Treesearch

Although bull trout (Salvelinus confluentus) and tailed frogs (Ascaphus montanus) have coexisted in forested Pacific Northwest streams for millennia, these iconic cold‐water specialists are experiencing rapid environmental change caused by a warming climate and enhanced wildfire activity. Our goal was to inform future conservation by examining the habitat associations of each species and conditions that facilitate co‐occupancy. We repurposed data from previous studies in the northern Rocky Mountains to assess the efficacy of bull trout electrofishing surveys for determining the occurrence...

Forest ecosystems sequester approximately half of the world’s organic carbon (C), most of it in the soil. The amount of soil C stored depends on the input and decomposition rate of soil organic matter (OM), which is controlled by the abundance and composition of the microbial and invertebrate communities, soil physico-chemical properties, and (micro)- climatic conditions. Although many studies have assessed how these site-specific climatic and soil properties affect the decomposition of fresh OM, differences in the type and quality of the OM substrate used, make it difficult to compare and...

During the COVID-19 pandemic, US public land managers faced the challenge of catering to large increases in camping demand, while maintaining social distancing guidelines. In this paper, we use multivariate linear regression to analyze weekly changes in reservations to US Forest Service (USFS) campgrounds between 2019 and 2020. The regression models estimate the impact of local COVID infection rates, public health restrictions, and spatial spillovers from proximity to National Parks (NPs), metropolitan areas and wildfire on camping demand. Our sample includes 1,688 individual USFS campgroun...

Accessibility of multispectral, multitemporal imagery combined with recent advances in cloud computing and machine learning approaches have enhanced our ability to model habitat characteristics across broad spatial and temporal scales. We integrated a large dataset of known nest and roost sites of a threatened species, the Mexican spotted owl (Strix occidentalis lucida), in the southwestern USA with Landsat imagery processed using the Continuous Change Detection and Classification (CCDC) time series algorithm on Google Earth Engine. We then used maximum entropy modeling (Maxent) to...

This report summarizes the most recent Forest Inventory and Analysis data of Nevada’s forests based on field data collected between 2009 and 2018. Many of the results were compared to those from the 2004-2013 evaluation period. Results show that Nevada’s forest land covers 10.6 million acres, most of which (63 percent or 6.7 million acres) are administered by the United States Department of the Interior Bureau of Land Management. The State’s most abundant forest type is Pinyon-juniper woodland, which covers almost 7.3 million acres. At 1.9 billion live trees, woodland softwoods (principally...

We revisited a Pinus ponderosa planting 32 years after it was established with one-year-old seedlings grown in copper-treated containers that modified their root systems. This technique was intended to promote more root egress after outplanting from the entire length of the root plug with a goal of providing greater stem stability. After excavating and digitizing the root systems of five treated and five non-treated plants, we observed that regardless of treatment, all trees initiated more roots and accumulated more root volume in apparent response to mechanical stresses invoked by wind...

The increased abundance of historically rare native tree species is symptomatic of land-use change, which causes ecosystem regime shifts. I tested for an association between mean agricultural area, a proxy for land-use change, and native tree species. I first modeled agricultural area during the years 1850 to 1997 and the historical and current percent composition of tree genera, along with the dissimilarity and difference between the historical and current composition, for the northern part of the eastern U.S. I then modeled agricultural area and current genera and species for the eastern...

Ancient giant sequoias Sequoiadendron giganteum (Lindl.) J. Buchholz are highly valued trees with limited distribution. They are the most massive trees on earth, and they have exceptional longevity (>3,000 years). Given their extraordinary resilience to wildfire, insects, and disease, most managers hoped giant sequoias would be resistant to anthropogenic change. However, the warming climate and fire exclusion-caused fuel build-up has dramatically increased the amount of high-intensity wildfire in giant sequoia groves since 2015. To better understand recent wildfire effects on large, legacy...

Arctomecon humilis (dwarf bear poppy) is an endangered gypsophile restricted to the St. George area in southern Utah, USA. Extirpation of the rare oligolectic bee Perdita meconis and decline of other native pollinators within the last 20 years has been largely attributed to the advent of invasive Africanized honeybees (AHBs), which have become the predominant pollinator for A. humilis. A three-year study was carried out to determine if reliance on AHBs had a negative effect on reproductive output. In the first year, pollen addition experiments were carried out in a small, isolated populatio...

1. Individual tree detection (ITD) and crown delineation are two of the most relevant methods for extracting detailed and reliable forest information from LiDAR (Light Detection and Ranging) datasets. However, advanced computational skills and specialized knowledge have been normally required to extract forest information from LiDAR.2. The development of accessible tools for 3D forest characterization can facilitate rapid assessment by stakeholders lacking a remote sensing background, thus fostering the practical use of LiDAR datasets in forest ecology and conservation. This paper introduce...