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DEMOGRAPHIC STUDIES OF
IPOMOEA SINDICA STAPF, A DESERT SUMMER ANNUAL
SEEMI AZIZ AND SYED
SHAHID SHAUKAT
Abstract:
This study focuses on
the population ecology of a desert summer annual, Ipomoea sindica
Stapf, the abundant flora after the monsoon rains in Karachi, Sindh. Two
sites were selected for the study, designated as site ‘A’ and ‘B’. Site
‘A’ was dry having low water holding capacity, on the other hand, site
‘B’ had high water holding capacity. Vegetation was comparatively sparse
at site ‘A’, whereas, relatively high water holding capacity and
nutrient status of the soil ‘B’, presumably enable the population to
flourish with higher densities. I. sindica exhibited Deevey type
I survivorship curves at both the sites. Plants inhabiting site
‘B’showed better vegetative and reproductive growth than those surviving
at site ‘A’. Large quantity of seeds were present in the buried seed
pool. Their number decreased after the monsoon rains i.e., after the
germination of seedlings. Rise in the seed bank was observed after
dispersal from the existing vegetation, thus exhibiting persistent type
of seed bank. I. sindica produces heavy seeds in smaller numbers. That’s
why the dispersal distance travelled by the seeds was less. Most of the
seeds fall near the mother plant due to their heavy weight and
horizontal growth of plants.
Department of Botany, University of Karachi,
Karachi-75270, Pakistan.
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