Ecology: Compilation of Term Papers on Ecology | Branches | Biology

Here is a compilation of term papers on ‘Ecology’. Find paragraphs, long and short term papers on ‘Ecology’ especially written for school and college students.

1. Term Paper on the Definition of Ecology
2. Term Paper on the Classification of Ecology
3. Term Paper on the Levels of Ecology
4. Term Paper on the Subdivisions of Ecology
5. Term Paper on the Principles of Ecology
6. Term Paper on the Need for Ecological Balance

Term Paper # 1. Definition of Ecology:

Life processes of living organisms are affected by the environment in which they live. Similarly organisms also affect their environment and cause changes in it. The scientific study of the interaction between the organism and their environment is called ecology. It is a multi-disciplinary science and includes geology, chemistry, physics along with the biological disciplines like physiology, genetics, morphology, etc.

The word ‘ecology’ has a greek origin. ‘Oikos’ means home, ‘logos’ means to study. Thus ecology is concerned with organisms in their environment. Ernst Haeckel coined the term ‘ecology’ in 1869. The term ‘environment’ refers to the surrounding of the organism.

It includes non-living and living components that affect the life and development of the organism in its natural surroundings. The natural surroundings of an organism is called ‘habitat’. The non-living components are called abiotic factors; living components are called biotic factors.

The scope of ecology is wide and varied. Ecology is a basic division of biology and forms an integral part of all the taxonomic divisions.

In a simple term ecology may be defined as that science which studies, interrelationships between abi­otic and biotic components of the biospheric ecosys­tem on one hand, and among biotic components on the other hand.

Generally, ecology is divided into autecology and synecology wherein autecology is concerned with the study of ecological relations of individual species in a given ecosystem whereas synecolgy is the study of plant communities in relation to their habitats of given ecosystem.

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Term Paper # 2. Classification of Ecology:

1. On the basis of nature of study ecology can be subdivided as:

a. Autecology:

Autecology deals with the study of the individual organism or an individual species and its population. Here, the focus on life-histories and behaviour, as means of adaptation to the environment, is made. Autecology is also called “species ecology.”

b. Synecology:

Synecology deals with the study of groups of organisms which are associated together as a unit. In other words it is study of communities, their composition, their behaviour and relation to the environment.

Synecology is also called “Ecology of communities.”

Synecology is further sub divided into:

(i) Population ecology:

It relates the organism with various groups of organisms and their inter-relationship.

(ii) Gene ecology:

It deals with the genetic make-up of species in relation to the environment.

(iii)Taxonomic ecology:

It includes ecology of taxonomic groups as microbial ecology. Verte­brate or invertebrate ecology.

For e.g., if a study is carried out of the relation of a Neem tree with the environment, then the approach is said to be autecological in nature. But if the study is carried out of the forest (of which Neem tree is a part), then the approach is said to be synecological in nature.

2. On the basis of the kind of environment or habitat, ecology has been sub divided into the following branches:

3. With advancing trends in the fields of ecology present day ecologists decide ecology into the following branches:

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Term Paper # 3. Levels of Ecology:

Ecology can also be considered in terms of the concept of levels of organisation. In ascending order of complexity, the hierarchy of organisation includes cells, organs, organisms, population, community, ecosystem, landscape, biome and the biosphere.

Hierarchy includes ‘an arrangement into a graded series’. Ecology is concerned with levels beyond an organism (Fig. 1).

The different levels are as follows:

a. Organism:

An organism is the basic unit of study in ecology. At the organism level we are con­cerned with taxonomic position, morpho­logical characters, reproduction, life cycle, geographical distribution, and behaviour in relation to specific environmental conditions. Similar organisms that can interbreed and produce fertile offspring form a species.

b. Population:

Population denotes a group of individuals of a particular kind capable of interbreeding with one another inhabiting a particular place.

c. Community:

A Community includes all the populations occupying a given area.

d. Ecosystem:

The community and the non-living environ­ment function together as an ecosystem.

e. Landscape:

It is defined as a heterogeneous area com­posed of a cluster of interacting ecosystems.

f. Biome:

Biome is a large regional or subcontinent system of characteristic vegetation type. Similar biomes share similar climatic conditions. For example, the hot deserts in the world exhibit similarity in flora and fauna.

g. Biosphere or the Ecosphere:

It is the largest and nearly self-sufficient biological system which includes all the living organisms of the earth interacting with the physical environment. Hierarchies in nature are nested, i.e. each level is made of groups of lower level units. For example, population is made of groups of organisms that can interbreed. In contrast, human organised hierarchies as seen in governments, military, etc., are non-nested.

Organisms interact with the environment at different time and spatial scales. For instance, a bacterium interacts with its environment within a narrow fraction of a cubic cm. A tree on the other hand interacts with its environment at a large time and spatial scale. Organisms, big or small, exchange matter and energy continuously with the environment.

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Term Paper # 4. Subdivisions of Ecology:

Ecology can be commonly divided into animal ecology and plant ecology. However, two major subdivisions are recognised by ecologists, i.e. autecology and synecology. Autecology is the study of individual species in relation to their environment, while synecology is the study of the groups of organisms in relation to their environment. It comprises population ecology, community ecology and the study of the ecosystems.

Useful subdivisions may also be made according to the habitat, taxonomic divisions and the level of organisation.

Some important subdivisions are described below:

a. Population Ecology:

It deals with the growth, trophic structure, metabolism and regulation of a population.

b. Community Ecology:

It deals with the ecology of different populations in the same habitat and the same environmental conditions.

c. Habitat Ecology:

It includes the study of animals and plants in their habitat. According to the habitat it can be further divided into freshwater ecology, marine ecology and terrestrial ecology.

d. Applied Ecology:

It deals with the application of ecological concepts to human needs and includes wildlife management, biological control, forestry and conservation of natural resources.

e. Paleoecology:

It deals with the environmental conditions and the life of the past.

f. Human Ecology:

It deals with the effects of human activities on the environment and vice versa.

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Term Paper # 5. Principles of Ecology:

(1) Ecosystem is a fundamental unit of ecologi­cal study because it comprises both abiotic and biotic components.

(2) Physical and biological processes follow the principles of uniformitarianism.

(3) All living organisms and physical environ­ment are mutually reactive. In other words, living organisms interact among themselves and affect each other on the one hand and living organisms and physi­cal environment are interrelated through reciprocal interactions and these affect each other on the other hand. The varying degrees of interactions among or­ganisms, at both inter-and intraspecific levels, are positive, negative and sometimes neutral.

(4) Ecosystem functions through the input of energy mainly solar radiation which is trapped by green plants (primary producers) and is used to prepare food (chemical organic matter) through the process of photosynthesis. Thus, the solar radiation is the main driving force of the ecosystem. Energy flow (transfer of organic molecules) is unidirectional (passes through various trophic levels) and is non-cyclic.

Ecosystem energetics or energy flow also helps in the circulation of chemical substances (nutrients) within the ecosys­tem. There is progressive loss of energy by respiration of organisms through increasing trophic levels.

The energy pattern and flow are governed by the following first and second laws of thermodynamics:

Law I:

In any system of constant mass, energy is neither created nor destroyed but it can be transformed from one type to another type. The energy inflow or input in a system is balanced by energy outflow.

Law II:

When work is done, energy is dissi­pated and the work is done when one form of energy is transformed into another form.

(5) The circulation of energy in the biospheric ecosystem is unidirectional. There is increase in the relative loss of energy through respiration with in­creasing trophic levels.

(6) Circulation of matter in the biosphere is accomplished through cyclic pathways e.g., through geobiochemical cycles. The materials are cycled in such a way that their total mass remains almost constant.

(7) Ecosystem productivity refers to the rate of growth of organic matter per unit time per unit area by autotrophs at trophic level one through the process of photosynthesis with the help of solar energy.

This depends on two factors e.g.:

(i) Availability of the amount of solar radiation to the primary producers (green plants) at trophic level one, and

(ii) The efficiency of plants to convert solar energy into chemical energy which is used by green plants to build their tissues.

Since solar energy (insolation) decreases from equator towards the poles, and hence ecosystem (ecological) productivity also decreases. Thus, it is evident that there is positive relationship between insolation and primary productivity.

(8) There is inbuilt self-regulatory mechanism known as homeostatic mechanism in natural ecosys­tem. Any change brought in the natural ecosystem is counter balanced by this mechanism and ecosystem and ecological stability is reestablished.

(9) If the changes brought by external factors are so immense that they exceed the resilience of ecosystem stability and adjustment of ecosystem to such changes becomes difficult, the ecosystem be­comes unstable and several environmental problems are created.

(10) Following Charles Darwin evolution of species is accomplished through the processes of natu­ral selection and adaptation. Contrary to this, following D. Vries there are spontaneous evolutionary changes in species through the processes of mutation and repro­ductive isolation.

(11) There is successional development of plant community in a habitat of given environmental condi­tions. There are five sequential phases in the successional development of vegetation e.g., phases of nutation, migration, ecesis, reaction and stabilization. The successional development of vegetation is of two types e.g., primary succession and secondary succession.

(12) The transitional stages of sequential changes from one vegetation community to other vegetation community are called sere which is complete when the succession of vegetation community after passing through different phases culminates into equilibrium condition. The vegetation community developed at the end of succession is called climax vegetation, climax community or climatic climax (due to dominant control of climate on the evolution and development of vegetation).

(13) Man, being an active agent of environmen­tal change, modifies the ecosystem through the exploi­tation of natural resources. He reduces the ecological diversity and complexity of the ecosystem by remov­ing a host of biotic communities for different purposes.

The disruption of ‘climax vegetation’ and ecosystem stability is caused by man through:

(i) Purely destruc­tive actions (forest clearance through mass felling and extensive burning),

(ii) Introduction and establishment of new types of vegetation in the ecosystem which were not previously present in that ecosystem (for example, natural forest replaced by food crops),

(iii) Introduction of species of plants and animals into the areas beyond their native places,

(iv) Farming practices (for example, by allowing the economic plants, such as food crops, to grow while destroying the unwanted or uneconomical plants, such as weeds and bushes through the application of herbicides and pesticides),

(v) Habitat changes, and

(vi) Constructional actions (such as roads, settlements-urbanisation, field drainage, canals etc.).

(14) The ultimate goal of ecological study is to preserve ecological resources by maintain the eco­logical diversity and ecosystem stability. ‘Preserving diversity in a world of rapidly shrinking land resources will require a prompt and universal response on an appropriate application of ecological knowledge. Every nation should possess an inventory of its biological endowment’ for the purposeful eco­logical and environmental management for future gen­eration of human society to which the present society has to bear the obligation.

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Term Paper # 6. Need for Ecological Balance:

Plants are basic for all. Some small animals feeding on plants are eaten by larger animals. Plants or animals which serve as food for others become a part of the food chain. Destruction of theses plants or animals may affect the lives of others in the food chain. We can locate several food chains around us.

Existence of different plants and animals in sufficient number to support the food chain is an indication of a good ecological balance. Let us now look at the reasons for the break in food chains. Mosquitoes lay eggs in still water. Frogs eat’ mosquito larvae and other insects. Frogs are eaten by snakes. Snakes are eaten by mongoose and eagles.

If a large number of frogs are collected from paddy fields by people for food, the frog population of mosquitoes and other insects will increase. This may cause damage to the crops and spread diseases like malaria. In the absence of adequate number of frogs, snakes will come to residential areas in search of alternate food like rats, eggs and small birds.

In the same way, when the number of tigers and lions decrease, the population of deer and bosons will increase and these animals that depend on vegetation will destroy forests. When elephants do not get adequate foliage and bamboo shoots in the forest, they will move to nearby villages to graze in agricultural fields.

With increasing population, more and more people have to live on the same piece of land, and this will lead to an ecological imbalance. In the olden days, a large number of people died of diseases caused by germs. With the advancement of science, vaccines were developed to prevent diseases like small pox, cholera, diphtheria, typhoid, tuberculosis, etc. Hence, most of the people now survive deadly diseases and live long. This has resulted in overpopulation.

Arrow indicates that insect is the food for frog. With more people, we need additional houses, more food, fuel and other commodities. But, we cannot create additional Land. We need to produce more on the available land itself. In India, In 1951 about 117 people used to live on a square kilometer of land, but now 250 people are living on the same area. A cropping area of 147 million hectares, which was supporting 361 million people in 1951, now has to produce food for 850 million people.

Hence, the agricultural scientists have introduced the following modern practices to increase our food production:

(i) Development of high yielding varieties of crops. However, new varieties require more manure, assured irrigation, protection from diseases and insect attacks.

(ii) Application of agro-chemicals such as chemical fertilizers, insecticides, fungicides, bacteri­cides and weedicides.

(iii) Application of chemical fertilizers, because a large quantity of cattle manure required for growing high yielding varieties, is not available.

(iv) Spraying of insecticides on crops control insect attack. Fungicides and bactericides control diseases. Weedicides kill the weeds and unwanted plants which compete with crops.

Agro- Chemical help to grow more food, but they can pollute the air, water and soil when used in large quantities. Even with these efforts and risk of health hazards, we may not be able to produce sufficient food to feed everyone, because our population is still increasing.

It is difficult to guess what the hungry people will do, when they cannot get food. They may cut jungles, start eating animals and fight among themselves for survival. These are the worst possible effects of an ecological imbalance. Thus, ecological balance is necessary for our survival! Control oh human and livestock populations and better management of your natural resources would cer­tainly help to achieve this.