A multidimensional framework for measuring biotic novelty: How novel is a community?

Area of Science:

• Ecology
• Environmental Science
• Conservation Biology

Background:

• Anthropogenic changes drive ecosystem transformations, creating novel ecosystems with unprecedented species assemblages.
• Current metrics for biotic novelty often fail to capture functional and evolutionary dimensions.
• Understanding ecological novelty is crucial for assessing environmental change impacts.

Purpose of the Study:

• To introduce the Biotic Novelty Index (BNI), a multidimensional measure for quantifying ecological novelty.
• To integrate functional differences and temporal dynamics of species introductions into novelty assessment.
• To provide a flexible framework for measuring biotic novelty across various scales and data qualities.

Main Methods:

• Developed the Biotic Novelty Index (BNI) as an additive partition of Rao's quadratic entropy.
• Incorporated functional trait differences between native and non-native species.
• Included temporal dynamics of species introductions.
• Applied the BNI to dry grassland plant communities along an urbanization gradient and national-scale plant assemblages.

Main Results:

• The BNI effectively quantifies the novel interaction component of functional diversity.
• Simulations demonstrated predictable variation in BNI with functional novelty from recent arrivals.
• Case studies showed strong correlations between biotic novelty and urbanization (abiotic novelty).
• The BNI proved applicable across different scales and data qualities.

Conclusions:

• The Biotic Novelty Index (BNI) offers a robust framework for measuring ecological novelty.
• BNI aids in understanding the ecological and evolutionary consequences of global change.
• The index's flexibility supports diverse ecological research applications.