# Presentation: 173858

- Riparian Thinning Logic
- Jack Sleeper - Siuslaw National Forest
- March 20, 2008

## Talk Outline

- Riparian Processes
- Human Impacts to Riparian Areas
- Siuslaw NF Thinning Design and Effects

## Large Trees

## Debris Flows

## Wood & Sediment from Debris Flow 

**Upper Green River Landslide**

**Valley Floor Buried with Landslide Deposit**

## Beaver Ponds

## Floods

## Spruce & Alder Seedlings

**Spruce & Alder Seedlings**

**Notes:**
Upper Yachats

## Slide 13

**Notes:**
Audubon Sanctuary on Tenmile Creek

**Notes:**
Preacher Trib

## Slide 15

## Natural Conifer Stands

- Large diverse tree species
- Disturbance & competition limit dense conifer stands near streams
- Conifer stands mostly on toeslope and high terraces
- Trees/Acre-lowest in riparian areas and increase upslope
- Conifer stands have irregular riparian edges

## Large Wood in Streams

- Riparian Impacts

## Settlement Reduced Large Treesin Riparian Areas 

## Large Trees Removed

- Cape Perpetua

- Florence

## Roads Disconnect Riparian Area from Stream

## Debris Flow Intercepted by Road

- Tenmile Creek

## Stream Cleaningfor-Transportation-Fish Passage-Cedar Shakes

## Slide 25

## Natural & Managed Riparian Stands

- _Natural Stands_
- Large conifer with few trees/acre
- Diverse species
- Understory shrubs and trees present
- _Managed Stands_
- Small conifer with many trees/acre
- Mostly Douglas-fir
- Understory shrubs and trees absent

## Why Thin Close To Streams?

- Large wood has a major influence on aquatic processes and habitat
- Large diameter conifers near streams have been reduced
- Large wood in streams and on floodplains reduced
- Thinning accelerates development of large diameter trees and diverse tree species
- Northwest Forest Plan, Endangered Species Act, Essential Fish Habitat

- Riparian Thinning Design and Effects

## Interdisciplinary Team Plans  Restoration Activities Including Thinning

## Thinning Concerns

- Stream Temperature
- Stream Sedimentation
- Wood Recruitment to Streams
- Windthrow

## Stream Buffer Design

- Variable width
- Based on site specific conditions
- Follows edge of dense plantation
- Protect Unstable Areas
- Perennial Streams
- First 2 rows of conifer near stream-no cut
- Minimum 30 ft no cut buffer from floodplain
- average 50-80 ft
- Intermittent Streams
- First row of conifer near stream-no cut
- Minimum 15 ft no cut buffer

## Slide 32

## Stream                        

- No Cut | Thin

## Thinned Unit                 No Cut Buffer

## Slide 35

## Stream Shade from No Cut Buffer

## Dense Vegetation ShadesSmall Streams

## Sedimentation

## Wood Recruitment

## Douglas-fir Stand Development in Western Oregon

**Unthinned**

**100 Trees/Acre**

**60 Trees/Acre**

**30 Trees/Acre**

**Douglas-fir**** ****Stand Development in Western Oregon**
**Seven Years After Thinning and Underplanting**

**Notes:**
All treatments 7 years after thinning  stands were underplanted with hemlock and Douglas-fir.
Point out Yachats treatments.

## Uncertainty

- Thin Density-trees/acre
- Thin heavy or light?
- Distribution across the landscape
- Down Wood
- Small pieces now or larger ones later?
- Windthrow
- How to contract & fund complex design?
- Climate Change

## Commercial Thinning Funds other Restoration Activities

## Precommercial Thinning

## Riparian Planting

## Conifer Release

## Add Large Wood to Streams & Floodplains

## Road Decommission

**2002**

**2003**

**2006**

**2002**

**2003**

**2006**

## Slide 48

**Notes:**
Yachats River near Beamer Creek