Aquatic/Riparian Ecosystem Dynamics and Associated Management Implications

1
Aquatic/Riparian Ecosystem Dynamics and
Associated Management Implications
Recent Findings
2
Presentation covers threesets of science findings

1. Long-term Aquatic/Riparian system dynamics
2. Large Woody Debris relationships in riparian
   systems
3. Shorter-term disturbances processes in riparian
   systems

3
Aquatic/Riparian Ecosystem Dynamics Coastal
Oregon,S.W. Washington

• Principal Investigator
• Gordie Reeves, PNW Station
• Sampling and modeling study on geomorphology,
  streams, fisheries and disturbance dynamics

4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
3000-year simulation of pre-settlement landscape
dynamics generated with the LADS model
8
The Aquatic View Is this realistic?
9
Time 1
Time 1
10
(No Transcript)
11
Adaptations to Dynamic Ecosystems

• Persist throughout all ecological stages
• Exist in refugia and move among patches
• Adaptations used by anadromous fish in following
  the second strategy
• - Straying of adults
• - Large amount of young
• - Mobility of juveniles

12
Key Findings

• Aquatic Systems are dynamic in space and time
  similar to terrestrial ecosystems
• Stream conditions change over time (often as
  pulses of activities wildfires, floods)
• Disturbances are needed to maintain long-term
  ecosystem productivity
• Fish are mobile and can respond to these changes

13
Management Implications

• All streams cant be in good condition at the
  same time
• Assume catastrophic disturbances will occur
• Plan for those disturbances Landslide
  management
• Model available to identify stream potential to
  provide materials

14
Management Implications

• Modeling tool can be used for stream restoration
  programs to optimize sediment wood delivery
• Landscape level tool for active riparian zone
  management (harvest, fish habitat)
• Concentrating management activities, then
  allowing long recovery time may be most
  appropriate
• Developing dynamic model for cumulative effects
  analysis

15
(No Transcript)
16
(No Transcript)
17
Large Woody Debris Production and Input in
Western Oregon

• Principal Investigators
• D. Hibbs J. Shatford
• OSU/USGS-BRD
• LWD survey part of larger ecosystem study on
  plant species diversity and patterns of tree
  regeneration

18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Key Findings

• Variations in LWD volume and size distributions
  occurred across sub-regions
• Variations in riparian forest density and
  composition occurred across sub-regions

22
Management Implications

• Baseline LWD volume/size info for LWD retention
  in riparian thinning activities
• Science basis for different thinning and LWD Rxs
  across W. Oregon
• Landscape level planning aid for LWD amount for
  specific locations Landslide Management

23
Short-term processes in Aquatic/Riparian Systems
and Silvicultural Activities

• Density Management and Microclimate Effects in W.
  Oregon
• Principal Investigator Sam Chan
• Study of riparian and adjacent upland
  silvicultural treatments and associated
  changes/responses to stand manipulation

24
(No Transcript)
25
(No Transcript)
26
Management Implication

• Thinning activities in riparian forests may not
  have large effects on relative humidity beyond
  75-100 feet from streams

27
(No Transcript)
28
Key Findings

• Hemlock-DF canopies respond quickly to thinning
• Tree crowns become longer and denser
• Management Implications
• Thinning in dense stands may improve structural
  diversity, old growth conditions
• Thinning may speed recruitment for LWD part of
  Landslide Management