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BIOLOGY IN THE SERVICE OF MAN 195 small number of infants. However, an agent without effect on experimental animals, but which induces diabetes in man, for example, would probably go undetected for a lone period. ~ . ~ . . ~ . . ~ , ~ . . ~ ~ _ ~ ~ ^C ~ ~ ~ . . ~ ~ ~ ~ ~ ~ ~ ~ Extrapolation of animal data to man must ce cone wren one utmost Or; and caution. One study comparing the reactions of rats, dogs, and human beings to six standard test drugs revealed many similarities, but of 86 dis- tinct recorded effects, 33 appeared only in man! In the final analysis, after careful and extensive animal experiments have been completed, controlled human trials are imperative to measure the full range of a drug's effects. But, at present, these should be undertaken only after extensive trials with animals, tissue preparations, and, when appropriate, enzyme systems. In the end, whether our concern be with drugs, food, or the physical environment, the hard question is what the American public is willing to oav for. Monitoring the environment while insisting on the right to drive rev ~ o She's own car is a costly matter. The more rigorous the standards, the more costly it must be. Similarly, the only effective approach to a multi- tude of disorders to which man is subject is the development of new drugs, which, in our society, is largely the function of the pharmaceutical industry. If these are to be thoroughly tested for safety and efficacy before they are marketed, the public must be prepared to bear the costs, not only of the marketed drugs, but also of the studies that discard those chemical entities that prove either unsafe or inefficacious. The biological capability, thanks to years of fundamental research, is well established. Although much yet remains to be done, a national capability for maintaining the human environ- ment is attainable providing we continue to train the manpower and bear the costs. What other alternative is acceptable? ~ ~ _ V ~ ~ ~ A ~ ~ ~ RENEWABLE RESOURCES The biological and physical elements of the earth are vital to man. Soil, water, air, and populations of plants and animals can, under certain con- ditions, be used over and over again. These are man's renewable resources, and their sound management has become a prime concern to man, both for his well-being and, perhaps, for his survival on this planet. The greatest single threat to environmental resources and to man himself is his own "population explosion." with the concomitant rising pressure on food, land, and water needs. _ Only by understanding the function and interaction among biological and physical elements of the environment and applying that understanding to the management of resources can man control his numbers and keep his environment livable.

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196 THE LIFE SCIENCES Although the major portion of man's food comes from only about 100 species of plants and animals, many thousands of species, including micro- organisms, interact to provide the environment required by these major food sources. It has been estimated that at least 150,000 plant and animal species in the United States are involved in the collection and transfer of the sun's energy for the maintenance of life. In addition, some of these species are decomposers serving to break down waste products and dead organic material to make such essentials as carbon dioxide, nitrogen, and other elements available to plants for reuse and transmission to animals through the food chains of the biotic system. Beyond these material needs, living organisms are important in fulfilling esthetic and recreational needs. Living systems have evolved for many millions of years to become a part of the environment as we know it today. Although civilization has devel- oped throughout history at the expense of natural resources, population growth and technological achievements in the twentieth century have pro- duced a disruptive assault on the environment on a greater scale than ever before. Contamination emanating from technological developments and urban concentrations has altered the chemical and physical characteristics of our seas, lakes, rivers, soils, and air. While simplified food chains have been exploited on some land to satisfy civilization's requirements for food and fiber, other vast land and aquatic areas have been developed for uses not associated with biological production. Economists project that within the next 20 years some 28 million acres (an area larger than Ohio) will be converted into urban areas and highways in the United States; four fifths of this land will come from croplands, pastures, and forests. Poor manage- ment in the past has resulted in loss of a third of the topsoil in the United States, with consequent lowered potential productivity. It is difficult to return land to cultivation once it has been built upon. The quality of some of our surface waters and groundwaters can be restored, but, with the knowledge currently available to us, the results of pollution can be reversed only at great cost. For example, even if the introduction of fertilizing nutrients is terminated and if the waters of a historically heavily polluted lake can be completely exchanged over a period of time, the enor- mous amount of harmful matter bound in the bottom mud may continually replenish the pollutant materials. How much more can we abuse our renewable resources how much area can we remove from production, how many species can we destroy- before our resources will be unable to support man in an environment of acceptable quality? These crucial questions need answers now before renewable resources deteriorate irreversibly to an unacceptable level. We must maintain a continuing assessment of our renewable resources land, water, air, and living things- because their status constantly changes. Only

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BIOLOGY IN THE SERVICE OF MAN 197 with such information can we find new and better ways to ensure their continuing availability. Role of Science in the Management of Renewable Resources The observations of early naturalists made important contributions to understanding of the environment. More recently, studies by pioneering systematists, geneticists, physiologists, evolutionists, and morphologists have provided much information of value to problem-solving ecology, although the significance of their contributions was not recognized for many years. During the past half-century or so, ecologists have searched for the principles underlying the interacting relationships of living things and their environments. Gradually they have come to recognize the complexity of these interrelationships and have categorized the influences on them as physical, biological, and, in some instances, social and cultural. Modern concepts of these dynamic arrangements recognize the constant interaction among all factors that make up the ecosystem. Detailed studies of ecosystems or communities provide impressive dem- onstrations of mutual adaptation of species to one another and to their physical conditions. Host and parasite, prey and predator, and herbivore and plant are integrated in their life histories and requirements. These con- ditions can be understood in the light of modern evolutionary theory, which is based on genetic variability and natural selection and provides a satis- factory framework for understanding the diverse characteristics of the biological world. In this area, understanding and appreciation of popula- tion genetics is most critically needed. Understanding of the principles of natural selection is essential to the intelligent management of renewable resources, which almost always involves manipulation of populations by methods that depend heavily on selection of genetic traits governing such group properties as productivity, longevity, and reproduction rates. Ability to predict results will increase as more is learned about the mechanisms involved, both in the individual and in the interaction of populations. Living organisms depend upon and are influenced by the physical and chemical elements of their environments. . At the same time, they perform certain functions that are requisite to the structure and behavior of their physical environments e.g., production of oxygen by plants through photo- synthesis. Thus, understanding of the biosphere requires information about the physical nature of the environment (geology and soil science), the trans- port systems that move substances to and away from living things (meteor- ology and hydrology), the transformations that take place in the nonliving parts of the environment (physics and chemistry), and the means of mod- ifying the environment (engineering, including weather modification).

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198 THE LIFE SCIENCES Principles of Management Rational plans for managing an environment either intensively (as in agriculture) or less intensively (as with wildlife) recognize that every area has a certain set of characteristics, that each living organism has a certain range of physical conditions that it can tolerate, and that for each physical condition there is some point or zone within the range that is near optimum. Organisms are aggregated into communities, the members of which are determined equally by their common ability to tolerate the physical con- ditions of the site and by their interactions with the other members of the community. The relationship is not passive, for the organisms in turn interact with and may change the site. Their tolerance levels are not neces- sarily identical, but they may overlap in the range of conditions present on a site. As conditions change, new forms, with tolerances that fall within the new ranges, may become a part of the community; some of those origi- nally present may be eliminated. The less rigorous the conditions of the site the greater will be the variety of niches and inhabitants. Two basic courses are open to us in using our surroundings: We can adapt our needs and demands to the capabilities of an area, or we can modify the area to change its capabilities. Urban and regional development, waste disposal without overloading the water or the air, and some recrea- tional pursuits are examples of the former. Environmental Management AGRICULTURE Agriculture has evolved beyond crop culture to become an environmental technology with emphasis on the management of land, water, air, and bio- logical resources for the production of food and fiber and for the preserva- tion of natural resources. The successful farm or ranch is, in fact, a well- regulated ecosystem in which renewable resources are effectively conserved. More than ever before in man's history, it is imperative to develop the technology by which agricultural practices can more effectively conserve our vast land, water, and biological resources. Through sound management, agriculturists have been successful in mak- ing permanent use of renewable resources, especially land. In many places, the quality of the resources has been improved by careful use and manage- ment, with resulting increases in production and income. For example, in studies of individual farms in Illinois, yearly investments of about $35 per acre in conservation practices for soil and water returned about $41 per

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BIOLOGY IN THE SERVICE OF MAN acre per year. Similarly, land that had yielded an average per acre of 15 bushels of corn, yielded 304 bushels per acre after six years of effective rotation and cropping practices. This kind of management makes possible the continuous and efficient use of the same natural resources year after year. In coming decades, with expanding world population, this aspect of conservation will become even more vital. In sharp contrast is the unsound use of renewable resources that has led to disasters of the magnitude of the "Dust Bowl" of the 1930's. Before settlement in the 1870's and 1880's, the Great Plains had been protected against erosion during periods of drought by the natural cover of the short grasses. The first white settlers cultivated the land for wheat and in doing so destroyed the protective natural sod, exposing the bare soil to wind and other eroding forces until the soil structure was broken down. Thus, when severe droughts came in 1930 and 1931, soil conditions were ripe for dev- astation such as had never before occurred in the Great Plains areas. The Dust Bowl, involving 100 million acres, was a costly lesson to American agriculture; as a result of it, the Soil Conservation Service was formed in 1935 to devise and encourage sound land-management techniques. Only a small fraction of the Dust Bowl has been returned to production. Soil- conservation practices (contour farming, strip-cropping, rotation) illustrate effective use of applied ecology to maintain and even improve soil resources. Other ecological principles have been employed to increase crop and animal production but often have not been extended far enough to protect our renewable resources. Water will always be a precious resource. In agriculture, much ground- water and surface water is lost or polluted by current practices. Manure, silts, and pesticides are some of the most serious pollutants. It is estimated that a fourth of all water stored for irrigation is lost by evaporation before use; yet water use in agriculture is increasing. Research has begun but more is needed to find ways to reduce evaporation of water in storage; some new chemical films offer considerable promise under special condi lions. Control of transpiration by plant hormones also offers a real opportunity to conserve water. This problem is well illustrated by the fact that, of the 500,000 gallons of water absorbed by an acre of corn in Illinois in one season, 498,750 gallons are lost to the atmosphere by transpiration. FORESTRY Forestry deals with the management of wooded lands for various goods and services. The term "wooded lands" is liberally construed to mean forest landscapes, including areas of alpine rockland, native grass, brush, and 199

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200 THE LIFE SCIENCES swamps. Such areas often influence management of adjacent lands. Lumber production is the principal objective of most large corporate ownerships, but water yield, watershed protection, recreation, grazing, and protection of wildlife and scenic values are explicitly recognized on many private lands and are primary aims in the management of most public holdings. The obvious economic value of lumber has led to a tendency among many conservation writers including some foresters to equate forestry with timber production. A century and a half of historical development, as well as present-day practice over large areas, has emphasized game pro- duction, stream flora, steep-land protection, and nontimber products. This emphasis finds its modern expression in the "multiple use" doctrine, which Congress has now declared to be the guiding principle for some 180 million acres of national forest. It is likewise espoused in varying degree by many public and private forest landholders. For example, revenues from hunting- club leases approximately offset land taxes on some industrial forest hold- ~ngs. In forestry practice, biology is the major but by no means the exclusive scientific tool. The earth sciences (geology, physiography, hydrology, climatology, and soil science), engineering, and a large economic, social, and managerial component often dictate the framework for biological appli- cations. Protection from accidental fires has been the sine qua non of forest management through much of North America and necessarily absorbs a sub- stantial part of the resources and technical effort devoted to forest land. The protection, manipulation, and efficient use of vegetation are the domi- nant aim of most forestry activities. Hence, an understanding of the dy- namics of this vegetation and its associated populations of animals interact- ing with the physical environment is the forester's primary tool. The need for applications of biology to forest-land management are more readily appreciated in view of the very different levels of management cur- rently practiced. The most extensive management for wood products is simply exploitation of useful trees, usually with protection against severe fire and pests, with the hope of natural renewal. The input of biological skill is minimal, and the results range from excellent, as in many of the eastern Canadian spruce fir pulpwood cuttings, to the destruction of the resource. As intensity of management increases, measures such as re- stricted harvesting, timing of operations, prescribed fire, and thinning are employed to favor reproduction and growth of desired species and reduce competition with less valuable species. Such measures may be insufficient to perpetuate recalcitrant species, such as the American bald cypress or the New Zealand podocarps, whose regeneration requirements are neither met nor understood. At the highest intensities of management, desired strains are planted or otherwise made dominant, and density and structure as well

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BIOLOGY IN THE SERVICE OF MAN 201 as composition of the forest are closely controlled. For this purpose, the environment is modified by reduction of competition and pests, and some- times by soil treatments. At the lowest intensity of management, reliance upon natural processes is complete. At intermediate intensities, great dependence is placed on understanding the requirements of individual species, their competitive positions, and the nature of successional trends that may be either rein- forced or combated. This concern diminishes at the highest intensities as regeneration, composition, and density are brought under control, with marked reduction in age and species diversity. Attention then shifts to altering genotypes, additional manipulation of soil and plant features, and specific measures against injurious insects and diseases. FISHERIES True aquiculture, with complete control over all phases of a tended organ- ism's life cycle, including a well-regulated harvest, has only regional importance (e.g., carp in the Far East and Israel, trout in North America and Europe). Fishery resources range from marine algae to whales and from the brook trout of alpine streams to benthic crustaceans at 200 fathoms in the sea. With few exceptions, fisheries are restricted to the lighted zone of the waters. Considering the gamut of aquatic plants and animals, the important species harvested are relatively few in number about 200 among the over 20,000 kinds of fishes and far fewer algae, mollusks, crusta- ceans, or aquatic mammals. Only 12 of these constitute 80 percent of the total catch. Management for sustained yield is based on several factors, including (a) information about the stocks or populations and subpopulations that are often the effective breeding units (knowledge of age, growth, fecundity, longevity, and mortality due to natural causes and to exploitation); (b) information about the taxonomy, life histories, and behavior of the species under natural conditions and when confronted with capturing tools (in- cluded here are foods; food habits; sensory capacities; territorial or school- ing behavior; knowledge of the action, including selectivity, of the capturing gear); and (c) information about the environment and the influences on the stocks of such variables as temperature, salinity, currents, and pollutants. The deficiency in information needed for the adequate management of aquatic organisms can be ascribed to (a) lack of planning and failure of political boundaries to correspond to biological boundaries, (b) the short duration of studies in relation to the time span over which natural forces act and in which natural fluctuations take place, and (c) lack of funds, personnel, and interest.

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202 THE LIFE SCIENCES The intensity of management measures applied to living aquatic re- sources decreases as the population dispersion and area occupied increase. Carp and trout, with their tolerance of confined freshwater areas, can be bred and tended intensively like domesticated animals with good control over their environment, while we can do little or nothing in the vast marine areas required by tuna or herring. With fishes of the latter type, manage- ment now depends upon prediction of population levels and controlled harvest. In the case of tuna in the Pacific, enough is now known about the relationship between tuna distribution and environmental conditions to permit satisfactory forecasts of distribution of tuna stocks several weeks in advance for the benefit of fishing fleets. Recent advances in tracing the life history of salmon at sea, coupled with detailed simulation models of the fishery, including the freshwater phase, provide an improved basis for prediction. Manipulation of spawning areas certainly provides oppor- tunity for genuine management. Management possibilities and the impact of man differ in the various regions of the hydrosphere. Fish and mammal stocks in the high seas can be managed only if characteristics of population and environment are known. Research on the high seas should be international in scope. Re- gional fisheries councils facilitate pelagic fisheries research. Agreements on apportionment of harvest through exclusive or joint exploitation are feasible. However, the common-property nature of high seas resources makes en- forcement of harvest limitations difficult (e.g., only about 1,000 blue whales exist today). Furthermore, catch limits can be quickly filled with modern mechanized gear, and this leads to difficulties in keeping vessels and man- power profitably occupied, a problem encountered with the tuna stocks of the Western Pacific. Offshore fish resources are most important in relation to bulk and dollar value. Such fishes as herrings, sardines, anchovies, and ground fishes (flat fishes) occur in abundance in various seas the North Sea and the Caspian Sea for instance and on the west coasts of certain continents, where cur- rents and winds stimulate the upwelling and mixing of nutrients. Geo- graphically, this region coincides with the continental shelf and overlying waters. Management in these areas, like that of the high seas stocks, must rely on regulation of gear and times of capture. More intensive methods of management are not presently feasible. There exist here common-property- resource problems that can be solved by bilateral agreements (e.g., Canada and the United States in the halibut fisheries). More and better agreements of this kind are needed; some may require new legal concepts because of the impending exploitation of this zone for other resources (minerals). Near or inshore resources are often concentrated in shallow waters or near deltas and estuaries, or are associated with coral reefs. They are exploited by operators of small craft who, throughout history, have made up

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BIOLOGY IN THE SERVICE OF MAN the bulk of the world's fishermen. Of the ocean environments, the inshore resources are most susceptible to overexploitation and to environmental deterioration caused by man. Along both coasts, estuaries are being filled with wastes at an alarming rate by industrial and housing developments. In addition, streams and rivers dump pollutants, collected from their drain- age basins, into the estuaries. All this has already altered the ecology of these regions. Now many of these inshore resources will be subjected to further change by the addition of heated effluents from both nuclear and fossil-fuel power plants along our coasts. These plants require enormous quantities of water for cooling, and the low-grade waste heat carried by this water will also be enormous. If, for example, sufficient combined nuclear power and desalting plants were constructed on the West Coast to meet the needs for both fresh water and electric power, the rise in temperature of inshore waters might be as much as 4° F. Such a change in temperature would certainly alter the kinds, distribution, and abundance of animals inhabiting this area. We must be mindful of the opportunities to modify parts of this environment beneficially with this vast resource of low-grade heat, which could, with careless use, become a destructive pollutant. There is an attractive alternative, however the use of this heat to maintain the environment of aquatic species that flourish in warmer waters, as has been done in England for cultivation of plaice. The inshore marine environment, together with freshwaters that support the sport fisheries, suffer most from man's activities. Ecological imbalances resulting from events on the land are often difficult to correct, mainly be- cause of traditional divisions in jurisdiction over and management of land and water. Authorities entrusted by society with the management of inshore waters have few or no organizational ties with those who determine land use, location and operation of industrial enterprises, and urban devel- opment. Sport fishery in inland waters is strongly selective of predaceous fish (e.g., bass and pike) near the top of the food chain that constitute a small fraction of the total fish population available for harvest. Commercial fish- ermen stop fishing when it is no longer profitable. Anglers continue fishing for the large fish even though the numbers of fish decline and they have small chance of success. While the demand for large sport fish increases, the supply is limited. It may be preferable to modify the life habits of their predators, the anglers, so as to conserve the fish and their environment. WILDLIFE Wildlife may be defined as wild plants and animals in their natural environ- ment (though often only animals are considered and here we consider mainly birds and mammals). The purpose of wildlife management is to

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204 THE LIFE SCIENCES maintain desired populations of wildlife. Wildlife management includes production and harvest of game species; maintenance of nongame species; and control of damage by wildlife to crops, forests, range, livestock, or human life. Management techniques have developed in a historical sequence that began with restrictions on time or methods of taking game, later in- cluded predator control and refuges, still later moved to artificial replenish- ment, and finally incorporated environmental manipulation. Even though knowledge of habitat manipulation is considerable, we still rely on seasonal and bag-limit restrictions as the principal management measures for game species. Artificial game propagation attracts much public interest, but most wildlife biologists have come to regard this prac- tice as better suited to intensively managed, private or commercial shooting preserves than to public hunting areas. A great deal of the effort of fish and game agencies is directed toward gathering information on mortality, nasality, and welfare factors that will be integrated to form the basis of the annual announcements concerning time and limits of harvest. Judgment gained from decades of trial and error still weighs heavily in the interpretation of field data; increasingly, however, sophisticated techniques are being employed. For example, in big-game management, many states conduct an annual survey of sex-age distribution in the population as well as estimating productivity from fawn-adult ratios and other population indices. Additional information on ovulation rate, placental scars, and weight and condition of carcasses is gained at hunter- checking stations. On many big-game ranges, annual surveys of forage are included as part of the information needed to establish the recom- mended harvest. Habitat manipulation is potentially a far more responsive tool for man- aging areas intensively than is the regulation or restriction of harvest. Un- fortunately, the manipulation of habitats is not feasible on some public and private lands, where other uses have high priority. The most success- ful widespread use of habitat manipulation came as a result of investigations in the fire ecology of the pinelands of the Southeast. Scientists have de- veloped a high degree of skill in the use of fire in that region to manipulate forest communities for maximum wildlife production combined with timber or pulpwood production. Among wild terrestrial vertebrates, particularly birds and mammals, much of the descriptive work at the species level has been accomplished, but many species occupying important niches over large areas are still little known. For example, until the appearance of a recent monograph, the mountain gorilla was largely a creature of mystery and misunderstanding. Similarly, the Wilson's snipe, an important migratory game bird in the United States, was largely unknown until a thorough field study of this

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BIOLOGY IN THE SERVICE OF MAN species was completed recently. There are gaps in knowledge of some of the dominant members of the widespread communities in North America. For example, there is little knowledge of the actual effects of weather on deer, field voles, cottontail rabbits, and upland game birds, and of the physiological and behavioral adaptations of these species. The interactions among closely related species also need much more study. For instance, the effect of an expanding starling population upon other cavity-nesting species and the role of the starling as a vector of domestic-animal diseases should be studied more thoroughly. The use of electronics, telemetry, and photography in remote sensing offers opportunities for real gains in dealing with wildlife problems. Re- search using some of these capabilities is under way, but progress is con- siderably short of what seems possible. The space program may launch a satellite with some components suitable for use by wildlife ecologists; however, many more applications are immediately feasible. For example, there are now microtransmitters with sufficient lifetime to permit following waterfowl or seabirds through an entire pattern of seasonal migration. With receivers that could be mounted in present satellite packages, continuous surveillance could be maintained on a sample of migrants fitted with micro- transmitters. The same technique seems promising for marine mammals, large terrestrial predators, and wide-ranging ungulates. Perhaps one of the greatest shortcomings in application of existing knowledge is reflected in the harvest of deer and other large ungulates. Satisfactory inventory techniques have been developed, but the public seems unconvinced of the high productivity of healthy deer in favorable habitats and fails to realize the resilience of a thriving deer population. Hunters, especially in the Northeast and Lake States, cling to their ideal of "bucks only" and frequently refuse to support a more flexible policy. The resulting underharvest of big-game herds has resulted in semipermanent damage to millions of acres of overutilized range. Another area of confusion in applying research findings is in the control of pest animals. Numerous investigations have questioned the wisdom of pursuing traditional statewide predator control programs with little evalu- ation of either the need for the program or the effectiveness of the control effort. Excessive populations of deer and elk are a nagging problem in national parks and on large military reservations, where hunting cannot be used to achieve population reduction. In these situations the use of chemosterilants offers promise of being a highly effectual technique. Considerable experi- mental research has already been done using these compounds on feral pigeons, gulls, and carnivores. This pattern of applied research should be extended to ungulates. Furthermore, increased effort in reproductive 205

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206 THE LIFE SCIENCES physiology would greatly enlarge our understanding of the effectiveness of antifertility compounds. The effects of environmental pollution on wildlife is a subject of some importance. While the task of measuring direct effects of new spray ma- terials is demanding, the subtle, pervasive phenomenon of bioaccumulation is of greater importance and is much more difficult to evaluate. The first step is to work out the pathways of pesticide-residue transfer and accumu- lation. The uptake, metabolism, and storage of pesticides are obvious objects for physiological studies that would support this effort. The ulti- mate fate of pesticide residues would be much better understood if concepts of major drainage basins as ecosystems were more clearly defined and de- scribed. The monitoring of pollution loads would be greatly expedited by advances in analyzing ecological systems. RECREATION Provision of adequate opportunities for outdoor recreation requires an understanding of the needs and desires of the potential participants, the kind and location of environment that will meet these needs, and the effects of use on these environments. Until we understand better why people seek outdoor recreation and the motivation that determines their recreation choices, and until there is general awareness of the deleterious effects of recreational activities upon the natural scene, much restorative effort will be of the stopgap variety. But treatment of the symptoms does not identify and eliminate the cause; thorough knowledge of the physical and biological components of the recreation environment is imperative. Equally necessary, however, is a deeper understanding of human behavior. In many instances, biologists and other recreation-resource managers have not considered the visitor and the resource to be part of the same ecological situation. The use of the term "visitor," in this case, may be un- fortunate. Nonetheless, at a time when perpetuation of the resource depends in part upon the visitor's understanding and cooperation, he and his fellow citizens, many of them urbanites, seem uninformed and careless about soils, plants, animals, and their interrelationships. The recreation visitor and his activities influence not only the immediate site being occupied but also the adjacent areas that form the scenic back- drop. His presence may generate problems beyond those that already exist. Wilderness areas and national parks are good examples in which visitor- recreation problems extend beyond the immediate site being occupied. Although many such areas are more than several hundred thousand acres in size, the direct physical contact of visitors is concentrated on a very few acres. Within these small areas of intensive use, vegetation is trampled,

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BIOLOGY IN THE SERVICE OF MAN soils are compacted and eroded, and water supplies are subjected to pollu- tion. Overuse and abuse-albeit unintentional prevail. Further, these sites of intensive use are often in aesthetically pleasing but fragile areas least capable, biologically and physically, of withstanding great visitor pressure. To a certain degree, the selection of such sites is a result of uninformed management or poor planning of land use. There is some evidence, how- ever, that these are the kinds of areas that many visitors the recreation public prefer. To be sure, some persons wish to camp in relatively iso- lated sites in more stabilized vegetation systems regardless of the lack of modern conveniences. However, most recreation campers prefer to con- gregate in high-density campgrounds where electricity, sanitary facilities, hot and cold water, cooking accommodations, and other refinements are available, and where the vegetation is in a highly vulnerable, unstable stage of development. In periods of peak activity, present ability to handle the masses of out- door-recreation enthusiasts is rapidly becoming quite inadequate. The number of visitors to our national parks and national recreation areas begins to pose a serious problem (Figure 329. The visitor load in these public areas has increased nearly sixfold in 20 years and in 1968 was 151 million; the number of parks has increased at a much slower pace. Indeed, the number of units in the national park system, including national parks, monuments, seashores, and historic sites, has increased only 50 percent in this period. Potential sites for additional large-scale and magnificent recrea 240 200 _ 220 180 .~-' 160 _ / .m ) to 140 _ o 120 _/ .__ ~ 100 _ / - / FIGURE 32 Total visits to national parks (30 - ~and related areas, 1950-196S, and projected 60 _ / visits to 1975. (From Biology and the Future _ ~of Man, P. Handler, ed. Copyright (I) 1970 40 A/ by Oxford University Press, Inc. Data from ~ ' Statistical Abstract of the United States, 1969, 20 - ~ ~Statistical Information Division, U.S. Depart 1950 1960 1970 ment of Commerce.)

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208 THE LIFE SCIENCES lion outlets are not unlimited. If visitor pressure on national forests, other wilderness areas, and state or local recreation facilities follows the general pattern experienced in the national parks, and if there are not substantial changes in the concepts of visitor management, we are clearly in danger of running out of space for certain types of recreational activities. On wild lands managed for several purposes, the need for both more thorough ecological understanding of the landscape and greater insight into the physical requirements of an attractive landscape is coming into sharp focus. Much of the public seems more concerned about the "visual resource" than about the physical resource. The outdoor-oriented Ameri- can public evidently does not wish to become reconciled to the fact that natural processes must sometimes be accompanied by temporary ugliness. Yet good silviculture may entail controlled burning to permit regeneration of more desirable trees, burning to maintain a plant community charac- teristic of a true prairie, reduction in an elk herd to forestall starvation of the animals and destruction of their range, or introduction of native preda- tors to assist in the control of big game or other animal populations. URBAN AND RURAL DEVELOPMENT Man needs dwelling places, stores, industries, schools, museums, places of worship; he needs arteries for transport by rail or motor vehicle; he needs airports, canals, harbors, and dams. Once land is committed to these uses, the commitment is essentially irreversible. Man's activities in these places change raw materials and natural products into new forms, often resulting in waste products that must somehow be disposed of or recycled. When these waste products reach the air or water or land in forms or concentra- tions that are detrimental, they are "pollutants." Unacceptable means of waste disposal are the cause of one of the major impacts of man on his environment. With increasing numbers of people, needs for food, fiber, industry, and transport indeed for all kinds of goods and services increase. Expansion of our cities converts more than a million acres of land a year to paved, biologically unproductive areas. At the same time that command of enor- mous amounts of energy for excavation, construction, and earthmoving gives ever greater freedom of choice in the location of cities and changes in the landscape, the changes are, all too often, unplanned and unthinking. The big changes canals and dams, perhaps even interstate highways- are considered with some care, and the more obvious costs and benefits publicly weighed. The results are not always those biologically most de- sirable, but they are, for the most part, democratically acceptable. The more pervasive and uncontrollable changes result from incremental changes,

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BIOLOGY IN THE SERVICE OF MAN as in creeping suburbia and filled-in wetlands. No single acre in these latter categories elicits much public defense, but the aggregate loss exceeds what we should be willing to accept. In urban renewal or modification of existing metropolitan areas, the problem is to make the "best" use of the area. Zoning is useful to this end. Heavy, dirty industry can be positioned in relation to dwellings, open space, and other living parts of cities so that air pollutants are carried away, noise does not reach the dwellings, and offensive odors and the grime of industry are out of range of the senses of most inhabitants. Some trees, shrubs, and other plants will tolerate even existing congested and polluted conditions, and can thus be used for beautification. Transportation and communications systems can be planned so as to minimize conflicts among the diverse demands of metropolitan life. The imminent location and construction of whole new cities affords both superb opportunities and difficult challenges. Before the turn of the cen- tury this nation will need to provide housing for an additional 100 million people, or a population equivalent to the sum of 500 Restons, 100 Co- lumbias, 50 Atlantas, 5 Philadelphias, and 5 New Yorks. This new hous- ing may either sprawl and congest the surroundings of existing cities or start afresh in entirely new locations. Much less concern will be necessary than heretofore with the needs for transportation and communications or nearness to primary resources. Locations can be based upon the amenities; water, raw material, and various modes of transportation can be brought to them as required. Whether present cities are expanded or entire new ones built, it is im- perative that their effects on the environment be considered. Paving of groundwater recharge areas, scalping of steep slopes, and placement of septic tanks in impermeable soil can all be avoided. Waste-treatment facili- ties can improve rather than damage their surroundings. Planners, archi- tects, and engineers will be largely responsible for appropriate use of the environment. Development of understanding of land-use capabilities and a reciprocal interaction between the desired design and land-use-capability criteria will permit optimum use of the environment. Local governmental and federal agencies should recognize a public right to live in an environment of acceptable quality. The true costs of any program in the management of renewable resources, be it in industry, agriculture, recreation, health, forestry, fisheries, or urban development, should be evaluated, and decisions should be made, upon the advice of groups of specialists, by representatives of society as a whole, seeking what is best for local, continental, and planetary ecosystems. Only by knowl- edge and understanding of the function and interaction of the biological and physical elements of the environment and by application of this knowl 209