Riparian Long-term Monitoring

tree measurements

Staff record tree measurements in a riparian permanent sampling plot.

From 2003 to 2005, we established a network of 61 permanent sampling plots (PSPs) located in riparian areas throughout the watershed. Each of the plots is 20 x 45 meters in size and subdivided into five subplots to capture variation away from the stream channel, which is often high due to sharp topographic, moisture, and disturbance gradients.

We measured a variety of tree, shrub, and herb characteristics, similar to the array of measurements made in upland PSPs. The data from these plots have been used to characterize current conditions, assess how riparian forest structure is related to disturbance regime and topographic position, and model trajectories of riparian forest succession. In addition, they will be used to track long-term changes in riparian conditions in the watershed.

We also utilized hyper-spectral remotely sensed digital imagery (Modis/Aster or MASTER) collected in August 2001 to classify riparian forest cover in the watershed link to. This classification provides a valuable description of spatial variation in riparian forest, serves as a baseline to measure long-term change in riparian forest cover type, and is essential for prioritizing riparian restoration treatments in the watershed.

Description of riparian sampling protocols (pdf)

Map of distribution of riparian permanent sampling plots (pdf)

Example of riparian cover type classification from upper Cedar River (pdf)

Published papers using data from riparian permanent plots and remote sensing:

  • Villarin, L.A., D.M. Chapin, and J.E. Jones III. 2009. Riparian forest structure and succession in second-growth stands of the central Cascade Mountains, Washington, USA. Forest Ecology, and Management 257: 1575-1585.
  • Mollot, L.A., R.A. Bilby, and D.M. Chapin. 2008. A multivariate analysis examining the effect of landform on the distribution of riparian plant communities of Washington, USA. Community Ecology 9(1): 59-72.
  • Mollot, L.A., and R.A. Bilby. 2008. The use of geographic information systems, remote sensing, and suitability modeling to identify conifer restoration sites with high biological potential for anadromous fish at the Cedar River Municipal Watershed in western Washington, U.S.A. Restoration Ecology 16(2): 336-347.
  • Mollot, L.A., D. Munro, and R.A. Bilby. 2007. Classifying fine-scale spatial structure of riparian forests using hyperspectral high-resolution remotely sensed imagery at the Cedar River municipal watershed in western Washington, USA. Canadian Journal of Remote Sensing 33(2): 99-108.