The composition and dynamics of associated plant communities of sal plantations.
Developing plant communities with sal (Shorea robusta) as the main forest tree crop, were studied at two sites (Ramgarh and Lachhmipur) in the Gorakhpur Forest Division, Uttar Pradesh, in order to obtain data on their composition, structure and dynamics through a series of 5-, 10-, 20- and 40-yr-old stands (established by the taungya system). Despite the similarity in soil, topography and general climate of the two sites, differences were apparent in several phytosociological indices. Data are given on frequency, density, basal cover and Importance Value Index (IVI) for all species present, and also on constance [constancy] value, similarity index, and indices of dominance, species diversity and evenness. At both sites Diospyros tomentosa and Syzygium cumini increased in frequency and density in higher age groups, while Holarrhena antidysenterica [H. pubescens] decreased in density with increasing maturity. Differences between the sites were exemplified by the shrub stage which at Ramgarh was dominated by Jatropha and at Lachhmipur by Moghania, while the 40-yr-old stands were dominated respectively by Pterocarpus and Bauhinia. However, species growing in association with sal were little affected by site. Close associates included Mallotus philippinensis [M. philippensis], S. cumini, Clerodendron [Clerodendrum] infortunatum and Tiliacora acuminata. Associates used locally for medicinal and other purposes were less common at Ramgarh, which was nearer Gorakhpur town. It is suggested that study of the dynamics of associate species may be a useful monitoring technique for the sal system.