Growth pattern and photosynthetic activity of different bamboo species growing in the Botanical Garden of Rome

Growth pattern and photosynthetic activity of different bamboo species (Phyllostachys viridi-glaucescens Riviere et C. Riviere, Phyllostachys pubescens Mazel ex Lehaie, Phyllostachys bambusoides Siebold et Zucc., and Bambusa ventricosa McClure) growing at the Botanical Garden of Rome were studied. Among the considered species, P. pubescens had the highest mean culm height (14.3 +/- 0.6 m) and diameter (10.7 +/- 1.5 cm), while B. ventricosa had the lowest mean culm height (6.0 +/- 0.2 m) and internodes number (35 +/- 1). The highest net photosynthetic rates (NP) of the considered species were measured in early autumn, while the lowest ones in spring (30% of the maximum in the genus Phyllostachys), in the period of vegetative activity, and in winter (10% of the maximum in B. ventricosa). The correlation between NP and leaf temperature (LT) indicated that the favourable temperature enabling 50-100% of NP was in the range 2.2-32.1 and 16.2-36.3 degrees C for the genus Phyllostachys and B. ventricosa, respectively. According to their origin, the species of the genus Phyllostachys, originating in a temperate climate had a higher sensibility to high air temperatures than B. ventricosa, originating in a tropical and subtropical climate, and having a lower sensibility to low air temperatures. Owing to the great potential for biomass production bamboos could be a significant net sink for CO2 carbon sequestration; nevertheless, by the highest whole culm photosynthetic rate (WNP = 272 +/- 7.2 mu mol CO2 s(-1)), calculated by the total leaf surface area per culm. (28.6 +/- 1.1 m(2)) and the mean maximum yearly assimilation rate (9.5 +/- 4.5 mu mol m(-2) s(-1)), P. pubescens contributed in major role to carbon sequestration (14 +/- 0.6 kg CO2 year(-1) per culm) compared with the other considered species (on the average 3.0 +/- 1.6 kg CO2 year(-1), mean value). (C) 2008 Elsevier GmbH. All rights reserved