pages about
today's forests


The Basic Bookshelf

50-year Harvest Statistics

Backlot Logging Equipment

Yellow Island Change

Productivity Maps


     Abstract. Certain forest soils suffer long-term damage from wet-season logging practices. Such soils are scattered diffusely throughout Washington State, but in San Juan County they comprise the vast majority (91% of the area). Informed people also know that logging practices in San Juan County are notoriously undisciplined and unsupervised. This unfortunate set of circumstances inspired me to search for a painless, low-cost technical fix.

     In 1999, in an attempt to protect long-term forest productivity wherever there are vulnerable soils, I petitioned the state authority mandated to protect natural resources to regulate damaging logging practices on the most sensitive soils. The petition was based on sophisticated but little known technical data generated and published by the state's very own professional soil scientists. My suggested regulatory and administrative remedies were sensible, easily administered, and inexpensive. Perhaps naively, I submitted and promoted the petition entirely by myself, without organizing any backing and not realizing that they would be reviewed in a highly charged and politicized setting.

     My petition requesting protective regulations followed published procedures and seemed scientifically sound, nonetheless it was denied by the regulatory Forest Practices Board, which happened to be dominated by members closely tied to the industrial logging business. The reasons for the denial were patently nonsensical in technical terms, but of course were consistent with the entrenched, "don't give a inch" political conservatism of the Board's majority.

     This narrative tells the story of the petition and its rejection. Future efforts to bring good sense to logging practices in Washington state may benefit from the experiences reported here. The problem of unregulated logging on San Juan County's vulnerable soil persists to this day, and the "fix" that I proposed still seems like an enlightened solution to protect these soils.

Section 1. How the petition was developed and presented to the state

Section 2. Petition for protective rules

Section 3. Relevance to San Juan County


pages about
forest history

The Presettlement Forest

Lost & Found Prairie

Impact of the Lime Industry

Late 19th-Century Landcover

Bigfoot's Forest (in prep)

Early Forest Composition


Section 1.

How the petition was developed and presented to the state

     ALL SOILS ARE not equal. Each of the one thousand different soil types in the state of Washington has been rated for its particular characteristics. Some of these data are reported in county soil surveys, but, in addition, the State Soil Survey (1983) describes and rates each soil's potential to be harmed by various kinds of logging activities. Unfortunately, the State Soil Survey (a multi-volume document) does not map the location of these soils, nor are its findings easily related to county soil survey maps, because the two reports use incompatible soil-indexing codes.

     By chance, I discovered that the incompatible soil codes in the county and state surveys can be matched and linked through each soil's official descriptive name. By reconciling state and county soil surveys in this "Rosetta Stone" manner, and by consulting the state's digital data maps for soils (SOILS), it became possible for the first time to locate and quantify the acreage of soils that share certain attributes. When this exercise was performed for San Juan County, soils in nearly all of the county's forest acreage (>90%) received the state's highest rating of vulnerability to long-term damaging soil compaction by logging practices carried out during the wet season. These compaction-vulnerable of San Juan County soils are mapped in Section III of this report; although highly revealing, the map has never appeared in an official document.

     THE DISCOVERY THAT most of the forest soils in the San Juans are seasonally susceptible to serious damage from logging raises important questions: Why does logging continue in the winter if the soils are being damaged? Do landowners know or care? Are logging contractors operating with or without knowledge of the harm they may be doing? Has the state's role in resource protection led to rules aimed at safeguarding soils? Does the state know or care?

     My curiosity about these issues uncovered the fact that state logging regulations are nearly silent on matters of soil protection, except in evident wetlands. Accordingly, I decided to submit a citizen's petition to the Washington Forest Practices Board (FPB) to adopt clearer rules. The content of the petition was derived directly from the state's own analysis and recommendations as published in the State Soil Survey; in addition, the petition outlined an innovative, efficient and economical administrative procedure involving an electronic information system to flag permit applications involving sensitive soils. The text of this petition is reproduced below in Section II. Because the content of the petition was so intimately derived from the state Department of Natural Resource's (DNR) own data, I pointedly avoided soliciting political or technical support for my petition; I was anxious to see if the merits of DNR's own analysis and recommendations were sufficient to be converted into resource-protection regulations by DNR's overseeing authority. It is also true that I possessed no political connections. This naive strategy was undoubtedly a miscalculation.

     Washington's Administrative Procedure Act, as spelled out in 34.05.330(1) RCW (Revised Code of Washington), states that a citizen's petition for new rules will receive attention and written reply within 60 days. My petition was submitted March 31, 1999. After 100 days without any reply I reminded the Commissioner for Public Lands and Chair of the Forest Practices Board, Jennifer Belcher, about the existence of my petition. On March 22, 2000 - a full 354 days after the petition was submitted and 10 months beyond the RCW-stipulated response time - the FPB held an official hearing to address the petition and to decide for or against new rules based on the petition.

     IN PREPARATION FOR the hearing of March 22, 2000, the Forest Practices Board arranged with selected DNR staff to review the petition and to make a recommendation. The hearing agenda did not include a provision for public testimony, although, as we shall see, such opportunity was eventually created without equal notification and lobbyists for the logging industry participated with pre-arranged testimony. Ultimately, DNR staff recommended that the request be denied because four existing rules already covered soil protection. The four rules underlying this conclusion were: WAC 222-30-070(1), -070(3b), -070(5), and -090. DNR staff deceived the public and the FPB by asserting that these rules addressed the issues raised in my petition, which they patently do not.

     The first two rules are in fact totally irrelevant since they relate specifically to wetlands, not to upland forest soils where compaction problems also exist. The last rule pertains to post-harvest site preparation and thus also appears to have nothing to do with soil vulnerability. Only the third rule was conceivably germane to soil compaction as the main problem addressed by the petition.

WAC 222-30-070(5). "Tractor and wheeled skidders shall not be used on exposed erodible soils or saturated soils when soil moisture content is so high that unreasonable soil compaction, soil disturbance, or wetland, lake or pond siltation would result."

     The text of the -070(5) rule seems applicable to the issue behind my petition, even though it uses such elastic words as "unreasonable," but questions arise: How does it relate to the more specific warnings and soil identities specified in the State Soil Survey? Is there any realistic mechanism for administering the -070(5) rule or any evidence that it is enforced? In its analysis of the petition, why didn't DNR generate a state map showing the statewide extent of compaction susceptibility throughout Washington, as had been done for San Juan County? Why did the DNR analysis fail to follow the interpretations and recommendations of its own soil scientists, as published in the State Soil Survey?

     Rule -070(5) is lumped with other regulations exclusively addressing overt wetlands, not to upland soils that are seasonally soaked. And, anyway, it is neglected administratively so it is a rule without teeth. Consequently, soil compaction by heavy logging equipment during the wet winter months continues without relief regardless of professionally documented damage to the fundamental natural resource that underlies forest productivity, namely the soil.

     In any event, DNR recommended against adopting new and clearer rules, and it failed to consider any improvements for monitoring and enforcing rule -070(5).

     AT THE HEARING, immediately after DNR's recommendation an unscheduled (and thus improper) opportunity was presented for public testimony. Three people spoke up. Even though I was caught off-guard by the unannounced opportunity to testify, I, as petitioner, restated the need for new science-based rules in order to achieve actual soil protection, not merely a rhetorical gesture; I further reiterated that the petition was science-based, founded on DNR-generated soil data and that the regulatory remedy was technically and administratively simple, fiscally responsible, and fair to all stakeholders. After I finished, the second and third testifiers read their prepared statements; the fact that their comments were prepared in advace indicated that they either 1) accurately anticipated the possibility of public testimony, 2) had been advised in advance that such opportunity would be presented (which I was not), or 3) were somehow parties to arranging an opening for their testimony, for example in cooperation with one of the FPB members allied with the timber industry.

     Kevin _, an employee of Weyerhaueser, advocated denial of the petition on the illogical grounds that there was no need for statewide regulations since his company already knew how to avoid soil compaction without regulations. The subtext of this odd statement seemed to be: whatever is true and good for Weyerhaueser must be true and good for Washington state and all of the forests under state management.

     Charles _, speaking on behalf of the Washington Forest Protection Association (an organization that lobbies for the protection of the timber industry) also supported denial of the petition. He disembled that whatever problem may exist could be handled through educational efforts by the state's Conservation Districts. (As a former CD supervisor, which is a voluntary position,I can attest that these organizations are notoriously hamstrung by limited budgetary support, frail political will, bureaucratic infighting, and compromised conservation objectives. They have no clout to intervene in permitted forest practices.)

     AFTER A DISMISSIVELY brief discussion, a vote on the "question" was called and the industry-dominated FPB board board summarily voted to deny my citizen's petition for rules protecting vulnerable forest soils. Thus, the many months of deliberation and delay since I submitted my proposal were followed by a few very short moments of denial.

     Enigmatically, right after its vote (as the public record of the hearing shows) a brief general discussion ensued among FPB members in which soil compaction was openly admitted to be a real and significant problem deserving attention of some sort. Nothing in that paradoxical discussion, however, hinted how that frank admission was reconciled with the negative vote taken just moments before.

     After the vote to deny my petition I departed with a final, private question: When a government agency denies a citizen's petition, is that the end of it? Not necessarily is the answer.

     ACCORDING TO STATE law, namely 34.05.330(3) RCW, a petitioner who has been denied action by a state agency can appeal the decision to the Governor's office, which is then mandated to reply. The FPB's denial of effective rules for soils was, therefore, appealed to Governor Locke's office on April 18, 2000. In a timely manner, but without evidence that the content of the original proposal had been reexamined, the Governor's office ineptly routed my appeal back to the Commissioner of Public Lands (who directs DNR and chairs the FPB). In other words, the petition had traveled a complete a circle back to the agency that had just denied it. Of course, the Commissioner stood by her agency's decision.

     Subsequently, I resubmitted my appeal to the Governor's office on May 1, 2000 with the explicit request that the Governor follow state law and reconsider the substance of the issue. This re-appeal went totally unanswered, and even the submission went unacknowledged. So much for the appeal process....

     I HOPE THAT the account of this experience proves instructive to other citizens or groups who might endeavor to protect natural resources in Washington State through existing official channels. The eminent validity of my petition is undiminished, in my opinion, but any success in the future will require a more pragmatic strategy by a petitioner, and it will require a more responsible consideration of the factual issues by the governing bodies.

Section 2.

Petition for New Forest Practices Rules
Governing Vulnerable Forest Soils

(Proposed March 31, 1999 by Tom Schroeder. Denied March 22, 2000 by State of Washington Forest Practices Board)

[click on links to go directly to subsections]



     Proposed new rules are aimed at safeguarding long-term timber productivity on forestland sites throughout the state whose soils are seasonally susceptible to lasting degradation as a consequence of certain forest practices. Such sites are not protected by existing rules or administrative provisions, and their future timber productivity through soil abuse is being compromised by changing patterns of resource management.

     This proposal targets forestland sites whose soils exhibit a high potential for compaction when they are moist or wet. New rules would restrict the use of heavy, ground-based equipment on these targeted sites during seasons of heightened vulnerability.

     This proposal further suggests concrete administrative steps, using existing electronic databases and information technologies, to implement the proposed new rules in conjunction with the permit application process. These steps will expeditiously identify the targeted sites, execute the approval process according to predetermined criteria, and suitably notify forestland owners of management restrictions and alternatives.

     The proposal is based on available scientific and technical knowledge in soil science, timber management, and information technology. It recognizes and respects legislatively mandated governmental authority, private landowner rights and responsibilities, commercial imperatives, and recent sociological changes in forestland tenure and management decision-making.

     The new rules are limited in scope but will be statewide in applicability. They seem well-suited for consideration under the Expedited Rule Making process by the Forest Practices Board.


     Heavy, ground-based equipment will be restricted from forestland sites known to exhibit a high potentiality for soil compaction during the local season when soils are moist or wet, as these terms are used in the State Soil Survey (1983).

     Approval of applications for forest practices on such sites will be seasonally conditioned, and landowners will be notified in writing in a manner that explains and educates.

     Possible waivers of restrictions will require verification that lasting soil damage will be avoided by such mitigating factors as the use of special equipment or methods, a limited pattern of equipment usage, a climatic anomaly, or an inaccurate site classification.

     Forest practices on sites exhibiting medium potentiality for soil compaction will not be restricted by regulation, but landowner-applicants and resource managers of such sites will be apprised by written advisories of the risks to future productivity posed by the excessive use of heavy, ground-based equipment during the season of vulnerability


     If designed and administered properly, the proposed rules would safeguard the productive capacity of those forested sites throughout the state that could be harmed by soil disturbances caused by aggressive ground-based timber harvesting and other practices undertaken when the soils are moist or wet. The rules will not change forest practices when these same soils are dry.

     Instituting these new forest practices rules is deemed socially and environmentally responsible for at least five reasons:

  • Long-term protection of timber-growing capability, forest soils, and sensitive components of our productive ecosystems are acknowledged public policy goals in Washington State
  • Vulnerable sites are presently experiencing long-lasting damage by forest practices involving inappropriate use of heavy, ground-based equipment, whether intentional or not
  • Public agencies have already located and identified vulnerable forestland sites, and they already possess the technical and scientific knowledge necessary to predict the detrimental consequences of some forest practices, but that knowledge has not been conveyed successfully to private decision-makers and resource managers
  • Passive voluntary measures and non-regulatory advisories have failed to educate or convince many landowners, operators, and resource managers that compaction-prone sites can be lastingly damaged
  • Statewide, consistent, and science-based regulatory intervention would increase resource protection and management predictability.

     The proposed rules would apply exclusively to those forestland sites that are seasonally vulnerable to degradation by soil compaction, as defined by DNR. Only forestland owners and owners of timber on such sites, and operator/contractors who would conduct forest practices upon such sites would be affected. No other sites or individuals would be impacted.

     Affected equipment types, patterns of usage, and local calendric seasons would be specified by DNR.


     Jurisdiction. The Forest Practices Act of 1974 makes it clear that forest soils, as the foundation for timber growth, deserve careful protection.

"The forest land resources are among the most valuable of all resources in the state.... It is important to afford protection of forest soils... by utilizing all reasonable methods of technology." 76.09.010 RCW.

     The Forest Practice Board is authorized to develop rules to achieve the goals of the Act, but current rules do not address fragile or vulnerable soils other than those of typed waters and wetlands.

"Within all wetlands... tractor and wheeled skidders shall not be used... when soil moisture content is so high that unreasonable soil compaction [or] soil disturbance... would result." WAC 222-30-070 (1c, 5).

     On a seasonal basis, some non-wetland soils also exhibit very high potentials for degradation due to soil compaction when they are subjected to heavy, ground-based equipment. These vulnerable soils have been unequivocally identified in DNR's multi-volume State Soil Survey (1983) (see definitions and rating system in Appendix A), but they have not been safeguarded by forest practices rules, administrative provisions, or operational standards.

     Consequences. Extensive soil compaction significantly reduces a site's capability for timber productivity in the long-term through degraded reforestation potential, rate of tree growth, and stand health (see Appendices B-D). Compaction and other equipment-related soil problems may also cause unacceptable changes to on-site and off-site hydrology, including water quality and quantity.

     Recent public and official attention has highlighted the impacts of forest practices upon public resources and certain forest "externalities," such as wildlife habitat, salmon recovery, and stream ecology. In contrast, the disruptive consequences of certain forest practices on intrinsic forest processes such as forest health, long-term timber productivity, the lasting importance of genetic complexity, etc. have received less attention. One way to attend to these omissions is to tailor specific rules to remedy identifiable problems as they arise and are understood. The present proposal addresses compaction, but it does not thereby minimize other hazards and detrimental occurrences on forested sites; such problems as puddling, soil and forest-floor displacement, erosion, slope instability, and mass wasting are also grave concerns.

     It is now well-recognized that some forest soils, particularly when they are wet or even moist, are lastingly damaged by heavy equipment during conventional ground-based timber harvesting. Such damage to below-ground processes and nutrient availability can cause future timber growth to be retarded for decades. One might suppose that compaction-related problems could be avoided through thoughtful and voluntary management, either by using alternative harvesting methods or by simply waiting until the soils are dry. Realistically, however, this is not happening as uniformly as may be wished; many sites, particularly small ones, are allowed to become de facto conversions by being seriously degraded by wet-season harvest operations.

     Social and land-use context. Throughout Washington today, society's relation to timber land is changing dramatically. The term "exurbation" captures some of these alterations - urban people migrating onto subdivided parcels of resource land without the appropriate knowledge or experience to manage the natural resource judiciously. These social and land-use changes alter the entire landscape of management by simultaneously increasing the number of individual forest landowners, shrinking the acreage of management units, shortening individual tenure on the land, and diluting the average expertise in resource matters.

     Also, ironically, despite ever-increasing understanding of the functional intricacies of complex ecosystems, funding support is being withdrawn from the very public agencies that can transfer needed stewardship advice to new forestland owners. These conditions conspire to deprive an entire generation of new landowners of the resource information and technical skills needed for prudent and voluntary management decisions. They are also a recipe for resource exploitation, depletion, and abuse.

     Because novice landowners on small forestland parcels often lack experience and stewardship skills, they are inclined to relinquish management decisions and responsibilities to contract operators. The resulting forest practices are often unsupervised, improperly scheduled, and opportunistically aimed at maximizing short-term economic gain without regard for seasonal soil vulnerabilities or protection of long-term forest productivity. In these circumstances, harvesting is hardly ever done with cable systems; the ground-based equipment is often no more specialized than excavators and dozers (which find dual use in residential and commercial construction), and they are operated without regard for defined skid trails. Thus, certain forest practices not only do extensive damage to the natural resource through destructive extraction and soil abuse, but they also become entangled in the processes of incremental conversion and urban sprawl.

     Remedy. Site damage in forestlands can happen quickly, but recovery of timber productivity can be slow, disheartening and expensive. How can vulnerable sites be protected over the time scale appropriate for timber growth and maturation when sound management is interrupted by volatile land ownership? Seamlessly sound management evidently cannot be assured through voluntary individual behavior alone. Integration of management decisions over time, and protection of vulnerable sites, can be facilitated by regulatory intervention, although no single rule will solve all problems.

     The new rules proposed here address certain soil-protection issues in a simple and pragmatic way. They embrace the spirit of Commissioner Belcher's call "to protect fragile ecosystems" (introductory letter to Washington Forest Practices Rules & Manual, 1998) and the directives of the Forest Practices Act of 1974 to safeguard forest productivity and forest soils. The suggested administrative procedures outlined below also conform to the mandate of the Forest Practices Act to enlist emerging technologies in the service of protecting natural resources. The rules and implementing provisions are aimed at damage prevention and resource protection.


     Information technology is the key to administering the proposed rules in a cost-effective manner, and the main components of a feasible system presently exist. The three technical pillars of an integrated information system for protecting compaction-prone soils are as follows:

  • a database that rates all of Washington's forestland soil types according to soil compaction potential (low, medium, and high; see Appendix A). This database exists in hardcopy form as the State Soil Survey, developed by DNR staff in 1983, and in digital form as SOILS, in which all thematic data is geo-referenced and so is suitable to generate maps; in other words, SOILS is a data layer of a geographic information system (GIS).
  • a database that identifies local precipitation with sufficient temporal and spatial resolution to specify the calendric season when local soils are sufficiently moist or wet for their compaction vulnerabilities to be expressed. DNR's GIS data layer ANPRECIP, augmented as needed with additional regional information, will comprise this database.
  • digitized data from forest practices applications (FPAs) that identify site location (township, range, section, subdivision) and the address of the legal landowner. Data in this form are presently entered into the DNR's MAPS information-management program.

     An innovative information technology system would link these databases to work together. FPAs would provide the input data to an information system for automated analysis, and the output products would include permit approvals and advisory correspondence directed to applicants. The system would screen in-coming FPAs through a multi-layered GIS and thereby discriminate (i.e. "flag") those sites containing compaction-prone soils. This new information will initiate an automated approval process as well as semi-customized correspondence to each affected landowner at the given address, as guided by predetermined standards and notification policies.

     Accordingly, based on local differences in site vulnerabilities, FPAs would be electronically processed into the following categories:

A. unconditioned approval (low compaction potential; no seasonal restrictions would apply),

B. approval with a cautionary notification (medium compaction potential; landowners and managers would be alerted to the potential for damage when soils of moderate vulnerability are periodically very wet, and they would be advised to exercise cautions appropriate to distinct microsites),

C. approval with seasonal conditions (high compaction potential; equipment restrictions would be imposed during specified periods when highly vulnerable local soils are moist or wet).

     In this administrative scheme, essential technical and decision-making information would flow from DNR (where the technical knowledge resides or can be acquired) to landowners (who may need it for sound resource management). The combination of regulatory restriction and information transfer provided by this system should help restrain further degradation of vulnerable forest sites caused by careless and unenlightened forest practices.

     While considering the administrative scheme outlined above, it is worth noting that there are precedents for flagging FPAs and for restricting forest practices according to seasonal variables. FPAs are presently screened by the Department of Fish and Wildlife's GIS information-management system called TRAX in order to protect seasonal raptor habitat and other sensitive environmental parameters. Processing FPAs for site vulnerability would be analogous in design, purpose, and outcome.


APPENDIX A. Definition of compaction potential, from State Soil Survey (1983), pp. 5-6.

     "Compaction is the compression of soil particles closer together, reducing the amount of pore space of the soil. The process of compaction increases soil density. Compaction occurs as result of the movement of wheeled and tracked equipment and other logging practices (e.g., yarding logs) on the soil surface.

     "Compaction can reduce the growth rate of trees by:
(1) reducing the size or extent of root systems and the number of fine roots by increasing soil density. The moisture stress and nutrient stress potentials are greater as a result.

(2) reducing the oxygen uptake of roots, thereby decreasing absorption of water and nutrients.

(3) impeding water movement through soils.

     "The Compaction Potential Rating refers to the susceptibility of a soil to compact. The ratings are based on moist surface soil behavior.

     "Definitions of the ratings:

Low The potential for compaction is insignificant. This soil is able to support
standard equipment with minimal compaction. The soil is moisture insensitive, exhibiting only small changes in density with changing moisture content.

Medium The potential for compaction is significant. The growth rate of seedlings may be reduced. After the initial compaction (i.e. the first equipment pass), this soil is able to support standard equipment with only minimal increases in soil density. The soil is an intermediate between moisture insensitive and moisture sensitive (below) soils.

High The potential for compaction is significant. The growth rate of seedlings will be reduced following compaction. After initial compaction, this soil is still able to support standard equipment but will continue to compact with each subsequent pass. The soil is moisture sensitive, exhibiting large changes in density with changing moisture content."

APPENDIX B. Some testimonials on the fundamental value of soil.

     Wallace, H. A. (1938). In: Soils and Men. USDA Yearbook of Agriculture. 1232 p.
"No man has the right to destroy soil even if he does so in fee simple. The soil requires the duty of man which we have been slow to recognize."

     Janda, R. J. (1981). In: Heilman, P. E., et al. Forest Soils of the Douglas-fir Region. WSU/Cooperative Extension, Pullman, WA.
"Over socially meaningful spans of time the soils of this region should be considered a nonrenewable resource and managed accordingly."

     Senyk, J. P. and D. Craigdallie (1997). Soil properties and forest productivity. Technology Transfer Note #8, Natural Resources Canada.
"The effects of forestry operations on soil productivity are a serious concern.... Maintaining the quality of the soil is crucial to the future well-being of the forest and to sustaining ecosystem integrity.... Soil degradation from forestry reduce annual wood yield by 400,000 m3.... Displacement and compaction are the most common forms of soil degradation caused by ground-based skidding and harvesting.... The degree and severity of soil disturbances from ground-based operations... are influenced by the following factors [including] soil moisture."

     Kimmins, H. (1997). Balancing Act: Environmental Issues in Forestry. UBC Press, Vancouver. 305 p.
"There is still far too little understanding by many loggers and some foresters about forest soils and the impact that timber harvesting and other forest practices have on them.... Damage has... been done to soil by inappropriate harvesting equipment (e.g., soil compaction)."

APPENDIX C. Broad consensus that soil compaction is caused by ground-based equipment and should be avoided.

Washington State DNR (1997). Forest Practices Illustrated. 62 pp.
"Select harvest system appropriate for conditions.... Ground-based harvesting systems are typically used on gentle terrain, on soils not wet or easily compacted.... Cable systems are generally used on steep or broken topography, or on soil that is wet or easily compacted, where ground-based systems cannot be used.... Design and locate skid trails and skidding operations to minimize soil disturbance. Disturbing the soil can... affect the soil's ability to grow trees."

"Harvest operations at the wrong time of year for the site can create problems, including soil compaction.".

"Minimize soil disturbance when using mechanical equipment.... Do not use heavy equipment when soils are saturated and compact easily.... These suggestions may exceed forest practice rules."

Trappe, J. M. and W. B. Bollen (1981). In: Heilman, P. E. et al. Forest Soils of the Douglas-fir Region. WSU Cooperative Extension, Pullman.
"Minimizing soil compaction during timber harvest is useful to maintain not only good soil physical properties but also optimum populations of soil organisms."

OSU Extension Service (1993). Extension Circular 1110. 6 pp.
"Ground-based skidding may cause unacceptable damage to woodland soils.... Soil compaction can reduce the soil's productivity to grow trees."

Gibbs, S. (1998). Forest Stewardship Notes. WSU Cooperative Extension. Fall, p. 6.
"Schedule any timber harvest or tree removal activity when the soils are dry or frozen."

Hatz, R. (1995). Northwest Woodlands [a W.F.F.A. publication]. Fall, 20-21.
"Equipment operability... indicates the need to consider choosing between wheeled, tracked or cable harvesting equipment, or the need to time operations to avoid seasonal limitations."

Beets, P. N., T. A. Terry, and J. Manz (1994). In: Impacts of Forest Harvesting on Long-Term Site Productivity, (Eds. Dyck, W. J., D. W. Cole, and N. B. Crawford). Chapman & Hall, London. p. 219-246. [last two authors employees of Weyerhaeuser Co.]
"One of the main tenets of sustainable commercial forest management is to maintain and enhance the capability of forest sites.... Prudent management regimes must... reduce evaporation, increase water infiltration and nutrient availability, and minimize detrimental soil disturbance.... Information on the time periods that one could expect to operate with ground equipment on the various soils based on average local rainfall patterns and evapotranspiration and experience should be [made available]... in a manner that facilitates decision making."

Dyck, W. J. and D. W. Cole. (1994). In: Impacts of Forest Harvesting on Long-Term Site Productivity, (Eds. Dyck, W. J., D. W. Cole, and N. B. Crawford). Chapman & Hall, London.
"Inappropriate harvesting and site preparation operations that remove nutrients or seriously compact the soil may have a negative impact on productivity, and also on site quality."

USDA/FS (1994). Sustaining Forest Soil Productivity. Woodland Owner's Guide. PNW Res. Sta., Portland, OR.
"Compaction... influences forest productivity directly by influencing the movement of water and oxygen into the soil and the penetration, growth, and distribution of roots. Soil is most easily compacted when machinery applies ground pressure and vibration to the soil during forest harvest operations and mechanical site preparation.... What you can do - Operate heavy machinery during the dry season."

Wigg, M. (1995). Northwest Woodlands [a W.F.F.A. publication]. Summer, 14-15.
"Soils are the most complex part of a forest ecosystem and contain more species than are present above the soil surface. Keeping soils alive requires reducing erosion, compaction, disturbance and excessively hot fires.... Most biological activity occurs near the surface of the soil... the loss of the organic matter and the upper soil layer is very damaging."

WSU Cooperative Extension (1991). Managing Forestlands in Washington. MISC #0138. 46 pp.
"Heavy equipment used during the rainy season can permanently damage the land and watershed."

McIver, J. (1998). Natural Resource News, Blue Mts. Nat. Res. Inst. 8(3): 3.
"Loss of productivity can result from several different types of soil damage, including outright loss of soil through erosion, disruption of the soil surface by displacement or exposure, or loss of soil porosity through compaction. In each of these cases, damaged soil is less productive because the processes that occur within the soil do not operate normally."

Harvey, A. E. et al. (1994). USDA/FS PNW-GTR-323.
"Substantial losses in productivity have been reported... as a result of forest-floor and surface soil displacement and soil compaction."

Adams, P. W. and H. A. Froelich (1984). Compaction of forest soils. PNW Extension Publication #217.
"Soil compaction can persist for decades, or it can be significantly reduced [where there are] very active plant roots, soil organisms, or regular freeze-thaw... cycles.... Unfortunately, the moderate climate and particular soil common to the Pacific Northwest seem to produce some very slow rates of recovery from compaction.

"Mechanization typically improves the time- and cost-efficiency of... forest operations.... Soil compaction is one commonly observed consequence of the use of machinery on forest sites. The negative impacts of soil compaction on these sites include the reduced growth of seedlings and residual trees."

Harvey, A.E. (1995). Blue Mts. Nat. Res. Inst. 5(1): 6-9.
"Ground-based systems often result in the highest vegetation and soil disturbance.... Where units have reach-out arms, mechanical harvesting has been purported to cause less disturbance than conventional skidding, because there appears to be potential to stay on specified trails and travel on logging slash... but the validity of such claims remains largely unsubstantiated."

APPENDIX D. Some relationships between soil compaction and biota.

Meurisse, R. T. Natural Resource News (1995) Blue Mts. Nat. Res. Inst. 5(1): 13-16.
"Operation of heavy equipment can have significant effects on soil properties.... Detrimental soil conditions normally occur on from 10% to more than 70% of an activity area... The majority of soil damage was from soil compaction. Only a small percentage was from soil displacement.... Significant reductions in height and diameter growth [are] related to soil compaction."

Conlin, T. S. S. and R. van den Driessche (1996). Soil compaction studies. FRDA 264, Canadian Forest Service.
"Growth reduction in trees due to soil compaction has been shown to occur for as long as 32 years after harvest. The amount of compaction that occurs is related to soil moisture content."

BC Environment (1995). Hazard assessment keys for evaluating site sensitivity to soil degrading processes guidebook. 24 pp.
"Data required for soil disturbance hazard assessment [should include] reliable seasonal occurrence of dry soil > 15-30 cm deep."

WSU Cooperative Extension (1996). Forest Ecology in Washington. 22 pp.
"A group of soil organisms known as mycorrhizae-forming fungi actually colonize the roots of some trees and greatly improve their ability to take up water and nutrients. The tree and the fungi depend on each other, both greatly benefiting from the partnership. Mycorrhizal fungi are very susceptible to changes in environmental conditions, especially those caused by soil compaction."

Amaranthus, M. P., D. Page-Dumroese, A. Harvey, and L. F. Bednar (1996). Soil compaction and organic matter affect conifer seedling nonmycorrhizal and ectomycorrhizal root tip abundance and diversity. USDA-FS PNW-RP-494.
"Timber harvest and soil compaction can alter forest soil productivity by reducing organic matter. Timber harvesting can also reduce site productivity by compacting soils. The effects of soil compaction can last up to 45 years. Soil compaction degrades soil structure and restricts movement of oxygen and water through the soil, and flushing out of carbon dioxide and populations of ectomycorrhizal fungi may be adversely altered as a result. In addition, compaction reduces the pore space for root penetration and production of feeder rootlets where mycorrhizae form. Sustaining forest productivity requires understanding the complex interactions among soils, roots, and mycorrhizae."

Ingham, E. R. (1995) Natural Resource News. Blue Mts. Nat. Res. Inst. 5(1): 10-12, 16-17.
"Most conifers are obligately mycorrhyzal: conifers can grown in hydroponic systems without mycorrhizae, but when they must compete with other plants, conifers such as Douglas-fir... won't survive without the mycorrhizal fungi growing on their root systems. This mycorrhizal network is destroyed when soil is compacted with large machinery.... It would be wise to modify our management so that the biomass of these organisms isn't severely reduced.
"The soil foodweb is a prime indicator of ecosystem health for a variety of reasons. If soil processes are disrupted, if bacterial or fungal biomass is decreased, if the ratio of fungal to bacterial biomass is altered to something inappropriate to the desired system, if the number or diversity of protozoa is reduced, or if nematode numbers and nematode community structure is altered, loss of natural vegetation or even human health can be predicted."

Section 3.

Vulnerable Forest Soils in San Juan County

     SIXTY PERCENT OF the county's landcover is forest, and, not surprisingly, most of those 70,000 acres of forest are located on so-called "forest soils," as designated by various soil surveys. Such soils were formed in conjunction with forests over thousands of years and today are naturally and theoretically capable of supporting at least a threshold amount of forest growth (regardless of the forest they presently sustain). Some areas of forest soil have been cleared of trees, yet the soil is largely unchanged, so a map that shows existing forest is nearly, but not quite the same as a map of forest soils.

     The map that follows shows all forest soils in red, brown or yellow, whereas non-forest soils (meaning grassland soils and rockland) are white. The colors distinguish different vulnerabilities to soil compaction from heavy logging equipment. Strikingly, nearly all of the forest soils in San Juan County are colored red, which signifies that state soil scientists have rated them as the most vulnerable to soil compaction as a result of logging equipment operated when the soils are moist or wet.

     THE LARGE RED areas on the above map represent soils that exhibit a high potential for damaging soil compaction by heavy logging equipment, at least when they are moist or wet. The State Soil Survey (1983) warns that these soils are "moisture sensitive." Since soil compaction increases soil density by compressing out the tiny but vital spaces for air and water, the consequences for future tree growth (forest productivity) can be dire:

"Compaction can reduce the growth rate of trees by:

(1) reducing the size or extent of root systems and the number of fine roots.... Moisture stress and nutrient stress potentials are greater as a result.

(2) reducing the oxygen uptake of roots, thereby decreasing absorption of water and nutrients.

(3) impeding water movement through soils."

     Once they have been compacted, forest soils in San Juan County do not readily recover their porosity and ability to hold sufficient moisture and air for forest growth because of our local climate. The natural mechanism that is most able to restore compacted soils is largely absent from our environment, namely deep winter frosts. Deep frosts, and the accompanying soil expansion (heaving), are characteristic of some climates, but they rarely occur here in the temperate northwest. As a result, soils that become compacted can tend to remain damaged for decades.

     CONSIDER THE COMBINED effects of the following local realities:

  • under natural circumstances, forest productivity in San Juan County is already the lowest of all counties in western Washington
  • the annual rate of timber harvest is the highest of all counties (that is, entries by logging equipment and volume of logs removed relative to standing volume)
  • more than 90% of our forest soils are highly susceptible to long-term damage by wet-season logging
  • logging activity persists indiscriminately throughout the year, including when the soils are wet and most vulnerable to damage.

     IF FUTURE FOREST productivity is to be conserved, doesn't it seem reasonable that heavy logging equipment should be seasonally off-limits from soils that are known to be vulnerable to compaction damage? Admittedly, if logging activity was seasonally restricted, logging contractors and their employees would be impacted economically. But which option is more responsible for a culturally advanced society: a) persisting with short-term opportunistic forest practices that fail to look out for long-term negative consequences, or b) enlightened restraint of logging practices that harm the natural resource? Some part of the responsibility for improper logging practices rests with landowners. However, so long as landowners are uninformed and are gullibly influenced by aggressive loggers, some other authority needs to step in to educate and to protect the natural resource from abuse. My petition (Section II, above) provided such benefits and protections.

     When challenged to face up to its state-wide responsibilities for protecting natural resources, the Washington State's Forest Practices Board decided not to design regulations that protect vulnerable forest soils (see Section I, above). This setback at a higher level of government need not dissuade San Juan County from acting on its own. As a community and a government, San Juan County should be able to find a way to regulate harmful logging practices within its own jurisdiction, however it has not yet done so.


State Soil Survey (1983). Volume 2: Report of the Northwest Area. Washington, Department of Natural Resources, Forest Land Management Division. (A ~100-page abridgment of this multi-volume document, customized by Tom Schroeder in 1999 for San Juan County's soils, is available in Lopez, Orcas and San Juan Island Libraries).

Soil Survey of San Juan County, Washington (1962). Schlots, F.E. et al. USDA Soil Conservation Service, Series 1957, No. 15.

SOILS (n.d.) Digital data file of soils and soil attributes in Washington State. Washington Department of Natural Resources.

The author gratefully credits Greg Frister for generating the map in Section III.


Return tofOREST iNFO Home

Tom Schroeder