San Diego Management & Monitoring Program

Aseasonal Flow and Associated Nonnative Species in San Diego: Data Summary

Type: report

Article abstract: This document provides a summary of data collected for the purpose of understanding aseasonal flow in 14 watersheds in southern California. Aseasonal flow is an increased discharge of runoff during dry seasons resultant from land use changes. Visual surveys, Stream Temperature, Intermittency, and Conductivity loggers (STICs), and GIS analysis of land use and land cover were used to identify maximum hydroperiods for 56 sites in San Diego County. Visual surveys were conducted to record presence of native and nonnative aquatic species as well as physical characteristics of the stream morphology and surrounding vegetation. Data were collected between 2015 and 2016. This document is not meant to provide a comprehensive report and interpretation of the data but to simply present the data collected and how it was collected. This summary is one piece of a larger on-going project with San Diego Association of Governments (SANDAG) and San Diego Management and Monitoring Program (SDMMP), implemented to better understand the biological processes and anthropogenic affects driving local community dynamics of native species. Preliminary investigations of some of the relationships between species presence and upstream land use and cover are presented graphically for the reader’s interpretation. Appendices include detailed site information and individual graphs and photographs depicting the stream conditions at each site.

Number of pages: 158

Authors: Brown, Chris; Perkins, Emily; Hitchcock, Cynthia J.; Aguilar Duran, Angelica; Guerra Salcido, Omar ; Watson, Elise; Fisher, Robert N.;

Day: 23

Month: April

Year: 2020

Prepared for: San Diego Management and Monitoring Program; San Diego Association of Governments;

Prepared by: U.S. Geological Survey, Western Ecological Research Center;

Keywords: aseasonal flow;

Threats: Altered hydrology; Invasive animals