J.L. Harley
J.L. HARLEY an ecologist, heads the Commonwealth Forestry Institute, Oxford. This article is adapted from an address he gave to the Royal Society of London in 1977.
The aims of conservation of nature are many and complex. There seems to be great diversity in the stated aims of different people and different organizations. Some seem to wish to retain the countryside as it is, essentially an area of pleasure; others would conserve natural communities and their species of plants and animals for scientific study as living museums of wildlife. To still others, the main aim is to use land wisely, that is, to ensure that it produces enough natural products food, timber and minerals for human needs and the nonmaterial benefits of recreation, amenity and scientific study as well. The author is of this last group.
However, whichever view is taken of its aims, conservation demands that some land be allotted for purposes which are non-productive of material things. Land may be so required totally, as in nature reserves or experimental areas, or in part, as in national parks where constraints are put on the use or the changes of use of the land. Hence much land conservation must inevitably enter into competition with land for production of food, timber and pasture and for mining, quarrying, communications, living accommodation and recreation.
There is no escaping such competition, so it is worth while pausing to think about it. Production of food, wood and other materials from land concerns the whole world. There is a world shortage of food now, and a world timber shortage is expected in the next 25-30 years. We have to accept, therefore, that any act of conservation that has as a consequence reduced biological production in any developed country would seem to mean either a reduction in its present standards of life, or that it would parasitize further a world already suffering shortages, or that it should reduce its population. But. must it inevitably mean one of these things? There is a further possibility: that production per unit area of the cropped land must be increased.
The fundamental and immediate effort of conservation must be in elaboration of methods of increased efficiency of crop production, not in the examination of details of nutrient cycling of ecosystems or of habitat requirements of rare plants, although these have their importance. In so far as their efforts concentrate upon increased production per unit area and decreased fossil energy input per metric ton of crop, the researches of such bodies as Britain's Agricultural Research Council are more fundamental to conservation than those of many ecologically orientated research bodies.
There has been a continued upward trend of production per hectare in agriculture in the United Kingdom and in the United States since 1947.
It is this kind of increased production per unit area which makes conservation of nature even possible to contemplate.
This competition between conservation for non-material benefits and for scientific research on the one hand and the use of land for production on the other will always exist. It is a problem for politicians to solve, with scientists, especially biologists, providing sound advice on how ecological, agricultural and silvicultural research can improve productivity in the long term and make conservation of nonmaterial benefits possible.
A change of attitude is also necessary for the ecologist. His work is scientific investigation and the scientist is no better at judging good from bad than the next man.
Problems concerning increased production and efficient use of land for crops may include as important components direct conservation of ecosystems and environments. A pertinent example of this is the work being done at the Unit of Tropical Silviculture at the Commonwealth Forestry Institute in Oxford. In the Tropical Pines Project there are several clear objectives. First of these is to provide for lowland tropical areas fast-growing timber trees which can be grown on cut-over or derelict land. These will provide a source of timber and forest products and so reduce the pressure on natural tropical forests for fire-wood and constructional material. To bring this about the Unit is collecting as wide a range as possible of ecological (perhaps genetic) variants of Central American pines, such as P. caribaea and P. oocarpa. The seeds collected are being stored and distributed for trials in 40 or more countries. Many of the ecotypes are found already to be in danger of extinction in their native areas, and when this is so the matter is brought to the notice of the countries in which it is taking place. Indeed, the collections themselves are an important step in the conservation of ecotypes, to be followed by their growth in trials or in conservation areas. Implicit in the collection of variants is an intraspecific taxonomic appraisal of the species and a consequent spin-off of taxonomic and ecological problems.
Of course this project is only about seven years old, but it is going ahead in the foreseeable future and it is an example in which production considerations are basic to efficient and effective conservation. The project has been directly financed mainly by the United Kingdom's Overseas Development Ministry with help for a period from FAO. But the invisible input far exceeds the direct finance because of the contributions in scientific work by the 40 or so countries which are involved in the trials. As a corollary to this set of problems the Institute is now joining in with research on the structure and regeneration of natural tropical high forest ecosystems which it is helping to conserve.
This example is not by any means unique in world forestry. The New Zealand Beech Scheme (Kirkland & Johns, 1973; Thompson, 1973) which has been criticized, often unfairly, by extremists as destructive is potentially a similar kind of conservation exercise in a country where the export of wood chips and pulp and the reduction of unemployment might be politically and economically expedient. It should be possible to combine conservation of Nothofagus ecosystems, the conservation of montane soils and water catchment areas, the conservation of amenities and the provision of recreational areas with efficient wood production and processing if the diverse interests combine to refine and perfect the plan as it is now.
The danger of this plan lies not in the plan itself but in the frailty of the human species. The introduction of Pinus radiata and Eucalyptus spp. into certain areas is a regrettable necessity to make the plan viable in terms of production. It requires honest self-discipline to limit the areas given to these exotics to the minimum which is essential now and in the future. The risk is that their production will be so much greater than the natural Nothofagus that there will always be pressure to extend their areas.
The application of these ideas to conservation in industrially developed countries is possible. It requires, however, a change of outlook not only of the people in general but of many ecological scientists. For too long, in such countries, drawing their food and raw materials from the whole world was considered a right, and we still have the idea that we can buy what we want. But if we use our land for amenity, recreation or pleasure, if we waste it by inefficient biological production or building, we parasitize the rest of the world for the products of the land. We must realize that efficient production and conservation must go hand in hand.
For the ecologist a change of outlook is also necessary. He must accept that you cannot measure good or bad with a metre rule nor even with a flame photometer or Geiger counter, and the scientist is no better at judging good from bad than the next man. The work of the ecologist is to carry out scientific investigation, to predict what changes will take place in the distribution of organisms in the survival of species or structure of ecosystems if this or that constraint is put upon them. Only by scientific work of this kind with no overtones of good or bad or quality judgements can conservation be furthered by ecologists as such.
It seems to me that in the narrower view of nature conservation we are seeking to ensure the existence for the future of living species in their natural or semi-natural ecosystems. The purposes of these objectives of conservation are to provide a desirable backdrop for the human stage, and also amenity and recreation. We are seeking to conserve living species with their full range of genetic variation, including useful species whose use to man may be negligible or yet unknown. Implicit in the conservation of species is the conservation of the diving systems, the ecosystems, of which these species are a part, because in this way their variation, evolution and activities can also be conserved.
Upward trends for production per hectare in agriculture are what make it possible even to contemplate nature conservation in industrialized countries. We must realize that conservation and efficient production go hand in hand.
All these activities require far more ecological knowledge and ecological insight than we at present possess. And we can classify the efforts required of scientists under the now conventional headings of strategic and fundamental research. Strategic research involves in particular problems of protection and maintenance of areas or biological systems chosen for conservation. Fundamental research involves the study and explanation of the range of variability of species, their environmental demands, their interaction with one another and the structure and physiology of the ecosystems which they together comprise. The carrying out of such research requires precise objectives of conservation of each particular area to be clear and we can discern two broad kinds of objective: one, to conserve an ecological situation as it exists and the other to conserve an ecological area for scientific investigation. These objectives are different, although they may at times be combined.
The first consideration of importance in the conservation of an ecosystem as it exists is to determine its status, that is, the factors which tend to maintain it in its present state and those which promote most rapidly its change. I think that to me the most enlightening contribution to the consideration of this general problem was Dr. A.S. Watt's presidential address to the British Ecological Society in 1947, "Pattern and process in the plant community." This paper graphically illustrated a well known but inadequately appreciated feature of ecosystems - that they are compounded of parts, each of which is not stable but passing through a series of changes dependent on growth, senescence and regeneration of the plants of which it is compounded and with these changes the consequent changes in the dependent animals. This thesis emphasizes that there must in theory be a minimum area which can be maintained in constant structure. The concept of such a minimum area is founded on probability. The probability that calamities such as flooding, wind will occur and so on are rare. If we take these relative improbabilities into account our required area is increased. The impact of such infrequent but highly influential factors has been emphasized especially in the study of forest communities, as for instance by Dr. T.C. Whitmore in the Solomons (Whitmore, 1974), but it is of importance in many types of community.
However, there is yet a further complicating feature; this is the recognition of the relationship of an ecosystem to the surrounding pattern of other such systems. An illustration of this is the example of the raised bog. Here we have a pattern of ecological communities exactly arranged and compounded to give a total ecosystem whose structure depends on their spatial and lateral arrangement in the context of topography. The central raised area of ombrogenous peat is dependent on the existence of the less acid lag which causes any drainage water containing bases to be carried away without affecting the central acid region. The change in structure from down-slope to up-slope in the central peat area is a change from Calluna-dominated relatively static conditions to Sphagnum-dominated peat-growth conditions which depend upon a maintained high-acid water level on the up-slope side. The whole could be conserved, but the parts cannot really exist with out the whole. This applies to many ecosystems.
This elementary example was chosen to emphasize that conservation of the status quo demands a detailed knowledge of the ecological situation and usually, even now, considerable research in any particular case.
Ecological research, research upon the interaction of organisms and their effects upon one another requires areas, open-air laboratories, where observations can be made and experiments done. In experimental work, rather than pure observation, the ecologist may destroy his experimental materials as surely as does a physiologist or biochemist. Consequently areas conserved for ecological research are of two kinds, those carefully managed or controlled so that they remain stable or undergo change while being observed and recorded by ecologists making the minimum disturbance; and those in which ecosystems are disturbed, or to use modern jargon, "perturbed," that is, subjected to destructive sampling for experimental purposes. Of course these two kinds of activity are not entirely separate; sampling which may be destructive to a small-scale community may be irrelevant to a large ecosystem. Nor does ecological work require only natural or semi-natural diverse systems: much can be learned from artificial situations. A highly pertinent example of this can be found in the advantages of the uniformity of a perennial crop like a forest plantation for the initial studies of complex problems. Their value has been demonstrated extremely well by Ovington (1962), for instance, in his widely quoted work on nutrient cycling. In a similar way Mr. P.F. Entwistle and his friends in the Unit of Invertebrate Virology of the Commonwealth Forestry Institute, Oxford, are using the uniformity of spruce plantations in Wales to study the movement and spread of pathogens in a population of insects. The nuclear polyhedrosis virus of the spruce saw-fly has provided an example for study not only of the spread of the pathogen but also its effect on the host population and on the populations of predators and food plants of that host - a study both of direct ecological and economic relevance. The complexity of a natural community would impose almost insuperable complications until the initial work has been done.
Whatever the aims of the conservationist, conservation demands that some land be allotted for purposes which are non-productive of material things.
When areas or ecosystems are set aside for ecological research the objectives for their use must be clear and must be planned in great detail. Planning how to use natural experimental areas must in the long run be as detailed as that of the experimental plans at Rothamsted or any other field station. If it is not, complicated errors of interpretation will result and great confusion caused. Indeed, over and above curiosity are the more mundane ecological problems of land use directly and intensively relevant to pure research.
To complete the cycle, let us ask the question, "Can we increase the ecological productivity of land like we can increase the agricultural productivity?" The answer is of course we can. There are great and interesting problems concerning the ecology of destroyed and derelict land, pit heaps, slag heaps, mining spoil, sand and gravel quarries and the like. Here there are real problems of conservation, and there are problems of resistance of organisms to toxic compounds in the soil and its genetic variation. If such areas of land can be used for experimentation and following that for amenity, recreation, pleasure and wildlife, they increase available space and reduce the competition between food and essential production and conservational ecology.
One of many experiments going on at the moment is the work of Chadwick (1973a, b) on pit heaps and mining spoil. The experimental work of his group has included research on the weathering of soil materials, leaching of substances and toxic chemicals, origins of soil acidity, tolerance of species and their genotypes to soil environments. Recreation, amenity and pleasant areas have been created out of a mess as a result of their work.
Conservation of nature is a large and extensive enterprise. It is an international or global enterprise and it has to be paid for. It is an activity not to be entered upon with prejudice or emotion but coolly and scientifically. It requires a consideration both of the physical needs of man as well as his intellectual needs. Conservation should consider the beauty of the countryside. Some think that wilderness is essential to this beauty; but aesthetic uplift can sometimes also be given by a countryside where every possible square centimetre is given to production and only the rocks are left untouched.
CHADWICK, M.J. 1973a Methods of assessment of acid colliery spoil as a medium for plant growth. In Ecology and reclamation of devastated land (eds. R.J. Hutnik & G. Davis), Vol. 1, pp. 81-90. New York, Gordon & Breach.
CHADWICK, M.J. 1973b Amendment trials of spoil in the north of England. In Ecology and reclamation of devastated land (eds. R.J. Hutnik & G. Davis), Vol. 2, pp. 175-186. New York, Gordon & Breach.
ENTWISTLE, P.K. 1971 Possibility of control of a British outbreak of spruce sawfly by a virus disease. Br. Insectic. Fungic. Conf. pp. 475-479.
KIRKLAND, A. & JOHNS, J.H. 1973 Beech forests. N.Z. Forest Service, Wellington, New Zealand, p. 48.
OVINGTON, J.D. 1962 Quantitative ecology and the woodland ecosystem concept. Adv. Ecol. Res. 1:103-192.
THOMPSON, A.P. 1973 Government approval of West Coast and Southland beech forest utilization proposals. N.Z. Forest Service, Wellington, New Zealand, p. 16.
WATT, A.S. 1947 Pattern and process in the plant community. J. Ecol., 35: 1-22.
WHITMORE, T.C. 1974 Change with time and role of cyclones in tropical rain forest on Kolombangara in the Solomon Islands. Inst. Pap. Common. For. Inst.
