Effects of nine years of mowing on tallgrass prairie grassland community, and, Review of the ecology of montane grasslands of the Western Ghats.

摘要

The thesis reported is a two chapter study on grassland their ecology, diversity and conservation primarily at the level of community. The first chapter is a study on the how mowing maintains small scale species richness of tall grass prairie grassland community. A grid of 144 1m2 permanent plots was established at north central Oklahoma and a fixed mowing regime was maintained for a period of 9 years since 1996. The study demonstrated that species richness generally increased under mowing irrespective of the mowing treatment and mowing favored species with prostrate habits or perennials. Species composition showed significant changes under various combinations of mowing treatments, except for mowing frequency, season of mowing and time-period of mowing showed significant effects on species composition. Mowing over long time-periods showed a shift in species composition, while season of mowing appeared to favor species that seed outside mowed season.; The second chapter is a review on the montane-grasslands of Western Ghats, in South India which is located approximately 8° N of the equator. These tropical montane grasslands are famous for the endemic Nilgiri Tahr (Hemitragus hylocrius) that inhabits these grasslands. This review compiles and evaluates the literature to identify the conservation potential of these grasslands. Studies on these grasslands have suggested that these grasslands with adjacent forests are likely to be frost controlled. Long history of anthropogenic activities have been recorded on these grasslands, hence the role cattle grazing and pastoral burning are also likely to play key role in modulating these grassland systems. However, there is a lack of more comprehensive well planned long-term studies for the management of these grasslands.