Any perturbations in the broad framework of the inter-relationships between living organisms and their environment may influence the availability of resources to human societies.
However, a note of caution is warranted in-so-far as the application of this ecosystem concept to the study of human societies is concerned; viz., that because of their distinctive cultural character, human societies are partially independent from the natural environment. It is a well known fact that the interaction between the natural environment and human civilizations is not always governed by the same set of principles which apply to the inter-relationships between the components of the natural system itself. Societies very often do not adapt to alterations in the natural environment according to some general predictable model. Some important sources of energy are: (a) solar radiation; (b) tidal energy from the combined potential and kinetic energy of the earth-moon-sun plexus; (c) energy from within the earth itself, such as heat conduction and the convection of energy by the material transport of hot springs, volcanoes and the upheavals of mountains, etc. Nuclear energy from the atomic nucleus and nuclear reactions constitutes a very important modem source of energy and when properly used and released, can also be converted into electrical power. Sooner or later man must take cognizance of the limitations of his environment.
During the last two centuries, our industrial activity as well as energy consumption has increased greatly, but these abnormally high rates of growth cannot be sustained for long and it seems inevitable that before very long such growth must become fairly constant and stable. This can happen in two ways, viz., either by a continuation of high industrial activity with a high level of energy utilization, or by reverting back to the eighteenth century status by decreasing industrial growth to a primitive low energy level, consistent with the balance of nature. The main limitations in the future sustenance of high rates of energy consumption are not the scarcity of energy resources but the ecological principles determining ecosystem functioning. In fact, power production and industrialization may be viewed as constituents of ecosystems. Natural resources can be broadly classified into biological and non- biological, and include such resources as mineral and industrial, agricultural, forestry and food resources, power and energy, plant and animal, range and water. Resources may be renewable or non-renewable. Biological resources such as fish are of course, mostly replenishable, but even such resources as nitrogen, iron and energy may also some time be renewable though not to the same extent as forests and fisheries.
It is well known that agriculture generates most of our food but it is always appreciated that our crops and forests have outputs other than food and fibre. In fact, many of the resources cannot be considered in isolation but have to be discussed collectively because of various interactions/exchanges amongst them. Renewable resources are crucial to an enduring human civilization. Modem, industrialized, technological society requires a vast array of raw materials which may be supplied in numerous ever-changing forms. Most of these raw materials require reduction into useful states through such processes as concentrating, mining, harvesting, smelting, processing, refining, alloying, composting or fabricating. Natural resources, which furnish materials, constitute the base of our material wealth. Society’s activities or work require the conversion of materials to a useful state and this conversion occurs at the expense of energy from coal, oil, natural gas, nuclear power or other resources. Various kinds of ores are required to supply mankind’s needs for new mineral, raw materials and such needs are likely to continue until fusion or some other fairly cheap and inexhaustible energy source is developed.
Materials and energy are intimately linked and interdependent. With the ever-widening gap between our metals and minerals requirements and the remaining easily accessible world supplies of these materials, recourse to metallurgical recycling can help solve, at least to some extent, the problem of materials shortage. Some of the valuable mineral constituents could be recovered from metallurgical wastes and also the recovery and quality of some of the secondary resources being recycled can be improved. At least some of our metal needs, e.
g., iron, may well be met by scrap. Some attention is now being given to recovery and better recycling of metals and minerals from various waste by-products generated during the refining of such secondary metals as copper, zinc, brass and lead.
Some metals can also be recovered from waste solutions of such industrial operations as electroplating, etching and pickling. In the context of food production and agricultural farming, the basic physical resources are land, water, energy, fertilizer and pesticides. Of these, solar energy and atmospheric nitrogen are mostly unlimited and renewable. Modern farming practices aim at enhancing the production and utilization of renewable resources with the least possible expenditure of non-renewable resources. Water may be regarded as either renewable or non-renewable resource as far as its irrigational use is concerned (see Wittwer, 1975).
The development of appropriate technology to ensure maximally efficient utilization of water by plants deserves a high priority and may be expected to lead both to increased crop productivity and to conservation of limited and value resource. Non-renewable resources consist of geochemical concentrations of naturally occurring elements and compounds that may be exploited profitably. The distribution of geological resources over the globe’s surface is quite uneven and their greatest concentration occurs in the outermost part of the earth’s continental crust. Such phenomena as weathering, erosion, and groundwater leaching which concentrate chemical elements most effectively usually operate very close to the earth’s surface. The history of economic exploitation of non-renewable resources during the last two centuries has, in general, been one of decreasing costs, increasing reserves, and rising energy and work cost requirements (Cook, 1976). Cook is of the opinion that most of our mineral and energy resources are finite, and yet the world is not likely to run out of such resources they will merely become more and more expensive.
Some examples of non-renewable resources are: non-metallic minerals, e.g., sand and gravel, stone, cement and clays; metals, e.g.
, iron and steel, aluminium, copper, lead, zinc and others; polymers, e.g., plastics and resins, synthetic rubber and non-cellulosic fibres. Some examples of renewable resources are: wood and wood products, e.
g., lumber, plywood and veneer, and pulp products, natural rubber; fibres, e.g., cotton, jute, animal wool and silk and synthetic (cellulosic) fibres; and leather. Water is one of our most precious resources. It is more abundant than anything else; it is virtually the only natural inorganic liquid which occurs as gas, liquid and solid; it has a remarkably high solvent power, and it is the source of all life on earth. It is the major constituent of protoplasm and is necessary for life activities.
Large volumes of water are being consumed in agriculture and industry, and domestic and municipal use also imposes a further demand on this resource. However, this resource is generally renewable but is subject to abuse and misuse. Most of our water problems, however, are not those of quantity or even necessarily of quality, but are rather caused by our way of thinking and attitudes. If man 1 earns to live with man not on a competitive but a cooperative basis, the water problem, like many other ecological problems, could be solved. Provisional estimates assess that the replenishable ground water resources in India are sufficient to provide assured irrigation to 40 million hectares. The present level of development is estimated at 25 million hectares, i.
e., about 40 per cent of the total irrigation potential created in the country. The Government has created dining the Sixth Plan, an additional irrigation potential of 13 million hectares out of which the share of about ground water may be 7 million hectares. Drinking water becomes doubly important in a developing country because it serves as a source of micronutrients that are so essential for good health. Deficiency or excess of the essential trace elements can cause disorders. Drinking water is an important source of intake of trace elements. Dang et al.
, (1984) surveyed the trace element content of drinking water in several cities of India and found marked variations in the concentrations of As, Mn, Mo, and Zn, but lesser variation in Cu content. They concluded that Zn and Mo intakes through drinking water may be higher in northern India, Mn intake is probably higher in northern and eastern India, and Cu intake is more or less the same in the different parts of the country. Natural resources set an upper limit to world population, but we do not know enough whether or not conditions of resources availability and/or exploitation would change significantly in the future. However, it is generally approximate Concentrations (ng/ml) of Four Trace Elements in the Drinking Water of Some Indian Cities. Agreed that a given resource, e.
g., minerals, is unlikely to become unavailable globally all at the same time, and also that each resource cannot be considered independently of all other resources. Similar limiting factors and uncertainties are applicable to the case of environmental degradation and we might already have reached a limit in the case of pollution. In fact, resource exploitation and pollution are two faces of the same coin since exploitation of resources in one place can become environmental degradation either in the same place or in a remote area. One good example of the latter situation is evident in many adverse effects on the ocean harvest which are often caused by man’s activities on land.
Thus, biocides and persistent inorganic pesticides which are used to increase crop yields on land are responsible for decreasing the yields of fish-and other proteins from the oceans. Increasing use of biocides for boosting carbohydrate yields on land is expected fairly soon to lead to such high increases in their concentration in the oceans as to significantly reduce the productivity at the lower trophic levels. There are limits to the size of population that can be sustained on the spaceship Earth. Our goal should be to strive for an optimum, rather than maximum, sustainable population size on Earth, and to arrive at the optimum figure after due consideration of the complex environmental problems. The optimum size permits long-term persistence of the population in equilibrium with its environment.
One can also speak of the optimum as representing that stage when any further addition of more members would result in a deterioration of the quality of life of those already present. Despite their critical importance in any strategy for sustainable development, the social dimensions of environment have been largely neglected in public discussions. The importance of an integrated and holistic approach in tackling environmental problems cannot be overemphasized. Environmental strategies and programmes must be based on a thorough analysis of technical and economic factors as well as of social and political dimensions of the environmental problem. Such an approach includes not only an analysis of balance of political forces but also of issues of livelihood for disadvantaged groups. The general strategy for exploiting natural resources must need be based on the population density of the region.
However, there is sometime no definite correlation between a poor environment and a sparse population or between high population densities and a particularly favourable climate or soil. Overexploited and underexploited lands can coexist side by side, and the population centres are the result of human decisions that were largely indifferent to the quality of available natural resources. In under populated regions, the methods of natural resource utilization are mainly based on extensive cultivation, i.
e., temporary land clearing, with long fallow periods for restoring the organic and mineral nutrients taken up by crops. These methods are widely practised in tropical environments.
In contrast, the strategies for management of natural resources in densely populated regions are highly efficient and sophisticated, especially in certain African countries (see MAB Technical Report No. 9, 1978). Until over a decade ago the general belief used to be that there were no great mineral deposits on the ocean floor and that the floor was composed largely of basaltic lava flows that became buried by sediments. These sediments were mostly formed by the gradual accumulation of the dead remains and skeletons of small marine animals. In recent years, seyeral kinds of ore have been discovered from the deep oceans (see Bullard, 1974). Certain blue, yellow and red sediments from the Red Sea have been found to contain an extensive variety of metals including sulphides of zinc and copper.
The Atlantic floor also contains several mineral deposits such as magnetite, zinc sulphide, nickel ore and copper deposits, etc. It now seems very likely that discoveries of major mineral resources in the deep oceans are just around the corner. In Far East Asia the major fraction of human population (about 65-75%) is directly dependent upon natural resources for their livelihood. But most of the resources in this part of the world have scarcely been examined in the light of ecological principles. In most developing countries, sound management and conservation practices cannot be recommended since the ecological data on which to base such measures are either not available at all or are inadequate. Thus, for instance, it is necessary to know various facts about wild and domestic yak, blue-sheep, goral, musk-deer, pigmy hog and other wild animals of tropical and subtropical mountains and highlands before prescribing any reliable wildlife management practices. About most of these animals we just do not know population densities and rates of natality and mortality, age and sex ratios, rates of food uptake and reproduction, social behaviour, and carrying capacity of their environment.
The entire range of the Himalayas extending from Kashmir to Assam and North Burma is an ecological syntype complex, apparently rich in various kinds of natural resources. The Himalayan aquatic resources show characteristic horizontal spatial distribution in having a trout section, a barbel section, and a bream section, in streams, and the lakes may be oligotrophic or eutrophic. In India, our primary goal is to increase the agricultural productivity per unit land area, with most of the available and sparable land having already been pressed into farming use. We have virtually reached a stage where we cannot bring any more areas under the plough. In developing countries, soils are required to sustain much larger population sizes per unit area as compared to the advanced countries, and our agriculture is tending to become input- intensive, requiring more and more of fertilizers, pesticides, water, etc.
The plant cover is extremely important for the maintenance of the soil in a balanced and healthy state. Over-exploitation of forests and deforestation practices lead to soil erosion with the topsoil washing down the stream; this ruins soil fertility. In India, we are annually losing millions of tons of nitrogen, phosphorus and potassium through soil erosion. It is estimated that at least 5,000 million tons of soil are being annually lost in India by water erosion, and the loss of valuable nutrients in this way often reaches colossal proportions. Thousands of acres of arable soil are also being rendered unfit for fanning due to salinity and alkalinity problems. The Green Revolution has further generated some newer problems of soil fertility depletion, mineral nutrient imbalances, agricultural residues, etc. In some parts of Punjab, for instance, paddy straw of the high-yielding rice variety IR-8 has been implicated in the deterioration in health of cattle because of its abnormally high content of certain mineral salts.
Agricultural use of soil is intimately linked with that of water which is required for irrigation. Considerable progress has been made in India in the large-scale storage of water in Dams and Reservoirs for agricultural use and for generation of hydroelectric power, but economic criteria for evaluating the integrated water requirements of contemporary agricultural industry, and municipalities cannot often be gleaned from a historic water policy (if there is one!) which is largely an instrument of a maximum land development policy, Water being one of the most valuable resources, it stands to reason that policies directed toward the maximum economic yield from a fixed amount of water will result in maximum conservation and also that planning for the maximum use of water ought to be correlated with planning for the optimum use of land resources. The land resources of India have been increasingly degraded during the last few years.
Excessive, unplanned canal irrigation without proper drainage and water management has led to seepage, water logging and salinity. Seven million hectares are already affected and another ten million are threatened. About 150 million hectare area suffers from wind and water erosion; this results in the loss of valuable topsoil.
Rising water tables also contribute to increasing sanitization of farm lands. Soil erosion causes premature silting up of many reservoirs and tanks.