BIO 3108 – NATURAL RESOURCES AND POPULATION GROWTH
CONSERVATION AND MANAGEMENT
What are natural resources?
A natural resource is defined as a form of energy and/or matter which is essential for the functioning of organisms, populations and ecosystems. In the case of humans, a natural resource refers to any form of energy or matter essential for the fulfillment of physiological, socio-economic and cultural needs, both at the individual level and that of the community. Life on our planet earth depends upon a large number of things and services provided by the nature, which are known as natural resources. Water, air, soil, minerals, coal, forests, crops and wild life are all the examples of natural resources. The basic ecological variables- energy, space, time and diversity are sometimes combined called natural resources. These natural are maintaining ecological balance among themselves. Man is the only organisms who have disrupted this duplicate balance. A natural resource is a form of energy and/or matter, which is essential for the functioning of organisms, populations and ecosystems. In the case of humans, a natural resource refers to any form of energy or matter essential for the fulfillment of physiological, socio-economic and cultural needs, both at the individual level and that of the community. The basic ecological variables- energy, space, time and diversity are sometimes combined called natural resources.
These natural resources are maintaining ecological balance among themselves. Man is the only organism who has disrupted this duplicate balance.
Classification of natural resources:
According to Odum (1971), natural resources can be divided into two categories: renewable and non-renewable resources.
1. Renewable resources are those resources that can be replenished through rapid natural cycles.
These resources are able to increase their abundance through reproduction and utilization of simple substances. Examples of renewable resources are plants, (crops and forests), and animals who are being replaced from time to time because they have the power of reproducing and maintain life cycles. Some examples of renewable resources though they do not have life cycle but can be recycled are wood and wood-products, pulp products, natural rubber, fibers (e.g. cotton, jute, animal wool, silk and synthetic fibers) and leather. In addition to these resources, water and soil are also classified as renewable resources. Solar energy although having a finite life, as a special case, is considered as a renewable resource in as much as solar stocks is inexhaustible on the human scale.
2. Non-Renewable Resources are resources that cannot be replenished through natural processes.
These are available in limited amounts, which cannot be increased. These resources include fossil fuels (petrol, coal etc.), metals (iron, copper, gold, silver, lead, zincetc.), minerals and salts (carbonates, phosphates, nitrates etc.). Once a non-renewable resource is consumed, it is gone forever. Then we have to find a substitute for it or do without it. Non-renewable resources can further be divided into two categories: recyclable and non-recyclable.
Recyclable non-renewable resources can be collected after they are used and can be recycled.
These are mainly the non-energy mineral resources, which occur in the earth’s crust (e.g. ores of aluminum, copper, mercury etc.) and deposits of fertilizer nutrients (e.g. phosphate sock and potassium and minerals used in their natural state (asbestos, clay, mica etc.). Non-

recyclable non-renewable resources, on the other hand, cannot be recycled in any way.
Examples of these are fossil fuels and uranium, which provide 90 per cent of our energy requirements. How do we use our natural resources?
Even our renewable resources can become non-renewable if they are exploited to such extent that their rate of consumption exceeds their rate of regeneration. For example if a species is exploited so much that its population size declines below the threshold level then it is not able to sustain itself and gradually the species becomes endangered or extinct. It is very important to protect and conserve our natural resources and use them in a judicious manner so that they do not become exhausted. It does not mean that we should stop using most of the natural resources.
Rather, we should use the resources in such a way that they will be available for our future generations. Forest resources, water resources, mineral resources, food resources, energy resources and land resources are some examples of natural resources.
Forests provide us a large number of commercial goods which include timber, firewood, pulpwood, food items, gum, resins, non-edible oils, rubber, fibers, lac, bamboo canes, fodder, medicine, drugs and many more items, the total of which is estimated to be more than $ 300 billion per year. The forest also provides many ecological services such as the production of oxygen, acts as a carbon sink, provides habitat for wildlife, regulates the hydrological cycle, conserves soil, and moderates pollution. Deforestation rates are very alarming especially in the tropical regions where deforestation rate is estimated at 40-50%. The major causes of deforestation is shifting cultivation, fuel requirements, raw materials for industrial use, developmental projects, growing food needs (conversion of forest to agriculture use) and overgrazing. Deforestation has major impacts on the ecological services provided by the forests.
Water is an indispensable natural resource on this earth on which all life depends. About 97% of the earth’s surface is covered by water and most of the animals and plants have 60-65% water in their body. The water we use keeps cycling through the environment through the hydrological cycle. Although water is very abundant on this earth, yet it is very precious. Out of the total water reserves of the world, about 97% is salty water (marine) and only 3% is fresh water. Even this small fraction of fresh water is not available to us most of it is locked up in polar ice caps and just 0.003% is readily available to us in the form of groundwater and surface water. Overuse of groundwater for drinking, irrigation and domestic purposes has resulted in rapid depletion of groundwater in various regions leading to lowering of water table and drying of wells. Pollution of many of the groundwater aquifers has made of these wells unfit for consumption. Rivers and streams have long been used for discharging the wastes. Most of the civilizations have grown and flourished on the banks of rivers, but unfortunately, growth in turn has been responsible for pollution of the rivers.
Minerals are naturally occurring, inorganic, crystalline solids having definite chemical composition and characteristic physical properties. There are thousands of minerals occurring in different parts of the world. Minerals are generally used for development of industrial plants, generation of energy, construction, equipment and armament for defense, transportation means, medical system, communication, jewelry- gold, silver etc. Environmental impacts of mineral extraction and use are removal of vegetation and defacing of landscape, subsidence of land,

groundwater contamination, surface water pollution, air pollution, and occupational health hazards etc. Remedial measures include adoption of eco-friendly technology, microbial leaching technique, restoration of mined areas by re-vegetating them with appropriate plant species, stabilization of the mined lands, gradual restoration of flora etc.
Every year food problem is killing as many people as were killed by the atomic bomb dropped on Hiroshima during World War II. There is drastic need to increase food production, equitably distribute it and also to control population growth. Although India is the third largest producer of staple crops, an estimated 300 million Indians are still undernourished. India has only half as much land as USA, but it has nearly three times population to feed. Our food problems are directly related to population. Because of overgrazing the agricultural land gets degrade, the soil erodes and many useful species are lost. Agriculture also makes impact on the usage of land resulting in deforestation and depletion of nutrients.
Energy resources are primarily divided into two categories: renewable and non-renewable sources. Renewable energy resources must be preferred over the non-renewable resources. This will seek to end the energy crisis which the world is currently facing. It is inevitable truth that now there is an urgent need of thinking in terms of alternative sources of energy, which are also termed as non-conventional energy sources which include: 1. solar energy- made up equipment such has solar heat collectors, solar cells, solar cooker, solar water heater, solar furnace, solar power plants are must. 2. Wind energy 3. Hydropower - Tidal energy, ocean thermal energy, geothermal energy, biomass, biogas, biofuels etc. The non-renewable energy sources include coal, petroleum, natural gas, nuclear energy.
Land is a finite and valuable resource upon which we depend for our food, fiber and fuel wood, the basic amenities of life. Soil is also a valuable resource. Because of increasing of population growth the demands for arable land for producing food and fuel wood is also increasing. Hence, there is more and more pressure on the limited land resources which are getting degraded due to over-exploitation. Soil erosion, water logging, salinization and contamination of the soil with industrial wastes like fly-ash, press mud or heavy metals all cause degradation of land.
There is a big divide in the world with regards to more developed countries and less developed countries. It has been observed that more developed countries have only 22% of world’s population but they use 88% of natural resources, 73% of energy and command 85% of income.
In turn they contribute very big proportion to its pollution. On the other hand less developed countries have very low or moderate industrial growth and have 78% of world’s population.
They use only 12% of natural resources, 27% of energy and have only 15% of global income.
There is a huge gap between those two worlds. This is not sustainable growth. The solution to this problem is to have more equitable distribution of resources and wealth. A global consensus has to be reached for balanced distribution. There are two major causes of unsustainability over population in poor countries and over consumption of resources by rich countries. Ideally, the rich countries will have to lower down their consumption levels and bare minimum needs of the poor must be satisfied by providing them with resources.

Why should we manage our natural resources?
Harvesting of populations by people is clearly in the realm of predator–prey interactions and harvest management relies on the theory of predator–prey dynamics. When a natural population is exploited by culling or harvesting – whether this involves the removal of whales or fish from the sea, the capture of ‘bushmeat’ in the African savanna or the removal of timber from a forest – it is much easier to say what we want to avoid than precisely what we might wish to achieve. On the one hand, we want to avoid overexploitation, where too many individuals are removed and the population is driven into biological jeopardy, or economic insignificance or perhaps even to extinction. But harvest managers also want to avoid underexploitation, where far fewer individuals are removed than the population can bear, and a crop of food, for example, is produced which is smaller than necessary, threatening both the health of potential consumers and the livelihood of all those employed in the harvesting operation. However, the best position to occupy between these two extremes is not easy to determine, since it needs to combine considerations that are not only biological (the well-being of the exploited population) and economic (the profits being made from the operation), but also social (local levels of employment and the maintenance of traditional lifestyles and human communities).
The first point to grasp about harvesting theory is that high yields are obtained from populations held below, often well below, the carrying capacity.
What is sustainability?
Sustainability entails meeting the needs of the people of today, and in the future (that is, the generations to come). The United Nations defines Sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Thus the terms sustainability and sustainable development are interchangeable.
Sustainability brings on a sort of a political character, and leads us to ask the question: how do we weight the needs of people today versus the people of the future who don’t exist yet? There are several stresses inherent in the whole concept, because there are real needs for people today, and we have to very finely balance that judgment with other people. So instead of asking “What do we owe future generations?”, we should probably ask “Is it sustainable for civilization to continue, more or less, on its current course?”.
There are three dimensions that sustainability seeks to integrate: economic, environmental, and social (including sociopolitical). Economic interests define the framework for making decisions, the flow of financial capital, and the facilitation of commerce, including the knowledge, skills, competences and other attributes embodied in individuals that are relevant to economic activity.
Environmental aspects recognize the diversity and interdependence within living systems, the goods and services produced by the world’s ecosystems, and the impacts of human wastes.
Socio-political refers to interactions between institutions/firms and people, functions expressive of human values, aspirations and well-being, ethical issues, and decision-making that depends upon collective action. These three elements are part of a highly integrated and cohesively interacting system.
The Brundtland Report (1987) makes it clear that while sustainable development is enabled by technological advances and economic viability, it is first and foremost a social construct that seeks to improve the quality of life for the world’s peoples: physically, through the equitable supply of human and ecological goods and services; aspirationally, through making available the

widespread means for advancement through access to education, systems of justice, and healthcare; and strategically, through safeguarding the interests of generations to come come. Overlapping Themes of the Sustainability Paradigm A
Source: International Union for the Conservation of Nature
The intersection of social and economic elements can form the basis of social equity. In the sense can of enlightened management, "viability" is formed through consideration of economic and environmental interests. Between environment and social elements lies “bearability,” the recognition that the functioning of societies is dependent on environmental resources and services. At the intersection of all three of these lies sustainability.
The maximum sustainable yield (MSY)
The maximum sustainable yield (MSY) is the largest harvest that can be removed from the population on a regular and repeated (indeed indefinite) basis. It is equal to the maximum rate of ation recruitment, and it is obtained fr from the population by depressing it to the density at which the recruitment rate curve peaks. much ing.
The MSY concept is central to muc of the theory and practice of harvesting. This theory has a number of shortcomings:
1. By treating the population as a number of similar individuals, or as an undifferentiated biomass, it ignores all aspects of population structure such as size or age c classes and their differential rates of growth, survival and reproduction. The alternatives that incorporate structure are considered below.
2. By being based on a single recruitment curve it treats the environment as unvarying.
3. In practice, it may be impossib to obtain a reliable estimate of the MSY. impossible 4. Achieving an MSY is by no means the only, nor necessarily the best, criterion by which success in the management of a harves harvesting operation should be judged.

Despite all these difficulties, the MSY concept dominated resource management for many years in fisheries, forestry and wildlife exploitation. Prior to 1980, for example, there were 39 agencies for the management of marine fisheries, every one of which was required by its establishing convention to manage on the basis of an MSY objective. In many other areas, the MSY concept is still the guiding principle.
Fixed Quota Strategy
A fixed quota at the MSY level might be desirable and reasonable in a wholly predictable world about which we had perfect knowledge. But in the real world of fluctuating environments and imperfect data sets, these fixed quotas are open invitations to disaster. Continuous harvesting below the minimum viable population could lead to extinction. The minimum viable is the smallest population size that would allow that population to regenerate itself.
Nevertheless, a fixed-quota strategy has frequently been used. On a specified day in the year, the fishery (or hunting season) is opened and the cumulative catch logged. Then, when the quota
(estimated MSY) has been taken, the fishery is closed for the rest of the year. An example of the use of fixed quotas is provided by the Peruvian anchovy (Engraulis ringens) fishery. From 1960 to 1972 this was the world’s largest single fishery, and it constituted a major sector of the
Peruvian economy. Fisheries experts advised that the MSY was around 10 million tonnes annually, and catches were limited accordingly. But the fishing capacity of the fleet expanded, and in 1972 the catch crashed. Overfishing seems at least to have been a major cause of the collapse, although its effects were compounded with the influences of profound climatic fluctuations. A freeze (or suspension) on fishing would have been an ecologically sensible step, but this was not politically feasible: 20,000 people were dependent on the anchovy industry for employment. The stock took more than 20 years to recover.
Fixed Harvesting Effort
The risk associated with fixed quotas can be reduced if instead there is regulation of the harvesting effort. Yield (amount harvested) increases with the size of the harvested population, it increases with the level of harvesting effort (e.g. the number of ‘trawler-days’ in a fishery or the number of ‘gun-days’ with a hunted population); and it increases with harvesting efficiency.
Harvesting a fixed proportion or allowing constant escapement
In the fixed proportion harvesting model, a constant proportion of the population can be harvested (this is equivalent to fixing a hunting mortality rate and should have the same effect as harvesting at constant effort). In the constant escapement strategy, a fixed number of breeding individuals at the end of each hunting season (constant escapement), an approach that involves the even greater expense of continuous monitoring through the hunting season. Constant escapement is a particularly safe option because it rules out the accidental removal of all the breeding individuals before breeding has occurred. Constant escapement is particularly useful for annual species because they lack the buffer provided by immature individuals in longer lived species. References:
Begon, Micheal, et al (2006). Ecology: From Individuals to Ecosystems (4th Edition). Blackwell
Publishing.
Odum, H.T., (1971). Environment, Power, and Society. Wiley Interscience.
Report of the World Commission on Environment and Development (1987). Our Common
Future. United Nations.
Theis, Tom and Jonathan Tomkin (2012). Sustainability: A Comprehensive Foundation. U of I
Open Source Textbook Initiative.