The biocomplexity grant will model the emissions and rate of deposition across the landscape, mainly in Riverside and San Bernardino Counties.

"We will use remote sensing and ground vegetation surveys to determine the current and historical rate of change of vegetation, examining when invasive grasses became large scale problems in different areas," Allen said.

"The subject has never been studied on this scale," Allen said. "People have long been concerned about the impact nitrogen deposition has, and other concerns about weed invasion, but there has never been a landscape-scale study that links nitrogen with invasive species."

The study will determine the amount of N required to build up different levels of invasive grass fuel, impacting fire frequency. The threshold at which N affects different vegetation types from forest to shrubland to desert is different, and the study will determine the different levels of sensitivity for each vegetation type. Future vegetation of the area will be modeled based on different levels of N emissions and different urban development scenarios.

This is the second large biocomplexity grant awarded to UC Riverside recently. The first, for $1.5 million, was to help monitor the unintended spread of engineered crop genes.

'"/>

Contact: Kris Lovekin
kris.lovekin@ucr.edu
951-827-2495
University of California - Riverside
1-Oct-2004