Los Fresnos
Flora and Fauna Survey
Students Integrating Academics and Conservation, University of Arizona
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Riparian areas in the Western United States are endangered due to impoundment, introduction of non-native species, and groundwater drainage (Stromberg 2001).  The San Pedro River basin in Arizona and Northern Sonora supports over 400 species of birds and 100 species of mammals and is the only un-impounded river in Arizona (Steiner et al. 2000).  The Nature Conservancy, in collaboration with two Mexican NGOs, Naturalia A.C. and Biodiversidad y Desarrollo Armónica (BIDA), has recently obtained a 10,000 acre preserve at the headwaters of the San Pedro River.  Los Fresnos preserves critical mid-elevation grasslands and a variety of wetland and riparian habitats. This project has several over-arching goals, including addressing some basic questions in conservation biology (indicator species; fire responses).

san pedro watershedgoogle earth los fresnos
San Pedro Watershed (left) with a general outline of the location of the Los Fresnos preserve (yellow box); aerial view of Los Fresnos (right)
We are conducting surveys of the flora and fauna of Los Fresnos. See links for preliminary descriptions.
bouteloua los fresnos
montezuma quail
Reptiles and

lizard los fresnos

fish los fresnos


cotton rat


phoebis los fresnos

We are framing our data collection to address basic questions in conservation biology:

Biodiversity and Indicator Species:
How does species diversity vary over space and time? Are particular taxonomic groups or species better indicators of the total biodiversity in an area?

Community Response to Fire:
How does fire affect the abundance and distribution of plants? How do responses vary between native and non-native species, or woody and herbaceous species?