The sequential inter- linking of organisms involves the transfer of food in the form of energy from producers by the series of organisms with repeated eating and being eaten is referred to as the food chain. And, these sequential steps in the food chain are referred as different tropic levels.
Example:- Grassland ecosystem food chain and their different tropic levels
Grasses ← Insects ← Frogs ← Snake ← Predatory birds
Producers Herbivores Primary Secondary Tertiary carnivores
carnivores carnivores
Trophic levels are the nutritional levels in which food energy is transferred from one level to another level. In this above example, producers are the green plant (grasses) which is first trophic level; herbivores (insects) are the secondary trophic levels which are the plant eaters also called primary consumers belongs to secondary trophic level; then came primary carnivores (frogs) also called secondary consumers which feeds on primary consumers. And, then secondary carnivores (snake) which are the flesh eaters as like primary carnivores also called tertiary consumers; And then quaternary consumer (predatory birds) level came which are the tertiary carnivores. The maximum step in the food chain is 4 or 5.
Decomposition is the process of breaking down the substances into the smaller particles or the parts. Decomposition of the decay organic matter like plants, wastage of animals etc. , also known as putrefaction. In the process of decomposition mainly two decomposers are responsible, i.e, bacteria and the fungi. These two organisms breaks the dead organic matter into smaller organic molecules (utilized as nutrients by themselves) or into inorganic compounds which are released into the environment.
Decomposition involves some enzymes for the degradation of organic matter. Mainly 3 steps are involved in this process fragmentation (breakdown of the organic matter into smaller fragments), leaching (fragmented detritus particles like sugar and several nutrients get dissolved in water percolating through the soil and removed due to the leaching process) and the catabolism (release the extracellular enzymes to decompose decay particles into the simpler compounds which are carried out by the decomposers like bacteria and fungi) process occurs.
The decomposition process plays vital role in any ecosystem because it involves the release of the nutrients from the dead matter. If there is no decomposers, all the nutrients would remain locked in the dead remains of plants and the animals, so these will not be available for the indefinite recreation of the living matter.
Some substances are biodegradable and some are non- biodegradable because some microbial actions, radiations and some pollutants may get biologically magnified as they passed through the food chain and some bacteria and the decomposers have a specific role to play.
Like, biodegradable substances (like paper, wood) are those which are degraded naturally. These can disposed by the action of microbes and the radiations. And, non- biodegradable substances are those which cannot be degraded or if degradation occurs, it will be very slow in the process. Non- biodegradable substances are man- made products like D.D.T (Dichloro- diphenyl- trichloroethane), glass, heavy metals, tins, radioactive materials and plastics.
The biodegradable substances would affect the environment and they can easily degraded by the natural actions. Two ways are following in which biodegradable substances affect the environment:-
Biodegradable substances decomposed easily, they are less harmful than the non- biodegradable substances. When the decomposition process occurs through the microbial action or the radiations they produce foul smell. Biodegradable wastes like green waste, food waste, paper etc. pollutes the environment only when they are present in the excess amount and produce some harmful gases like ammonia, methane gas, carbon dioxide that may cause global warming.
When the decomposition process occurs by some microbes of biodegradable wastes, which contains houseflies, mosquitoes which carry the parasites which are the main causes of the human diseases.
Unlike the biodegradable substances, the non- biodegradable substances would affect the environment in the negative ways and they cannot be degraded easily. They can be accumulated and biologically magnified when they get pass through the food chain. The two ways are following in which non- biodegradable substances affect the environment:-
As they do not degrade or degrade very slowly in nature. These non- biodegradable substances get accumulated in the ecosystem and get biologically magnified as they passed through the food chain, they remains in the environment and does not get decompose. This can cause pollution and kills many animals by eating these non- biodegradable substances.
Plastics, tins, glass containers, radioactive materials, polythene, biomagnifications of Dichloro- diphenyl- trichloroethane in aquatic food chain, detergents- these non- biodegradable substances affect the environment when they get accumulated it causes soil pollution, water pollution, electronic waste pollution, thermal pollution etc.
Ozone is a clear, blue gas layer which is also known as the layer of protection of the environment. Ozone is the form of oxygen and the molecules of ozone contains three oxygen atoms (O3) It is present in the stratosphere which protects the earth from the ultraviolet (UV) radiations that came from the sun. Stratosphere is present at the altitude of 15-50 km above the earth’s surface and at the lower altitude it has thick sheet of ozone known as ozonosphere. The amount of atmospheric ozone is measured by the Dobson Spectrometer. Reaction:- O2 + O → O3 (Ozone)
Ozone affects the environment in following ways:-
Ozone is very poisonous at the ground level but at the higher altitude it is a layer of protection present in the stratosphere which protects the earth’s surface from the ultraviolet radiations, specially UV- B rays (290- 320 nm). Increase in the amount of UV rays reaches the earth surface when ozone depletion occurs, it can affect the ecosystem like it can cause skin cancer, dimming of the eye sight, herpes and diminishing the functioning of immune system in human beings.
It can cause death (mortality) of the young ones of the human beings and the animals.
It can cause mutation and blindness of the land animals.
All food chains can get disturbed.
The main cause of the ozone depletion is chlorofluorocarbon (CFCs).
Waste disposal problems can be reduced. Two methods are following:-
When we buy plastic bottle of water or plastic glasses, single use plastic or any disposable items, they pollute the environment because they are non- biodegradable. So, by minimizing their use, we should promote the use of recycling items which will be beneficial for the ecosystem.
We should use jute bags instead of polythene when we go for shopping or for purchasing anything. It can help in reducing the waste disposal, and will reduce the pollution ultimately.
All options contains biodegradable substances which can decompose easily except the grass, wood and plastic because plastic is a non- biodegradable substance which cannot be degraded and get accumulated in the environment which is the main cause of the pollution.
Grass, goat and human
Food chain is defined as the sequential steps of interlinking of the organisms which involves the transfer of food energy from one trophic level to another with repeated eating or being eaten process. In this, grass is the producer makes first trophic level and goat is the herbivore or the primary consumers which feeds on the grass makes secondary trophic levels. And, then flesh eaters, carnivores come, also known as secondary consumers, i.e, human beings which eats goat.
All of the above.
If we carry cloth- bags to put purchases while shopping, we can deny the use of polythene bags that is provided by the shopkeepers because polythene is a non- biodegradable substance. We should switch off the unnecessary lights or fans for the conservation of energy, light and the bill. And, at last if we prefer walking instead of getting our mother to drop on scooter, we can minimise the use of petrol or diesel or can contribute in reducing the air pollution that is released by the vehicles, gases release like CO2. So, all of the above options contribute in environment- friendly practices.
Tropic levels in the food chain are interlinked with one to another level in the sequential manner. If we kill all the organisms in one trophic level, the flow of energy at each tropic level is reduced 10 percent and the food chain get disturbed that creates an imbalance in the ecosystem.
For example, food chain is:- crops ← Rats ← Owls
In this food chain, crops are eaten by rats and then rats are eaten by owl population. If all the owls in the one trophic level get killed, there will be increase in the rats population and will lead to the overeating of the crops will happen. And, due to the overeating can lead to barren land which will affect the another trophic levels due to the soil erosion. So, as a result if we kill one trophic level, the lower trophic level will reproduce and population will get increases that disturbs the ecosystem.
The impact of removing all the organisms in the trophic level will be the same at each independent trophic level. When we remove or kill the organism of any trophic level it will be an damage to the ecosystem.
For example, in a pond food chain:-
Phytoplanktons ← Zooplanktons ← Small fishes ← Large fishes ← Snakes, birds
In this food chain phytoplanktons are eaten by zooplanktons and then zooplanktons get eaten by the small fishes; small fishes are eaten by the large fishes in the pond and then at the last trophic level large fishes get caught and eaten by the snake or the birds. So, we can see that all the trophic levels in the ecosystem are dependent on each other. If we remove any one trophic level population like we remove zooplanktons in the food chain then the lower trophic level, i.e, phytoplanktons population will get increase in number which will disturb the entire ecosystem.
Some toxic substances chemicals and large number of pesticides like D.D.T (Dichloro- diphenyl- trichloroethane) are non- biodegradable. When the concentration of these chemicals and pesticides increases at each trophic level of the food chain, this phenomenon is known as biological magnification or biomagnifications. They are non- biodegradable substances, so they do not decompose then they get accumulated in the environment and affect each of the trophic level. And, our body get directly affected at some stage of trophic level or mostly human beings are on the top level because we consume most of the chemicals in our body.
The level of biological magnification will be different at the different trophic levels. The concentration of the biomagnification got increased with the increase in trophic levels. For example:- biomagnification of pesticide D.D.T in aquatic food chain;
Water ← Zooplankton ← Small fishes ← Large fishes ← Fish eating birds
(DDT 0.003ppm) (DDT 0.04 ppm) (DDT 0.5 ppm) (DDT 2 ppm) (DDT 5 ppm)
In the above example, when the pesticides are sprayed on the agricultural fields then they are carried out by running off water into the aquatic bodies in the pond or lakes etc. The pesticide DDT get accumulate into the water and then in the zooplanktons, the concentration of DDT goes on increasing with each trophic level in the food chain. The fish eating birds have the higher concentration of biomagnification, which affects the egg shells due to the effect on calcium metabolism. Egg shell becomes thin and breaks at the premature stage. Then mercury discharge into the ponds, rivers or lakes that is changed by the bacteria into the toxic forms which is very harmful, absorbes by the fishes and they may get killed.
Non- biodegradable resources cannot be degraded or decomposed easily. And when they do not decompose they get accumulated and affect the environment.
Problems caused by the non- biodegradable wastes that is generated by us:-
When we use plastic bottles and plastic glasses, we throw them on the road, lakes, beaches instead of dustbins and they get accumulate and then pollute the environment. And, many types of pollutants are present which are non- biodegradable like radioactive substances, tins, glasses, electronic wastes etc all pollutes the environment which causes biomagnifications.
These pollutants when get accumulated in the environment and cause very serious diseases to the human beings and the animals.
Biodegradable substances decompose easily but when the amount of degradable substances get increased it will create an negative impact on the environment but positive impact occurs more than the negative. If we burn maximum amount of biodegradable matter it will produce foul smell by the reaction of microbes and this foul smell carried by houseflies and mosquitoes which carries the disease with them and humans get affected by these diseases.
But biodegradable decomposition possess more the positive impact on the environment because they produces raw materials which are again used by the ecosystem after the decomposition process.
Ozone layer is formed of three oxygen atoms and known as the layer of protection which protects the earth from the UV rays. The photodissociation of ozone and generation are present in the equilibrium state. This ozone layer releases the energy of ultraviolet radiations as heat. So, ozone layer acts as the shield in the stratosphere which protect us from the harmful radiations. Decline in the thickness of the ozone layer over a restricted area is known as ozone hole. And, the chlorofluorocarbons are the main cause of the ozone depletion. CFCs are used as the coolants in refrigerators and air conditioners or as cleaning solvents etc. They get released into the troposphere and then they reach into the stratosphere and produce chlorine in the presence of the UV rays and these chlorine radicals does the ozone depletion by converting them into the oxygen.
This damage can be overcome by minimizing the release of chlorofluorocarbons. CFCs used as air conditioners or refrigerators should be replaced with environment friendly alternatives. Or CFCs released through the industries, should be controlled.
Improper disposal of waste pollutes the natural environment and also affects the health of the living organisms. These wastes get accumulated in the ecosystem and get biologically magnified as they pass through the food chain, they remain in the environment and do not decompose. This can cause pollution and kills many animals and causes soil pollution, water pollution, electronic waste pollution, thermal pollution etc.
In the food chain of pond ecosystem, phytoplanktons are eaten by zooplanktons and then zooplanktons get eaten by the small fishes; small fishes are eaten by the large fishes in the pond and then at the last trophic level large fishes get caught and eaten by the snake or the birds. So, we can see that all the trophic levels in the ecosystem are dependent on each other.
Phytoplanktons are the producers (first trophic level), zooplanktons are the primary consumers (2nd trophic level), small fishes are secondary consumers (3rd trophic level) and then large fishes are tertiary consumers (4th trophic level) and then at last, snake and birds possess last trophic level, referred as Quaternary consumers.
Some advantages of cloth bags over the plastic bags during shopping are following:
1. Cloth bags are biodegradable and recyclable whereas plastic bags are non- biodegradable.
2. They can be used again and again in many purposes.
3. They do not affect the environment in any way.
4. They are strong and can carry more things than the plastic bags.
5. They do not require any maintenance.
6. They are long lasting and we cannot tear them easily.
Crop fields are known as artificial ecosystems because they are made by human beings. Crops are grain, forage, sugar, maize, wheat, rice, sugar cane or any other fibrous variety etc. or any herbaceous plants grown on the large scale pattern will be cultivated in fields.
| Biodegradable Substances | Non-Biodegradable Substances |
|---|---|
|
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a) Environment or Biotope
b) Trophic levels
c) Abiotic components
d) Consumers
Decomposers help in the breakdown of the dead organic matter and convert it into the inorganic materials that are released into the environment. The process of decomposition plays an important role in the ecosystem because it involves the release of nutrients from the dead organic matter. There are two main decomposers- bacteria and fungi.
Ecosystem- Biotic components of the environment
This is the mis- matched pair because the ecosystem is made up of both biotic and abiotic components.
An aquarium is a manmade or artificial ecosystem whereas ponds and lakes are natural ecosystems. An aquarium is a closed artificial ecosystem which needs proper care and proper cleaning at regular intervals because the waste generated by the fishes mixes with water and remains untreated due to lack of decomposers. Thus the waste accumulates in the water and provides toxicity which is harmful for the fishes.
Ponds and lakes need not be cleaned as they are the open and natural ecosystem. They contain decomposers to clean the waste generated in the water of all aquatic bodies.
An ecosystem does not have its own source of energy so they receive the energy from the sun. Total incoming solar radiations trapped by the producers (green plants) and change this energy into the chemical energy in the synthesis of food. When the green plants are eaten by the herbivores with the efficiency of energy capture 1% of sunlight, a lot of energy is lost as heat or consumed in the metabolic reactions for their growth and the rest is used for the development or reproduction. When the primary consumers are the herbivores 10% (10% law) of the amount of energy of herbivores is transferred to the primary consumers level and the same process repeats for the next trophic level with the sharing of 10% energy from the previous level. There can be only 4-5 trophic levels. Thus when the energy is transferred at each level, less amount of usable energy is available for the last trophic level. Flow of energy is always unidirectional and shows an upright pyramid.
Flow of energy is unidirectional because energy captured by the producers or the green plants does not revert back to the solar input but it passes to the herbivores for their metabolic reactions. And, when the energy is passed to the herbivores it does not go back to the producers but passes to the primary consumers or the carnivores. At each trophic level there would be a progressive decrease in the energy due to the energy being lost as heat in respiration, development and reproduction.
Bacteria and fungi are the decomposers which break down the complex substances into the constituent parts. They break down the dead or decay organic matter (plants, animals and waste products of animals) in nature into small and simple inorganic compounds and they get released into the environment. Decomposition process occurs by two ways:- 1st by the environmental conditions- step 1 is Humification and then 2nd Humus. 2nd by fragmentation, leaching or catabolism process- then mineralization will occur and then CO2, H2O nutrients will form.
If the decomposers are absent in the ecosystem, the recycling process will not take place. Then the accumulation of decay organic matter will occur and all the nutrients would remain locked in the dead parts of plants and animals which affect the maintenance of the environment.
There are some activities that we do in our daily life which are eco- friendly are as follows:
1. Carry cloth- bags to make purchases, we can deny the use of polythene bags that are provided by the shopkeepers because polythene is a non- biodegradable substance.
2. Switch off the unnecessary lights or fans for the conservation of energy, light and the bill.
3. Prefer walking instead of going on a scooter, we can minimise the use of petrol or diesel or can contribute in reducing the air pollution that is released by the vehicles, gases release like CO2.
4. Plantation in our surrounding.
5. Maximize the use of recyclable items in our daily life like glass or jars in the kitchen, remaining food can be used by composting it.
Food chain:
1. The sequential inter- linking of organisms involves the transfer of food in the form of energy from producers by the series of organisms with repeated eating and being eaten is referred to as the food chain.
Example:- Grassland ecosystem food chain and their different tropic levels
2. It is always straight and contains unidirectional flow of energy.
3. Higher trophic level organisms feed on lower trophic level.
Food web:
1. Food web is the network of the food chains which become inter- connected at different trophic levels to form a number of feeding connections among different organisms.
Example:- food web on land
2. It provides alternative pathways, the greater the alternative pathway more stable is the ecosystem. It helps in checking the overpopulation.
3. Members of the higher trophic level can feed on various lower trophic levels of other food chains.
There are some wastes generated in our house daily are as follows:-
1. Polythene bags
2. Milk empty packets, empty cartons
3. Waste water generated from RO, when tap remains on during brushing teeth, washing car, taking shower instead of using buckets.
4. Waste newspapers, bags collection.
5. Vegetables and fruit peels, remaining food.
6. Electrical waste
7. Household garbage
Some measures are taken for their disposal:
1. Waste papers can be converted into the usable papers and boards by the paper mills or can be given to the rag pickers for recycling.
2. Use the recyclable items like jars for putting pickles again and again, glass bottles like jam bottles can be used again in the kitchen for storage.
3. Close the taps while we are brushing our teeth or shaving or do not take shower, use a bucket and close the tap when it gets filled.
4. Use the waste water of the aqua guard for watering the plants or connect the waste water pipe of aqua guard to the tanks and use this water for the animals or the birds for drinking.
5. Switch off lights, fans and energy or light appliances when they are not in use. Use solar panels instead of generators or inverters.
6. Separate the biodegradable and non- biodegradable, recyclable or non- recyclable waste.
7. We can use the vegetable or fruit peels for composting which improves the soil fertility by adding it into the garden.
8. The household and other waste can be given to the waste collectors.
Some chemicals and gaseous pollutants affect the environment produced in the fertilizer industry. Some waste management mechanisms in fertilizer industries are as follows:-
1. Incineration:- It is the waste treatment process which involves the combustion of the organic substances in the waste material by treating them with the high temperature, also known as thermal treatment. It converts the waste material into the ash and heat.
2. Proper disposal:- Proper management of waste is important for the building to be sustainable etc.
3. Recycling:- this results in recycling of the old items for the next specific use. These old items are proceeded to recover and convert them into energy in the form of usable heat, fuel or electricity.
4. Reduction:- By reducing the amount of waste and it can occur through recycling the old items like jars, bags, plastic bottles etc. instead of buying the new ones. Or by reducing the use of single use plastic.
5. Composting:- It is a bio degradation process which takes up the leftover plant parts, garden or kitchen waste and converts them into the nutrient – rich which improves the soil fertility.
6. Landfills:- By throwing daily waste of the household and the others in the landfills is the most widely used mechanism. This mechanism focuses on burying the waste in the land instead of throwing them into the water bodies (leads to the water pollution).
7. To control the air pollution chimneys are used as the absorption equipment which absorb harmful pollutants before the release of gases into the atmosphere.
The waste management leads to a better and disease free environment. It also contributes to the well- beings of the living organisms. It reduces the pollution and recycling process helps to conserve the energy. Example when we recycle the old papers into the new ones, through this we are ultimately saving the trees from cutting down.
Mainly the by- products of the fertilizer industries are- oxides of nitrogen and oxides of sulphur. Apart from these carbon monoxides, carbon dioxide are the by - products of the fertilizer industry. They cause very harmful effects to the environment.
Oxides of nitrogen:- These include nitrogen monoxide (NO) and nitrogen dioxide (NO2).
Nitrogen monoxide lowers the oxygen carrying capacity of the blood and Nitrogen dioxide when reacting with water, it forms highly corrosive nitric acid (HNO3). Nitrogen dioxide can cause irritation in eyes, nose, bronchial tubes and lungs. Oxides of nitrogen damage the plants also, cause defoliation and necrosis (death of the part of the tissue or the organs) and when NOx reacts with hydrocarbons they form peroxyacyl nitrate, are responsible for photochemical smog. Nitrates are also responsible for the eutrophication.
Oxides of Sulphur:- These include sulphur dioxide (SO2) and sulphur trioxide (SO3)
By the burning of fossil fuels they form hydrogen sulphide (H2S). Sulphur oxides are harmful to the plants and animals as well as the buildings etc. they can cause respiratory diseases in human beings like asthma, bronchitis. When sulphur trioxide reacts with water they form sulphurous acid (H2SO3) and sulphuric acid (H2SO4), which are the main cause of the acid rain and this destroys the crops and the buildings (eg. Taj mahal).
Some harmful effects of agricultural practices are as follows:
1. Run off from the field sprayed with the nitrates of the fertilizers when dissolved in ground water or the soil it produces harmful effects or can kill many useful microbes, this will lead to eutrophication.
2. When the fertilizers are added to the agricultural field, a part of the fertilizer goes down into the soil and to the ground water, then this will lead to the increase in the salt content of ground water.
3. Pesticides are non- biodegradable and when the large number of pesticides sprayed over the crops reaches the river or the water bodies and kills the biota. When the concentration of the toxic material increases at each trophic level of the food chain is known as biomagnifications.
4. Excessive use of the ground water lowers the ground water level.
5. Cutting down of the trees (deforestation) for agriculture results in the loss of habitat and niches for the animals and it will cause damage to the natural environment.
6. Loss of soil productivity by erosion of the top soil results in the formation of deserts, known as desertification.