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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.
What is the significance of the slope of regression in a species-area relationship?
Short answer type question
Tropical regions exhibit species richness as compared to polar regions. Justify.
Extent of global diversity of invertebrates is shown in the pie diagram below. Choose the most appropriate alternative that the four portions (a-d) represent.
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
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?
Select the correct alternative for x and y.
Amongst the animal group given below, which one has the highest percentage of endangered species?
Which of the below mentioned regions exhibit lees seasonal variations?
Which of these is true about tropical environments?
Which of these is true about tropical environments?
Is it possible that productivity and diversity of a natural community remain constant over a time period of, say one hundred years?
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?
Who observed that within a region, species richness increased with increasing explored area, to a certain limit?
When pre-reproductive and post - reproductive age group is same in structure, the population is______.
