Seedling recruitment and age-specific survivorship and reproduction in populations of Avena sterilis L. ssp. ludoviciana (Durieu) Nyman

Demography of this annual grass weed was studied on populations growing in winter wheat Triticum aestivum crops in C Spain. Seedling emergence took place from mid-October to mid-April, with a peak in November-December. The progress of emergence was described by a logistic model, closely related to cumulative rainfall during that period. Total seedling recruitment from the seed bank ranged from 31-46%. Average seedling survivorship ranged from 31-81%. Within each season, survivorship was highly variable for the different cohorts. The major causes of mortality during the life-cycle were pre-planting tillage, frost and drought stress and inter- and intraspecific competition. Average adult fecundity varied from 13-21 seeds per plant. Fecundity was highly dependent on age of the plant. The relationship between plant age and fecundity was well described by a negative exponential model. Overall, cohorts emerging soon after wheat planting were the most successful ones, having the largest contribution to the next generation.-from Authors