Altitudinal trends in photosynthetic rate and leaf characteristics of Miscanthus populations from central Taiwan

Abstract

Leaf photosynthetic rate and leaf characteristics including chlorophyll content, leaf width, leaf mass per area (LMA), stomatal density and the dimensions of guard cells were measured in C ₄ Miscanthus spp. growing along an altitudinal gradient from 390 to 2700 m in central Taiwan. The main objective of this study was to understand if morphological and physiological variation occur in leaves of the C ₄ plants growing along the altitudinal gradient. Measurements were taken during the growing season, May, July and September, of 1997. Photosynthetic rate, leaf width and guard cell dimensions decreased while LMA and stomatal density increased with altitude. The pattern of continuous variation in the analysed parameters suggests that it is related to some underlying environmental factors (mainly air temperature and CO ₂ concentration) associated with changing altitude.