干旱区生态环境知识资源中心

Variation in demography and life-history patterns of Tephrosia strigosa Willd., a summer annual of dry habitat, was studied under field conditions during 1988 and 1990 growing seasons. Seasonal data on persistent seed bank showed a substantial loss of seeds in the seed bank after dispersal especially after rainfall where seeds either germinated or were washed deep into the soil. A high degree of similarity was observed between the buried seed bank flora and vegetation. There was a significant increase in mortality soon after recruitment followed by little change in population size during late vegetative phase. Mortality rate again increased at the time of flowering. Vegetative growth of plants increases significantly at the seedling stage but declined at the time of flowering. Biomass allocated to reproduction increased with the increase in the size of the seedlings which was shared by roots and shoots and later by root, stem and leaf. During flowering and fruiting time the reproductive allocations approached up to 30%.