Read this essay to learn about ecology. After reading this essay you will learn about: 1. Introduction to Ecology 2. History and Scope of Ecology 3. Definitions 4. Origin of Ecological Crises 5. Four Laws 6. Objectives 7. Subdivisions 8. Community Ecology 9. Rules.
- Essay on Introduction to Ecology
- Essay on the History and Scope of Ecology
- Essay on Definitions of Ecology
- Essay on the Origin of Ecological Crises
- Essay on the Four Laws of Ecology
- Essay on the Objectives of Ecological Study
- Essay on the Subdivisions of Ecology
- Essay on Community Ecology
- Essay on Rules in Ecology
Essay # 1. Introduction to Ecology:
Every organism invariably depends upon the environment and other organism for its existence. It either eats other organisms or is eaten by others and competes with other for the necessities of life such as food, shelter and mate survival requires group association.
Such associations and concept of organisms and their environment in general constitute the science of ecology. The word ecology was coined by Ernst Haeckel in 1869 and is derived from two Greek words oikos meaning house or place of living and logos meaning study of.
The field of ecology deals with the influence of environmental factors on all the aspects of life such as morphology, physiology, growth, distribution, behaviour and survival of the organisms. Ecology or environmental biology pertains to the study of relationship between various organisms and their environment. This includes consideration of plants, animals and human beings.
Essay # 2. History and Scope of Ecology:
The word “Ecology” derived from the Greek words “Oikos” meaning habitation, and “logos” meaning discourse or study, implies a study of the habitations of organisms.
Ecology was first described as a separate field of knowledge in 1866 by the German Zoologist Ernst Haeckel, who established the relationship of the animals to its organic as well as its inorganic environment, particularly its friendly or hostile relations to those animals or plants with which it comes in contact.
In due course ecology was defined as “A study of animals and plants in their relations to each other and to their environment”.
Ecology can be considered on a wider scale moving from an individual molecule to the entire global ecosystem.
However, four identifiable subdivisions of scales are of particular interest:
(iii) Communities and
At each scale, the subjects of interest to ecologists change. At the individual level the response of individuals to their environment (biotic and abiotic) is key issue, while at the level of populations of a single species, species-species interaction is important.
In recent years it was realised that ecology is an interdisciplinary science, though its body of knowledge lies in biology yet its interaction with other disciplines are quite prominent. There are different approach for understanding the ecological sciences (Table 1.1), this include the study of ecology from the stand point of conceptual understanding, from organisms involved or habitat condition or even from point of application.
Each categories of ecological studies requires specialized understanding. As the science progressed much with time, the conceptual understanding became more and more complex and interactive.
There are many characteristics in ecological science.
Essay # 3. Definitions of Ecology:
Ecology has been defined in various ways:
i. Ecology is the study of an organism and its environment.
ii. The study of interrelationship of organism or groups of an organism to their environment is called ecology.
Human ecology is a social science that studies the relationship between man and its environment. It studies the relationship between human biological factors and the natural environment.
Social ecology studies the relations among natural environment, population, technology and society.
The physical and the biological world that we live in is our environment.
The activities of various organisms in the environment which interact with each other are so finely balanced that they are in equilibrium in a steady state. This is known as ecological balance.
The principal causes for ecological degradation are drastic changes in the technology of agricultural and industries production and transportation.
Essay # 4. Origin of Ecological Crises:
i. Exploding population
ii. Affluent and wastefulness.
The affluent society has become an efficient society.
iii. Man’s is made aggressiveness
Essay # 5. Four Laws of Ecology:
i. Everything is connected to everything else.
ii. Everything must go somewhere.
iii. Nature knows best.
iv. There is no such thing as a free launch.
The word is perceived notes a collection of isolated objects but as a network of phenomena that are fundamentally interconnected and interdependent.
It views humans as above or outside of nature as the source of all values and prescribe only instrumental or use value to nature.
Feminist Ecology and Echo Feminism:
It links the exploitation of nature with that of women and women’s history with the history of the environment.
Industrial process resembles those of a natural eco system where in materials and energy circulates continuously in a complex web of interaction. Microorganisms turn animal waste in to food for plants which are either eaten by animals or enter the cycle through death and decay.
Essay # 6. Objectives of Ecological Study:
The main objectives of this science are to study:
i. The inter-relationships between organisms in population and diverse communities.
ii. The temporal changes (seasonal, annual, successional etc.) in the occurrence of organisms.
iii. The behaviour under natural conditions.
iv. The structural adaptations and functional adjustments of organisms to their physical environment, i.e., Eco-physiology.
v. The development in the course of evolution i.e., evolutionary development.
vi. The biological productivity and energy flow in natural system, i.e., productive ecology.
vii. The development of mathematical models to relate intersection of parameters and to predict the effects.
The main objective of the study of ecology is to apply the knowledge gained from ecological study to safeguard against disasters caused by:
i. Uncontrolled interference with natural populations,
ii. Unchecked felling of trees,
iii. Environmental pollution.
Essay # 7. Subdivisions of Ecology:
I. Two important subdivisions of ecology are recognised by ecologists, these are:
i. Autecology and
It is concerned with the ecology of an individual species and its population. While studying the autecology of a particular species, an ecologist studies, its behaviour and adaptation to the environmental condition at every stage of that individual’s life cycle. Autecology is also called species ecology.
It is study of communities, their composition, their behaviour and relation to the environment.
Synecology is also called Ecology of Communities
Synecology is further divided into three fields:
i. Population ecology
ii. Community ecology
iii. Ecosystem ecology
II. On the basis of the kind of environment or habitat, ecology has been sub-divided into the following branches:
III. With advancing trends in the fields of ecology, present day ecologists divide ecology into the following branches:
Essay # 8. Community Ecology:
A population of a single species cannot survive by itself because there is inter dependence of one form of life on another. An aggregation of populations of different species living together (in inter dependence) in a specific area, having a specific set of environmental conditions constitute a biotic community e.g., the various plants and animals in a pond or lake constitute on biotic community whereas the plants and animals in a particular forest constitute another biotic community.
Broadly speaking, there are two types of communities.
These are major and minor community:
(i) Major Community:
It is large community which is self-regulating, self-sustaining and independent unit comprising of a number of minor communities in it. Examples of major communities are: a pond, a lake, a forest, a desert, a meadow and a grassland. Each of these major communities includes several minor communities.
(ii) Minor Community:
It is a smaller community which is not a self-sustaining unit. It is dependent on other communities for its existence. The major community exemplified by a forest has many minor communities namely the plant community (the plant population of the forest), the animal community (the animal population of the forest) and the microbial community (bacteria and fungi population).
Characteristics of a Community:
A community has the following characteristics:
Structure of a community can be studied by determining the density, frequency and abundance of species.
Usually a community has one or more species which occur in large number. Such species are called dominants and the community is often named after them.
The community consists of different groups of plants and animals of different species, may be large and small, may belong to one life from or another but are essentially growing in a uniform environment.
This includes study of various life processes (respiration, growth, reproduction etc.) in the various seasons of the year in the dominant species of a community.
The recurrence of these important life processes at regular intervals in a year and their manifestation in nature is termed periodicity.
Natural forest communities possess a number of layers or storeys or strata related to the height of plants, for example, tall trees, smaller trees, shrubs and herbaceous layers form the different strata. This phenomenon in a plant community is called stratification.
(vi) Eco-tone and Edge-effect:
A zone of vegetation spreading or separating two different types of communities is called ecotone. These are marginal zones and are easily recognisable.
Usually, in ecotones, the variety of one species is larger than in any of the adjacent communities. A phenomenon of increased variety and intensity of plants at the common junction is called edge-effect and is essentially due to wider range of suitable environmental conditions.
(vii) Ecological Niche:
Different species of animals and plants fulfil different functions in the ecological complex. The role of each is spoken of as its ecological niche i.e., the role is that a species plays in its ecosystem: what it eats, who eats it, its range of movement etc., in other words, the total range of its interaction with other species of its environment.
We can also say that ecological niche is a small habitat within a habitat in which only a single species can survive.
E.P. Odum has differentiated habitat and ecological niche by saying that the habitat is an organism’s address and the ecological niche is its profession.
(viii) Ecological Succession:
Communities are not static but progressively change with time in a definite manner. This change of the plant and animal communities in an orderly sequence in an area is called ecological or biotic succession. Ecological succession finally leads to a stable nature community called climax community.
(ix) Interspecific Association:
This is the study of two or more species growing together in close association in regular occurrence.
(x) Community Productivity:
The study of production of biomass (organic matter) is known as production ecology.
The net production of biomass and storage of energy by a community per unit time and area is called community productivity.
(xi) Biotic Stability:
A biotic community has the ability to quickly regain equilibrium after a disturbance in population fluctuation. This is called biotic stability and is directly proportional to the number of interacting species it contains i.e., the diversity in the community.
Before man encroached upon it, the world biosphere was a large climax community resulting from thousands of years of evolution. With increase in population, the demand for space has been steadily increasing and so the ecosystem have been rapidly exploited beyond the capacity of the environment to adjust, thereby totally disrupting the balance of nature.
Before a point of no return is reached, man should stop manipulating the environment to his advantage. The survival of mankind will be in peril of pollution of the environment, degradation of the land, over consumption and wasteful use of natural resources are not checked immediately. Development should be the result of scientific management based on ecological principles.
Concern for environment protection was shown in the conference on Human environment held at Stockholm in June, 1972. The prime objective of the conference was to focus attention on the major environmental issues, to recognise and identify the causes for environmental degradation and the need to prevent and control it.
The conference called upon all the nations of the world to protect, improve, preserve and enhance the environment for the present and future generations.
In the United Nations conference on Environment and Development at Rio de Janeiro held in June, 1992, an action plan was formulated for solving the major environmental problems threatening the environment, like,
(a) Global warming
(b) Ozone layer depletion
(c) Pollution of air, water and land
(d) Acid rain or acid precipitation
(f) Soil erosion
(g) Deforestation and
(h) Depletion of genetic resources
The pressing need today is environmentally compatible development to protect the environment for the future generation and to restore the ecological balance on earth.
Some recent initiatives for defining ecological standards ISO 14000.
i. BS 7750
ii. Eco Management and audit scheme
iii. Life cycle assessment
Essay # 9. Rules in Ecology:
i. Ecology is a Science:
It is a purely scientific discipline which aims to understand the relationships between organisms and their wider environment.
ii. Ecology is only Understandable in the Light of Evolution:
The huge diversity of organisms and the wealth of variety in their morphologies, physiologies and behavioural all are the result of many millions of years of evolution.
iii. Nothing Happens ‘for the Good of the Species’:
The patterns of behaviour organisms is regulated by natural selection even though it is detrimental for species.
iv. Gene and Environment are both Important:
The environment of an organism finds itself in playing an important role in determining the options open to any individuals.
v. Understanding of Complexity Requires Models:
Ecology is a complex subject with huge variation in almost every scale. To understand these complexity mathematical model is required.
vi. Story Telling is Dangerous:
To explain the ecological process hypothesis has to be explained properly.
vii. There are Hierarchies of Explanations:
For any observation there is often an immediate and delayed causes. These hierarchies need to be explained properly.
viii. There are Multiple Constrains on Organisms:
In evolution of species there are a number of constrain (physical and evolutionary) on organisms.
ix. Chance is Important:
Chance events in ecology play a crucial role.
x. The Boundaries of Ecology are in the Mind of the Ecologist:
Domain of ecological understanding is highly flexible. Modern ecology is thus an interdisciplinary science with various subdivision like plant ecology, animal ecology, and microbial ecology. It can further be segmented as ecology of individuals (autecology) or groups (synecology). With passage of time, varieties of dimensions of ecological sciences were developed with their interlink ages (Fig. 1.1).
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Copyright ©1999 by The Resilience Alliance*
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Holling, C. S. 1999. Visions: a personal essay. Conservation Ecology 3(1): 12. [online] URL: http://www.consecol.org/vol3/iss1/art12/
EditorialVisions: A Personal EssayC.S. (Buzz) Holling
University of Florida
I'm suspicious of folks with visions. They are too certain. Blind to surprise. Deaf to other voices.
I do not have a vision for Conservation Ecology.
I do develop senses that help listen to intriguing voices that are hidden amongst the noise. Owlish ways to hear the rustle of the mouse. So I guess I try to discover visions rustling out there.
The simplest example of what I mean is in sculpting. I start with a number of hazy ideas, and then I discover the image caught and hidden in the swirls of the wood's grain. I listen to the voice of the wood.
My research has always been like that. In the early days of predatorprey functional responses, the device was components analysis. A way to engage levels of complexity and maintain generality. It was a beast-for-the-moment design; the beast most appropriate for the step in hand. The result was many voices, each playing facets of one song. Praying mantis, deer mice and shrews, barracuda and iao, salmon, the suite of insectivorous birds in the boreal forest. Lions and gazelles. It was a way to listen to the hidden voice of nature. Those voices led to the discovery of resilience. Not a song but a composition!
Most recently, it led to the "world is lumpy"-- patterns at scales from centimeters to kilometers, from days to millennia. And an approach that is a bit of strong inference, but more of adaptive inference and multiple lines of evidence-- from every major biome in the world, from endangered and invasive species, from nomadic and sedentary organisms. And beyond that, similar rhythms, once heard, seem to be in economic systems, social and behavioral.
But I was never smart enough to create all that. I had to nurture senses to hear nature's voice.
Adaptive ecosystem management has been the same process. The workshops evolved to let voices speak: scientist, scholar, and practitioner. We learned who they were, in heart and spirit, and each had a different contribution. The Peerless Leader gave the guiding melody. The Blunt Scot was on percussion. The Snively Whiplash gave the creative dissonance. And the Compleat Amanuensis knit it together. The Benevolent Despot hummed a lot.
And now Conservation Ecology. What is it? It is a foundation to develop devices to listen to the quiet voices of people-- scientists and scholars of many stripes, practitioners -- and for them to listen to each other. In universities, government, and the private sector. In business as well, I wish. People in the Netherlands and Sweden, in Spain and Malaysia, South America and Madagascar, Canada and Australia. In Africa. And not just in the United States. Voices masked by the noise, wherever novelty and experience combine. We are finding ways to have deliberative conversations among listeners.
That is much more valuable, now, in this time of turbulence and transformation, than policy and planning exercises.
C. S. Holling
Cedar Key, Florida
26 May 1999
Responses to this article are invited. If accepted for publication, your response will be hyperlinked to the article. To submit a comment, follow this link. To read comments already accepted, follow this link.
Address of Correspondent:
C.S. (Buzz) Holling
Department of Zoology
University of Florida
223 Bartram Hall
Gainesville, Florida, USA
Phone: (352) 543-6955
Fax: (352) 392-3704
*The copyright to this article passed from the Ecological Society of America to the Resilience Alliance on 1 January 2000.