The ecology of ferns is a rapidly growing discipline that offers new and exciting insights into general ecological principles and applications. Progress has been made in studying fern biogeography, population dynamics, natural resource use, disturbance responses, species interactions and links with humans (Table 10.1). In this concluding chapter, we explore the lessons learned about each of these topics and how they clarify the ecological role of ferns. We then raise some unanswered questions that might become the foci for future research on fern ecology and improve the integration of ferns into general studies of ecology.
Ferns (and lycophytes) differ from seed plants in fundamental ways. Ferns have a different evolutionary background, phenology, nutrient acquisition patterns, adaptations to xeric environments, responses to disturbance, interactions with fungi and animals and invasion patterns that provide an excellent contrast to seed plants. However, ferns also share fundamental similarities with seed plants, especially herbaceous perennials. Ferns have similar physiological pathways of energy capture and nutrient distribution and share some common traits such as colonization abilities, habitat specificity, leaf function, growth patterns, vegetative propagation, population dynamics, species interactions (e.g., shading) and mycorrhizal infection. Examining differences and similarities between ferns and seed plants is one useful approach to the rapidly expanding field of fern ecology.
Biogeography: dispersal, habitats and diversity
Ferns have only one potentially long distance dispersal phase (spores) while seed plants have two (pollen and seeds). The ecological implications of these contrasting dispersal modes are unclear.