Landscape attributes determine bobcat (Lynx rufus escuinapae) presence in Central Mexico

Central Mexico has experienced a decline of its natural vegetation due to anthropogenic pressure. In 12 sites in the southeastern portion of Guanajuato, we deployed camera traps and analyzed landscape characteristics. We recorded the presence of bobcats in four sites. Their presence was explained by a combination of patch size and tree cover. Because bobcats are sensitive to fragmentation and habitat loss, it is essential to increase sampling and conservation efforts to define the minimum patch size and maximum area of human development that can limit their long-term persistence and the establishment of breeding populations.

Detection of Leafy Spurge (Euphorbia esula) Using Multidate High-Resolution Satellite Imagery

Leafy spurge is a deep-rooted perennial weed that displaces native rangeland vegetation and replaces forage for cattle and other forages used by vertebrate herbivores. Strategic planning to control this weed requires monitoring its distribution and spread. Classical monitoring techniques, which often involve extensive ground survey efforts, can be aided by the synoptic nature of remotely sensed imagery. This research addresses the use of Space Imaging's 4-m multispectral Ikonos imagery for the survey and detection of leafy spurge infestations. Survey data were collected at a site in western North Dakota and used to produce supervised classifications of leafy surge infestations with Ikonos imagery. Multiple image dates per year were combined with each other to assess the added accuracy afforded by multitemporal imagery. Finally, individual patches of leafy spurge were analyzed to determine the minimum patch size and percent cover that were detectable with supervised classification of Ikonos imagery. Under some circumstances, the imagery was effective at detecting leafy spurge, but in areas with a higher forb component, the classification was not as effective. Multidate imagery provided increased accuracy, but improvements were not consistently significant. Leafy spurge infestations of <30% cover and 200 m2were not reliably detected.

Satellite mapping of gorse at regional scales

The spatial distribution of gorse in the Wellington Region was mapped using Landsat satellite imagery This satellite is capable of mapping at regional scales (150 000) with a large spatial extent (180 km x 180 km) and has spectral bands in both the visible and infrared parts of the spectrum (6 bands in total) A spring Landsat image distinguished flowering gorse enabling mapping of gorse as a separate scrub type We chose a minimum patch size of 05 ha with a boundary precision of 15 m An error assessment using 1200 stratified random samples across the Wellington region compared the satellite classified result with colour aerial orthophotography and found the mapping accuracy of gorse to be 95 Gorse area by catchment was calculated using an existing GIS of catchment boundaries The area and percent cover of gorse within a catchment is a potential way to target management at regional scales