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प्रश्न
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?
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उत्तर
Ecologists have discovered that the value of Z (slope of the line) lies in the range of 0.1 to 0.2, regardless of the taxonomic group or the region (whether it is the plants in Britain, birds in California or molluscs in New York state, the slopes of the regression line are amazingly similar). But, if you analyse the species-area relationships among very large areas like the entire continents, you will find that the slope of the line is much steeper (Z values in the range of 0.6 to 1.2). For example, for frugivorous (fruit-eating) birds and mammals in the tropical forests of different continents, the slope is found to be 1.15.
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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?
Explain, giving three reasons, why tropics show greatest levels of species diversity.
On a log scale the relationship of species richness and area becomes linear (straight line) and is given by the equation.
With reference to graph select the correct alternative
The graph of species richness and area for a number of taxa like angiospermic plants, freshwater fishes, and birds is found to be ______.
Which of these is true about tropical environments?
The pattern of biodiversity is affected by ______.
Which of the following countries has the highest biodiversity?
Amongst the animal groups given below, which one appears to be more vulnerable to extinction?
Is it possible that productivity and diversity of a natural community remain constant over a time period of, say one hundred years?
There is greater biodiversity in tropical /subtropical regions than in temperate region. Explain.
Is it true that there is more solar energy available in the tropics? Explain briefly.
The relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola. Give a brief explanation.
Write the inference drawn by Alexander von Humboldt after his extensive explorations of South American jungle.
The relation between species richness and area for a wide variety of taxa appears as ______.
Rivet Popper Hypothesis is an analogy to explain the significance of ______.
Match the scientist in column I with their contribution in column II and choose the correct option.
| Column I | Column II | ||
| i. | Alexander Van Humboldt | a. | Estimated 7 million species round the globe |
| ii. | Robert May | b. | Rivet popper hypothesis |
| iii. | David Tillman | c. | Species Area Relationship |
| iv. | Paul Ehrlich | d. | Productivity stability hypothesis |
Which of the following environmental conditions becomes harsher as altitude increases on a mountain slope?
What does the variable S represent in the species-area formula log S = log C + Z log A?
What does the variable Z represent in the species-area relationship formula log S = log C + Z log A?
