A project report on ecosystem. This project report will help you to learn about: 1. Meaning of Ecosystem 2. Various Terms Used in Ecology and Their Definition 3. Structural and Functional Attributes 4. Food Chain and Food-Web 5. Energy-Flow 6. Biogeochemical Cycles 7. Artificial Ecosystem.
Contents:
- Project Report on the Meaning of Ecosystem
- Project Report on Various Terms Used in Ecology and Their Definition
- Project Report on the Structural and Functional Attributes of an Ecosystem
- Project Report on Food Chain and Food-Web in Ecosystem
- Project Report on Energy-Flow in Ecosystem
- Project Report on the Biogeochemical Cycles (Material Cycles) of Ecosystem
- Project Report on Artificial Ecosystem
Project Report # 1. Meaning of Ecosystem:
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Living organisms cannot live in isolated from their non-living environment because the latter provides materials and energy for the survival of the former i.e., there is intersection between a biotic community and its environment to produce a stable system; a natural self- sufficient unit which is known as an ecosystem.
The term ecosystem (‘eco’, the environment; ‘system’, an interacting, inter-dependent complex) was first given by A. G. Tansley in the 1935. Ecosystem is the basic functional unit of ecology which consists of the biotic and abiotic community.
According to Fitze and Patric (1974) a group of organism which interact with each other also interact with environment. This is called ecosystem.
An ecosystem is, therefore, defined as a natural functional ecological unit comprising of living organisms (biotic community) and their non-living (abiotic or physiochemical) environment that interact to form a stable self-supporting system. A pond, lake, desert, grassland, meadow, forest etc. are common examples of ecosystem.
Project Report # 2. Various Terms Used in Ecology and Their Definition:
i. Trophic Levels:
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Trophic (trophe, nourishment) literally means feeding. So trophic levels are the nourishment levels or positions at which species feed. The trophic structure of an ecosystem is one kind of producer-consumer arrangement.
It may be measured and described either in terms of the standing crop per unit area or in terms of the energy fixed per unit area per unit time at successive trophic levels. Trophic structure and trophic function can be shown graphically by ecological pyramids.
ii. Standing Crop:
Standing crop is the total number of living organisms or amount of living material present in different trophic levels. It is a term applicable to both plants and animals. Standing crop can be expressed in terms of number of organisms present per unit area or in biomass (organism’s mass present in unit area).
Biomass is measured either in living weight, dry weight, ash-free weight, carbon weight, calories or any other convenient units suitable for comparative studies. Biomass present at any given time should not be confused with productivity.
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iii. Turnover Rate:
Turnover is the ratio of the standing state (amount present) of biotic or abiotic components to the rate of replacement of the standing state. It relates structure to function in an ecosystem. If we assume that the biomass of a forest is 20,000 grams per square meter (g/m2) and the annual growth increment is 1,000 g, then the ratio 20,000/1,000 or 20/1 can be expressed as the turnover time or replacement time of 20 years.
The reciprocal 1/20 being equal to 0.05 is the turnover rate. The turnover time for phytoplankton in a pond is measured in days rather than years.
iv. Detritus:
The term detritus is obtained from the Latin word deterere meaning to wear away. It was traditionally used in geology to designate the products of rock disintegration. ‘Organic detritus’ refers to all the organic matter involved in the decomposition of dead organisms.
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Dissolved organic matter that leaks out of or is extracted by saprotrophs from both living and dead tissues, are included under the heading of detritus since it has a similar function. Environmental chemists use shorthand designation for the two physically different products of decomposition — POM for particulate organic matter and DOM for dissolved organic matter.
Animals that feed on detritus are known as detritus-feeding animals or detritivores. Intense activities of microorganisms on detritus often result in protein enrichment, thus providing a more nutritious food for detritus-feeding animals.
v. Humus:
Humus or humic substances are end-products of decomposition that are quite resistant to further decay and are never found inside cells. They remain for some time as a structural part of the ecosystem.
Humus is generally referred to the dark, yellow-brown, amorphous or colloidal substance that is readily visible in soils, sediments and suspended in the waters of streams and lakes (noticeable particularly in swamp or bog water). The role of humic substances in ecosystem is not fully understood, but they do contribute to soil properties favourable for plant growth.
Project Report # 3. Structural and Functional Attributes of an Ecosystem:
Each ecosystem has two main components:
i. Abiotic components,
ii. Biotic components.
i. Abiotic Components:
The non-living environment of an ecosystem factors or the physical environment prevailing in an ecosystem form the abiotic components. They have a strong influence on the structure, distribution, behaviour and interrelationship of organisms.
Abiotic components are mainly of two types:
(a) Climatic Factors:
Which include rain, temperature, light, wind, humidity etc.
(b) Edaphic Factors:
Which include soil, pH, topography, minerals etc.
It also includes inorganic and organic factors. Inorganic factor includes Ca, CO2, H2O, N2 etc.
Organic Factors:
Protein, carbohydrate, lipids and amino acids.
ii. Biotic Component:
The living organisms including plants, animals and micro-organisms (Bacteria and Fungi) that are present in an ecosystem form the biotic components.
On the basis of their role in the ecosystem the biotic components can be classified into three main groups:
(a) Producers
(b) Consumers
(c) Decomposers or Reducers.
(a) Producers:
The organism which produce food for themselves and for other living organism known as producer, e.g. All green plant → photosynthetic bacteria.
The green plants have chlorophyll with the help of which they trap solar energy and change it into chemical energy of carbohydrates using simple inorganic compounds namely water and carbon dioxide. This process is known as photosynthesis. As the green plants manufacture their own food they are known as Autotrophs (i. e., auto = self, trophos = feeder).
The chemical energy stored by the producers is utilised partly by the producers for their own growth and survival and the remaining is stored in the plant parts for their future use.
(b) Consumers:
The animals lack chlorophyll and are unable to synthesise their own food. Therefore, they depend on the producers for their food. They are known as heterotrophs (i.e., heteros = other, trophos = feeder). They are known as consumers.
The consumers are of four types, namely.
Primary Consumers or First Order Consumers or Herbivores:
These are the animals which feed on plants or the producers. They are called herbivores. Example are rabbit, deer, goat, cattle etc.
Secondary Consumers or Second Order Consumers or Primary Carnivores:
The animals which feed on the herbivores are called the primary carnivores. Examples are cats, foxes, snakes etc.
Tertiary Consumers or Third Order Consumers:
These are the large carnivores which feed on the secondary consumers. Examples are Wolves.
Quaternary Consumers or Fourth Order Consumers or Omnivores:
These are the largest carnivores which feed on the tertiary consumers and are not eaten up by any other animal. Examples are lions and tigers.
(c) Decomposers or Reducers:
Bacteria and fungi belong to this category. They breakdown the dead organic materials of producers (plant) and consumers (animals) for their food and release to the environment the simple inorganic and organic substances produced as by-products of their metabolisms.
These simple substances are reused by the producers resulting in a cyclic exchange of materials between the biotic community and the abiotic environment of the ecosystem. The decomposers are known as Saprotrophs (i.e., sapros = rotten, trophos = feeder).
Project Report # 4. Food Chain and Food-Web in Ecosystem:
Food Chain:
In a food chain each organism eats the smaller organism and is eaten by the large one. All those organisms which are interlinked with each other through food together constitute a food chain. The different species in a food chain are called trophic levels. Each food chain has three main trophic levels-Producers, Consumers and Decomposers.
In ecosystem green are known as produce because they produce food for organism. For example, herbivores like deer, goat feed on plants for their food, i.e. they obtain energy directly from the plants. The herbivores are eaten by carnivores like lion tiger etc.
In this way energy transferred through a series of organism. Such sequence is known as food chain and each state of food chain is called trophic level. A food chain can be defined as food chain is the sequence of organisation in which energy flows in the form of food from the organism to another organism through a series of repeated eating and being eaten.
There are three types of food chain:
i. Predator food chain.
ii. Parasitic food chain.
iii. Saprophytic food chain.
Food Web:
Various food chains are often inter-linked at different trophic levels to form a complex interaction between different species from the point of view of food. This network like interaction is called the food web.
If any of the intermediate stage of the food-chain is removed, the succeeding links of the food chain will be affected.
The food web provides more than one alternatives of food to most of the organisms in an ecosystem and, therefore, increases their chances of survival.
The basic nutritional links in an ecosystem are shown in Fig. 1.3.:
Project Report # 5. Energy-Flow in Ecosystem:
To maintain life activities, energy is required. The plants make use of the raw materials from the environment in the form of water, salts and carbon dioxide to prepare food, namely starch.
This synthesis is aided by the energy they derive from the sunlight trapped by the chlorophyll. Thus, energy from the sun enters the living world through photosynthetic organism and passes on from one organism to another in the form of food.
The flow of energy through the ecosystem is unidirectional and noncyclic.
This one-way flow of energy is governed by laws of thermodynamics which state that:
(i) Energy is neither created nor destroyed but may be transferred from one form to another, and
(ii) During energy transfer there is degradation of energy from a concentrated form (mechanical, chemical or electrical etc.), to a dispersed form (heat).
Thus, there is a continuous loss of energy within each trophic level from producer to consumer within an ecosystem.
This is accounted for largely by the energy dissipated as heat during metabolism of the organisms present in the food chain. It also indicates that shorter the food chain, greater would be the available food energy and with an increase in the length of the food chain, there is a corresponding increase in loss of energy.
Project Report # 6. Biogeochemical Cycles (Material Cycles) of Ecosystem:
The producers of an ecosystem take up several basic inorganic nutrients from their non-living environment. These materials get transformed into the bio mass of the producers. Then they are utilised by the consumer population and are ultimately returned to the environment with the help of the reducers or decomposers.
This cyclic exchange of nutrient material between the living organisms and their non-living environment is called biogeochemical cycle. As indicated by the name the nutrients circulate through life (bio) and through the earth (geo) repeatedly (cycle). The biogeochemical (material and nutrient) cycles conserve the limited sources of raw materials in the environment.
Common Biogeochemical Cycles are:
(i) Water Cycle or Hydrologic Cycle:
In this cycle:
(a) Water from the transpiring plants, oceans, rivers and lakes evaporates into the atmosphere.
(b) These water vapours subsequently cool and condense to form clouds and water.
(c) Water returns to the earth as rain and snow.
(ii) Carbon-Cycle:
Most of the carbon dioxide enters the living world through photosynthesis. The organic compounds synthesised are passed from the producers (green plants) to the consumers (herbivores and carnivores).
During respiration plants and animals release carbon back to the surrounding medium as carbon-dioxide. The dead bodies of plants and animals as well as the body wastes which accumulate carbon compounds are decomposed by micro-organisms to release carbon dioxide.
Carbon is also recycled during burning of fossil fuels.
(iii) Nitrogen-Cycle:
Nitrogen of the atmosphere is in the elemental from and cannot be used as such as by living organisms. It has to be “fixed” i.e., combined with other elements such as hydrogen, carbon or oxygen to become usable for the green Plants. Nitrogen is continuously entering into the air by the action of denitrifying bacteria and returning to the cycle through the action of lightening and electrification.
(iv) Oxygen-Cycle:
Oxygen required for respiration in plants and animals enters the body directly from the surrounding medium (air to water). Oxygen returns to the surroundings in the form of Carbon-dioxide or water. It also enters the plant body as carbon dioxide and water during photosynthesis and released in the form of molecular oxygen as a by-product in the same process for use in respiration. Thus, the cycle is completed.
Ecosystem is a functional system which in a balanced condition, is self-sufficient and self-regulating. A balanced ecosystem is essential for the survival of all living organisms. Organisms at each trophic level in a food chain are preyed upon by an organism at the next higher trophic level, for example, herbivores feed on the plants and are in turn eaten by the predators.
If the numbers of herbivores increase in a specific area, there will be a rapid destruction of the vegetation, which in turn will eventually destroy the herbivores (due to lack of food). So, the population of herbivores is kept in check by predators such as lions and tigers.
Through these interactions in the food web, the population of each species is held in check by the carrying capacity of the environment i.e., the environment’s ability to provide space and food to the organisms, and the ecosystem maintains its balance (ecological balance or balance of nature).
The tendency of the biological systems to resist change and to remain in a state of dynamic equilibrium is known as homeostasis (homeo = same; stasis = standing).
Generally, the ecosystem are named after the type of organism and habitat condition, e.g:
(i) Grassland ecosystem
(ii) Crop ecosystem
(iii) Forest ecosystem
(iv) Desert ecosystem
(v) Aquatic ecosystem
(vi) Urban ecosystem
However several ecosystems can be interrelated and sometimes several small ecosystems (micro ecosystems) form a large ecosystem (macro ecosystems) for instance,
Project Report # 7. Artificial Ecosystem:
Ecosystem is a collection of living and non-living entities in a space, connected by a complex web of interactions. Natural ecosystem has evolved over millions of years manifesting a wide variety of life forms with complementary interactions and a dynamic equilibrium. Subsequently as the time passed, man developed intelligence which enabled him to manipulate the environment for his gain.
The deliberate manipulation of the environment attributes in larger and larger measures has brought large changes in the ecosystem. The ecosystem dynamics has deviated from natural trends that existed prior to man and is losing the equilibrium obtained through evolution and tests of time.
Thus the ecosystem has become fragile facing the threat of collapse, in which case man has to perish along with them. The time has now come for human intelligence to take over the management of ecosystems with the objective of ensuring his happy survival and preserving the biosphere for that purpose.
Characteristics of Artificial Ecosystem:
Artificial ecosystems are likely to have the following characteristics:
i. Diversity will be lesser compared to natural systems. Unfavourable and less favoured species are likely to taper off slowly.
ii. Whereas the natural systems do not have definite goals and evolved by trial and error and their survival value, the artificial ecosystem is pragmatic with well-defined goals. Artificial systems are more fragile and are more vulnerable of failure due to lack of diversity and strong self-regulatory systems, characterizing the natural systems.
iii. Artificial ecosystems are more productive from anthropocentric perspectives. Land yield improved cultivation techniques, cloning techniques, milk yield with recent animal husbandry practices etc., are examples of enhancing productivity of natural processes with human intervention.
iv. Artificial ecosystems with further improvements in design can enhance the sustenance capacity of population in a given space and enable the expansion of human habitat into oceans, outer space, extra-terrestrial bodies and subterranean spaces.
v. Artificial ecosystems depend on natural cosmic laws. Man is only a discoverer but not a maker of natural laws. Here artificial ecosystems are not contradictions and negations of natural systems. It is only the proportions and speeds of the ecological interactions that can be meddled with, for man’s advantage. Hence all the so- called artificial ecosystems are only the semi-artificial.
The examples of artificial ecosystems are:
Modern cities, Hydroponics (cultivation of plants without soil and sunlight), sky labs and space ships, camping of South Pole explorers, urban squatter settlements, poultry, piggeries, zoos, social forests industrial green belts, mechanized agricultural farms, bio reactors in industry and waste treatment plants. In all the above artificial ecosystems, most of the inputs, outputs and interactions are planned or ill-planned by man.