Relationship between economics and ecology

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Relationship between economics and ecology


We do not inherit the earth from our ancestors, we borrow it from our children.

Concerns for sustainable development have become more and more apparent in the last four decades since the Stockholm Conference in 1972. In 2012 Rio+20 came out with a document titled “The Future We Want” and called for ensuring the promotion of an economically, socially and environmentally sustainable future for our planet and for present and future generations. Such an effort also set the stage for planning a detailed agenda for future action, which took the form of preparing another important document, “Transforming Our World”, which lays the groundwork for sustainable development during the coming 15 years. is going to guide our search for. It develops a list of 17 Sustainable Development Goals and 169 targets to achieve them. Five areas of critical importance to humanity and the planet have been identified in the draft 2030 Agenda for Sustainable Development which was released on 3 August 2015. Those 5P’s are:


  1. People: eradicating poverty and hunger, in all their forms and dimensions, and ensuring that all human beings can fulfill their potential in dignity and equality and in health


  1. The Planet: “Preventing the planet from degradation through sustainable consumption and production, sustainably managing its natural resources and taking urgent action on climate change, so that it can support the needs of present and future generations”.


  1. Prosperity: To ensure that “all human beings can enjoy prosperous and fulfilling lives and that economic, social and technological progress is in harmony with nature”.


  1. Peace: “Promoting peaceful, just and inclusive societies that are free from fear and violence (as the authors of the document firmly believe) There can be no sustainable development without peace and no peace without sustainable development” may be” and


  1. Partnership: Mobilizing the necessary means to implement this agenda through a revitalized global partnership for sustainable development, based on a spirit of strong global solidarity, focusing especially on the needs of the poorest and most vulnerable and with the participation of all countries, all stakeholders and all people”.

In short, the document calls for a strategy that will ensure inclusive growth for humanity in the days to come as well as protect the planet from rapid degradation, unless dealt with sensibly from now on, especially human life. may threaten the existence of, and the ecosystem in general, in the near future. While the first concern traditionally falls within the realm of economics, the second concerns the realm of ecology. The present section looks at the apparent contradictions between the two branches of knowledge in terms of their “conceptual frameworks” and also tracks recent attempts at an interdisciplinary approach to reduce the apparent conflicts between the two


A Facebook meme, which recently went viral, reads:


“Earth is 4.6 billion years old. Let’s do this on a scale of 46 years. We’ve been here for 4 hours. Our

The Industrial Revolution started 1 minute ago. In that time we have destroyed more than 50% of the world’s forests”.


Some stylistic facts from Barbier (2014) would also be in order in this context.


  • “Since 1970, the World Bank’s World Development Indicators have provided estimates for most countries adjusting for national income, income growth and savings that result from net depletion of forests, energy resources and minerals. This rate of natural-capital depreciation as a percentage of adjusted net national income over the past four decades is alarming.
  • “The decline in natural capital has been, on average, five times greater in developing economies than in the eight richest countries”.
  • “Natural capital depreciation has increased significantly in all countries since the 1990s. There was a decline during the global recession of 2008–09, but as the world economy has recovered, so has the rate of resource use.
  • “According to the worldwide Millennium Ecosystem Assessment, approximately 60% of key global ecosystem services are degraded or used unsustainably, including fresh water, wild fisheries, air and water purification, and regional and local climate , includes regulation of natural hazards and pests. ,


These facts underline the conflict between the pursuit of economic growth and maintaining the ecosystem in its desired state, which will be on the mind for many years to come.

Ensures sustainable livelihood for the people.

Thomas Malthus was perhaps the first to express concern about the possibility of such a conflict which coincided with the height of the Industrial Revolution in Europe. He argued that while the Earth’s food-producing capacity was increasing in arithmetic progression, human population was increasing at a rate of geometric progress, aided by a continual increase in economic activity.

n, a cautionary note about the possibility of limits to growth – an issue taken up in right earnest by the “Club of Rome” in the early 1970s. This reflects the potential for exhaustion of finite resources – namely mineral reserves – at the prevailing rate of growth of the economy and population, as well as at the current rate of use, unless new reserves and sources are identified to increase the supply of those resources. Is done Despite serious criticisms of the data and the methods used and the conclusions drawn, believers pushed the limits of evolution and produced its final sequel in 2011, with Ugo Bardi insisting that “the warnings we received in 1972 . ..they are becoming. increasingly more worrisome because reality is closely following the curves that the ..scenario generated.”



Economics and Ecology: Fundamental Difference

What are the fundamental differences between the basic premises followed by an economist and an ecologist?

  • While an ecologist considers human beings to be a part of the ecosystem and linked to other natural resources – both living and non-living – in an integrated series of relationships, an economist considers human beings to be located away from the ecosystem. The ability to use its components in ways that optimize human well-being in the material sense.


  • Economists believe in optimizing human welfare by increasing their ability to produce and consequently consume those goods and services which are continuously added to the increased GDP and subsequently the Human Development Index. Various components of nature are used to facilitate the movement of the economy along such a desired path, in which the earth is used as the source of the resource and as the sink of the “bad” produced in the process. Used in, but not suitable for human consumption.


  In doing so, economists do not differentiate between man-made resources and resources produced by nature. There has also been a strong belief among economists over the years that technological advances will facilitate man-made production of most natural resources as and when such a need arises. On the other hand, ecologists believe that most natural resources, if not all, can only be consumed by humans, but can never be produced by them and should therefore be used sparingly. Furthermore, the use of nature as a sink for “bad” may endanger ecosystem functioning in a way that may lead to the eventual collapse of the ecosystem threatening the survival of mankind as Noah did. One of the thousands of species found on the ark.


Concern for “sustainable development” and the realization that neither economics nor ecology can pursue their disciplinary pursuits oblivious to the asymmetries emanating from each other have led to efforts to resolve “ideological” conflicts. A recent article by Herman Daly outlines the different world views of economists and ecologists and, very succinctly, one possible way of reconciling them. According to him, such integration is attempted through three different strategies:

  1. Economic Imperialism
  2. Ecological reductionism and
  3. Steady State Subsystem.


In each of these three strategies, the economy is treated as a subsystem of a finite ecosystem. However, the strategies differ in terms of their paths.


economic imperialism

The strategy of economic imperialism “seeks to expand the range of the economic subsystem until it encompasses the entire ecological sector. The target is a system, the macro-economy as a whole. In a typical neo-classical world view the aggregate is subjective Individual preferences are taken as the ultimate source of value. And expansion is considered legitimate as long as the cost of such expansion – the cost of ecosystem degradation – is internalized, i.e. the cost of ecosystem degradation. All resulting costs will be identified and added to the value of the products or services.


Only those people who are willing and able to pay such increased price will be able to consume them, the rest will be kept out of bounds. With the increasing extent of degradation of ecosystems and the resulting rise in prices of goods and services produced, there will be a built-in control mechanism that will limit the extent of degradation before a sustainable level is reached. The following diagram explains the perspective in detail. The consumption of goods and services produced by an economic system provides utility. Following the law of diminishing marginal utility, the utility derived from an incremental unit of a good or service decreases as consumption increases.

Will go The internalization of the costs of ecosystem degradation—in terms of the use of natural resources beyond the limits of natural evolution and the use of nature as a sink for production waste—will also add to the inadmissibility of consuming a product. And incremental inefficiency will increase with increasing consumption of the goods or services in question. Hence the marginal utility curve slopes downward

to the right, while the marginal inefficiency curve moves in the opposite direction. In a typical neo-classical framework, the intersection point between these two lines gives the economic limit to growth. If resources are still consumed to ensure increased levels of production and consumption, nature may reach a tipping point of environmental catastrophe – akin to ecosystem collapse. Ideally, the point of economic limit to growth is expected to lie to the left of the point of environmental catastrophe and hence provide mankind with some precious time to wake up to the desired course of action. The indifference curve marked at the right corner of the diagram refers to the point of complete satisfaction on the part of the consumer – beyond this point, there is no increase in total utility. It is realized that if the costs of ecosystem degradation are internalized in the process of production and consumption, environmental catastrophe will ensue even before the point of complete satisfaction is reached.


This strategy gives rise to a special discipline in economics called environmental economics. However, the outlook is unreliable. Many of these costs have not been imagined, let alone imagined, following Herbert Simon’s argument for limited rationality. Simon argued that humans are not capable of accurately predicting all future events as assumed under the condition of rationality. Thus full internalization of the costs of ecosystem degradation is difficult to achieve in reality. Furthermore, even if some such external costs are visible, proper enforcement mechanisms often take a long time and may be partial in affecting the desired level of internalisation.

The debate on climate change is still a matter of inconclusive. Thus the process of effective internalization may not be correct either, which leads us to a similar situation, that of an ideal market system as presented by the neo-classical school of economic thought, as lacking a complete set of ideal markets. deviation is characteristic. Here we end up with a lack of a mechanism to ensure complete and correct internalization of ecosystem degradation.


This is known as the polluter pays principle


At this juncture it would be appropriate to mention a question raised by Daly:

“Are we better off with the new large-scale formerly free goods at the right price, or with the old small-scale free goods also at the right price (at zero)? In both cases the prices are right. This is optimal by neoclassical economics. There is the pressing question of scale, which has not been answered, in fact not even asked.


ecological reductionism

Ecological reductionism holds that human behavior can be explained by the same set of natural laws that explain the behavior of other components of nature and thus proposes to remove the boundary of the economic subsystem and incorporate it within the natural system. Huh. Daly argues that it “begins with the true insight that humans and markets are not free from the laws of nature. It then proceeds to the erroneous presumption that human action can be fully explained by the laws of nature, less is doable…..taken to the extreme, this view explains all by a materialistic deterministic system (of nature) that leaves no room for purpose or desire (which separates men from the other constituents of nature ).


The argument for ecological reductionism derives its strength from the second law of thermodynamics. It was Manjh N Georgescu-Roegen, in his book “The Entropy Law and the Economic Process” published in 1971, who argued that it was the phenomenon of free energy’s tendency to scatter and be lost as bound energy, that drives an economic process. He is thus considered one of the founding fathers of ecological economics, even though he called his new approach bio-economics. His argument centered on the fact that humans, like all other living beings, depend on the energy available in the usable form of natural resources—referred to in the literature as free energy. However, once the resources are used up and the fact that they are not fully recyclable, some part is thrown back into nature as waste, we generate energy which is now Not available for consumption. They are called bound energies. According to Georgescu-Roegen entropy is a measure of the unbound or bound energy that arises within the natural system in which we live.


the rate of extraction of natural resources and the elimination of waste into the environment” (Gaudi and Messner 1998, p 147). Other living organisms also feed on low entropy sources of energy to build and preserve their complex structures, and diffuse energy into higher entropy states. However, Ant

Their contribution to the increase in Rape level is negligible compared to that of humans.

Evidence of humans contributing to an alarmingly increasing entropy in ecosystems can be located in abundance in the existing literature. The increase in entropy manifests itself in a number of ways, affecting human life and well-being. Some of them are direct and some others are indirect. For direct effects, we have already mentioned above the observation of Barbier (2014) who found that the share of natural resource scarcity in the adjusted GNI of most countries was quite significant. Some effects from rising temperatures are already happening, according to a document available on National Geographic’s website.

  • Ice is melting around the world, especially at the Earth’s poles. This includes mountain glaciers, the ice sheets covering West Antarctica and Greenland, and the Arctic sea ice.
  • Researcher Bill Fraser has tracked the decline of Adelie penguins on Antarctica, where their numbers have fallen from 32,000 breeding pairs to 11,000 in 30 years.
  • There has been a rapid rise in sea level in the last century.
  • Some butterflies, foxes, and alpine plants have moved farther north or to higher, colder regions.
  • Precipitation (rain and snow) has increased on average worldwide.
  • Spruce bark beetles are booming in Alaska because of 20 years of warmest summers. The insects have chewed through 4 million acres of spruce trees.

It also notes that if warming continues.

Sea level is expected to rise between 7 and 23 inches (18 and 59 cm) by the end of the century, and continued melting at the poles could lead to a rise of between 4 and 8 inches (10 to 20 cm).

  • There is a possibility of intensification of thunderstorms and other storms.
  • Species that depend on each other may become out of sync. For example, plants may bloom before their pollinating insects are active.
  • Floods and droughts will become more common. Precipitation in Ethiopia, where drought is already common, could decrease by up to 10 percent over the next 50 years.
  • Less fresh water will be available. If the Quelcaya Ice Cap in Peru continues to melt at its current rate, it will be gone by 2100, leaving thousands of people who depend on it for drinking water and electricity without a source.
  • Some diseases will spread, such as malaria, which is spread by mosquitoes.
  • ecosystems will change—some species will move further north or be more successful; Others will not be able to move and may become extinct. Wildlife research scientist Martin Obard has found that since the mid-1980s, due to less ice to live on and fishing for food, polar bears have become significantly thinner. Polar bear biologist Ian Stirling has found a similar pattern in Hudson Bay. They fear that if sea ice disappears, polar bears will disappear as well.


Now for the indirect effects. Bartoloni (2003) argues that negative externalities in two forms contribute to the economic development process of human societies. They are positional externalities—humans’ desire to achieve a higher relative position in the social ladder—and environmental externalities that limit the availability of free goods to humans. For example, economic development has ensured that a price is being paid today even for pure drinking water, which until a few decades ago was freely available around the world.


Thomas F. Homer-Dixon (1994) identified six types of environmental change as potential causes of violent intergroup conflict:

  1. Greenhouse-induced climate change;
  2. Stratospheric ozone depletion;
  3. Degradation and loss of good agricultural land;
  4. erosion and deforestation;
  5. Depletion and pollution of fresh water supplies; And
  6. Lack of fisheries.


They tested three hypotheses linking these changes to violent conflict and finding them to be positive. “First, the dwindling supply of physically controlled environmental resources, such as clean water and good agricultural land, will provoke interstate “simple-scarcity” conflicts or resource wars. Second, the large population movements caused by environmental stress can lead to “group-identification” will induce conflicts, especially ethnic conflicts. And third, severe environmental degradation will simultaneously increase economic deprivation and disrupt key social institutions, which in turn will lead to “deprivation” conflicts such as civil strife and extremism.


Adherents of ecological reductionism firmly believe that like the “tragedy of the commons” detailed by Garrett Hardin [1968], we are in for a “tragedy of entropy”. The process of increasing entropy cannot be reversed. Daley disagrees and suggests that collective actions that successfully avoid the tragedy of the commons [see Ostrom, 1992 for details] are necessary to overcome the “tragedy of entropy”. One should not give up and claim a process that suggests erasing the boundary between the ecosystem and the human economic system. Literature on the issue of social and ecological systems connectivity and their resilience



We can mention some of the relevant debates in India regarding conservation versus development.

“The Debate on Biodiversity Conservation in the World” by Nagarajan et al [July 25, 2015, pp 49-56] in Economic and Political Weekly

A recent paper titled “Eastern Ghats” may provide us with a point of departure in furthering our argument. The study is based on the findings of the Western Ghats Ecology Expert Panel [WGEEP] chaired by Madhav Gadgil and the High Level Working Group [HLWG] chaired by K. Kasturirangan. In response to the same set of terms of reference, the former proposed the entire Western Ghats as ecologically sensitive – closer to the philosophy of ecological reductionism, while the latter identified only 37% of the area as ecologically sensitive. declared.

Similar to the ideas of economic imperialism. The two studies used methodologies and data that were completely different from each other, reflecting their respective worldviews. And interestingly, none of them considered the grassroots political conditions that would outline possible collective actions in an attempt to reach a mutually acceptable settlement point.


The debate on the issue of conservation around the Western Ghats also raises a fundamental issue in comparison to the entropy literature. Even though human activities on a macro scale contribute to increasing entropy in the ecosystem, there are communities that live in close harmony with nature and rarely disturb the process of disturbing the ecological balance. nor do they use natural resources


at a rate that goes beyond their natural growth rate, nor do they generate wastes that are highly biodegradable and therefore beyond nature’s own ability to absorb. However, these micro-entities are not powerful enough to influence the discussion on what measures should be taken to bring about a balance between economics and ecology in order to keep Mother Earth a habitable planet on a sustainable basis. As a result, they are held hostage by both groups professing economic imperialism and ecological reductionism and are often cut off from the close relationship they have maintained with nature since ancient times. Arguments in the context of collective action demand their effective inclusion in the process of dialogue.


steady state subsystem

The idea of a steady state subsystem has its origins in John Stuart Mill (1857), who coined the concept of a steady state – when both the rate of population growth and the growth rate of capital accumulation are zero. Zero rate of growth of population would mean equality between birth and death rates, whereas zero rate of increase in capital stock would mean output equal to depreciation. However, such a state would need to equate rates at a low level, reflecting high human longevity and the durability of goods and services produced, subject to the maintenance of sufficient stocks for a high quality of life.



Differences in approach also feed the divergence in the methodological toolkits available to economists and ecologists to tackle the issue of sustainable development. Recent efforts to develop “Green National Accounts” are a step in the right direction. The “Inclusive Wealth Report 2014”, prepared by a group of experts led by Partha Dagupta, also seeks to fill some of the data gaps with a well-thought-out framework for conceptualizing inclusive wealth that will put us on the path to sustainable development. as well as thrive in an inter-generational tandem to ensure intra-generational equity.


However, there are some methodological challenges to identifying the desired pathways to achieve a reconciliation between economics and ecology. A conceptual framework that facilitates understanding of the relationship between humanity and nature at the micro level and is capable of being extrapolated to the macro level is the urgent need of the day. Otherwise we will be trapped in arguments seeking solutions that deliver the highest social and environmental returns in our pursuit of sustainable development. Needless to add, such an approach would fail to separate the effects of macro policies on the multiplicity of species and human communities from those at the micro level. Furthermore, there is a need for a welfare economics framework that includes nature as a key stakeholder. looking at many


The non-convexity and non-linearity found in the production and consumption behavior of nature and the rest of its non-human species, the conceptual challenge will be difficult.



Due to pollution of water, air and land on daily basis the carrying capacity of the earth has become very high. Scientists, scholars and even governments around the world have realized that the global environment is changing rapidly as a result of global warming and climate change induced by human industrial and domestic emissions of greenhouse gases. Related environmental crises such as floods, desertification, drought, loss of biodiversity, erratic rainfall patterns, overgrazing, pollution, and so on have affected the lives of millions of people across the world. Millions of livelihoods have been destroyed, cultures have changed, communities have been displaced as the effects of climate change devastate communities globally. The nature of climate change suggests that the global environment is at risk and human societies are at greater risk as human beings themselves are at risk; This is because

Because environmental problems respect no national boundaries, they can be local in cause but global in effect.

Man’s contribution to this environmental quagmire cannot be overemphasized, since the advent of the Industrial Revolution in 18th and 19th century Europe and the spread of industrialization around the world, the incidence of environmental degradation has skyrocketed. Therefore, to understand contemporary global environmental problems, one must first understand the nature and operation of modern industrial society. One may ask what is the concern of sociology with the study of environmental problems. Did the classical sociologists include environmental issues in their theorizing? The answer to these questions is not far-fetched, if sociology studies the interaction of human society and human groups, and human society does not exist in a vacuum, it operates within a limited space called the environment, and both




Institutions influence and shape each other’s existence, so the environment is the subject of sociological investigation. The sub-discipline that studies this society-environment-relationship is called environmental sociology. According to Catton and Dunlap (1978 cited in King and McCarthy 2009: 9) environmental sociology should examine how humans change their environment and also how they are affected by their environment. He developed a “new ecological paradigm”, which represented an early attempt to explore society-environment relationships. This new ecological paradigm is a conscious attempt to challenge the perceived anthropocentrism of classical sociology (i.e. the emphasis on environmental processes in early sociological theory) by including environmental forces as objective variables in social explanations (Gross and Heinrich, 2010: 3). ) Anthony Giddens (2009: 159) supported this stand when he argued that the founders of early sociology – Marx, Durkheim and Weber – paid little attention to what we now call ‘environmental issues’ (p. 159).


In contrast, Butel (1986 cited in Hannigan 2006:8) believes that arguably the trinity of Marx, Durkheim and Weber had an underlying environmental dimension to their work, although this was never brought to the fore , largely because their American translators and interpreters favored social structural interpretations over physical or environmental interpretations. However there have been attempts to show that classical sociologists captured the society-environment relationship in their theory and these include the work of Caton 2002; West 1984; Bellamy Foster 1999; Dickens 2004; Dunlop et al. 2002; Murphy 1997; Verdu 2010 and so on. Accordingly, Giddens (ibid) believes that the role of sociology in the study and analysis of environmental issues can be summarized as follows: First, sociology can provide an account of how patterns of human behavior interact with natural processes. create pressure on the environment; Second, sociology can help us understand how environmental problems are distributed. Third, sociology can help us evaluate policies and proposals aimed at providing solutions to environmental problems.


There is no generally accepted definition of the term environment among scholars and this is because the term environment means different things to different people (Sibiri 2009). For Enger and Smith (2004), the environment is anything that affects an organism during its lifetime. From this point of view, the environment encompasses the web of relationships of human beings. whatever human beings do, whether in a social, economic, political, technological, cultural or religious context




Guided by the limits of your environment. Similarly, Cunningham and Cunningham (2004) state that environment refers to all the circumstances and conditions that surround an organism or group of organisms. He extended his definition of environment in terms of social and cultural conditions.




that affect an individual or a community. According to Varika (cited in Okaba 2005) although environment means different things to different people, it is defined as a physical environment, conditions, circumstances etc. in which people live. For him, the environment includes nature which is the physical part of the physical world including all the phenomena of the physical world including plants, animals, landscape, etc. and the entire ecosystem, the biological community of interacting organisms. Waripamo (cited in Jack 2014) states that the environment is more concerned with the conditions that support the existence of human beings.


  For him, environment means a large set of elements which include water, air, land and all plants and man himself; the other animals living in it and above all the interrelationships that exist between these or any of them. Overall, the way one views the environment, it is the total conditions that surround an organism (biological or social) during its life that facilitate or hinder the development and survival of that organism.



components of the environment

Burstein, J. (1996) claimed that environment is made up of two categories; living and non-living. He called the living component of the environment “biotic”, which includes plants, birds, mushrooms, insects, etc. on

Other non-living components of the environment, which he called “abiotic”, include things such as water, soil, air temperature, air, and wind. the sunlight. He emphasized that the environment is an interaction of biotic and abiotic factors.

These biotic and abiotic components of the environment are further divided into four categories:

  1. Lithosphere (Land): Outer layers of earth’s soil e.g. Rocks, sediments and soil.
  2. Atmosphere (Air): The layer of gases that extends from the surface of the earth to the outer limits of our planet for about 100 km.
  3. Hydrosphere (Water): The layers of water that cover our planet oceans, lakes, rivers, streams and ice sheets Ice and water in the soil.




  1. Biosphere: It is the thinnest layer, consisting of organic matter such as plants and animals. This layer covers most of the land surface and extends into the atmosphere and into deep water bodies. Human beings are part of the biosphere and exist by interacting with the other three spheres.

An environment is therefore a system or community of biotic and abiotic components that are maintained by the interactions of food chains and energy cycles as seen in food webs.



Environment – Society Relations

The history of man and human society can be clearly described, characterized by the continuous interaction between man and his environment. It is interesting to note that this interaction between humans and the environment has been constant over time and the nature of this interaction is changing as human societies undergo changes in their organisation, structure and advances in technology (Sibiri 2009). Human society does not exist in a vacuum but within a physical environment, so the importance of this relationship is underlined in the sense that human existence is entirely dependent on the environment to maintain its welfare needs (food, shelter). depends on capacity. more clothes). Environmental sustainability, on the other hand, is also bound by man’s judicious use of the physical environment and its innumerable resources, which ensure and guarantee the real source of man’s continued existence (Okaba 2005).

However, as the human population grows, with associated urbanization and technological advancement, man has not been as judicious in his use of environmental resources (food, water, energy, mineral resources, forests and wildlife) over time as he has been able to sustain his basic needs. Struggles to meet needs. In an effort to meet the growing demands of a larger society, it encroaches on the environment.


Therefore, the relationship between man and his environment can be measured and summarized by defining the functions of the environment. Thus, Schaefer and Laman (1986) pointed out three basic functions of the environment which are basic prerequisites for human life, these include: (a) that the environment provides essential resources for life (air, water and raw materials) provides; (b) that the environment also serves as a waste reservoir, e.g. body waste, garbage and sewage; (c) Human beings and other living organisms live in it.

Therefore, as highlighted above, the interaction of man with the environment is based on the ability of the environment to provide these three basic functions to man and his society. Historically,




The human population was small and life was simple. The human waste was purely organic i.e. biodegradable material, which acted as a source of food for the decomposers. The relationship between man and his environment was reciprocal and symbiotic because an ecological system exists in balance and equilibrium. However, environmental pollution began to occur as the population grew, generating more waste than the ecosystem could absorb. to improve human society

Advanced technological inventions to exploit natural resources, which subjugated the ecosystem. Agriculture alters the species mix, timber harvesting for industry leads to deforestation, grazing of arid and semi-arid lands leads to desertification, aquatic ecosystems are polluted by agricultural chemical runoff and industrial waste destroys biodiversity. Habitat loss and extinction result from the inability of species to adapt to changes in their environment. Rapid population growth has resulted in increased demands on Earth’s resources, leading to rapid environmental degradation, and potentially leading to severe global climate change.


  Human impact on the land has been immense, as land-use has changed, natural vegetation has been cleared for agricultural use and urbanization has increased, resources have been created, minerals extracted, and more for recreational purposes. The land has been developed. Widespread concern is now expressed over the deforestation of boreal and tropical forests, the degradation of grasslands, land and wetlands, and desertification. Such destruction of natural ecosystems has resulted in decreased biodiversity, and soil depletion, In efforts to counter the harmful effects of land abuse in the regions, exotic plants and animals are being carefully monitored and They are being encouraged. Human influence on the soil has also caused some significant damage, usually due to poor agricultural practices, excessive drainage, poor irrigation, and compaction by heavy vehicles and animals. Cumulative of

The effects can be devastating for countries whose economies are heavily dependent on agriculture.


Correcting these poor practices and improving soil quality require an understanding of soil chemistry and nutrient supply cycles. Oceans and seas cover more than two-thirds of the Earth’s surface. It is thought that life almost certainly evolved from the sea and that there is more species diversity in the sea than anywhere else on Earth. Many food chains and food webs begin with organisms living in the seas and oceans. The ocean-atmosphere system controls the global climate. This is a sensitive thermostat. The seas and oceans are rich in food and mineral resources. However, over-exploitation and population




Threat to this huge life. Humans think that the vastness of the ocean makes it an ideal place for virtually every type of waste, including toxic chemicals and nuclear waste. Exploiting the Earth’s resources inevitably produces waste, some of which may be hazardous or toxic. For the past few decades, most waste has been disposed of without any real concern for damage to ecosystems and often under the auspices of “not in my backyard”.




The science of ecology deals with the study of organisms in their environment and their relationships with each other. Here the term ‘environment’ refers to the surrounding world, which includes all entities, both living and non-living, that surround a living entity.

The word ‘ecology’ is derived from the Greek words oikos, meaning household and logos, meaning study. Thus ecology means the study of life at home or the interrelationships and interdependence of plants, animals, microbes and their environment. Because ecology is specifically concerned with the biology of groups of organisms and their functional processes in land, water, and air, it can also be defined as the study of the structure and function of nature. Ecology as a distinct field of knowledge emerged in the early years of the last century. In its early stages, ecology was considered synonymous with natural history.

Y or nature study. With the greater documentation of observations by students of nature studies, the importance of “quantification” of data came into force. Since then several definitions for the term have been proposed by various authors. Some definitions are:

  1. Ecology is the sum total of the relations of organisms to the surrounding external world, to organic and inorganic conditions of existence (Haeckel, 1886).
  2. Ecology is the study of organisms in relation to their environment (Warming, 1895).
  3. Ecology is the scientific natural history concerned with the sociology and economics of animals (Elton, 1927).
  4. Ecology is the science of the relationship of all organisms to their environment (Taylor, 1936).
  5. Ecology is the interaction of forms, functions and factors (Mishra, 1967).
  6. Is the study of the structure and function of the ecosystem (Odum, 1969).
  7. Ecology is the scientific study of the interactions that determine the distribution and abundance of organisms (Kerbs, 1985).






Just as cells are grouped into tissues and tissues into organs and then systems, organisms can also be grouped into groups. A population is a group of organisms of the same species that live in an area during a specific period of time. A species is considered to be a group of organisms that are able to breed with each other under natural conditions and produce fertile offspring. For example, mosquitoes on the surface of a pond in spring and maple trees in a Vermont forest in autumn form two populations.

Populations can be grouped together. All populations of different species interacting with each other within an area form a community. All the protists, plants and animals interacting on a coral reef make up a reef community.

Within a community, each organism is found in a specific niche. Habitat is the environment of a particular type of organism. For example, ferns are found in moist, shady floor habitats of a forest community.


The habitat of some snails is the leaf litter on the forest floor. In a pond community, a frog’s habitat is near the water’s edge and includes both water and land. Trout fish live in a single community in the deeper, cooler part of the pond.

All biological, chemical and physical factors of a species’ environment are part of its niche. Niche includes what a species needs to survive and reproduce in its environment. Which animals do they eat? How do they get food? How do they attract mates? Where do they live? And what do they do in their environment? Make a niche Habitat is part of an organism’s niche. Ahabitat is sometimes considered the address of the species. Niche is the lifestyle or occupation of a species.

Habitats often overlap and different organisms can be found in the same place. However, no two species can live in the same place at the same time for very long. If they do, they start competing for the same basic and essential needs. We might think that birds have only one place within a tree. If you look carefully, you will find that some birds are insects.

Some eat the seeds while some eat the seeds; Some feed under the tree while others feed in the tree. Some birds also get their food away from the trees. Birds can also have different methods of reproduction. They may have different mating behaviours, and may nest in different places.





Introduction to the concept of ecosystem – What is ecosystem?

In 1935 A.G. The term ecosystem was proposed by Tansley, who defined it as ‘a system resulting from the integration of all living and non-living factors of the environment’. Environmental factors. Thus any unit that includes all the organisms i.e. the community in a given area, interacting with the physical environment so that the flow of energy drives the clearly defined trophic structure, biological diversity and physical cycles within the system is called an ecological system or ecosystem. is referred to as. Ecosystem is the structural and functional unit of ecology. Being a structural unit, an ecosystem has well-defined sub-structures and boundaries, and being a functional unit, it serves as a medium and platform for many processes necessary to maintain steady state equilibrium. Works in Several definitions of ecosystem are available in the literature and these differ depending on its usage and the purpose of its use. Originally the term ecosystem originated from biology and refers to a self-sustaining system. From the perspective of economics and sociology, which are closely related to ecology, the term ecosystem refers to the relationships established among different countries and industries for mutual benefit and sustenance. Ecosystem is also defined as the complex of living organisms, the physical environment and all their interrelationships in a particular unit.

Ecosystem studies are based on the assumption that all life supporting elements, weather natural or anthropogenic, are integral


The part of a network where elements interact. All ecosystems are contained within the largest of all ecosystems, called the ecosphere, which includes the entire physical Earth called the geosphere and all living components called the biosphere.

An ecosystem consists of the biotic community that occurs in an area, and the physical and chemical factors that make up its non-living or abiotic environment. There are many examples of ecosystems such as a pond, forest or grassland. Boundaries are not easy to determine, although sometimes they may seem obvious, such as along the shoreline of a small pond. Usually the boundaries of an ecosystem are chosen for practical reasons related to the goals of the particular study.

The study of ecosystems primarily deals with the study of some of the processes that link living, or biotic, components with non-living, or abiotic components. Energy transformation and biogeochemical cycles are the main processes that comprise the field of ecosystem ecology. There is no size limit to the ecosystem. They can be as large as a desert or as small as water droplets on a plant leaf.


Plants, soil bacteria, soil nutrients, air space, and light and temperature are all part of an interacting system within a garden.

An ecosystem is self-sustaining when three conditions are met. First, it must have a relatively stable source of energy. Sunlight supplies energy to most ecosystems. Second, the energy in biological molecules must be converted into chemical bond energy by a living system. Plants, algae and some groups of bacteria accomplish this through the process of photosynthesis. Third, organic matter and inorganic nutrients must be recycled for reuse. In most ecosystems, this recycling is done by decomposers.

An ecosystem becomes unstable when any of these three conditions are affected. For example, if the flow of energy from the sun is interrupted, photosynthesis is affected. Without plant food, other organisms and the plants themselves would die. If essential nutrients are unavailable or if some species die out, the ecosystem may lose its ability to sustain itself. To remain stable, an ecosystem needs to maintain a dynamic balance between its biotic and abiotic factors.

Ecological systems are always open i.e. there is an exchange of energy and matter (or input-output relationship) with neighboring systems. Collier et al. distinguished four levels of






Organization in Ecosystem:


  • Organism level: At this level, ecological studies focus on the study of individuals and are mostly concerned with the physiology, reproduction, development or behavior of individual members of a species or ecosystem.


  • Population Level A population is a group of individuals of a species living in a certain area. Such groups exhibit characteristics that cannot be explained at the organismal level. The study of populations typically focuses on the habitat and resource needs of individual species, their group behavior, population growth, and whether their abundance is limited or threatened by extinction.

Causes, but focuses.



  • Level of communities: A community is an assemblage of different populations within a certain area. The interaction between populations is very important for the structure of the community. The study of communities examines how populations of multiple species interact with each other, such as predators and their prey, or competitors that share common needs or resources. So in ecology the term “population” refers to all the members of a particular species within an ecosystem, while “community” is the collection of all the different populations of different species living in an ecosystem.


  • Ecosystem Level: An ecosystem is a system in which communities interact with the abiotic environment. In ecosystem ecology we put all the levels together and try to understand how the system operates as a whole. This means that instead of worrying primarily about particular species, we try to focus on key functional aspects of the system. These functional aspects may include the amount of energy produced by photosynthesis, how energy or materials flow along multiple steps in a food chain, or controlling the rate at which materials are decomposed or the rate at which nutrients are recycled. things are included. Arrangement
  • According to the above definition of ecosystem, the earth itself can be considered as an ecosystem. However, for the convenience of study, it is common to limit the range of ecosystems to more easily recognizable units such as a forest, or a lake.










– the population of all the different species living in a particular place




  components of an ecosystem

All ecosystems have two main ‘parts’: the living (biotic) part and the non-living (abiotic) part.

biological factors

Biotic components are living organisms classified on the basis of the way they obtain nutrition. Within an ecosystem, organisms that make food by photosynthesis are called producers and plants, some protists and some monerans use energy from the sun in this process. Producers become food and energy sources for consumers. Consumers are organisms that eat other living things. These include animals, fungi, bacteria and some protists.

Consumers that feed directly on producers are called primary consumers. Primary consumers are food for secondary consumers. Animals that obtain almost all of their food resources from plant matter are called herbivores. Secondary and higher level consumers who obtain most of their food by eating the flesh of other animals are called carnivores. Omnivores eat both plants and animals.


Decomposers are the consumers who break down the remains and wastes of plants and animals. They break down organic matter, making its parts available for reuse. The most common decomposers are bacteria and fungi. Scavengers are animals that eat the dead bodies of other animals. Saprobes are organisms that obtain their nutrition from plant and animal remains.

Energy flows through an ecosystem when organisms eat. A high level of consumers is not required for an ecosystem to be self-sustaining.

Producers are called autotrophs, meaning “self-feeders” because they “feed themselves” by making food in the process of photosynthesis. Autotrophs, such as plants, convert inorganic sources of energy into organic forms. Consumers are called heterotrophs meaning “other-feeders” because they feed on other organisms. Heterotrophs require organic molecules to carry out their life functions.


abiotic environment

Abiotic Components: The various physico-chemical components of the ecosystem make up the abiotic composition:

(i) Physical components include sunlight, solar intensity, rainfall, temperature, wind speed and direction, availability of water, soil texture, etc.

(ii) Chemical constituents include major essential nutrients like C, N, P, K, H2, O2, S etc. and micronutrients like Fe, Mo, Zn, Cu etc., toxic substances like salts and pesticides.

These physico-chemical factors of water, air and soil play an important role in the functioning of the ecosystem. The abiotic components of an ecosystem including all the physical and chemical factors present in the ecosystem determine the types of organisms that live in a particular environment and affect the biotic components. In an ecosystem, biotic communities interact with non-living environments. Abiotic environmental factors control the distribution, size, reproduction, nutrition and overall metabolism of living communities.

  limiting factor

The effect of environment on plant growth can be easily seen in gardens and house plants. Many plants grow best in fertile, well-draining soil, while others have developed

To grow in more extreme soil conditions. Some plants are shade tolerant; Others thrive under lots of daily sunlight. Gardens and houseplants represent small-scale ecosystems that we can affect by changing the environment.

Can cry One of the characteristics of an ecosystem is that under normal conditions its growth is limited by competition for resources within the system and by external factors such as environmental change. If the presence or absence of a factor limits the growth of the elements of the ecosystem, it is called a limiting factor. There are many fundamental factors that limit the development of ecosystems, including temperature, precipitation, sunlight, soil composition, soil nutrients, etc., which play a major role in the distribution of plant and animal communities and keep on changing. These changes affect the well-being and survival of organisms in an ecosystem because they thrive as long as all the necessary factors for life are available. Maybe someone has tried growing houseplants outside and found that the sun burned the leaves. Perhaps we forgot to water the plants in your garden and we found that they withered or died in the summer heat.


Different plant species have different light requirements. Ferns on the forest floor require shade or diffused sunlight. Other plants, such as desert cacti, require bright light. The intensity and duration of light affect the growth and distribution of plants. At the equator, plants receive 12 hours of light per day. In Alaska, plants receive 22 hours of light each day in the middle of summer and about 2 hours each day in the middle of winter.

Light energy (sunlight) is the primary source of energy in Nia

Flow ecosystems. This is the energy used by green plants (which contain chlorophyll) during the process of photosynthesis; A process during which plants combine inorganic substances to form organic substances. Visible light is of greatest importance to plants as it is essential for photosynthesis. Factors such as light quality, light intensity and light duration (day length) play important roles in an ecosystem.

  • Quality of light (wavelength or color):

Plants absorb blue and red light during photosynthesis. The quality of light does not change much in terrestrial ecosystems. In aquatic ecosystems, the quality of light can be a limiting factor. Both blue and red light are absorbed and as a result cannot penetrate deep into the water. To compensate for this, some algae have additional pigments which are


Capable of absorbing other colors as well.

  • Light intensity (“Light power”)

The intensity of light reaching the earth varies with latitude and season of the year. The Southern Hemisphere receives less than 12 hours of sunlight during the period between March 21 and September 23, but receives more than 12 hours of sunlight during the following six months.

  • Length of day (length of light period):

Some plants flower only at certain times of the year. One reason for this is that these plants are able to “measure” the length of the night (the period of darkness). However, it was thought that it is the length of the day (light period) to which plants respond and this phenomenon is called photoperiodism. Photoperiodism can be defined as the relative length of daylight and darkness that affects the physiology and behavior of an organism.

  • Short-day plants

These plants flower only when they experience nights that are longer than a certain critical length. Chrysanthemum (Chrysanthemum sp.), poinsettia (Euphorbia pulcherrima) and prickly apple (Datura stramonium) are examples of short day plants.

  • Long Day Plants

These plants flower if they experience nights that are shorter than a certain critical length. Spinach, wheat, barley, clover and radish are examples of long day plants.

  • day-neutral plants

Flowering of day-neutral plants is not affected by the length of the night. Tomato (Lycopersicon esculeutum) and maize plant (Zea mays) are examples of day-neutral plants.

The following definitions are also important:


Phototropism is the directional growth of plants in response to light where the direction of the stimulus determines the direction of movement; stems display positive


Phototropism means when they grow up they turn towards the light.

  • Phototaxis

Phototaxis is the movement of an entire organism in response to a unidirectional light source, where the stimulus determines the direction of movement.

  • Photokinesis

Variation in the intensity of the locomotory activity of animals that depends on the intensity of the light stimulus, and not on its direction, is called photokinesis.

  • Photonasty

Photonasty is the movement of parts of a plant in response to a light source, but the direction of the stimulus does not determine the plant’s direction of movement.

Plants have different light requirements and as a result different layers or stratification can be seen in the ecosystem. Plants that grow well in bright sunlight are called heliophytes (Greek helios, sun) and plants that grow well in shady conditions are known as psychrophytes (Greek skeia, shade).


Temperature affects the rate of metabolic processes, reproduction and survival of plants. air temperature difference

Creates wind movement that moves moisture towards or away from plants. Air temperature determines the amount of water vapor and other gases that air can hold. Soil temperature determines the rate of water absorption by plant roots and the rate of root development.

The distribution of plants and animals is affected by extreme temperatures, for example hot weather. The presence or absence of frost is a particularly important determinant of plant distribution because many plants cannot prevent their tissues from freezing or survive the freezing and thawing process. The following are examples of temperature effects with ecosystems:

  • The opening of flowers of different plants during the day and night is often due to the temperature difference between day and night;


  • The seeds of some plants (biennials) usually germinate in spring or summer;

This phenomenon is well observed in carrots and is called vernalization;

  • Some fruit trees, such as peaches, require a cold period each year to bloom in spring;
  • Deciduous trees lose their leaves in winter and go into a state of dormancy, where the buds are covered to protect them from the cold;
  • Seeds of many plants, eg. Peaches and plums must be exposed to cold periods before they germinate; it cold

ensures that the seeds do not germinate during autumn, but after winter, when the seedlings have better chances of survival;

  • In animals, a distinction is made between ectothermic (“cold-blooded” or poikilothermic) animals and endothermic (“warm-blooded” or isothermic) animals, although the distinction is not clear;
  • Desert conditions have greater temperature variation between day and night and organisms have different periods of activity, eg. Many cacti flower at night and are pollinated by nocturnal insects;
  • Seasonal changes also have a great impact on animal life in the ecosystem; Hibernation is common in reptiles and some mammals in southern Africa, but bears in the Northern Hemisphere hibernate; Some animals store fat or other resources during favorable periods (often summer and autumn) and become inactive (this is called hibernation), there are also animals that remain inactive in hot and dry conditions and this is called hibernation. Known as beautification; Examples of such animals are snails and the African lung-fish;
  • Some animals have seasonal movements; This phenomenon is called seasonal migration, examples of such animals are migratory locusts, butterflies and various marine animals such as whales, penguins and sea turtles.


The distribution of the species depends on the humidity. Some creatures live in rain forests where it rains daily. Others are adapted to life in deserts where water is scarce. Well aerated soil is full of air passages allowing movement of gases like


Oxygen, carbon dioxide and nitrogen. Moisture clings to the surfaces of soil particles, creating conditions that support bacteria, fungi and protists. These soil microbes make chemical nutrients available to the plants. Some microbes use up the nutrients, thus slowing plant growth.

Plant and animal habitats vary from completely aquatic environments to very dry deserts. Water is essential to life and all living beings depend on it for survival, especially in desert areas.

  • Water Requirements of Plants

Plants can be classified into 3 groups according to their water requirement: Hydrophytes: Hydrophytes are plants that grow in water. Water lilies and reeds. Mesophytes: Mesophytes are plants with average water requirement e.g.

Rose, Sweet Pea.

Xerophytes: Xerophytes are plants that grow in dry environments where they often experience water scarcity eg. Cacti and often succulents.

Plant adaptations to survive without water include reverse stomatal rhythm, sunken stomata, thick cuticles, small leaves (or absence of leaves), and the presence of water-storing tissues.

  • Water requirements of animals

Terrestrial animals are also exposed to desiccation and some interesting adaptations are mentioned here:

  • Water loss is limited by covering the body eg. chitinous body covering of insects, scales of reptiles, feathers of birds and hair of mammals;
  • Some mammals have few or no sweat glands and use other cooling devices, which are less dependent or independent of evaporative cooling;
  • Animal tissues can be tolerant to water deficit eg. The camel can live without water for long periods because of this adaptation in its body tissues;
  • There are also known cases where insects are able to absorb water


Water vapor directly from the atmosphere for example dew from coastal fog is an important source of moisture for the insects of the Namib.

Atmospheric gases.

The most important gases used by plants and animals are oxygen, carbon dioxide and nitrogen.

  • Oxygen: Oxygen is used by all living organisms during respiration.
  • Carbon dioxide: Carbon dioxide is used by green plants during photosynthesis.
  • Nitrogen: by some bacteria and through the action of electricity

Through this nitrogen is made available to the plants.


Global-scale winds or air currents result from a complex interaction between the expansion and upwelling (convection) of warm air in the mid-latitudes. This has various effects on the Earth’s rotation and results in a centrifugal force that lifts the air at the equator. This force is known as the Coriolis force and deflects winds to their left in the Southern Hemisphere and to their right in the Northern Hemisphere. Winds carry water vapor that can condense and fall as rain, snow, or hail. Wind plays a role in the pollination and dispersal of seeds of some plants, as well as the dispersal of some animals such as insects. Wind erosion can remove and redistribute topsoil, especially where vegetation has been reduced. The hot berg winds result in dryness which creates a fire hazard. If plants are exposed to strong prevailing winds they are usually smaller than plants in less windy conditions.




soil (edaphic factor)

These factors include soil texture, soil aeration, soil temperature, soil water, soil solution and pH, as well as soil organisms and decaying matter.


  • The size of soil particles varies from microscopic particles called clay to larger particles called sand. Loamy soil is a mixture of sand and clay particles. Sandy soils are suitable for growing plants because they are well aerated, excess water drains quickly, they heat up quickly during the day and are easy to cultivate. Sandy soils are unsuitable because they do not hold much water and dry out quickly, and the soil nutrients needed for plant growth are low.


  Clay soils are suitable for plant growth because they hold large amounts of water and are rich in mineral nutrients. They are unsuitable because they are badly aerated, quickly become waterlogged and are difficult to cultivate; It is cold even during winters. Loamy soil has desirable properties of both sand and clay – it has high water holding capacity, good aeration, good nutrient content and is easily cultivated.


  • Soil Air: Soil air is found in the spaces between the soil particles that are not filled with soil water. The amount of air in soil depends on how firmly the soil is compacted. Well-aerated soil has at least 20% of its volume composed of air.
  • Soil temperature: Soil temperature is an important ecological factor. It is found that the soil temperature below a depth of about 30 cm remains almost constant


During the day but there is a difference in seasonal temperature. Little decay occurs by decay-causing micro-organisms at low temperatures.

  • Soil water: Soil water can be classified into three types, namely hygroscopic, capillary and gravity water. Hygroscopic water forms a thin film of water around each soil particle. Capillary water is water that is held in the small spaces between soil particles and gravimetric water is water that flows downward through the soil.


  • Soil slurry: Soil slurry is the decaying remains of plants and animals, together with animal excretory products and faeces, forming humus. This increases the fertility of the soil.


  • pH: The acidity or alkalinity of the soil (soil pH) affects biological activity and the availability of certain minerals in the soil. Thus soil pH has a greater impact on plant growth and development. Some plants such as azaleas, Ericas, ferns and many Protea species do best in acidic soils (soils with a pH below 7), while lucerne and many xerophytes do better in alkaline soils (soils with a pH above 7).



geographic factor

These factors are related to the physical nature of the area, such as altitude, slope of the land, and the position of the area with respect to the sun or rain-bearing winds. Elevation plays a role in vegetation zones. Slopes are important when considering soil surface temperature on north-sloping land, on the plain and on south-sloping land. In South Africa the rain-bearing south-eastern slopes are covered by forest in some areas, while the windward slopes are rain-shadowed and thorny shrubs are often found growing on these slopes. A very good example of this is the south east wind blowing in Cape Town.



  laws governing limiting factors

  1. The “law” of big lies minimum:

The required material available will be limited to amounts approaching the minimum required amount required under “steady state” conditions and the concept is


Also called Liebig’s minimum rule. According to the law, the growth of crop plants depends on the amount of nutrients which are available in minimum quantity. He therefore came to the conclusion that plant growth is limited by essential nutrients that are in short supply relative to the plant’s needs. Liebig focused more on factors such as light, temperature, nutrients and essential elements. He explained the absence of some plants in the shaded areas on the Alps or the lack of vegetation above certain altitudes.

Tried to They gave justification in terms of insufficient light, temperature or nutrients. His hypothesis was that crop yields are often limited not by nutrients that are in abundant supply such as carbon dioxide and water, but by others that are needed in lesser amounts and are in short supply such as zinc in modern agriculture. This rule of minimum is less applicable under “transient state” conditions, when the amounts, and hence the effects, of multiple components are changing rapidly.


Shelford’s Law of Tolerance:

In 1913 V.E. Shelford expanded the concept of limiting factors to include the limiting effect of maxima as well as minima on organisms. He proposed that not only can a factor be limiting in small amounts, but very high amounts can also prove detrimental to the growth and development of an organism. Thus, any environmental factor that is below the critical minimum requirements or above the critical maximum requirements of an organism will certainly limit the growth of the organism in a given region. In other words attendance and success

The state of an organism depends on the fulfillment of a complex of conditions. The absence or failure of an organism to be controlled by a qualitative or quantitative reduction with respect to any one of a number of factors may approach the tolerance limit for that organism.

Organisms have ecological maximum and minimum requirements for each environmental factor. These are the limits of tolerance of the organism to that factor. According to the law of tolerance, each environmental factor has two zones i.e. zone of tolerance and zone of intolerance (Nair, 1990).

  1. i) Zone of tolerance is the zone which is favorable for the growth and development of the organism and is made up of parts
  2. a) Optimum area which is most favorable for growth and development



Life is maximum.

  1. b) The critical minimum area and the minimum limit of any environmental factor beyond which the growth and development of the organism ceases.
  2. c) Critical maximum zone is the maximum limit of any environmental factor beyond which organisms usually stop their normal activities.
  3. i) Intolerable Zone: This zone is well below the critical minimum zone and above the critical maximum zone. This region is unfavorable for the growth and development of organisms and they cannot survive here for long.


  Combined Concept of Limiting Factors:

The survival and success of an organism or group of organisms depends on a complex set of conditions. A more general and useful concept of limiting factor can be obtained by combining the idea of a minimum and the concept of limiting factors. It is based on i) the quality of the material which is the minimum requirement and the physical factors which are important and ii) the tolerance limits of the organisms to the different components of the environment (Odom, 1971).



Conditions of existence as regulatory factors:

Light, temperature and water are important ecological environmental factors on land; Light, temperature and salinity are the big three in the ocean. Other factors such as oxygen in fresh water may be of major importance. All these physical conditions of existence can be limiting factors not only in the harmful sense, but also regulatory factors in the beneficial sense – that is, adapted organisms respond to these factors in such a way that the community of organisms maintains maximum homeostasis under the conditions. receives. Blackman (1912) stated that a process is affected by a number of factors and the rate controlling ones are slowest and are known as limiting factors.







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