Functional Diversity
Also known as: functional traits, trait diversity, ecological niche, functional space
Functional diversity quantifies the range and abundance distribution of functional traits (morphology, physiology, behavior) among species in a community. Developed by Mouillot and colleagues (2008), functional diversity indices measure how different species are in their ecological roles and resource use strategies. Unlike species richness (number of species), functional diversity captures the breadth of ecological strategies, predicting ecosystem function and stability.
Key highlights
- Captures ecosystem functional organization beyond species identity, predicting stability and function
- Decomposes diversity into multiple dimensions (richness, evenness, divergence) revealing different community assembly patterns
- Trait-based approach is mechanistic: directly links species' ecological roles to ecosystem processes
- Applicable to any community and any set of traits, enabling broad comparative analysis
Intuition
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How it works
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When to use it
Use functional diversity analysis to assess ecosystem stability and functioning, compare communities beyond species lists, or predict ecosystem response to species loss. Requires comprehensive trait data; incomplete data bias results. Most powerful when traits are directly linked to ecosystem function (e.g., leaf nitrogen content predicts productivity).
Strengths & limitations
- Captures ecosystem functional organization beyond species identity, predicting stability and function
- Decomposes diversity into multiple dimensions (richness, evenness, divergence) revealing different community assembly patterns
- Trait-based approach is mechanistic: directly links species' ecological roles to ecosystem processes
- Applicable to any community and any set of traits, enabling broad comparative analysis
- Requires comprehensive trait data; incomplete trait matrices bias richness estimates
- Trait selection is subjective; different traits may yield different conclusions about functional diversity
- Distance metrics are arbitrary; Euclidean distance assumes traits are independent (often false)
- Does not account for trait correlations; species cannot occupy all combinations of trait values
Common pitfalls
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Applications
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Frequently asked
What traits should I measure?
Choose traits directly related to ecosystem function or resource use: leaf nutrient content, body size, diet breadth, reproductive mode, habitat use. Avoid phylogenetically conserved traits (all congeneric species identical) as they add redundancy. Pilot studies help identify key trait axes.
How do I handle missing trait data?
If <20% missing: delete species or traits. If >20%: use imputation (phylogenetic prediction, mean-filling). Perform sensitivity analysis: recompute indices with and without imputation to assess robustness.
Which functional diversity index should I use?
FRic quantifies breadth of trait space; FEve quantifies evenness; FDiv quantifies differentiation. Use all three for complementary information. For simple comparisons, FRic alone is often sufficient.
Sources
- 1.Villéger, S., Mason, N. W., & Mouillot, D. (2008). New multidimensional functional diversity indices for a multifaceted framework in functional ecology. Ecology, 89(8), 2290-2301.
- 2.Mason, N. W., Mouillot, D., Lee, W. G., & Wilson, J. B. (2005). Functional richness, functional evenness and functional divergence: the primary components of functional diversity. Oikos, 111(1), 112-118.
- 3.Petchey, O. L., & Gaston, K. J. (2002). Functional diversity (FD), species richness and community composition. Ecology Letters, 5(3), 402-411.
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Cite this page
ScholarGate. (2026, June 3). Functional Diversity. ScholarGate. https://scholargate.app/ecology/functional-diversity