Treesearch

Since the 1940s, the USDA Forest Service has surveyed roundwood receiving facilities to report on timber products output (TPO). The TPO program provides information on forest removals, processing capacity, and wood product markets, complementing inventory estimates of status and change. The program adopted an annual state-level probability sampling design in 2019 and this research evaluates rates of unit nonresponse (UN) in surveys of eleven western states over reference years 2019–2021. The overall response rate for this region and period was 43.7%, which appears low relative to prior...

Spaceborne lidar provides a unique opportunity to supplement the field plot measurements of national forest inventories (NFIs) by providing dense measurements of vertical canopy structure. For full waveform instruments such as the Global Ecosystem Dynamics Investigation (GEDI), measurements take the form of reflected energy as a function of height within an observed footprint. Many forest attributes cannot be directly computed from the waveforms, and thus statistical models relating the measurements to target attributes must be trained using field plot data. Because the discrete footprint...

Background: Western forests in the United States are facing multiple threats that have the potential to permanently alter forest composition and structure. In particular, wildfire can either have beneficial or adverse effects on overall forest health and resilience. Monitoring and assessing the effectiveness of existing forest treatment plans for meeting forest management goals is becoming more critical to increase the capacity for managers to prepare for and accommodate uncertainty associated with changing disturbance regimes. We used a combination of fine-scale vegetation and microclimate...

Research on human-elephant interactions (HEI) seeks to better understand relationships between people and elephants with the goal of reducing unwanted interactions for the long-term survival of elephants in social-ecological systems. Many examinations of HEI often rely on a short temporal scale of several seasons to several years, often because of limited data availability across time. These examinations offer limited understanding of processes that influence HEI and mutual adaptations of people and elephants. In this synthesis, I present an ethnographic case study from the Okavango Delta,...

Genetic rescue - an increase in population fitness following the introduction of new alleles - has been proven to ameliorate inbreeding depression in small, isolated populations, yet is rarely applied as a conservation tool. A lingering question regarding genetic rescue in wildlife conservation is how long beneficial effects persist in admixed populations. Using data collected over 40 years from 1192 endangered Florida panthers (Puma concolor coryi) across nine generations, we show that the experimental genetic rescue implemented in 1995 - via the release of eight female pumas from Texas -...

Human-facilitated introductions of nonnative populations can lead to secondary contact between allopatric lineages, resulting in lineage homogenisation or the formation of stable hybrid zones maintained by reproductive barriers. We investigated patterns of gene flow between the native Sacramento Valley red fox (Vulpes vulpes patwin) and introduced conspecifics of captive-bred origin in California's Central Valley. Considering their recent divergence (20–70 kya), we hypothesised that any observed barriers to gene flow were primarily driven by pre-zygotic (e.g. behavioural differences)...

The first record of captive-bred red foxes (Vulpes vulpes) dates to 1896 when a breeding enterprise emerged in the provinces of Atlantic Canada. Because its domestication happened during recent history, the red fox offers a unique opportunity to examine the genetic diversity of an emerging domesticated species in the context of documented historical and economic influences. In particular, the historical record suggests that North American and Eurasian farm-bred populations likely experienced different demographic trajectories. Here, we focus on the likely impacts of founder effects and...

Characterizing natal dispersal can help manage the spread of invasive species expanding their ranges in response to land use and climate change. The Barred Owl (Strix varia) is a prominent example of an apex predator undergoing a rapid range expansion, having spread from eastern to western North America where it is now hyperabundant - threatening the Northern Spotted Owl (Strix occidentalis caurina) with extinction and potentially endangering many other native species. We attached satellite tags to 31 Barred Owl juveniles at the southern leading edge of the Barred Owl’s expanding range in...

In Utah, and much of the Intermountain West, riparian forests make up a small percentage of the landscape but provide disproportionately large ecological functions and societal values. Since the early 1800s, Utah’s riparian forests have experienced shifts in natural disturbance regimes, changes in flow regimes and water tables, changes in vegetation composition and structure, introduction of exotic plant and animal species, and land use conversion. Today, managers need science-based guidance to assess ecological integrity, detect causes of degradation, and select appropriate methods for...

Insects and diseases are significant disturbance agents in many forests. In some places, annual surveys by observers in aircraft are valuable resources but can have significant issues that result in gaps. Using remotely sensed data is therefore attractive. Here we provide a review of this topic that is novel in several ways. We describe tree, stand, and landscape responses to insects and diseases, then link these responses to remote sensing technologies and methods for detection and attribution. We focus on insects and diseases that cause substantial damage and mortality to conifers in the...