SHEEP GRAZING STIMULATED PLANT AVAILABLE SOIL NITRATE ACCUMULATION IN A TEMPERATE GRASSLAND

摘要

Seed bank studies of Peristrophe paniculata was carried out for two consecutive years at two different sites. Although,both the sites were dominated by P. paniculata, however differ in vegetation pattern. Site ‘A’ possessed populations ofannuals fully exposed to sunlight. While, site ‘B’ possessed annuals along with perennials located in somewhat shady area.Input to the seed bank was mainly determined by the seed dispersal. Persistent seed bank was observed in annual plantspecies with increasing numbers in the third collection (i.e. after seed dispersal). On the other hand, perennial plants mostlyexhibited transient nature of seed bank, with no or low numbers in some collections. Significant difference in seed numberswas observed on temporal and spatial scale. Seed densities were higher in the samples collected before rainfall and afterdispersal of seeds at both the sites in both the years. High degree of similarity was observed between above and belowground vegetation; however this similarity was more pronounced at site ‘B’ which was located in shady area, thus providingbetter soil moisture conditions for seed germination. Moreover, above and below ground vegetation was diverse andflourished in 2013, due to high germination rates, followed by heavy summer rains, providing ample amount of moisturealong with high temperature. This study can be used to predict the above ground vegetation and vise versa.