1. The role of woody debris in riparian zones Jon M. Flinders

2. Wildlife nesting and rearing sites Mediation of stream temperatures Habitat for rare plants Growth of trees Riparian areas are important for forested landscapes

3. Trees growing in riparian areas may enter river channel through natural and human processes Production of dead wood is often called “woody debris” or WD The significance of WD has been realized in last couple of decades Importance of trees

4. Historical Perspective 1800’s to early 1900’s rivers & streams used to transport logs Rivers cleared to prevent log jams Splash dams were used in streams

5. Post-World War II Fisheries Mangers thought woody debris obstructed migration of anadromous fish Removed logjams with the intention of opening new reaches of streams & rivers Thus, many rivers and streams have not recovered to pristine undisturbed conditions

6. The Role of Woody Debris 1.Creates Pools & Stream Complexity Salmonids need pools for feeding locations Logs extending across streams deflect the current

7. The Role of Woody Debris 2.Traps sediments Moderates sediment transport rates Protects salmonid spawning areas & invertebrate pop. from sediment deposition

8. The Role of Woody Debris 3.Stores organic material Most organic material stored is allocthonous material Organic material is an important energy source for invertebrates

9. The Role of Woody Debris 4. Provides habitat for salmonids Fry utilize WD for refuge from predators Pools created allow over wintering areas

10. Input of Debris in Stream Channels NATURAL PROCESSES: Bank failure Blow down Avalanches Collapse due to ice or snow

11. Input of Debris in Stream Channels HUMAN CAUSED: Logging major source of woody debris and major loss Usually small debris entering channel - Less stable - More prone to movement

12. Debris Management MANAGEMENT IDEAS: Buffer strip Predetermined fraction of timber Double rotation basis - 150 yrs instead of 75 yrs Substitute structures - Large boulder - Rock-filled gabions

13. Debris Management CONCLUSION: Removal of large, stable debris causes loss of important habitat and decline in fish populations Thus, need to have a management goal of conserving large, stable debris prior to logging