ELANA KETCHIAN

Western Nevada College
Mentors: Peter Weisberg, University of Nevada, Reno
Renee Magrini, Western Nevada College

The desert mountains surrounding Reno, Nevada contain unique outcroppings of hydrothermally altered, andesitic soils that are extremely acidic and low in concentrations of essential plant nutrients. The isolated patches of altered soils contain a distinct “tree island” plant community of Sierran conifers (Jeffrey, Ponderosa, and Washoe pines) as well as understory plant species that are in some cases native to these habitats, in other cases more characteristic of mountain climates that contain cooler temperatures and more precipitation. This plant community is in striking contrast to the adjacent, sagebrush steppe and pinyon-juniper woodland vegetation that is more characteristic of the Great Basin.

This undergraduate research project will focus upon the premise that local populations of plants specific to the altered-andesitic patches are functionally connected within the framework of metapopulations. Concentrating on a subset of plant species that are easily detected and identified (the three confiders as well as several shrub and herbaceous species), we address the question of how patch occupancy relates to patch area and patch isolation. This requires mapping the network of altered-andesitic patches, implemented in GIS, as well as field surveys to record presence or absence of each species in the mapped areas. We predict that the probability of a species occurring in a given patch will be positively associated with patch area and negatively associated with patch isolation, after accounting for differences in habitat quality with regards to each site. By relating results directly to traits of commonality through generations of the different plant species, such as dispersal capacity and longevity, the study will result in critical inferences concerning spatial population dynamics of plants in a highly heterogeneous, semi-arid landscape.