Physiological ecology of ferns: Biodiversity and conservation perspectives

Ferns have a long geological record extending over millions of years, and they are distributed in diverse environments worldwide; including swamps, coastal locations, open grasslands, mountain terrains, drylands and deserts. Consequently, their physiological ecology is rich with examples of the fern species diversity, and remarkable adaptive variability. This is a review of some major aspects of their physiological ecology (that is, water relations and desiccation tolerance, light and photosynthesis, and temperature and physiological responses), focusing on terrestrial and epiphytic ferns in diverse global geographic locales. Ferns are important economically in horticultural commerce and provide significant ecological services. Climate change and destruction of their natural habitats may lead to extensive loss of fern biodiversity; and some of the current issues related to the protection of their natural habitat and conservation of fern species are addressed.   Key words: Biological adaptation, climate change, geographic distribution, human impact, plant evolution.