(tt/Avvs)

technical bulletin

NATIONAL COUNCIL OF THE PAPER INDUSTRY FOR AIR AND STREAM IMPROVEMENT, INC., 260 MADISON AVENUE. NEW YORK, N.Y. 10016

INDUSTRY, STATE, AND FEDERAL

PROGRAMS DESIGNED TO ASSESS AND PROTECT

WATER QUALITY ASSOCIATED WITH MANAGED WESTERN FORESTS

TECHNICAL BULLETIN NO, 466

JULY 1985

TABLE OF CONTENTS

INFLUENCE OF STREAM SIZE ON THE FUNCTION ANDCHARACTERISTICS OF LARGE ORGANIC DEBRIS 1

Dr. Robert E. Bilby, Weyerhaeuser Company

I INTRODUCTION 1

II ROLE OF LARGE ORGANIC DEBRIS IN STREAMS 1

III MANAGING FOR LARGE ORGANIC DEBRIS IN STREAMS 2

Relationship Between Debris Stability andSize 3Relationship Between Debris Size and StreamSize in Old-Growth Watersheds 6

IV INFORMATION NEEDS TO ADDRESS DEBRIS MANAGEMENT 12

V REFERENCES 12

A STATUS REPORT ON THE FOREST MANAGERS GUIDE TOSTREAM MANAGEMENT 14

Dr. George G. Ice, NCASIDr. William H. Lawrence, Weyerhaeuser Co.

I INTRODUCTION 14

II DEVELOPMENT OF A GUIDE 14

III MATERIAL PRESENTED IN THE GUIDE 17

Salmon Biology 17Salmon Resource 17Forest Management Practices - Their Impactson Fish Habitat 17Hydrologic Processes 17Organic Debris in Streams 17Stream Management Zones 17

G. Forest Practice Rules ,18

IV BIOLOGICAL EFFECTS SUMMARIZES 18

Streambed Siltation 18Increased Turbidity 18

C. Blockage 18

V REPORT STATUS 20

ACCESSING TECHNICAL INFORMATION ON THE EFFECTSOF FOREST MANAGEMENT PRACTICES ON WATER QUALITYTHROUGH NCASI

20

Dr. George G. Ice, NCASI

I INTRODUCTION 20

II DETERMINING AVAILABLE PUBLISHED INFORMATION 20

III NCASI LITERATURE REVIEWS 21

IV NCASI REVIEWS OF RESEARCH AND WATERSHED INVENTORY 21

V NPS PROGRAM REVIEWS 22

VI CATALOG OF LANDSLIDE INVENTORIES FOR THE NORTHWEST 22

VII BULLETIN BOARD ARTICLES 22

VIII STAFF CAPABILITIES 22

A METHOD OF IDENTIFYING LANDSLIDE HAZARD 24

Dr. Raymond M. Rice, USDA Forest Service

I INTRODUCTION 24

II DISCRIMINANT ANALYSIS 25

III EXAMPLES 25

Little North Fork, Salmon River 25Six Rivers National Forest 27

IV LITERATURE REFERENCES 29

THE STUDY OF THE USE OF LEAVE AREAS TO CONTROLIN-UNIT LANDSLIDES 29

Dr. Frederick J. Swanson, Duane Dipert,and Chris Roach, USDA Forest Service

I INTRODUCTION 29

II METHODS 31

III RESULTS 32

IV DISCUSSION 35

PROPOSAL FOR CUMULATIVE EFFECTS ANALYSIS - FORESTPLANNING - SIUSLAW NATIONAL FOREST

36

George S. Bush, USDA Forest Service

I INTRODUCTION 36

II CAUSE-EFFECT RELATIONSHIPS FOR MODELING 37

General Harvest Effects 37Resource Effects 38

III ASSESSMENT AREA DEFINITION 39

IV DATA COLLECTION AND APPLICATION 40

V ASSESSMENT OF CUMULATIVE EFFECTS 41

Significance of the Effects 41Threshold of Concern 41

C. Watershed/Fisheries Threshold-of-Concern 42

VI LITERATURE REFERENCES 45

ASSESSING THE EFFECTIVENESS OF THE IDAHO FORESTPRACTICES ACT 45

Dale J. McGreer, Potlatch Corporation

I INTRODUCTION 45

II BMPs WORK 45

III THE POLITICAL PROCESS 45

IV EVALUATION OBJECTIVES AND METHODS 47

V RESULTS AND CONCLUSIONS 47

ASSESSING THE EFFECTIVENESS OF CALIFORNIA'SFOREST PRACTICE RULES 49

Arne Skaugset, Simpson Timber Company

I INTRODUCTION

49

II WATER QUALITY PROTECTION AND FOREST MANAGEMENTIN CALIFORNIA

50

Recent History of Forest Practice Regulationin California 50California's Silvicultural 208 Program 52

III SUMMARY 59

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IV LITERATURE REFERENCES

Rice, R.M., "Multivariate Methods Useful in Hydrology," Pro-ceedings, International Hydrology Symposium, Fort Collins,CO, September 6-8, 1:471-478 (1967).Rice, R.M., Pillsbury, N.H., "Predicting Landslides inClearcut Patches," Proceedings Exeter Symposium, Inter-national Association of Hydrological Sciences PublicationsNo. 137 (1982).Furbish, D.J., Rice, R.M., "Predicting Landslides Related toClearcut Logging, Northwest California, U.S.A.," Mountain Research and Development 3 (3) 253-259 (1983).Dixon, W.J., Brown, M.B., [Ed.] "Biomedical Computer Pro-grams," Univ. of California, Berkeley, CA (1979).Ziemer, R.R., "Roots and the Stability of Forested Slopes,"in Erosion and Sediment Transport in Pacific Rim Steeplands,IAHS Pub. 132, Christchurch, New Zealand, 343-361 (January1981).Fisher, R.A., "The Use of Multiple Measurements in TaxonomicProblems," Annals of Eugenics 7 179-188 (1936).Kerlinger, F.N., Pedhazur, E.J., Multiple Regression inBehavioral Research, Holt, Rinehart, and Winston, Inc., NewYork, 534 (1973).Green, P.E., Analyzing Multivariate Data, The Dryden Press,Hinsdale, IL 519 (1978).Gorman, J.W., Toman, R.J., "Selection of Variables forFitting Equations to Data," Technometrics 8 27-51 (1966).Daniel, C., Wood, F.S., Fitting Equations to Data, Wiley-Interscience, New York 342 (1971).

THE STUDY OF THE USE OF LEAVEAREAS TO CONTROL IN-UNIT LANDSLIDES

Dr. Frederick J. Swanson, Duane D. Dipert, and Christopher J. RoachUSDA Forest Service

I INTRODUCTION

The effect of landslides on fish habitat has been a pivotalissue in management of the Mapleton Ranger District on the Sius-law National Forest since the 1960's. (Here the terms landslide

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and slide refer to shallow, rapid soil mass movements onhillslopes which, in the Mapleton area, typically involve 10 to1000 yd 3 of soil.) Analysis of slides occurring in storms in themid-1970's identified clearcut areas as the predominant sites ofslide initiation, unlike most other areas in the Pacific North-west where roads have been the major initiation sites. In res-ponse to t4e fisheries issue and the high frequency of slides inclearcuts,) the_Mapleton District began to prescribe vegetation'leave areas in'.an effort to reduce the occurrence of landslidesin clearcuts. Leave areas are patches of forest vegetation whichare left on areas judged to have high potential for sliding and

i . damaging fish habitat if clearcut.j The intent is to maintainroot strength andother slope-stabilizing functions of vegeta-tion. Leave areas are designated along streams with steep sideslopes and in headwalls which are steep concave areas at theheadward tips of 0-order or first-order channels. Headwall leaveareas are commonly 1 to 4 acres in size. The first headwallleave area was established in 1975. Use of streamside leaveareas for slope stability purposes began several years earlier.

The process of prescribing and implementing leave areas hasbeen developed progressively since the early 1970's. Generally,the current process involves: (a) identifying prospective cut-ting units by evaluating areas of about 1000 acres on aerialphotographs and assigning pieces of ground with concentrations ofhighly unstable headwalls to the Inoperable-Marginal for Leavecategory of forest lands, removing them from the landbase onwhich the allowable cut is calculated, (b) in prosepctive cuttingunits identified in the remaining area, locating headwalls withhigh potential for failure and damage to fish in downstreamareas, (c) a soil scientist or other specialist on the Districtprescribing a leave area, (d) modifying the prescribed leave areain the Interdisciplinary Team process or by the District Rangeras other factors such as logging systems, site preparation, wind-throw hazard, and timber value are considered, and (e) implement-ing the final presciption, including the steps of marking boun-daries on the ground and felling, bucking, yarding, and disposingof slash in the adjacent area. The ultimate success of a leavearea also depends on: (a) it having been properly located in thefirst place, (b) its survival during wind storms, and (c) itsperformance in slide-triggering precipitaiton events.

Leave areas gained a bit of the spotlight during the lawsuitbrought by the National Wildlife Federation against the UnitedStates Forest Service. In his Amended Opinion, Judge Solomoncommented that "landslides damage fish habitat, but it is uncer-tain whether leave areas used by the Forest Service will effec-tively prevent landslides." As a result of this lawsuit, whichis under appeal to the Ninth Circuit Court of Appeals, we haveundertaken a study of the "implementation effectiveness ofheadwall and stream adjacent leave areas", as described in thelanguage of lawyers working on the case. We have broken thistask into six questions:

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What has been the success of implementing prescribedleave areas?What has been the (a) frequency of sliding, and(b) frequency of slides entering channels for slidesoriginating in clearcut areas and headwall and stream-side leave areas?How do (a) the frequency of slides and (b) theirfrequency of entry into streams differ among clearcut,completely forested, and leave area conditions forheadwall and streamside areas?How consistently and thoroughly are unstable areasidentified in units proposed for clearcutting?What is the variance among individuals in assigningrelative risk ratings to headwalls?What is the accuracy of predictions of headwall sta-bility based on the headwall rating system used on theDistrict?

Rephrased, these questions consider the consistency of leavearea prescription, the appropriateness of prescribed leave areasin meeting District objectives, success of the District in im-plementation, and performance of leave areas in mitigating in-unit slide frequency. The study is now underway.

Here we present only a preliminary analysis of results onhalf of the first question - How successful has the District beenin implementing prescribed headwall leave areas? This paper doesnot address the issues of whether headwall leave areas wereproperly prescribed to meet District objectives and their degreeof effectiveness.

II METHODS

The history of implementation of headwall leave areas hasbeen compiled by Soil Scientist Dipert and Hydrologist Roach withassistance from several Timber Sale Officers (TSO's) on theMapleton District. The history of each timber sale with anexisting or prescribed headwall leave area was reconstructedusing all available records, including Environmental Analyses(EA's), aerial photographs, and written reports and recollectionsof soil scientists and TSO's. Records pertaining to implement-ation of each headwall leave area considered for implementationwere collected in a folder along with one-page summary sheet.

In the study plan for this project (Study No. PNW 1653-93),we listed 36 possible headwall leave areas identified in a quickreview of photographs and recollections of District personnel.After field examination and more thorough analysis of records,five of the candidate headwall leave areas were removed from theanalysis. Reasons for removal include: (a) reclassification asstreamside leave areas because they did not extend upward into aheadwall, (b) location on BLM land or the Waldport Ranger Dis-trict, and (c) although the area appeared to be a headwall leave

area on aerial photographs, vegetation had been left at leasttemporarily for other purposes, such as maintaining advancedregeneration in a blowdown patch. We also added one unit (Neely78 Unit 3) to the list of headwall leave areas to be studied. Weevaluated implementation of 32 headwall leave areas (Table 1).

III RESULTS

The implementation histories of the 32 headwall leave areascan be dividied into categories: (a) successfully completedwithout significant modification, (b) completed with some inten-tional modification which either increased or decreased extent ofthe leave area, and (c) unsuccessful implementation (Table 1).The term "success" used here and in Table 1 refers to implementa-tion of the leave area essentially as planned. Successful imple-mentation may involve some damage or loss of trees in the bufferzone surrounding the vegetation at the core of the leave areawhich is assumed to be enhancing the stability of the slide-proneportion of the headwall. Some damage in the buffer zone duringlogging is considered acceptable, because one function of thezone is to absorb minor accidental damage from logging and burn-ing, while maintaining the integrity of the core area. Theeffect of overall leave area size (core area plus buffer zone) onslide frequency in headwalls with leave areas will be evaluatedin later stages of the study when we consider factors influencingoverall "success" of leave areas in reducing frequency of slides.

Twenty of the 32 headwall leave areas prescribed by special-ists on the District were fully implemented without significantchanges. Seven addition headwall leave areas were successfullyimplemented, but with modifications that significantly increasedthe extent of the area left in forest vegetation. In four ofthese cases TSO's modified boundaries to enlarge leave areas. Inone case the TS0 added a landing to protect a leave area duringyarding. In another case, a proposed leave area was incorrectlymarked in the field, but it was remarked in the prescribed loca-tion before felling began. The seventh headwall leave area ofthis type was designed and implemented by the TSO overseeing thesale.

Five headwall leave areas were intentionally or inadvert-ently reduced in extent. A headwall leave area designated inNeely 78 Unit 1 blew down after the adjacent trees had been cut.At Neely 78 Unit 3, 5 to 6 conifer trees were removed from aheadwall leave area and only hardwoods were left. This modi-fication was justified by District personnel on the basis of theheadwall having low to moderate risk of failure and low potentialdamage to fish habitat.

A headwall leave area prescribed in Hoffman 77 Unit 1 wasimplemented through felling and bucking and then intentionallyremoved as part of a plan to redesign the road and yarding sys-tems for the unit. The decision to remove the leave area from

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TABLE 1 IMPLEMENTATION OF HEADWALL LEAVE AREASRANGER DISTRICT, 1975-1984IN THE MAPLETON

WasClearcut Prescription SignificantUnit Name Year Cut Implemented Modifications

Popo Billy 74 1978 yes noneUnit 2

Johnson Creek 73 1975 yes noneUnit 1

Johnson Creek 73 1975 yes noneUnit 1

Hadsall-Beaver 78 1980 yes noneUnit 3

Neely 78 1982 yes noneUnit 2

Hoffman 77Unit 1

1980 yes Originallymislocated bylayout crew

Maria 100 1982 yes noneUnit 2

Neely 78Unit 1

1982 no Blew down aftercutting began butbefore completion

Hoffman 77 1980 Implemented Removed intention-Unit 1 thru felling

and buckingally to facilitateredesign of road& yarding systems

Baldy East 1984 yes noneUnit 2

Baldy East 1984 yes noneUnit 3

Pawnee 1984 yes noneUnit 3

Pawnee 1984 yes noneUnit 3

Swisstide 1983 :yes noneUnit 1

Swisstide 1983 yes noneUnit 1

Swisstide 1983 yes noneUnit 2

Swisstide 1983 yes noneUnit 3

Swisstide 1983 yes noneUnit 6

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TABLE 1 (Continued)

ClearcutUnit Name Year Cut

WasPrescription

.Implemented SignificantModifications

El Rogers

1984 yes noneUnit 1

Pawnee

1983 • yes noneUnit 2

S. Indian

1983 yes boundary changedUnit 2

by TSO to enlargeleave area

East Fossback 1984 yes boundary changedUnit 4 by TSO to enlarge

leave area

East Fossback 1984 yes boundary changedUnit 4 by TSO to enlarge

leave area

East Fossback 1984 yes boundary changedUnit 4 by TSO to enlarge

leave area

East Fossback 1984 yes landing added byUnit 5 TSO to reduce

potential damageto leave area

Perkins 75 1978 yes noneUnit 4

Panther 76 1980 yes leave areaUnit 3 created by TSO

Cataract North 1982 yes noneUnit 1

El Rogers 1984 yes noneUnit 2

Neely 78 1982 yes 5-6 conifersUnit 3 removed, reduc-

ing extent ofleave area

Green 78 1982 no low to moderateUnit 1 risk headwall,

removed prior toyarding

Fivemile 77 1981 yes low to moderateUnit 3 risk headwall,

some burning

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this high risk headwall was balanced against the desire toeliminate a proposed equipment road along a steep ridge thatwould have given access to an additional landing in the unit.District personnel argued that overall slide potential would bereduced by not building the road and landing, although thisnecessitated removing the headwall leave area to yard felledtimber which would have been yarded to that landing.

A headwall leave area on a low- to moderate-risk site inGreen 78 Unit 1 was removed before yarding because it was con-sidered unnecessary. The sale layout crew working in Fivemile 77Unit 3 enlarged a streamside leave area to include some hardwoodson a headwall. Some burning occurred in this leave area whichthe District considered acceptable because the headwall was ofonly low to moderate risk.

IV DISCUSSION

-En-summary,--27 out of 32 (84 percent of the cases) headwallleave areas were implemented successfully and were not reduced insize or stocking level of trees intentionally or inadvertentlyduring implementation. Four of the 32 were reduced in extentintentionally, two being eliminated entirely, one having conifersremoved, and one was partially burned. Only at -Nee-l-y 78 Unit 1—was implementation unsuccessful as a result of outside factors(windthrow) preventing establishment of a forested leave area.

In 1979, the Siuslaw National Forest used the Delphi sam-pling technique to evaluate implementation of headwall leaveareas. The results were discussed in the legal proceeding con-cerning Mapleton. Although the Delphi method has been soundlycriticized as lacking rigor and failing to produce significantfindings, results of the Delphi study of leave areas offer aninteresting point of comparison with the observations reported inthis paper. Personnel from the Siuslaw National Forest inter-viewed 11 people who had field experience with unstable terrainin the Coast Range. The collective opinion of these people wasthat prescribed headwall leave areas would have 90 percent chanceof surviving each of the three steps of implementation:(a) locating headwall leave areas on the ground, (b) yarding, and(c) burning the adjacent areas. The collective probability of aheadwall leave area surviving these three steps is therefore 73percent (90 percent x 90 percent x 90 percent). In this Delphistudy the failure of a headwall leave area to survive each stepwas inferred to be the result of inadvertent circumstances,rather than an intentional modification of the prescription.Based on this criterion, the observations of actual managementpractices reported in this paper suggest a much higher level ofcontrol of those activities (97 percent) than was estimated inthe Delphi sampling procedure. People interviewed in the Delphistudy considered two additional steps in implementation ofheadwall leave areas (locating slide-prone areas on the ground

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and leave areas surviving high winds after implementation).These two issues are considered in other phases of our study ofleave areas.

Several factors may account for the greater success inimplementation of headwall leave areas in the field than wasestimated with the Delphi method. The original Delphi sample wasbased almost entirely on speculation, because only a few headwallleave areas had been attempted at that time and some of thepeople interviewed had never visited one. Furthermore, theincreasing attention that management of the Mapleton Districtand, indeed, all forest land has received from the general publicand numerous special interest groups has probably led to greatercare in carrying out forestry practices. In this spirit, imple-mentation of both headwall and streamside leave areas has prob-ably been improved by creating larger leave areas to provide moreof a buffer around vegetation that is judged likely to enhanceslope stability and by a greater effort to fall, yard, and burnaway from the leave areas.

Implementation of leave areas discussed here is only a smallpart of the overall assessment of their effectiveness in provid-ing a desired level of protection of fish habitat from damage bylandslides. Other essential questions include:

Are the leave areas placed on the landscape in a way thatmeets management objectives?

Do the leave areas survive blowdown?

How do leave areas perform during slide-triggering stormsrelative to clearcut and completely forested areas?

We are now working on these pieces of this complex puzzle.

PROPOSAL FOR CUMULATIVE EFFECTS ANALYSIS- FOREST PLANNING - SIUSLAW NATIONAL FOREST

George S. Bush, USDA Forest Service

I INTRODUCTION

To meet the requirements of Council on Environmental Quality(CEQ) regulations all Federal Agencies must consider cumulativeeffects and impacts. The following method was developed for use