Treesearch

Accurate census is essential for endangered plant management, yet lack of resources may make complete on-the-ground census difficult to achieve. Accessibility, especially for species in fragile habitats, is an added constraint. We examined the feasibility of using UAV (unmanned aerial vehicle, drone)-based imagery for census of an endangered plant species, Arctomecon humilis (dwarf bear-poppy), an herbaceous perennial gypsophile endemic of the Mojave Desert, USA. Using UAV technology, we captured imagery at both 50-m altitude (census) and 15-m altitude (validation) at two populations,...

Landscape resistance is often disregarded in studies of range expansions and population connectivity. To assess those effects, we simulated the expansion of the Egyptian mongoose (Herpestes ichneumon) in relation to landscape resistance through kernel resistance modeling, confronting it with previously published data regarding the observed pattern of expansion and genetic diversity of the population in Portugal.We modeled population expansion as a function of shrub cover and elevation through iterative simulation of a resistance model and a null model. We then performed an overlap analysis...

We have read Cruz and Alexander’s comments regarding our manuscript titled ‘‘Evaluating Crown Fire Rate of Spread Predictions from Physics-Based Models’’ [1] and appreciate the opportunity to respond to their comments. In our original manuscript [1], we presented an evaluation of crown fire rate of spread predictions from two physics-based wildland fire behavior models: FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS). Our approach, as outlined in our original paper, relied upon using a previously published dataset of real-world crown fires, hereafter referred to as...

Bark beetles are primary disturbance agents in western US forests. Outbreaks affect goods and services associated with forest ecosystems including timber, water, fish and wildlife habitats and populations, recreation opportunities, and many others. They can also affect wildfire behavior and its intensity. Assessments and evaluations of such impacts are important information to land managers, policy makers, and forest stakeholders, as well as to the broader public. Arriving at a complete and accurate assessment and evaluation is a complex process that necessarily considers effects and...

In this issue, we cover new research ranging from using chili powder to improve native plant restoration, searching for a link between exotic white pine blister rust and mountain pine beetle resistance in limber pine, identifying how melting arctic sea ice could open new pathways for invasive species introductions, and research into a relatively newly established biocontrol agent for rush skeletonweed. This issue also sees the return of a popular section called “Ask the Experts”, and it addresses a question about the important topic of secondary weed invasion.

Federal directives including the National Seed Strategy, the President’s Memorandum on pollinators, and greater sage-grouse conservation plans emphasize the use of native species to recover ecosystems damaged by fire, mineral extraction, energy development, recreation, road construction, or other disturbances. Forbs or wildflowers are essential components of resilient, biologically and functionally diverse communities. However, restoration and rehabilitation use of native forbs in the Intermountain West remains limited. Because of this, Western Forbs: Biology, Ecology, and Use in Restoratio...

Improved predictions of tree species mortality and growth metrics following fires are important to assess fire impacts on forest succession, and ultimately forest growth and yield. Recent studies have shown that North American conifers exhibit a ‘toxicological dose‐response’ relationship between fire behavior and the resultant mortality or recovery of the trees. Prior studies have not been conclusive due to potential pseudo‐replication in the experimental design and time-limited observations. We explored whether dose‐response relationships are observed in ponderosa pine (Pinus ponderosa)...

Three-dimensional point data acquired by Terrestrial Lidar Scanning (TLS) is used as ground observation in comparisons with fire severity indices computed from Landsat satellite multi-temporal images through Google Earth Engine (GEE). Forest fires are measured by the extent and severity of fire. Current methods of assessing fire severity are limited to on-site visual inspection or the use of satellite and aerial images to quantify severity over larger areas. On the ground, assessment of fire severity is influenced by the observers’ knowledge of the local ecosystem and ability to accurately...

There is evidence that forest resiliency is declining in the western US due to recent increases in both areas burned by wildfire and the number of large fires. Fire refugia may increase forest resiliency; however, for land managers to incorporate fire refugia into their management plans, methods need to be developed to identify and rank criteria for what make fire refugia important. As part of a larger effort to build a spatially explicit ranking model for unburned islands in the inland northwestern US, we investigated the perceived importance of criteria used to inform a ranking model to...

Background: Short-term post-fire field studies have shown that native shrub cover in chaparral ecosystems negatively affects introduced cover, which is influenced by burn severity, elevation, aspect, and climate. Using the southern California 2003 Old and Simi fires and the 2008 Sesnon Fire, we investigated the role of native shrubs in post-fire ecosystem responses across gradients of elevation, aspect, climate, burn severities, fire histories, and time. We collected field estimates of species cover in 2004 and 2015 at nested sampling sites. We used structural equation models with introduce...