You-Gui Tong1, Shing Yip Lee1, Brian Morton1
1The Swire Institute of Marine Science and Department of Ecology and Biodiversity, The University of Hong Kong, Cape d'Aguilar, Shek O, Hong Kong
Tóm tắt
The effects of defoliation on leaf and propagule production, and leaf chemistry
of the mangrove Kandelia candel (L.) Druce were evaluated in a manipulative experiment in
Hong Kong. Artificial defoliation of leaf lamina at 50% of the length of midrib resulted in
significant reduction in leaf, twig and propagule production, and size of the latter. Through the
negative effects on propagule number and size, severe herbivory may influence fitness of the
mangrove, and, thus, community structure. In contrast, no apparent adverse effects on growth and
production were observable at 25% defoliation. Defoliation also significantly affected leaf
chemistry of the trees, particularly those suffering 50% defoliation. Concentrations of soluble
tannins and carbohydrates in leaves were significantly lower at 50% defoliation compared with the
control. Total nitrogen also decreased significantly with increased per cent defoliation. Plants
surviving in stressful habitats, such as mangroves, are probably more affected by loss of leaf
biomass than those surviving in favourable environments.
