Riparian Ecosystems and Fish Habitat in the Nichyeskwa

1
Riparian Ecosystems and Fish Habitat in the
Nichyeskwa

• BWMT 2005-1

2
Introduction

• Collect indicator data on the status of riparian
  forest
• Reduce uncertainty about blowdown in natural and
  managed riparian forest
• Locate paired reaches for future monitoring

3
Design

• 6 sub-basins
• Three phases
• Existing GIS data
• New remote data
• New field data

4
Existing GIS data methods

• Classify streams
• Order
• Gradient
• Width
• BEC subzone
• Calculate age-class distribution in natural
  riparian forest
• Calculate age-class distribution in natural and
  managed forest

5
Existing GIS data methods

• Over 300 reaches
• Over 3,000 ha of forest
• 60-m GIS buffer for analysis
• Most streams either small, steep in ESSFmc or
  small, gentle in SBSmc2

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Existing GIS data results
Most natural riparian forest is old (SBS 73 over
140 years ESSF 91 over 140 years)
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Existing GIS data results

• Small gentle streams in SBS were most affected by
  harvesting (11 27 harvested)
• Most stream types lt 5 riparian forest logged
• Fish streams 8 forest logged
• Operational maps changed estimates very slightly
  (i.e. few buffers within blocks)
• Current risk is LOW (i.e. proportion old does not
  deviate more than 30 from natural)

8
New remote data methods

• Update buffer status
• Verify existing data

4 sub-basins
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New remote data results

• Very little blowdown
• Still photos give great record

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New remote data results
Canopy cover matches existing data well Snags did
not correlate well with canopy cover
(insufficient data)
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mounding
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New field data methods

• Determine reliability of remote data
• Test methods for linking blowdown and canopy cover

11 plots 10 x 50m
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New field data results

• Some recently-fallen trees in buffers none in
  natural riparian forest
• detected low levels not detectable remotely
• 20-m buffer
• similar structure to control (live and dead
  trees)
• 5-m buffer
• variesone very different structure one similar

15
Conclusions

• Current levels of harvesting pose low risk to
  riparian forest and fish habitat
• Blowdown poses very low risk in the Nichyeskwa
• Existing data describe riparian forest well
• If no blowdown
• If few within-block buffers

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Recommend for Babine

• Use existing remote data to check other
  sub-basinssufficient for monitoring IF
• Blowdown is similar
• Few in-block buffers
• Check blowdown elsewhere (flight)
• If blowdown is higher, investigate relationship
  between blowdown and canopy cover (field study)
• Monitor paired plots each 10 years
• Check hydrology in mounded cutblocks

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Investigate functionality?
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Disturbance