Abstract

Adiantum capillus-veneris is a cosmopolitan, globally distributed terrestrial fern in warm temperate to tropical regions. It is also widely cultivated in indoor and outdoor settings. The natural habitat of A. capillus-veneris includes limestone rocky places with consistent sources of water, including shady alkaline, moist cliffs and on vertical surfaces in moist forested locations, preferably with calcareous soils; however, it is also found on sandstone. There is increasing evidence that it is relatively tolerant of desiccation stress, under appropriate environmental circumstances. This is a report of a laboratory-based study of the photophysiology of A. capillus-veneris, including an analysis of the effects of leaf excision and varied degrees of desiccation on leaf resilience and physiological properties, with comparisons to Nephrolepis exaltata (L.) Schott and Adiantum tibeticum Ching. Evidence is also presented on the rate of excised leaf desiccation in relation to the role of humidity in mitigating stress due to limited access to moisture. The ecophysiologial variables examined include: Variations in photosynthesis rate relative to light intensity, dark respiration rate, leaf parameters including chlorophyll concentration index (CCI), specific leaf area (SLA), and leaf fluorescence evidence for functioning of photosystem II (PS II).

Key words: Adaptation, climate change, comparative physiology, desiccation stress, environmental research, functional anatomy, leaf fluorescence analysis, physiological ecology.