Microbial Diversity Analyzer

Calculate and analyze microbial diversity with Shannon Index, Simpson Index, and other ecological metrics.

Alpha Diversity
Beta Diversity
Sample Comparison

Alpha Diversity: Measures the diversity within a single sample, including species richness and evenness.

Key Metrics: Shannon Index, Simpson Index, Species Richness, Evenness

Give your sample a descriptive name for reference

Species Abundance Data

Enter the abundance (count or relative abundance) for each species in your sample.

Beta Diversity: Measures the difference in species composition between samples.

Key Metrics: Bray-Curtis Dissimilarity, Jaccard Index

Save samples in the Alpha Diversity tab to compare them here.

Sample Comparison: Compare diversity metrics between multiple samples.

Visualize differences in species composition and diversity indices.

Save samples in the Alpha Diversity tab to compare them here.
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Saved Samples

Understanding Microbial Diversity

Microbial diversity refers to the variety of microorganisms in a particular environment. It encompasses both the number of different species (richness) and their relative abundances (evenness).

Types of Microbial Diversity:

  • Alpha Diversity: Diversity within a single sample or habitat
  • Beta Diversity: Difference in diversity between samples or habitats
  • Gamma Diversity: Total diversity across multiple samples or habitats

Diversity Metrics

Metric Formula Interpretation Range
Shannon Index (H') H' = -Σ(pi ln pi) Measures species richness and evenness 0 to ∞ (typically 1.5-3.5)
Simpson Index (λ) λ = Σ(pi)2 Probability two random individuals are same species 0 to 1
Inverse Simpson (1/λ) 1/λ Effective number of common species 1 to S (species count)
Species Richness (S) S = number of species Total number of different species 1 to ∞
Pielou's Evenness (J') J' = H' / ln(S) How evenly individuals are distributed among species 0 to 1
Chao1 Index Chao1 = S + (F1² / 2F2) Estimates total species richness S to ∞

Diversity Classification

Shannon Index Range Diversity Level Interpretation Typical Environments
< 1.5 Low Few dominant species, low evenness Extreme environments, heavily disturbed sites
1.5 - 2.5 Moderate Moderate species richness and evenness Many natural environments, healthy gut
2.5 - 3.5 High High species richness and evenness Diverse ecosystems, healthy soil
> 3.5 Very High Very high species richness and evenness Highly diverse ecosystems, coral reefs

Factors Affecting Microbial Diversity

1

Environmental Conditions: pH, temperature, moisture, oxygen availability

2

Nutrient Availability: Carbon, nitrogen, phosphorus, and other essential nutrients

3

Disturbance: Physical disruption, pollution, antibiotics

4

Competition and Predation: Interactions between microbial species

5

Host Factors: In host-associated microbiomes (gut, skin, etc.)

Applications of Diversity Analysis

  • Ecological Monitoring: Assess ecosystem health and response to environmental changes
  • Human Health: Evaluate gut microbiome health and dysbiosis
  • Agriculture: Study soil health and plant-microbe interactions
  • Biotechnology: Optimize microbial communities for industrial processes
  • Conservation: Monitor microbial diversity in endangered ecosystems

Interpretation Note: Diversity indices should be interpreted in the context of the specific environment and research question. There is no universal "ideal" diversity level - what constitutes healthy diversity depends on the ecosystem and the organisms being studied.

Frequently Asked Questions

Species richness refers to the total number of different species present in a sample. Species evenness refers to how equally the individuals are distributed among those species. A community with high richness but low evenness would have many species, but most individuals belong to just a few dominant species. A community with high evenness has individuals more evenly distributed across all species.

The Shannon Index is more sensitive to changes in rare species, while the Simpson Index is more influenced by dominant species. Use Shannon when you're interested in overall diversity including rare species. Use Simpson when you're more concerned with the probability of encounters between different species or when dominant species are of particular interest. Many studies report both indices to provide a more complete picture.

High beta diversity indicates that the samples being compared have very different species compositions. This could mean they come from different habitats, have been exposed to different environmental conditions, or represent different time points in a changing ecosystem. Low beta diversity suggests the samples are similar in their species composition.

There's no fixed number, as it depends on the ecosystem and your research question. Generally, you want enough species to reasonably represent the community. For many microbial communities, including the 20-50 most abundant species often captures the majority of diversity. Rarefaction curves can help determine if you've sampled enough to capture the true diversity.

Direct comparison of absolute diversity values between different studies can be problematic due to differences in sampling methods, sequencing depth, and bioinformatics pipelines. It's better to compare relative differences within the same study using consistent methods. If comparing between studies, focus on patterns and trends rather than absolute values, and ensure the methodologies are as similar as possible.