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A file of R.H. Giles retrieved in 2000. It was a general description and used as a draft proposal, one of many sent in response to RFPs and sent to various funding agencies hoping for its continuance. There were no positive responses.
SPANS is a system that has been created that produces statements, illustrations, maps, and reports believed to be useful to owners and managers of natural resource areas. SPANS is not an acronym. It is only a name, a few letters that designate a total system that seeks to build linkages and appropriate relations among all relevant parts of resource systems past, present, and future. As bridges span rivers, so do the efforts within this system attempt to connect in meaningful, useful ways the many, many parts of all resource systems.
One fundamental concept within the system is unusual. It is that a plan is not as important as a planning system. The view taken by those working with SPANS is that a plan is like a newspaper, important today, but probably discarded tomorrow. In a rapidly changing world, plans are all-too-often referred to as "those dusty books on the shelf." The SPANS concept is of a dynamic planning system that can produce on demand, a book (once called "the plan") or any part of it.
A second concept is one of the system becoming a philosophical core of the operation of an area. The SPANS system, when fully developed, will have all relevant components of a large managerial system. It can provide the connecting central theme for all databases, inventories, and schedules -- from financial to farm forests and the future.
Another fundamental concept within SPANS is that prescriptions are the bases for decisions. Prescriptions can be taken or not; they are formal, serious advice. In the case of SPANS reports, they are based on vast literature research, experience of many people, and complex models. The whole natural resource system is the goal which is addressed by SPANS. Creating a comprehensive system is an elusive quest, probably never quite achieved. Minimum, unbiased, cost-effective inputs are one mark of the system. Reliance is placed on both centralized databases and detailed field observations recorded on standard forms. Another characteristic is balance, i.e, an effort to achieve relatively equal precision in all computations throughout the system. Another dimension is one of reasonable levels of confidence in a dynamic environment of economics, succession, policy, personnel change, and natural catastrophe.
The primary organization of SPANS is a non-hierarchial often overlapping mix of ecology or environmental topics, of economics, esthetics (the range of value judgements), and of energetics or energy budgeting.
Within the ecosystems (as well as most of the above four E's of the system (Fig. 1A), there are the four interlocked broad areas of the
SPANS reports typically include diagnoses and prescriptions. They are area-specific and related to objectives. They are not cast into an indefinite environment for unknown use. The objective-oriented analyses and descriptions are the area diagnoses, the bases for the prescriptions.
Just as follow-ups to prescriptions are made, so too should comments, observations, and advice be made about any part of SPANS to:
Robert H. Giles, Jr., Ph.D.
Department of Fisheries and Wildlife Sciences
Virginia Polytechnic Institute and State University
Blacksburg, Virginia 24061-0321 USA
Phone: (703) 231-5910
Fax (703) 231-7580
The entire system is dynamically changing. The purposes of a SPANS diagnosis report is to provide an analysis of an area for a land manager or owner. This is a comprehensive, detailed and summary description of the area. Prescription reports follow diagnosis.
Leopold (1949) discussed the concept of land health. It is a useful figure of speech. The land use expert, like the medical doctor, collects all of the facts and analyzes the land (develops a diagnosis) and then designs a set of alternatives or actions needed to fix problems or achieve landowner objectives (prescriptions). The U.S. Forest Service for years has used the idea of a prescription for forest stand or cutting unit.
In a special sense, SPANS is an expert system, reflecting the technology known by that name that is a computer knowledge-base, the accumulated wisdom of experts, a program that makes deductions about information supplied, and a procedure for back-tracking to find out the logic used within the system. Expert systems, like SPANS, have rules, constraints or limits, means for generating potential actions, and means for selecting best solutions.
The report produced is believed to be used best (1) disassembled and integrated into various reports, proposals, and responses to requests of various agencies and boards; or (2) as a document, but only one, in the processes used to decide how to allocate labor, expertise, resources, and funds in various land use projects. It provides diagnoses, and based on them and objectives, it produces a prescription. However, like one from a doctor, it must be the patient who decides whether to take it, and how conscientiously and fully it will be implemented.
A person following a prescription is someone with a plan. Planning means engaging in developing the needed inputs, operating and maintaining the SPANS system, and studying and agreeing to prescriptions (revised as necessary), then acting on them, making corrections or adaptations as necessary, and reporting on successes, failures, and adaptations so that SPANS itself improves.
Also, it is inconceivable that the report would ever be used alone. It should always be accompanied by a complete letter of transmittal and/or a comprehensive verbal presentation to every major user. Such a letter or supplementary report will likely contain inserts prepared by consultants and others to explain unusual numbers and results, to point out counterintuitive results, and to add data from local studies or other reports.
The system is dynamically changing in topics covered, equations used, generalization (how widely it can be used throughout the region), and database.
The system is composed of other systems. These subsystems are being secured and re-developed so they "fit." The intent is to create the system both by new programs and also existing systems slightly modified.
There are many parts to SPANS and the parts are kept separate so that inserts may be made. There are, however, great interactions that have been programmed. For example, the temperature section, while standing alone, relates directly to a section on stream temperatures, to reptile habitat, and to another on deer carrying capacity. The computer code is hidden; the interactions make this a comprehensive system rather than just a set of word-processor produced pages.
In one area in the Virginia coalfield, the range in annual precipitation has been from 40 to 51 inches. This difference in an 8000 acre watershed is 2.4 billion gallons (9.0 billion liters) of water. In the low-rainfall year there may have been an intense storm that caused more erosion in a brief period than all of that produced gradually. To try to be very accurate about ecological and wildlife statements in the face of such unpredictable difference is unwise. The SPANS concept is one of planning, of playing a reasoned game against nature so as to win most over the long run (e.g., in reduced erosion or stable populations). The concept is one of looking at costs of using the land in some reasonably long planning or investment period (e.g., 50 years) and dealing with expected returns. Expected returns include the element of risk which can be quantified and analyzed. The SPANS reports are intended to assist in sizing up the risk, a number fully as important to the decision maker as is the number of acres in cover type A, inches of snow fall, or depth of soil to bedrock.
The analysis produced is primarily for an area with emphasis on it as a forest compartment (usually less than 2000 acres). An area or compartment is conceived to be made up of stands or units. These stands are analyzed, then summarized as a compartment. The stands are composed of land "cells" about each of which many factors are stored in a geographic information system. For large areas, the best uses of the system (to avoid extensive reprogramming) are to separate the area into compartment-size units and make multiple runs, calling each area I, II, etc.
The SPANS concept is one of iterative improvement. This means that the future cannot be known but estimates of it are made and must be made in most land use decision-making. A SPANS run is made, looking 50 years ahead, and when appropriate, say 1 to 3 years later, the same run is made, again looking 50 years ahead. In these few years new knowledge will have been gained, maps completed, models developed, the price of money and objectives changed. The plan is not fixed but may change with each run. The system embodies an effort to have the best available information, well processed, at the time when a decision must be made. There may be change tomorrow, making a decision today less than good, but that is the nature of all decisions.
Because the data and models in SPANS can be changed, what may appear to be a lack of concern for data quality may be noted. Concern for quality is high, but through experience both with changes in data and models, the greater concern is placed in SPANS on completeness of the concept and inclusion of relevant models and factors in the watershed. SPANS designers have seen emphasis on runoff to the tenth of an inch in watershed models that have ignored inches of difference in soil moisture storage and unwillingness to consider 2 to 5 inches of drip of water from trees collected there from the morning fog and dew. In animal studies we weigh individuals to the ounce, but estimate density to within 60% accuracy. The perceived need is for both accuracy as well as inclusiveness, but in realistic balance. Realistic is difficult to define, too, but it includes the notion that SPANS is an open, dynamic system readily changed. These ideas of balance and significant figures have been discussed by Giles (1979) and Giles et al. (1993) and a paradigm of the "rationally robust" is followed within the system.
Closely related to the above is the SPANS concept of useful data. In an area as large as Virginia, (40,817 sq. mi. or 105,716 sq. km.) there are limited data on climate (about 170 stations with a long record), on soils (about 40 percent of the state), on geology (various precision, perhaps 50 percent). Many topographic maps are dated. The costs of this information is very great and it rarely can be gotten or afforded on a small-area or single-project basis. Thus, extrapolations have to be made to get and use many types of data. Thus, almost all projects (1) assume that the future will be very much like the past (e.g., temperature and forest cover), (2) that things close to each other are almost identical (e.g., precipitation in one area is like that reported at the nearest weather station), and (3) that the same laws of nature (e.g. gravity, freezing, succession) will be in operation. We intuitively know these assumptions are wrong or at least are suspect, yet we use them regularly. In one case, Anderson (1981) demonstrated significant differences in temperatures throughout one southwestern Virginia county. These differences have a major role in growing season, energy needs, and evapotranspiration in an area, and can readily account for differences observed among water runoff measures between areas.
SPANS has general concepts rooted in statistical sampling theory. The results have been controversial and continued dialogue about them is needed. A wildlife area is viewed as an organism, say a cow. In learning about cows, large herds are studied and even these are assumed to be a sample or sub-population about all cows for which conclusions will be reached. Large sample sizes are needed with highly variable systems (or organisms) like any natural resource management area. Large sample sizes are very costly and rarely are enough studies done to meet the requirements for good conclusions based on acceptable confidence levels, tolerable error, and expected averages and variance, both among areas and years. The situation is, unfortunately, that if the same rules of statistics were applied to areas as were applied to cows or crops or drugs, there would be few things people could claim they "know." This is not a criticism; herein an effort is made to acknowledge the context or environment in which resource area analyses and prescriptions are done. SPANS operates on the concept that more than 10 years of study would be needed in any one area to know its responses well. During that time no changes (cultivation, timber harvest, etc.) would be allowed because it would confound the results. This is usually intolerable--both non-use and the period, because interest in an area or project site usually is "now." The costs of a 10-year or longer study are also likely to be viewed as excessive, i.e., intolerable.
The results of the above phenomena are that resource area analyses and prescriptions are, have to be, like those of a medical doctor. They are clinical decisions made on unique patients with adjustments and modifications made in a discovery mode, which herein is called "heuristically." In a sense, SPANS operates on the premise that comprehensive models that include as many factors as possible of the ecosystem and economic system (broadly defined) will give better answers to decision makers for the long run than a very closely monitored wildlife area with abundant field checks, plots, and measures. The interactions in such studies are rarely measured. Previously, analysis separated the parts; the ecosystem activities are unifying them. Quite different conditions in a wildlife area can produce the same results (for example, a frozen natural north-facing surface may produce the same runoff as a compacted mine surface; or, for another example, there are many identical plant responses from the combinations among 3 nutrients, 3 levels of soil moisture, and 3 bulk densities). This is called equifinality, the occurrence of the same end-state, a classical systems theory concept.
By allowing a computer to examine the combinations of the dominant factors in an area, likely performance of the system can be estimated. This estimate is the best basis for long-term resource area management and the most likely basis for achieving pre-stated landowner objectives.
Acknowledgements
The analysis is based on the earlier work by James W. Teaford in developing the set of Fortran computer programs called HABAN in 1972. Mr. A. Blair Jones, III and Ashraful Huq completed extensive revisions of the system and developed it for operational use on Department of Game and Inland Fisheries lands and elsewhere in 1983. Mr. Michael Fies contributed substantially to its development in 1983. The system was designed by R. H. Giles, Jr. Assistance was provided from field discussions with biologists of the Virginia Department of Game and Inland Fisheries. The extensive work of Mr. Joe L. Coggin is gratefully acknowledged.
Financial support for the system prior to 1985 was provided by (1) the George Washington National Forest, (2) Virginia Commission of Game and Inland Fisheries, (3) Penn Virginia Resources Corporation, Duffield, Virginia, (4) Remington Farms Inc., Chestertown, Maryland, and (5) the Department of Fisheries and Wildlife Sciences at Virginia Polytechnic Institute and State University.
The use of trade, firm, or corporation names in this report is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by any of the parties involved in the SPANS project of any product or service to the exclusion of others that may be suitable.
Literature Cited
Anderson, D. R. 1981. A climatological information system for natural resource management: temperature. M.S. Thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA. viii + 220 pp.
Giles, R. H., Jr. 1977. A watershed planning and management system: design and synthesis. Virginia Water Resources Research Center Bulletin 107, Blacksburg, VA. vi + 133 pp.
Giles, R. H., Jr. 1979. Modeling decisions or ecological systems? Pages 147-159 in J. Cairns Jr., G. P. Patil, and W. E. Waters (eds.), Environmental biomonitoring, assessment, prediction, and management--certain case studies and related quantitative issues. International Co-operative Publication House, Fairland, MD. 438 pp.
Leopold, A. 1949. A Sand County almanac and sketches here and there. Oxford University Press. NY. 226 pp.
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