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प्रश्न
Give three hypotheses for explaining why tropics show greatest levels of species richness.
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उत्तर
Such hypotheses are as follows:
- Speciation is generally a function of time. Temperate regions have been subjected to repeated glaciation since ancient times, while tropical latitudes have been undisturbed for millions of years. Hence, there has been a longer time for species evolution and diversification.
- The tropical environment is different from the temperate environment and shows fewer seasonal changes. This stable environment has encouraged niche specialisation, which has led to greater species diversity.
- More solar energy is available in tropical regions, which leads to greater productivity, indirectly leading to more extraordinary biodiversity.
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संबंधित प्रश्न
The following graph shows the species-area relationship. Answer the following questions as directed.

(a) Name the naturalist who studied the kind of relationship shown in the graph. Write the observations made by him.
(b) Write the situations as discovered by the ecologists when the value of ‘Z’
(Slope of the line) lies between:
- 0.1 and 0.2
- 0.6 and 1.2
What does ‘Z’ stand for?
(c) When would the slope of the line ‘b’ become steeper?
What is the significance of the slope of regression in a species-area relationship?
The 'rivet' in the rivet popper hypothesis is considered to represent the ______.
With reference to graph select the correct alternative
All are true regarding graph showing species richness - area relationship, EXCEPT ______.
Which of the following is an observation of Alexander von Humboldt's documented pattern in ecology?
The graph of species richness and area for a number of taxa like angiospermic plants, freshwater fishes, and birds is found to be ______.
Select the correct alternative for x and y.

Which of these is true about tropical environments?
Which of these is true about tropical environments?
What does the term ‘Frugivorous’ mean?
A species-area curve is drawn by plotting the number of species against the area. How is it that when a very large area is considered the slope is steeper than that for smaller areas?
Is it possible that productivity and diversity of a natural community remain constant over a time period of, say one hundred years?
Is it true that there is more solar energy available in the tropics? Explain briefly.
Species diversity decreases as we move away from the equator towards the poles. What could be the possible reasons?
The relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola. Give a brief explanation.
Study the graph given below:

As per Alexander von Humboldt, what do the symbols S, A, Z and C in the graph stand for, in respect of a species and area relationship?
Lesser variation in biomass production over a period of time is called ______.
For frugivorous (fruit-eating) birds and mammals in the tropical forests of different continents, the slope of the species-area relationship is found to be approximately ______.
Which of the following hypothesis suggests that ecosystems are like aeroplanes where flight safety (ecosystem functioning) may or may not be compromised, depending upon which species are being lost?
Rivet Popper Hypothesis is an analogy to explain the significance of ______.
Tropical regions show greatest level of species richness because -
- Tropical latitudes have remained relatively undisturbed for millions of years, hence more time was available for species diversification.
- Tropical environments are more seasonal.
- More solar energy is available in tropics.
- Constant environments promote niche specialization.
- Tropical environments are constant and predictable.
Choose the correct answer form the options given below:
