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  • Cited by 13
  • Print publication year: 2010
  • Online publication date: June 2012

3 - Ecological insights from fern population dynamics

Summary

Key points

1. Any comprehensive population study of ferns is based on the demography of the three major stages of the life cycle of ferns (spore, gametophyte and sporophyte) and recognizes asexual alternatives to the main sexual life cycle such as apogamy and vegetative reproduction. Knowledge of spore and gametophyte viability and development in natural habitats is critical to our understanding of the life cycle of ferns and their ecology, but most studies have focused on the larger sporophyte.

2. Classifying sequential life history stages for ferns facilitates the assessment of growth and reproductive responses to environmental stimuli. Recognition of a life history stage in ferns is based on leaf and plant morphology because age estimates for fern individuals are complicated by several problems such as gradually decomposing older tissue in rhizomes of understory ferns and variable growth rates throughout the life of an individual tree fern.

3. Basic phenological variables (e.g., leaf count, leaf and spore production rates, and leaf life span) are monitored for a better understanding of seasonal patterns, population structure and biomass turnover. Factors that influence productivity of ferns have been addressed only recently for tropical species.

4. Population studies have compared different fern species within the same habitat and the ferns have shown surprising sensitivity to microhabitat characteristics. Recent investigations of fern population responses to altitudinal and latitudinal gradients and to environmental changes over time have been based on innovative monitoring methods and transition matrices of life history stages.

5. Future research in fern population dynamics should focus on the connection between critical demographic patterns in ferns and their relevance to comprehensive community and ecosystem studies by using consistent methodologies, expanding into larger geographic ranges (especially in tropical regions) and increasing the focus on long-term monitoring.

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