Class 12 · Biodiversity and Conservation

Species-Area Relationship Z Values — NEET Biology

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Ecologists have discovered that the value of Z 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 to be 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. What do steeper slopes mean in this context?

NCERT Biology · Class 12 · Chapter 13 · Paragraph 17
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In the species–area graph, if the slope Z becomes steeper, what does this indicate biologically?

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