Pinyon-juniper removal has long-term effects on mammals

Gallo, Travis; Stinson, Lani T.; Pejchar, Liba

doi:10.1016/j.foreco.2016.06.029

Cited by 14 publications

(5 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although black bear habitat quality can increase after burns (Crabb et al 2022), no information is available on black bear responses to wildfire in the Sierra Nevada and there is evidence for postfire conversion of conifer forest to shrubland in the region (Coop et al 2020, Paudel et al 2022). Furthermore, piñon‐juniper removal to benefit sagebrush‐obligate species is widespread in the Great Basin (Olsen et al 2021), leading to potential tradeoffs between black bear conservation in Nevada and conservation of sagebrush species imperiled throughout their range (Gallo et al 2016, Zeller et al 2021). Our study design and estimates presented here provide important population baseline information and a useful framework to assess the impact of these ongoing landscape changes on black bear distribution and abundance in Nevada.…”

Section: Discussionmentioning

confidence: 99%

Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition

et al. 2023

View full text Add to dashboard Cite

In the first 2 decades of the twenty-first century, American black bear (Ursus americanus) populations rebounded with range expansions into areas where the species was previously extirpated. While there are a number of factors that limit range expansion, habitat quality and availability are among the most important. Such factors may be particularly important in western Nevada, USA, at the transition zone of the Sierra Nevada and the Great Basin Desert. We deployed a multifaceted data collection system including motion-sensitive cameras, noninvasive hair sampling and genotyping, and global positioning system (GPS) tracking. We analyzed data using spatial capture-recapture to estimate population density and dynamic occupancy models to estimate habitat use. Black bear habitat use and density were substantially higher in the Sierra Nevada than the Great Basin Desert and had strong positive relationships with the presence of conifer land cover in the transition zone. The average black bear density was >4 times higher in the mixed-conifer forests of the Sierra Nevada (12.4 bears/100 km 2 ) than in desert mountain ranges with piñon (Pinus monophylla)-juniper (Juniperus spp.) woodland (2.7 bears/100 km 2 ). The low-elevation shrub and grassland portions of the study area had even lower estimated black bear density (0.6 bears/100 km 2 ) and probability of use (0.03, 95% CI = 0.00-0.09). Across these spatially variable configurations in black bear density, we estimated the population size to be

show abstract

Section: Discussionmentioning

confidence: 99%

Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Reference sampling sites ( n = 50) had been previously established across the study area for an ongoing wildlife‐monitoring program (Gallo et al ). All reference sites were randomly placed on the landscape using GIS and were buffered from all forms of known anthropogenic disturbance (e.g., historically chained areas, energy well pads, roads) by ≥250 m. We ground‐truthed each reference site to verify that it was within pinyon–juniper woodlands.…”

Section: Methodsmentioning

confidence: 99%

“…In addition to a diverse bird community (Sedgwick ), American black bears ( Ursus americanus ), coyotes ( Canis latrans ), mountain lions ( Puma concolor ), elk ( Cervus canadensis ), mule deer ( Odocoileus hemionus ), golden‐mantled ground squirrels ( Callospermophilus lateralis ), chipmunks ( Tamias spp. ), and mountain cottontails ( Sylvilagus nuttallii ) were common mammal species (Gallo et al ).…”

Section: Study Areamentioning

confidence: 99%

Woodland reduction and long‐term change in breeding bird communities

Gallo

Pejchar

2016

J Wildl Manag

Self Cite

View full text Add to dashboard Cite

Forested ecosystems in the western United States have been the focus of tree reduction efforts for decades, with the intent of improving forage for livestock and wildlife. Yet, the long‐term consequences of tree removal for biodiversity are virtually unknown. We conducted bird and vegetation surveys in northwestern Colorado where trees were mechanically removed over 40 years ago. We evaluated differences in avian species richness and community composition, and used a Bayesian hierarchical approach to determine if tree removal had long‐term effects on bird density. We found that tree reduction initiates a long‐term change from dense pinyon (Pinus edulis)‐juniper (Juniperus osteosperma) woodlands to sagebrush scrub, fundamentally altering bird community composition. Disturbed sites were used by fewer species and largely dominated by shrubland‐obligate birds. Further, bird densities were markedly different between historically disturbed sites and reference sites. Densities of many species were correlated with specific vegetative characteristics (e.g., mean tree diameter) that could be factored into management decisions to better sustain diverse natural communities. © 2016 The Wildlife Society.

show abstract

“…These results suggest caution in implementing treatments to restore ecosystem structure if changes in woodland extent from the very onset of settlement have not been assessed. This is critical as unnecessary piñon and juniper removal is likely to be detrimental to local wildlife species richness and diversity, as woodlands provide important habitat for many animals (Bombaci & Pejchar (2016); Gallo et al (2016)), and especially given recent and projected increases in widespread drought-induced piñon mortality over the past several decades (Breshears et al (2005); Shaw et al (2018);…”

Section: Conclusion and Management Implicationsmentioning

confidence: 99%

Change in Piñon-Juniper Woodland Cover Since Euro-American Settlement: Expansion Versus Contraction Associated with Soil Properties

Amme

Pague

Redmond

2020

Rangeland Ecology & Management

View full text Add to dashboard Cite

Woodland and forest ecosystems across western North America have experienced increased density and expansion since the early 1900s, including in the widely distributed piñonjuniper vegetation type of the U.S. Southwest. Fire suppression and grazing are often cited as the main drivers of these historic changes and have led to extensive tree-reduction treatments across the region. However, much of the scientific literature on piñon-juniper expansion dates back only to the early 1900s, which is generally a half a century after Euro-American settlement. This study uses General Land Office (GLO) surveys to establish piñon-juniper woodland extent in the late 19 th century at the incipient stages of Euro-American settlement in southeastern Colorado and compares this data with 2017 aerial imagery of woodland cover. We found substantial amounts of woodland contraction as well as expansion: approximately 61% of historically dense woodland is now savanna or open (treeless) whereas approximately 57% of historically open areas are now savannas or woodlands, although analyses at finer spatial scales suggest considerably more contraction relative to expansion. We assessed change in woodland cover and extent as a function of soil type, a dominant biophysical control, and found that the highest rates of expansion occurred upon shallow, rocky soil types with low soil available water capacity (AWC). These low soil AWC areas support little herbaceous vegetation and thus had less grazing pressure and were unlikely to carry frequent surface fires historically, suggesting iii that fire suppression and grazing were not the primary drivers of expansion. Meanwhile, the significant contractions in woodland extent occurred on deeper, upland soils with higher soil AWC, which support greater herbaceous cover and were likely where early settlement and treecutting was prevalent. Our results provide mixed support for the often widespread assumption of woodland expansion since Euro-American settlement and suggest that the expansion that has occurred in our study area is unlikely a result of past grazing or fire suppression. This paper uses important, underutilized sources of ecological data in order to more directly assess the earliest effects of Euro-American settlement on one of the U.S. Southwest's most prevalent and important vegetation types.

show abstract

Pinyon-juniper removal has long-term effects on mammals

Cited by 14 publications

References 41 publications

Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition

Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition

Woodland reduction and long‐term change in breeding bird communities

Change in Piñon-Juniper Woodland Cover Since Euro-American Settlement: Expansion Versus Contraction Associated with Soil Properties

Contact Info

Product

Resources

About