such as temperature and precipitation. Forty-eight sites were distributed throughout the Colorado Plateau,...

Wildfire has been an important force in shaping biological diversity in forests of western North America. Patterns of reburning helped to maintain heterogenous landscapes with low tree densities that naturally limited the extent of severe stand-replacing fires. However, anthropogenic impacts over the past two centuries have dramatically altered fire activity and its ecological function, creating conditions that promote large and intense fires with no historical analog. Fuels reduction treatments represent proven methods to mitigate extreme fire events, but there is controversy over their...

The U.S. Department of Agriculture Forest Service Pacific Northwest (PNW) Research Station has launched a research initiative to improve and organize policy-relevant understanding of forest carbon accounting and fill knowledge gaps about forest carbon dynamics. There are several dimensions to forest carbon accounting, including tracking wood products flow from the forest to various destinations. More information is needed to improve the accounting of timber harvested within the Pacific coast region (PCR; British Columbia, California, Oregon, and Washington) but processed elsewhere. We used...

Water vapor sorption is a fundamental characteristic of wood as a building material. Apart from empirical prediction, models are often used to interpret the time-dependent process of water vapor uptake (sorption kinetics) and equilibrium states of water in wood (sorption isotherms). This paper summarizes our recent investigations into measurement methods and popular models that are widely used for interpreting these physical phenomena. Commonly used criteria for determining equilibrium moisture content with the dynamic vapor sorption technique yield much larger errors than previously...

1. The colonization of suitable yet unoccupied habitat due to natural dispersal or human introduction can benefit recovery of threatened species. Predicting habitat suitability and conflict potential of colonization areas can facilitate conservation planning.2. Planning for reintroduction of gray wolves (Canis lupus) to the US state of Colorado is underway. Assessing which occupancy sites minimize the likelihood of human-wolf conflict during dispersal events and seasonal movements is critical to the success of this initiative.3. We used a spatial absorbing Markov chain (SAMC) framework,...

Bigseed biscuitroot is a widespread western species, ranging from southern British Columbia to southeastern Manitoba and south to California, Nevada, Utah, Colorado, and South Dakota (Fig. 8 – note this figure includes historic and contemporary herbarium records) (Currah et al. 1983; Lesica 2012; Welsh et al. 2016). In Washington and Oregon, it is much more common east of the Cascade Range (Baker 1956; Hitchcock et al. 1961). In California, it occurs as far south as Kern and San Luis Obispo Counties (Munz and Keck 1973).

Pale agoseris is widely distributed throughout the western United States and Canada (Table 1). In the US, it occurs in all states west of Colorado and in the Dakotas, Minnesota, and Michigan (Baird 2006). Distributions of the two varieties overlap but variety glauca occurs farther south and variety dasycephala occurs farther north. In the states and provinces where their distributions overlap, variety glauca generally occupies lower elevation sites and variety dasycephala higher elevation sites (Hitchcock and Cronquist 2018). The varieties become difficult to distinguish in the northern...

Premise of research. Plants remain underrepresented among species with sequenced mitochondrial genomes (mitogenomes) because of the difficulty in assembly with short-read technology. Invasive species lag behind crops and other economically important species in this respect, resulting in a lack of tools for management and land conservation efforts. Methodology. The mitogenome of Microstegium vimineum, one of the most damaging invasive plant species in North America, was sequenced and analyzed using long-read data, providing a resource for biologists and managers. We conducted analyses of...

Bigflower agoseris occurs in locations west of central Utah. It occurs in southern British Columbia, Washington, Oregon, California, Nevada, Utah, Idaho, and Montana, and is most common in those states bordering the Pacific Ocean (Baird 2006). Variety grandiflora is most common east of the Cascade Mountains and southward on both the east and west side of the Sierra Nevada Mountains to southern California (Fig. 1). Variety leptophylla is most common west of the Cascade Mountains from Vancouver Island through Puget Sound and the Willamette Valley to the Siskiyou-Klamath Mountains of southwest...

Fish invasions threaten native freshwater ecosystems worldwide, yet methods to map biodiversity in data-deficient regions are scarce. Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta fario) have been introduced to the Himalayan ecoregion where they are sympatric with vulnerable native snow trout Schizothorax plagiostomusand Schizothorax richardsonii. We aim to evaluate potential habitat overlap among snow trout and non-native trout in the Indus and Ganges River basins, Himalayan ecoregion. We transferred maximum entropy (MaxEnt) models developed with spatially continuous...