INTEGRATING AQUATIC RESTORATION & RIPARIAN BUFFER MANAGEMENT Dr. Deanna H. (Dede) Olson Research Ecologist Pacific Northwest Research Station US Forest Service
Landslide Potential
Stream species abundance
Bank stability
species abundance
Riparian tree growth
Sediment
There are numerous considerations for riparian buffer management Riparian
Riparian Buffers
Overridge connection
Riparian habitat & dispersal
(considerations)
Stream flows
Stream habitats
Stream Temp.
Down wood
Fire mitigation Climate change mitigation
AMONG FOREST ECOSYSTEM SERVICES, SPECIES AND WATER ARE THE MOST TREASURED AQUATIC NATURAL RESOURCES
Rare endemic aquatic species of greatest concern
Endemic species are becoming more of a concern with the 6th Major Mass Extinction Event for Earth Most imperiled:
Aquatic biodiversity and their ecosystems …Likely due to high endemism and cryptic spp.
Vulnerable to losses: >50% of freshwater turtles >40% freshwater fishes 30-40% of amphibians (>80% occur in forests) 25% of mammals 12% of birds
Riparian Areas are Biodiversity Hotspots for Wildlife in Western Forests 53% of general wildlife are riparian associates in OR and WA 75% of vertebrates are riparian associates in the OR Blue Mtns 79% of vertebrates are riparian associates in the OR Great Basin 36% of westside old-growth associated vertebrates are tied to riparian habitats
Dispersal Early Seral
Habitat
& Late Seral
Species
Species of concern
Fire
considerations
Disease
Genes to Communities
Chemicals Invasives Key Ecological Functions
Aquatic ecosystems are multi-state * Aquatic-riparian species differ by location and over time * Aquatic-riparian habitats differ by location and over time Olson et al. 2016; Penaluna et al. 2016; Reeves et al. 2016
Reference conditions are multi-state
Multi-state example: Up to 80% of stream network length may be headwater streams
Multi-state example: With Natural Disturbances, aquatic-riparian species and habitats change over time Here, landslide-prone areas deliver down wood and sediment to streams NOTE: Headwater distribution
Multi-state example: Shrinking Heads With Climate Variation Olson and Burton in prep.
Key Riparian Management Considerations for Fish Habitat • Intrinsic potential • Stream temperature and thermal loading • Down wood recruitment • Debris flow potential • Erosion/Bank stability • Substrate distributions • Fire regime
Key Riparian Management Considerations for Amphibian Habitat • • • • • • • • • • •
Intrinsic potential Stream temperature/thermal loading Down wood recruitment Debris flow potential Erosion/Bank stability Substrate distributions Fire regime Amphibian species Headwater stream habitats Riparian habitat conditions Overland connectivity
Key Riparian Management Considerations for Riparian Systems • • • • • • • • • • •
Intrinsic potential Stream temperature/thermal loading Down wood recruitment Debris flow potential Erosion/Bank stability Substrate distributions Fire regime Amphibian species Headwater stream habitats Riparian habitat conditions Overland connectivity
• Accelerating tree growth (and future large down wood) • Promoting minority tree species • Promoting structural heterogeneity • Habitat for >100 LSOG species • Habitat for 800 species of concern
Lessons Learned
• Riparian buffers serve multiple roles • Several benefits of 15-m (50foot) minimum-width buffer with our thinning treatment • Consider multi-state ecosystem • Consider hedging uncertainties with a mix of buffer approaches • Consider most important risks per area
50 ft
20 ft
Thank You!
Dede Olson
[email protected] http://www.fs.fed.us/pnw/lwm/aem/people/olson.html
1-hour webinar on this topic at: https://www.youtube.com/user/WAstateDNR
DENSITY MANAGEMENT AND RIPARIAN BUFFER STUDY OF WESTERN OR (1994 TO PRESENT)
OBJECTIVE:
Examine effects on headwater species and habitats of alternative buffer widths with upland thinning
200-300 TPA (430-600 TPH)
80 TPA
(200 TPH)
35 TPA (85 TPH)
After 1 and 2 Thinnings 15-m and 70-m buffers increased Dunn’s and Torrent salamander numbers after 2 thinnings
6-m buffers decreased Dunn’s salamanders after first thinning, and Dunn’s and Torrent salamanders after 2 thinnings
After 1 and 2 Thinnings: No detectable affect on fish and most stream habitat components Down wood recruited from within 15 m of stream More early-decay stage wood from 6-m buffer treatment No effect of buffers on stream temperatures Riparian amphibian habitats and activities within 15 m of stream Edge effect increasing riparian tree growth to 15 m of buffer edge
WATERSHED/LANDSCAPE-SCALE TOOLS e.g.: Reeves et al. 2016 model
CRITERIA: FISH INSTRINSIC POTENTIAL, THERMAL LOADING, EROSION POTENTIAL &DOWN WOOD DELIVERY 4 MANAGEMENT CLASSIFICATIONS Class 1. Most Ecologically Important Fish-bearing Streams
Qualifications Intrinsic potential > 0.5 OR > 10% increase in thermal loading potential OR Medium-high erosion potential
2. Other Fish-bearing Streams
Had none of the qualifications for most ecologically important streams
3. Most Ecologically Important Non-fish Bearing Streams
Medium-high probability of delivering of wood to fish bearing stream
4. Other Non-fish Bearing Streams
All other non-fish bearing streams
Variable Buffer Widths
Fish Bearing Ecologically Imp’t.
Non- Fish Bearing
Other
Ecologically Imp’t.
Other
Managed for Ecological Values
One tree height
One tree height 100 feet
One tree height
Ecological Forestry with tree tipping
One tree height 50 feet
