Treesearch

Monitoring of tree spatial arrangement is increasingly essential for restoration of dry conifer forests. The presented method was developed for high-density point clouds, like those from unmanned aerial system imagery, to extract and model individual tree location, height, and diameter at breast height (DBH). Extraction of tree locations and heights uses a variable window function searching point cloud-derived canopy height models. Tree DBH is extracted for a subset of point cloud trees using a slice at 1.32-1.42 m and a least-squares circle fitting algorithm. Extracted heights and DBHs...

The federally endangered Sonoran pronghorn (Antilocapra americana sonoriensis; herein, pronghorn) is endemic to arid desert landscapes in the southwestern United States (U.S.) and northwestern Mexico. Historically, the range of Sonoran pronghorn in the U.S. extended east from the Salton Sea in California to Tucson and Nogales in Arizona and extended south from the Salton Sea and Phoenix, Arizona, to the border with Mexico (Phelps and Webb 1981, Krausman et al. 2005). Factors that contributed to the decline of pronghorn include habitat fragmentation, livestock grazing, and historical...

Fire managers often make decisions about wildfire incidents on a landscape scale. While several well developed models can predict fire behaviour at these scales, the paucity of data they draw upon can limit their range of validity. Other models explicitly represent the physical complexities of a fire environment, but at increased computational costs and increased sensitivity to boundary conditions. In this paper, we explore a middle ground between landscape level, data-driven fire behaviour predictions and physics-based, computationally expensive models. As a first step, we employ machine...

Spatial modelling and machine learning are powerful techniques that can be used to identify patterns within data and build complex relationships between response and predictor variables. While powerful, many of these techniques are computationally intensive and are not designed to fully leverage high performance computing resources, especially when used within a geospatial context. To fully leverage system resources, while facilitating various spatial, machine-learning, and statistical modelling workflows, we developed a Python-based processing library called raster_tools. The raster_tools...

Post-fire seeding has been widely implemented in the semiarid Great Basin because natural vegetation recovery may be compromised. Non-native species are often seeded to rapidly establish perennial cover and compete with invasive annuals. We asked whether seeding treatments with different amounts of native and non-native species followed different successional trajectories and whether they became more similar to reference communities over time. We considered restoration implications of seed mix choices and reference community options involving: (a) local unburned vegetation; and (b)...

The taxonomy of sculpins (Cottus, Cottidae) remains one of the last major unresolved puzzles in the systematics of North American freshwater fishes. We used molecular approaches to identify candidate taxa and their distribution across western North America. We crowd-sourced the collection of specimens (n = 8272) via outreach to biologists in the western United States and Canada. From that collection, we sequenced - at up to 2 mitochondrial and 2 nuclear genes - a subset (n = 4009) of specimens from most basins in the western United States, added sequences from public sequence databases,...

Butterfly bush (Buddleja sessiliflora) reaches its northern range in southeast Arizona and herbarium records document seven historic localities from Pima and Santa Cruz counties. We visited all populations between 2014 and 2018, except for one reported from the Tohono O’odham Nation to discover that five historic localities were verified to be extant, and an additional locality was discovered in 2018. A total of 22 plants were documented during this study. All surveyed populations are isolated to 6–15 m areas and contained between one and seven plants. No propagules were found, except for...

El estado de Sonora cuenta con 126 especies de mamíferos, de las cuales, 18 especies (14.2%) corresponden a carnívoros. El presente estudio se efectuó en Rancho “La Volanta”, ubicado a 18.6 kilómetros al noreste de Bacoachi, Sonora, en la Cuenca del Río Sonora, y colindando con Sierra Los Ajos, que forma parte de la APFF Bavispe, un área natural protegida federal. Este estudio se llevó a cabo bajo la técnica de foto-trampeo, con la cual fue posible obtener información durante las 24 horas del día y sin ser invasiva para la fauna silvestre. Se instalaron 12 cámaras-trampas en 12 sitios...

La Reserva Jaguar del Norte (RJN) se creó en 2003 con la finalidad de proteger la población más norteña de jaguar (Panthera onca), y a otras especies igualmente importantes que habitan en el territorio de esa región. Con el propósito de generar información de la población de felinos silvestres: jaguar, puma (Puma concolor), ocelote (Leopardus pardalis), y gato montes (Lynx rufus) se realizaron monitoreos con 92 cámaras-trampa dentro de la RJN. Se obtuvo un esfuerzo de muestreo de 21,170 días-cámaras para los siete periodos en los que se dividió el estudio (enero-diciembre del 2014). Se...