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Pakistan Journal of Biological Sciences

Year: 2000 | Volume: 3 | Issue: 12 | Page No.: 2041-2047
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Research Article

Regeneration ecology of Chrysopogon aucheri and Cymbopogon jwarancusa in upland Balochistan: III. Effects of precipitation and seedbed microhabitat on seedling recruitment

S. Ahmad, C.A. Call, E.W. Schupp and E.W. Schupp

ABSTRACT

A number of seven microhabitats evaluated for seeding establishment were: under the canopy of Chrysopogon aucheri plants, under the canopy of Chrysopogon jwarancusa plants, within dead centers of Cymbopogon sucheri plantws, within dead centers of Cymbopogon jwarancuse plants, under the canopy of Artemisia maritima plants, gravel interspaces between plants, and soil interspaces between plants. Seeding emergence and establishment were evaluated under the natural precipitation regime of the 1997 growing season and a simulated, above-normal precipitation regime. Soil moisture and soil temperature data were recorded during the entire growing season. Above-normal precipitation increased the density of emerged seedlings for both species in all microhabitats. Cymbopogon jwarancusa had higher seedling densities than Chyrsopogon aucheri. Monsoon rains in late July 1997 enhanced emergence of both species from recently disappeared seeds. Seedling of both species emerged after monsoon rains but did not survive to the end of the growing season. Gravel interspaces were suitable microhabitats for seedling development, possibly due to the vertical entrapment of dispersal units and reduced competition from more distant, established plants. Above-normal precipitation did not have a significant effect on tiller development for either species. Cymbopogon jwarancusa seedling developed more tillers per plant than Vhyrysopogon aucheri seedlings.
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