Actual evapotranspiration and crop coefficients for five species of three-year-old bamboo plants under a tropical climate

Over the last decade, bamboo plantations have started to be used as vegetation filters for wastewater treatment. This treatment system can be useful in reducing wastewater discharge into the environment, thus contributing to the preservation of water resources by using the plantationʹs evapotranspiration to reduce the rate of water infiltration. The evapotranspiration rates of the bamboo species used is therefore an important factor. The actual evapotranspiration (ET) and the crop coefficients (kc) for the five tropical and temperate species of three-year-old bamboo plants, i.e. Bambusa oldhamii, Bambusa multiplex, Bambusa vulgaris, Phyllostachys aurea and Pseudosasa japonica, were studied in lysimeters for a period of more than one year under a tropical climate. The average ET rates for the bamboo species studied ranged from 4 to 7 mm day−1 with maximum values of between 10.7 and 17.1 mm day−1 during the wet season, and an average kc of 1.1 to 1.9. The ET was correlated to weather parameters, especially minimum temperatures. The differences in ET rates between the bamboo species can be explained by morphological parameters, in particular the total aboveground biomass. Among the five bamboo species studied, B. oldhamii had the highest ET rate and produced the most biomass. In comparison with other high-biomass-producing plants, the evaporation rates for young bamboo plants were similar to those for willow and poplar vegetation filters.