Geology topics

Research about Lincoln National Forest

Source-linked reports with geographic coverage including Lincoln National Forest.

3 recordsLinked to original sources

USGS2025

Evaluating slash piles as habitat for a threatened salamander

Background Amplified wildfire activity in forests of the western United States threatens biodiversity. Fuel treatments can reduce fire severity, modify fire behavior, and restore forest structure and composition, yet impacts of some treatments, including slash piling and burning, on wildlife have received little attention. Piling of residual woody material may create habitable microenvironments for species that require cool, moist microclimates for all biological and ecological functions. One such species, the Sacramento Mountain salamander ( Aneides hardii Taylor), a relictual, endemic salamander narrowly distributed in the mountains of south-central New Mexico, USA, has been found below constructed slash piles within its range, but the characteristics of occupied slash piles and the extent of their occupancy has not yet been quantified. We surveyed for Sacramento Mountain salamanders in slash piles and under logs (cover objects) adjacent to piles and within a surrounding survey plot, and related salamander occupancy to slash pile and cover object characteristics, soil moisture and temperature, and environmental setting. Results We found Sacramento Mountain salamanders in 50% of surveyed slash piles. About 90% of salamanders were found in piles that contained black plastic sheeting, which held accumulations of moist leaf litter and other forest debris. We found no differences in pile characteristics, soil variables, or environmental setting between piles occupied by salamanders and piles in which no salamanders were detected. Salamander density was highest in slash piles, ~ 10% lower under cover objects in the survey area, and ~ 23% lower under cover objects adjacent to slash piles. Conclusions Slash piles serve as habitat for Sacramento Mountain salamanders. Our results suggest that within our study area or similar environments within the species range, any comparable slash pile has the potential to be occupied by salamanders. Species and habitat conservation measures indicated by this study and the timing of historical detections into mid-October include constructing smaller, pyramidal piles that minimize log-on-log or log-ground contact, avoiding the inclusion of black plastic in piles, limiting residence time of piles on the landscape, and initiating pile burning in late October or early November, when most salamanders are likely to have retreated below the ground surface.

New Mexico↗

USGS2022

Long-term recovery of Mexican spotted owl nesting habitat after fire in the Lincoln National Forest, New Mexico

Background Dry mixed-conifer forests of the southwestern United States are experiencing rapid, anthropogenically driven fire regime change. Prior to the Euro-American settlement, most of these forests experienced frequent surface fires but are now vulnerable to uncharacteristically large, high-severity fires. Fire directly influences the structure and composition of these forests and, in turn, the wildlife that inhabit them. Changing fire regimes result in a certain decline of some species and uncertain consequences for others. The Mexican spotted owl ( Strix occidentalis lucida ) is a federally listed threatened species of particular note in southwestern mixed-conifer forests. High-severity fire is cited as the owl’s primary threat in the revised species recovery plan, but uncertainties surround the impacts of high-severity fire on the habitat of the threatened owl, particularly across a timeframe longer than a few years. Our objective was to explore the long-term (100-year) effects of fire severity on elements of forest structure vital for Mexican spotted owl nesting. We quantified structural attributes for nest/roost habitat across mixed-conifer forests that burned at varying severity levels and time periods in the last century. We then examined the drivers of structural attributes by detecting statistical differences between severity classes and time periods through permutational multivariate analysis of variance. Results High-severity fire has the strongest deleterious impact on elements of forest structure (total basal area, percent medium tree basal area, percent large tree basal area, large tree density, and canopy cover) vital to Mexican spotted owl nesting, and although the structural differences between severity classes diminish with time, it took ≥ 80–100 years to reach the structural conditions desired for Mexican spotted owl nesting after stand-replacing fires. The most important attribute measured, canopy cover, required 90–100 years after high-severity fires to reach levels most suitable for Mexican spotted owls in the Lincoln National Forest. Conclusions As fires increase in frequency, severity, and size compared to the last century, the Lincoln National Forest is projected to face an overall decrease in the structural conditions needed for Mexican spotted owl nesting habitat in this region. Short intervals between uncharacteristically high-severity fires in particular pose an imminent threat to nesting habitat.

New Mexico↗

USGS2022

Plague circulation in small mammals elevates extinction risk for the endangered Peñasco least chipmunk

Wildlife diseases are a major concern for species survival around the world. Vector-borne diseases, in particular, are problematic for both humans and wildlife. Plague is an introduced disease to North America where many species have low natural resistance to infection by the causative bacterium, Yersinia pestis . Plague in the United States is often associated with large-scale epizootic events that impact rodent populations. However, we need more information regarding the effects of plague at enzootic levels and in species that rarely if ever experience epizootic events. New Mexico is a state that experiences regular epizootic plague events in several species of rodents but comparatively less is known about enzootic plague impacts within rodent communities in New Mexico. The Peñasco least chipmunk ( Neotamias minimus atristriatus ) is state-listed as endangered in New Mexico and is a candidate for listing under the federal Endangered Species Act. It likely has been extirpated from the southern portion of its range and is now observed only at high elevations in isolated areas in the White Mountains. We evaluated plague presence in the more abundant small mammal species associated with these chipmunks. We used an F1 antigen plague-specific vaccine and a placebo injection to test whether plague was present and reducing survival in western deer mouse ( Peromyscus sonoriensis ) and vole ( Microtus spp.) populations in the Lincoln National Forest. The effect of plague on survival differed among years and sites. Monthly apparent survival was up to 60 % higher for rodents given the vaccine compared to those given a placebo. Our results suggest that plague is likely impacting the small mammal community in the Lincoln National Forest and is even present at higher elevation sites where the Peñasco least chipmunk was most recently extirpated. Because least chipmunks are highly susceptible to plague, our results suggest that this disease may be an important factor in the population decline of the Peñasco least chipmunk.

New Mexico↗