Human activities interfere with carbon cycle. List any two such activities.
Human activities have significantly influenced the carbon cycle. Rapid deforestation and massive burning of fossil fuel for energy and transport have significantly increased the rate of release of carbon dioxide into the atmosphere.
Given below is a figure of an ecosystem. Answer the following questions.
(i) What type of ecosystem is shown in the figure?
(ii) Name any plant that is characteristic of such ecosystem.
A farmer harvests his crop and expresses his harvest in three different ways.
(a) I have harvested 10 quintals of wheat.
(b) I have harvested 10 quintals of wheat today in one acre of land.
(c) I have harvested 10 quintals of wheat in one acre of land, 6 months after sowing.
Do the above statements mean one and the same thing. If your answer is yes, give reasons. And if your answer is ‘no' explain the meaning of each expression.
What is primary productivity? Give brief description of factors that affect primary productivity.
Among bryophytes, lichens and fern which one is a pioneer species in a xeric succession?
Why is the rate of assimilation of energy at the herbivore level called secondary productivity?
What will happen to an ecosystem if:
(a) All producers are removed;
(b) All organisms of herbivore level are eliminated; and
(c) All top carnivore population is removed
Arrange the following as observed in vertical stratification of a forest: Grass, Shrubby plants, Teak, Amaranths
Fill in the blanks.
(a)Plants are called as————- because they fix carbon dioxide.
(b)In an ecosystem dominated by trees, the pyramid (of numbers) is————- type.
(c)In aquatic ecosystems, the limiting factor for the productivity is————- .
(d)Common detritivores in our ecosystem are————- .
(e)The major reservoir of carbon on earth is————- .
Sometimes due to biotic/abiotic factor the climax remain in a particular serai stage (pre climax) without reaching climax. Do you agree with this statement? If yes, give a suitable example.
A part from plants and animals, microbes form a permanent biotic component in an ecosystem. While plants have been referred to as autotrophs and animals as heterotrophs, what are microbes referred to as? How do the microbes fulfil their energy requirements?
In relation to energy transfer in ecosystem, explain the statement "10 kg of deer's meat is equivalent to 1 kg of lion's flesh".
Name an omnivore which occurs in both grazing food chain and the decomposer food chain.
Climax stage is achieved quickly in secondary succession as compared to primary succession. Why?
The rate of decomposition of detritus is affected by the abiotic factors like availability of oxygen, pH of the soil substratum, temperature etc. Discuss.
Flow of energy through various trophic levels in an ecosystem is unidirectional and non-cyclic. Explain.
Give two examples of artificial or mail made ecosystems. List the salient features by which they differ from natural ecosystems.
What is a biogeochemical cycle? What is the role of the reservoir in a biogeochemical cycle? Give an example of a sedimentary cycle with reservoir located in earth's crust.
Poaching of tiger is a burning issue in today's world. What implication would this activity have on the functioning of the ecosystem of which the tigers are an integral part?
Justify the following statement in terms of ecosystem dynamics. "Nature tends to increase the gross primary productivity, while man tends to increase the net primary productivity".
Which of the following ecosystems will be more productive in terms of primary productivity? Justify your answer. A young forest, a natural old forest, a shallow polluted lake, alpine meadow.
Under what conditions would a particular stage in the process of succession revert back to an earlier stage?
What will be the P/R ratio of a climax community and a pioneer community? What explanation could you offer for the changes seen in P/R ratio of a pioneer community and the climax community?
Distinguish between
(a)Grazing food chain and detritus food chain
(b)Production and decomposition
(c)’Upright and inverted pyramid
(d)Food chain and food web
(e)Litter and detritus
(f)Primary and secondary productivity
