Thinking big: linking rivers to landscapes

Abstract

Exploring relationships between landscape characteristics and rivers is an emerging field, enabled by the proliferation of satellite date, advances in statistical analysis, and increased emphasis on large-scale monitoring. Landscapes features such as road networks, underlying geology, and human developments, determine the characteristics of the rivers flowing through them. A multi-agency team of scientists developed novel modeling methods to link these landscape features to in-steam habitat and abundance of coho salmon in Oregon coastal streams. This is the first comprehensive analysis of landscape-scale data collected as part of the state's Oregon Plan for Salmon and Watersheds.

The research team found that watershed characteristics and human activities far from the river's edge influence the distribution and habitats of coho salmon. While large-scale landscape characteristics can predict stream reaches that might support greater numbers of coho salmon, smaller-scale features and random chance also play a role in whether coho spawn in a particular stream and in a particular year. The team developed new models that successfully predicted the distribution of in-stream habitat features. Volume of in-stream wood and pool frequency were the features most influenced by human activities. Studying these relationships can help guide large-scale monitoring and management of aquatic resources.

Citation

Steel, Ashley E. 2012. Thinking big: linking rivers to landscapes. Science Findings 139. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 6 p.