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Shannon-Weaver Diversity Index:
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The Shannon-Weaver Diversity Index (H) is a measure of species diversity in a community. It accounts for both species richness (number of species) and evenness (distribution of individuals among species). Higher values indicate greater diversity.
The calculator uses the Shannon-Weaver formula:
Where:
Explanation: The index increases as both the number of species and the evenness of their proportions increase.
Details: The Shannon-Weaver index is widely used in ecology, environmental science, and conservation biology to assess biodiversity, monitor ecosystem health, and evaluate the impact of environmental changes.
Tips: Enter species proportions as comma-separated values (e.g., 0.2,0.3,0.5). All proportions must be between 0 and 1, and the sum must equal 1.
Q1: What is a good Shannon-Weaver index value?
A: Values typically range from 0 to 4-5. Higher values indicate greater diversity. Values below 1.5 indicate low diversity, 1.5-3.5 moderate diversity, and above 3.5 high diversity.
Q2: How does this differ from Simpson's diversity index?
A: Shannon-Weaver is more sensitive to species richness, while Simpson's is more influenced by dominant species. Both provide complementary information about diversity.
Q3: Can I use this for non-biological data?
A: Yes, the Shannon-Weaver index can be applied to any data where you want to measure the diversity or uncertainty in a distribution, such as in information theory.
Q4: What if my proportions don't sum to exactly 1?
A: The calculator requires proportions to sum to 1 (within a small tolerance). You may need to normalize your data before input.
Q5: How should I interpret the results?
A: Compare the index value with other communities or track changes over time. Higher values indicate more diverse and stable ecosystems.