Post on 04-Jan-2016
description
Managing the Effects of Forest Harvesting on Soil
Quality in B.C.
M.Curran, Ph.D,P.Ag. BCFS, Research
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
Case specific learning outcome:
Understand the common characteristics of forest soils– with an emphasis on soil physical
attributes and management tools to prevent compaction.
Accomplish the following tasks:
Interpret the results of a harvesting experiment and apply this knowledge to a new harvest site.
Describe your learning in written format (as individual students) and orally (as a working team).
Post on the course web site responses to the guiding questions.
References for tutorial:
Biophysical Resources of the East Kootenay Area: Soils by L.E. Lacelle. 1990.
Hazard Assessment Key Guidebook Soil Conservation Guidebook Soil Conservation Surveys
Guidebook
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
“Sustainable Forest Soils”
“Ensuring that the biological, chemical and physical integrity of the soil remains for future generations of ___(people, trees, etc.)
Addressed at many levels, through operations, standards, and now protocols
Often tracked in terms of Criteria and Indicators…
BUT the adaptive management process is likely just as important as the indicators
Adaptive Mgt. Process
Strategic Direction
Data/results Guidelines
Training
Best Mgt.PracticesOPERATIONS
Monitoring (C&E)R & D
“Sustainability Protocols”
Set Criteria and specific Indicators of sustainable forestry
Encourage countries to report on the status of these Indicators
However, protocols like the Montreal Process have a number of “b-type” indicators that require field validation (eg, compaction)
Therefore, compliance with standards is often used as a proxy (eg, CCFM C&I)
Soil Disturbance (a Proxy)
Any physical, biological, or chemical disturbance to the soil caused by ground-based equipment (operations)
May be inconsequential, beneficial, or detrimental depending on the net effect on growth limiting factors and hydrologic properties
BUT, what does compaction mean on a given forest site?
Bad air?
MP talks about area with “significant compaction”
Soil Disturbance as a proxy for productivity/hydrologic
effects In many NA ecosystems, we need at least 10 to
20 years data to draw conclusions about the effects of various practices
Therefore, we use soil disturbance as a proxy that we can observe and regulate at the time of harvesting, site preparation, etc.
However, when we discuss or read about “Soil Disturbance” there are inconsistent approaches and methods a common approach is needed.
@ 3 YRS @ 10 YRS
@ 15 YRS
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% o
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Mean Douglas-fir volume - Gates Creek
(Smith & Wass, 1991; Wass & Senyk, 1999)
Mean Douglas-fir volume - Gates Creek
(Smith & Wass, 1991; Wass & Senyk, 1999)
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
Soils information for planning
Soil maps provide general information on the soils and landforms present
Site-specific data collection verifies and (OR) provides information used in determining soil disturbance limits
Harvest planning should use both of these whenever maps are available.
“Soil Landscapes”
Soil = f (t) { pmtl + topog + veg + climate } Soil will vary with above Soil will be similar with above… Therefore, repeating units across landscape We can map these units and interpret them Maps = framework for communication of
experience with soil
Primary criteria for mapping
Origin of parent material Lithology (mineralogy) of coarse
fragments Texture (coarse frag’s; fine fraction)
Above of interest to Forest Engineering
Some secondary criteria
Soil development– degree of weathering– depth of horizons
Diagnostic horizons (eg, clay rich) Organic matter content
Survey Intensity Level (SIL)
SIL / Planning level
4 reccie / Regional 3 “baseline” 2 detailed / Local 1 site-specific
Field checks / scale
25 %, 1:100,000 50 %, 1:50,000 90 %, 1:20,000 100 %, 1:5,000
Typical soil individuals (map)
Soil Associations (typical maps)– “similar parent material and
development” Soil Series (detailed, agricultural
maps)– “same parent material, development,
texture”
Map Reliability
Reliability = how well it reflects a given point on the ground
Function of scale, access, surveyor skill
Will vary with the property of concern– eg, texture versus actual development– general purpose or specific mapping?
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
Soil Disturbance – is it all Degradation?
Tree growth limiting factors
Any factors that limit growth Concept of most limiting factor May be direct or indirect factors
Direct growth limiting factors
Direct growth limiting factors
Water Nutrients Light Aeration (CO2, O2) Temperature (soil, air)
Indirect growth limiting factors
Affects direct factors, eg:
Indirect growth limiting factors
Affects direct factors, eg: Competing vegetation
– light– water
Rooting substrate (volume) Root rot
Net effect on tree growth
Resulting tree growth is sum of positive and negative effects
Common negative effects:– reduced aeration from compaction– loss of nutrients and organic matter
Common positive effects:– reduced competition– warmer soils
Soil disturbance processes
what is soil disturbance what is soil degradation what processes lead to degradation (strategies to manage disturbance)
Soil Disturbance
Any physical, biological, or chemical disturbance to the soil
May be beneficial or detrimental, depending on net effect on growth limiting factors
Beneficial Disturbance Foresters often create disturbance on
purpose as site preparation to ameliorate seedling growth-limiting factors
Net effect would have to be positive Growth is limited by most limiting factor Identify and manage for these Don’t compromise long-term productivity
Soil degradation Any disturbance that negatively affects
soil productivity
In B.C. Forestry, trees are the “bioassay”
FPC/FRPA targets potentially detrimental disturbance– some of concern for drainage as well (FRPA)
Processes leading to degradation:
Compaction Displacement (min. soil; forest floor) Erosion Mass Wasting (cut/fill failures)
(Part of management framework)
Erosion
Surface soil eroded primarily by water (splash, sheet, rill erosion)
Loss of fertile topsoil layers Loss of effective rooting volume
– Exposure of unfavourable subsoils Drainage diversion Sedimentation of watercourses
Erosion
Controlling factors: texture, coarse fragments, slope, climate
Manageable factors: machine traffic, degree of scalping, drainage control
Mass Wasting
“Minor” cut and fill failures Often result in drainage diversion Can lead to larger landslides Loss of productive growing site Impacts on downslope values Safety concerns Also use slope stability indicators
(LMH47)
Mass Wasting
Controlling factors: parent material, climate, slope, topography
Manageable factors: amount and extent of excavation, drainage control, machine traffic, seasonal soil conditions (wetness, snow, frost)
Compaction
Compaction and Puddling result in the alteration / loss of soil structure (architecture of pores)
Bulk Density increase (penetrability) Infiltration decreases (more runoff) Aeration decreases (less biological
activity)
Compaction
Controlling factors: texture, coarse fragments, forest floor depth/type, (soil depth, mineralogy)
Manageable factors: machine traffic, machine type/dynamic loading, seasonal soil conditions (wetness, snow, frost)
Table 3. Bulk density (kg m-3) of 0-10 cm soil depth in 1981 and 1997 among three treatments and two disturbances at Gates Creek. Treatment Disturbance Year Prob>T
1981 1997
Non-stumpedUndisturbed 1231 1246 0.88Track 1613 1405 0.001
RakedRake 1469 1373 0.23Track 1671 1469 0.03
Scalped Scalp 1119 1210 0.20Track 1724 1420 0.000
Aeration Porosity (Nakusp)
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30U
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Dispersed traffic = concern Aeration porosity definitely affected Literature suggests is could affect trees Therefore, need to monitor and check Institute BMP for now Adjust guidelines as hard data available Hard data needs a framework (plasticity)
Soil Plasticity (Approx., CSSC)
Non-Plastic
Very Plastic
Slightly Plastic
Plastic
Displacement
Displacement of fertile mineral topsoil and forest floor layers of concern
Loss of available nutrients Loss of effective rooting volume
– exposure of unfavourable subsoils Loss of water holding capacity Increased runoff, drainage diversion
Displacement
Controlling factors: slope, topography, soil depth, subsoil type
Manageable factors: amount and extent of excavation, machine size/type, seasonal soil conditions (wetness, snow, frost)
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
BC Soil disturbance stds 1988 start, FPC in 1995, now FRPA Disturbance types of concern evolved
from bladed trails to compacted trails, ruts
Limits set in Silviculture Prescription (Site Plan) based on soil dist.hazards
Monitoring based on transects Disturbance at sample point categorized
Historical Disturbance Levels
late 70’s / early 80’s– over 20 % common
Interim Harv. guidelines (1988)– 13 % without rehab.
1993 Harv. guidelines– 13 % WITH rehab.
1995 FPC Act, now FRPA– 10 % AFTER rehab. “10 + 3”(5)
Types of counted disturbance
Machine traffic (compaction)– excavated and bladed trails– compacted areas– main (nonbladed) trails– ruts greater than 5 or 10 cm
Types of counted disturbance
Displacement– deep gouges– long gouges– wide gouges– very wide scalps
Forest and Range Practices Act (replaces Forest Practices Code)
“Simplified” planning steps Sets “results-based” standards for
11 values like Riparian, SOILS, etc. FPRA Objectives for Soils
– “conserve the productivity and hydrologic function of soils.”
FRPA Soil Disturbance Stds(others for drainage, revegetation, etc.)
Permanent access 7 % or less Temporary access up to 5 % Sensitive Soils 5 % “disturbance” Less-sensitive 10 % Roadside work areas 25 % Based on soil sensitivity
Types of monitoring
1. Implementation (Compliance)1. Did they meet the contract?2. (speeding?)
2. Effectiveness1. Contract and practices effective?2. (are ticketting, signing, etc. reducing it)
3. Validation (research)1. Underlying assumptions correct?2. (speeding causes more fatalities there?)
Field Map: Planned transects
B.C. has 5 replicated LTSP installations
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C0 C2 C0 C2 C0 C2 C0 C1 C0 C2
Challenge Wallace Owl Vista Central CampCamp
Other
Trees
CLAY LOAM SAND
BIO
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10-YR BIOMASS RELATIVE TO COMPACTIONON FIVE LTSP SITES IN CALIFORNIA
Rehab (amelioration)Plot on LTSP study
RehabilitatedHaul Road
“Soil test sites”
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
Harvesting strategies Independant of climate/weather Longer season, less shutdowns Can rehab. as you go, but stay under Rehab. can be haul roads, unbladed trails
– close trail spacing– close road spacing– designated/random skidding– hoe-chucking
Closer Trail Spacing
Gentle to moderate slopes (45 %?) Avoid seepage sites Avoid VH Mass Wasting, Compaction Avoid H Mass Wasting if clayey Minimize cuts into unfavourable
subsoil
Dispersed (Random)
Plan for designated trails (can’t be the preferred strategy) Take advantage of weather windows Can accomplish site preparation Can use feller buncher
Hoe-chucking (Interior)
Can augment other strategies Can often operate when wetter Good for complex topography in
W.Koot. Complements cable harvesting
Seasonal soil factors
How Wet is Too Wet discussed before
How Much Frost? How Much Snow? How Much Helium?
How wet is too wet? (1 pass)
Non-plastic soils– squeezed soil leaves < 100 % moisture
on hand Plastic soils
– squeezed soil leaves < 50 % moisture on hand
– AND clod breaks apart with easy finger pressure (tapping)
How much frost is enough?
7.5 cm (3 in.) in mineral soil PROVIDED not too wet below “can’t penetrate with body weigth on
a 3/8” rod with a 30 degree cone”
How much snow is enough?
Compressible snow: 30 cm? Dry snow: 60 cm? Try a “jump” or boot test... Frozen snow: 15 cm?
– (do a single pass at end of first day on it)
PROVIDED soil not too wet below!
Harvesting strategies
– close trail spacing– close road spacing– designated/random skidding– hoe-chucking
Adaptive Management Process (a package deal)
Strategy / Database
Data/results Tools / Guidelines
Training
Best Mgt.PracticesOPERATIONS
Monitoring (C&E)Research
Execution
Regional Database Indicators/Thresholds
Validation Implementation
Environmental Framework
Inherent Soil Sensitivity (HAZARD)– Compaction– Displacement– (Erosion and Mass Wasting [non-
alcoholic]) Potential Effects: (CONSEQUENCE)
– On-site (forest productivity)– Off-site (fish, water, property, life)
Recommendations BC Interior Winter log? Processors onsite for sensitive? Consider the “4 strategies” roadside reduce disturbance? Larger blocks and rehab all roads (all NAR) Equipment size? Operator effect is number one often Operator training materials
Funding sources
Invermere “enhanced mgt pilot” Science Council (FRBC) FIA/FII In-kind MoF Regions, Branch, District In-kind CFS Victoria, Edmonton In-kind UBC In-kind Tembec, Slocan, Kalesnikoff
Outline Tutorial case description “Sustainability” as context for guidelines Soil information for planning Soil disturbance processes (hazards) Soil disturbance standards Practical Application Questions/Discussion Tutorial Assignment
Session 1 questions
Based on the combination of five soil forming factors (parent material, topography, biota, climate, and time) describe the processes of the formation or genesis of the Rocky Mountain Trench soils.
Briefly describe soil diagnostic features of these soils that could be significant for forest management consideration.
List some soil quality indicators, with emphasis on soil physical properties that could be used to monitor the sustainability of the management of the Rocky Mountain Trench.
Session 2 questions The soil physical properties are derived from the
complex interaction of the soil mineral and organic colloids, weathering processes, vegetation, and past management. Given the information for the three soils in the attached materials, what are important indicators of its physical conditions for plant growth under the various disturbances studied?
Why does compaction take place on forest soil? What are the ways of preventing soil compaction on
forest lands? Why would soil erosion take place on forest soils? What are the ways to prevent soil erosion on forest
lands?
Session 3 questions What are general recommendations for sustainable
management of a forest soil in a semi-arid region like the southern interior of BC?
What are potential effects of the soil organic matter displacement on the soil physical properties of the site in southern interior of BC?
What is likely the “leading soil disturbance hazard” on benchland soils in the Rocky Mountain Trench? What are ground-based harvesting strategies to manage these concerns?
What is likely the leading hazard on steeper soils in the Purcells? In the Rockies? What are cable or ground-based harvesting strategies to manage these concerns?
Useful website?http://www.for.gov.bc.ca/
Forest Practices Code Guidebooks: Land Management Handbooks
Cool research: Southern Interior Forest Region – Active Projects - Nelson Test Site Directory
mike.curran@gov.bc.ca
The end…
The truth is out there
For every argument, it is often possible to find an example to support it in the natural world.
For us, what matters is which argument is most commonly correct, and what conditions dictate which holds true…
Need a system to track this knowledge and put it into practice…. [hazards/disturbance]
Desirable Attributes for Indicators (CCFM C&I):
Relevant? (related/sensitive/responsive)
Measurable? (scientifically valid, practical)
Understandable? (forest managers, public)
Can be Forecast? (expected future condition) Have Reference Values? (performance check
Climate change effects?
Precision?
The “Holy Grail” - TODAY’S SESSION
Calcareous Soils
Special case Limestone derived High pH Unfavourable subsoil.
Nutrient availability vs. pH
Calcareous pts (Golden Mt 7)
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ConH ConL ConC PushH PushL PushC
FPC Disturbance (Mt 7)
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Leaching study: FF pH
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FF ST2 ST8 EX2 EX8
1 yr
5 yr
Site and Treatment Vs. Available Iron
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300.00U M U M B U M B U M U M U M U M
Ava
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McMurdo Bloom Grave Lussier Hudu Caven Bell
Availabe Fe (ppm)
Height of lodgepole pine in presence or absence of CO3
CO3
DepthGood Medium Poor
< 40 cm 650 24 589 27 382 27
> 40 cm 752 48 649 34 465 34
Lussier Provenance trial (20 year growth of 5provenances in each category.
Marl Ck. Stumping trial
Disturb. Growth CO3
(9)No CO3
(12)Ttest
Track Dbh(cm)
2.6 5.3 0.02
0-10 cm Height(cm)
264 448 0.01
Volume(cm3)
4390 13, 649 0.008