8.6 Buffer Design Wood Recruitment

 

Terrainworks developed a riparian buffer and wood recruitment tool in support of Oregon Department of Forestry land management planning (2020). The technical help is divided into two sections: (1) an overview of the tool and its outputs and (2) technical background.

 

This tool can be customized for others using different channel types and protocols; contact Terrainworks for more details.

 

1) Determine the proportion of in-stream wood recruitment from different sources, including riparian tree fall (mortality), landslides and debris flows. Bank erosion is not considered.

2) Estimate relative change in recruitment with different buffer widths or along-stream extent. Compare to natural wood recruitment with full forest (no timber harvest).

3) Define spatial variability in relative importance of different recruitment mechanisms.

4) Juxtaspose wood sources with fish habitat type and quality (optiional).

 

1) Delinate and classify channels using DEMS (synthetic river networks); for more details go here.

2) Define fish presence/absence, perennial/seasonal streams, channel size and gradient, landslide and debris flow potential, depending on management and or regulatory guidelines.

3) Identify potential landslide and debris flow source areas and runout pathways.

4) Determine number, size, and location of trees available to fall into channels or be swept up and carried to channels by landslides and debris flows.

5) Estimate forest stand conditions (static, for example using LEMMA) or use forest growth simulations.