Forest Data

We have reviewed most of the available historical data on the forest in the watershed. This includes General Land Survey records from 1880 to 1910, King County timber cruise data from 1907 to 1914, and more recent cruise data for selected stands from the mid and late 1900s. These cruises generally sampled only selected areas of the forest.

data collection

SPU staff is collecting data after a restoration thinning project to validate model predictions.

We continue to acquire new forest habitat data, as needed, and have inventoried many high priority forest areas since the start of the HCP in 2000. We usually obtain inventory data prior to active forest habitat restoration projects, which are used to develop prescriptions that are tailored to each specific site. The forest data is used in conjunction with forest growth models to predict potential forest response to restoration treatments over time.

We have acquired and analyzed various remote sensing data sets that cover the entire watershed. These data sets include multi-spectral Landsat satellite imagery, multi-spectral MASTER data images that were used for classification of riparian forests, and King County LiDAR (airborne laser data of both the ground surface and top of the forest canopy). We expect that an array of forest attributes can be derived from the LiDAR data, and efforts to derive these attributes are under development.

One example is a forest structural complexity index that was recently developed that shows three-dimensional graphs of forest canopy surface area. View a comparison of the Forest Structural Complexity Index (pdf) for old-growth and second-growth forest. Ideally, watershed-wide remote sensing data will be updated periodically to reflect landscape-scale changes over time.

All data from monitoring and research projects will be stored in a new Forest Information Management System and integrated into a format that is compatible with the watershed GIS systems to provide mapping and analysis capability.