Defining plant ecological specialists and generalists: Building a framework for identification and classification

Area of Science:

• Ecology
• Evolutionary Biology
• Conservation Biology

Background:

• Ecological specialization is a key concept but lacks a standardized, quantifiable definition.
• Ambiguity in specialization hinders cross-study comparisons and scientific clarity of terms like "specialist" and "generalist."

Purpose of the Study:

• To develop and apply a metric-based framework for quantifying specialization in 141 oak (Quercus) species.
• To investigate the influence of functional traits, biogeography, species interactions, phylogenetics, and conservation status on specialization.

Main Methods:

• Quantified specialization using five metrics based on functional traits, biogeography, and species interactions across 141 Quercus species.
• Employed Ancestral Character State Reconstruction and Automatic Shift Detection for phylogenetic analyses.
• Correlated specialization rankings with expert assessments and IUCN Red List threat levels.

Main Results:

• Specialization showed a strong correlation with precipitation seasonality and moderate influence from evolutionary history.
• Data-deficient species tended to be more specialized, and higher specialization correlated with increased IUCN threat levels.
• Metric-based rankings aligned with expert assessments and conservation data, providing a practical measure of specialization.

Conclusions:

• A metric-based framework offers a consistent and practical method for quantifying ecological specialization.
• Quantifying specialization can reveal insights into evolutionary history and geographic distribution, aiding conservation strategies.
• This framework can identify species at risk and inform conservation priorities across diverse ecological systems.