The Effects of Roads on the Post-Harvest Condition of Streams, Riparian Areas, and Fish Habitats in British Columbia 1996 – 2010 The Effects of Roads on.

The Effects of Roads on the Post-Harvest Condition of Streams,Riparian Areas, and Fish Habitats in British Columbia 1996 – 2010

Peter J. TschaplinskiMinistry of Environment

Riparian ManagementEvaluation Question

Are riparian forestry and range practices effective in maintaining the structural

integrity and functions of stream ecosystems and other aquatic resource features over

both short and long terms?

Stream-Riparian Indicators

1. Channel bed disturbance

2. Channel bank disturbance

3. LWD characteristics

4. Channel morphology

5. Aquatic connectivity

6. Fish cover diversity

7. Moss abundance & condition

8. Fine sediments

9. Aquatic invertebrate diversity

10. Windthrow frequency

11. Riparian soil disturbance/ bare ground

12. LWD supply/root network

13. Shade & microclimate

14. Disturbance-increasers/ noxious weeds/invasive plants

15. Vegetation form, vigour, & structure

Evaluation Approach

• Assess physical and biological conditions in streams and their riparian areas with RSM checklist covering15 indicator-questions

• Site assessments vary, based on stream morphology and fish use

• 114–120 measurements, estimates, and observations are required to complete a stream-riparian assessment based on 38–60 specific indicators

• Each main question answered “Yes = OK” or “No = problem”

• Roll-up score = overall site condition

Roll-up Scoring System

Number of “No” Indicators out of 15:

1. Properly Functioning Condition 0 - 2 No’s

2. Properly Functioning, with Limited Impacts (= old “at Risk”) 3 - 4 No’s

3. Properly Functioning, with Impacts (intermediate = old “at High Risk”) 5 - 6 No’s

4. Not Properly Functioning > 6 No’s

2005-2011 Provincial Riparian-Stream Sample

HarvestYears S1 S2 S3 S4 S5 S6 Total

FP Code(1997-2003) 3 57 233 215 64 521 1093

Transition(2004-2006) 5 39 118 95 47 303 607

FRPA (2007-2010) 0 11 46 33 22 104 216

ALL 8 107 397 343 133 928 1916

Provincial RSM Summary of Post-harvest Stream-Riparian Condition Assessments, 2005 – 2011

0

100

200

300

400

500

600

700

800

722

563

393

238

Sample = 1,916

Num

ber

of S

trea

ms

12 % 29 % 38 %

21 %

Overall Stream/Riparian Condition by Stream Class, 2005 – 2011

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600

700

800

900

1000

Province, 2005-2011 Survey Years (n = 1,916)

Properly Functioning Condition

Properly Functioning, Limited Impacts

Properly Functioning, with Impacts

Not Properly Functioning

Stream Class

Num

ber o

f Str

eam

s

RiparianClass

Pre-Code

Percentage equivalent to FREP NPF

Early FPC Era(FP Board audit)

Percentage equivalent to FREP NPF

FREP2005–2011Percentage NPF

S1 5 0 0

S2 20 0.6 0.9

S3 41 4.4 5.0

S4 60 9.4 12.0

S5 45 3.3 7.5

S6 76 20.2 17.9

Comparison of Post-Harvest Outcomes for BC Streams Pre-Code vs. Post 1995

RiparianClass

FREP Monitoring by HARVEST ERA

FP Code Era

1997–2003

n = 841

Percentage NPF

Transition Era

2004–2006

n = 607

Percentage NPF

FRPA Era2007–2010

n = 216

Percentage NPF

S1 0 0 0

S2 2.0 0 0

S3 6.1 5.9 2.2

S4 9.9 12.6 15.2

S5 7.3 4.2 18.1

S6 17.9 16.5 18.3

Trends in Post-Harvest Outcomes for BC Streams:FP Code, Transition, and FRPA Eras

Overall Results by Main Indicator-Question

Channel bed disturbance (Q1)

Channel bank disturbance (Q2)

Channel LWD characteristics (Q3)

Channel morphology (Q4)

Aquatic connectivity (Q5)

Fish cover diversity (Q6)

Moss abundance & condition (Q7)

Fine sediments (Q8)

Aquatic invertebrate diversity (Q9)

Windthrow frequency (Q10)

Riparian soil disturbance/bare ground (Q11)

LWD supply/root network (Q12)

Shade and microclimate (Q13)

Disturbance-increaser plants (Q14)

Vegetation form, vigour & structure (Q15)

0% 20% 40% 60% 80% 100%

Yes = Not affected No = Affected (non-forestry-related causes) No = Affected (forestry-related impacts) NA

Percentage of Streams

Major Impact FactorCoastArea

Northern Interior

Area

Southern Interior

Area ALLRoads(sediment generation and transport)

81 62 65 68

Low RMA Tree Retention 59 43 44 48

Windthrow 23 33 38 32

Falling and Yarding(includes logging in-stream slash) 53 20 23 30

Fire, Beetle Infestation(non-forestry related) 17 30 40 30

Machine disturbance: Harvesting 20 23 34 26

Livestock Trampling < 1 3 24 9

Overall Sources of Impact for Affected Streams

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600Sediment from Road Surfaces and Ditches

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600Perched or Blocked Culvert

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600Road Crossing Leaks Fines into Stream

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

Frequency of Observed Impacts fromRoad-Related Sources

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600Trampling (livestock, wildlife)

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600

Machine Disturbance in RMA During Harvest

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

Frequency of Observed Impacts on Sediment/Debris from Non-Road Sources

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600Hillslope Failure

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

S1 S2 S3 S4 S5 S60

100

200

300

400

500

600

Windthrow

Affected

Not affected

Stream Class

Nu

mb

er

of

str

ea

ms

Stream

Class

Percentage of

Streams Buffered

Buffer Width (m) = Mean Distance from Streambank to Beginning of Tree Harvest

(Harvest Edge)

Mean Standard

Error Sample (n)

S1 100 67 16.9 5

S2 100 42 2.5 72

S3 100 32 1.4 211

S4 78 17 1.4 179

S5 84 28 4.5 76

S6 56 11 1.0 516

ALL 74 20 0.8 1,059

Province-wide Riparian Retention Levels by Stream Class

Functioning Condition

Percent of Streams

Fish Bearing with Riparian

Reserves(Class S1, S2,

S3)

Classes S4, S5, & S6 with Overstory and

Understory Retention

Classes S4, S5, & S6 with Mainly

Understory Retention

PFC 51 52 22

PFC-L 31 29 30

PFC-I 13 14 28

NPF 5 5 20

Functional Outcomes for Streams with Full Retention vs. Understory/Small Vegetation Within First 10 m of the RMA

1. Amount of road related sediment found at stream crossings ‑(all stream classes)• Management of fine sediments remains a concern in spite of

improvements• 83 % of non-fish-bearing class S6 headwater streams were affected

by fine sediments in the FP Code harvest years (1997 – 2003)• This has decreased to 60 % of class S6s during the FRPA years

2. Levels of riparian tree retention for many small streams (classes S4, S5, S6)• Functional outcomes or “health” of small streams with buffers 10 m

wide are equivalent to larger fish-bearing streams with riparian reserves 20 - 50 m wide

• Nearly 20 % of class S4s and 45% of S6s are without treed buffers

Key Factors Affecting Management Outcomes

for Stream-Riparian Systems

ADM Recommendations for Improved Practices Outcomes1. Establish full wind-firm buffers 10 m wide on all class S4 fish-bearing streams

and PERENNIAL non-fish-bearing class S5s and S6s that deliver water, alluvial sediments, nutrients, organic materials, and invertebrates to fish-bearing habitats and (or) drinking water sources

• Can be achieved without increasing overall retention levels in a landscape by re-distributing current levels of riparian retention for small streams to priority reaches

2. Retain, at minimum, all non-merchantable trees, understory trees, smaller vegetation and as many wind-firm trees as possible within the first 10 m of the RMA for all other S5s and S6s (e.g., INTERMITTENT and EPHEMERAL streams with low transport capability) directly connected to fish-bearing areas and (or) drinking water sources

3. Limit fine sediments input from road crossings and riparian practices• Follow well-established best management practices concerning fine sediment

delivery to streams and stream crossings.

• Forest Road Engineering Guidebook; Erosion and Sediment Control Practices for Forest Roads and Stream Crossings; and the Fish-stream Crossing Guidebook, Revised Edition, September 2012