Population structure and regeneration strategy of some common legumes in grassland communities of Gorakhpur, India

Legumes are known for their ability to provide good herbage cover even in the presence of disturbance. They evolved diverse strategies to ensure their survival and spread in various communities by employing both seed and non-seed regeneration. Out of 25 legumes, 13 showed only seed germination and 12 species can regenerate by non-seed method too. Among the common legumes the population density was maximum for Desmodium triflorum and minimum for Zornia gibbosa. Population status for common legumes was quite stable in grassland communities facing moderate disturbance having large number of young individuals. Moderate disturbance also favoured ramet proliferation in case of D. triflorum and Alysicarpus monilifer. The inter-ramet distance in case of D. triflorum showed significant difference (P < 0.05) along its age series among three disturbance levels as evident from F-test. Difference between the percentage of germination in open and light were significant at 5% P-level (paired t-test) for Alysicarpus vaginalis, Cassia occidentalis, Crotalaria sericea and Tephrosia purpurea. Relative light germination was maximum for C. occidentalis followed by A. vaginalis. The results are of considerable significance with respect to regeneration of legumes and maintenance of their population in grasslands of Gorakhpur. Besides information on the present status of common legumes, the result provides clues for management option in these grasslands and for the maintenance of legume diversity in such stochastic environment.