Phylogenetic and functional dissimilarity does not increase during temporal heathland succession

Area of Science:

• Community Ecology
• Evolutionary Ecology
• Plant Ecology

Background:

• Succession is a core ecological concept, but rarely studied using modern phylogenetic and trait-based methods.
• Most studies use static snapshots, limiting understanding of community assembly dynamics.
• Long-term data are crucial for testing theories on community trajectories.

Purpose of the Study:

• To investigate phylogenetic and functional diversity changes during ecological succession.
• To analyze community assembly in a fire-prone heathland over 21 years.
• To compare temporal dynamics with existing ecological theories.

Main Methods:

• Utilized a 21-year time series dataset from a fire-prone heathland.
• Measured within- and between-community phylogenetic diversity.
• Assessed functional diversity and trait shifts over time.

Main Results:

• Communities became more phylogenetically and functionally clustered as succession progressed.
• Significant directional shifts in species traits were observed, indicating deterministic processes.
• Phylogenetic and functional turnover were low relative to taxonomic turnover, suggesting functional redundancy.

Conclusions:

• Contrary to expectations, increased competition did not prevent clustering of related species.
• Deterministic processes shape communities, but functional redundancy may buffer against strong limiting similarity.
• Fine-scale analyses rarely show strict limits to the similarity of coexisting species.