Treesearch

Tests were conducted using 97 exploding targets (ammonium nitrate and aluminum powder) to examine the effects of product formulation, environment, and shooting on wildfire ignition. Tests in 2015 produced no ignitions in cold and humid weather conditions. Ignitions in 2018 under warm and dry conditions were positively related to the aluminum concentration (expressed as a percentage of the ammonium nitrate mass) and the placement of the target on a straw fuel bed rather than on a 6 in (15 cm) high steel pedestal. High speed videography and peak overpressure measured for each explosion...

Coarse woody debris has numerous functions in forest ecosystems, including wildlife habitat, fuel loading, and nutrient cycling. Standing dead trees, or snags, are particularly important resources for wildlife, and guidelines for snag recruitment and retention are integral parts of forest management. However, snag persistence is not well understood and existing models are poorly validated. We monitored fire-killed conifer snag persistence after four California wildfires and one prescribed fire. Species sampled included white fir (Abies concolor [Gord. & Glend.] Lindl. ex Hildebr.),...

This paper develops a theoretical argument for how place attachments are forged and become dynamically linked to increasingly common mobility practices. First, we argue that mobilities, rather than negating the importance of place, shift our understanding of place and the habitual ways we relate to and bond with places as distinct from a conception of place attachment premised on fixity and stability. Second, we document how the body of research on place attachment has both reinforced and contested ‘sedentaristic’ assumptions criticized within the so-called ‘mobilities turn’ in the social...

Carnivores in the central Iranian plateau have experienced considerable declines in their populations during the last century. Ecological niche models can inform conservation efforts aimed at increasing the suitability of carnivore habitat by providing valuable information on the scale-dependent relationships between species and their environment.

Wetlands play a vital role in terrestrial carbon (C) sequestration, but the sensitivity of their C stocks to disturbance remains uncertain, requiring enhanced understanding of the processes that govern C storage and removal. The unique conditions in wetlands from different hydrogeomorphic (HGM) classes likely regulate the cycling, storage and vulnerabilities of wetland soil C stocks. To determine how differences in hydrogeomorphic setting influence soil organic carbon (SOC) processing, we compared C content and composition between depressional and slope wetlands located in the Colorado...

Research Highlights: The biology of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, in Colorado’s lodgepole pine forests exhibits similarities and differences to other parts of its range. Brood emergence was not influenced by stand density nor related to tree diameter. The probability of individual tree attack is influenced by stocking and tree size. Findings have implications for understanding MPB as a disturbance agent and for developing management strategies. Background and Objectives: MPB causes extensive tree mortality of lodgepole pine, Pinus contorta Douglas ex Loudon,...

A better understanding of the response of plant growth to elevational gradients may shed light on how plants respond to environmental variation and on the physiological mechanisms underlying these responses. This study analyzed whole plant growth and physiological and morphological properties of needles in young Pinus koraiensis Sieb. et Zucc. trees at thirteen points along an elevational gradient ranging from 750 to 1350mabove sea level (a.s.l.) at the end of a growing season on Changbai Mountain in northeastern China. Sampling and analyses indicated the following; (1) many needle...

In mixed-species forests, species composition of the overstorey affects regeneration processes through its influence on seed rain intensity and micro-site characteristics. Based on extensive inventory data (1583 sample plots), this study investigated relationships between the percentages of silver fir (Abies alba Mill.), European beech (Fagus sylvatica L.), and Norway spruce (Picea abies (L.) H. Karst.) in the overstorey and in naturally established regeneration (seedlings of a height below 0.5 m). A useful framework for this analysis was the assumption that for a given stand density level...

The Great Plains is the grasslands of the central United States, but precise delineation of this region has evaded agreement due to the transition between Great Plains grasslands and forests of the eastern United States. After comparing Great Plains delineations in readily available geographic information system layers, I established a northeastern boundary using evidence from historical tree surveys during the 1800s. Additionally, I described tree presence within the Great Plains over time and potential drivers of change. The definition documented here diverges from others by including...

An accurate simulation of the sensible heat flux (H) over vegetation from thermal remote sensing requires an a priori estimate of roughness length and the excess resistance parameter kB-1. Despite being the subject of considerable interest in hydrometeorology, there still does not exist a uniform method for estimating roughness length from remote sensing techniques. This study demonstrates a turbulent diffusion method to simulate canopy‐air sensible heat. The performance of the roughness length scheme as described in Chen et al. (2013, https://doi.org/10.1175/JAMC‐D‐12‐056.1) was examined...