Cohort-dependent seedling recruitment, survival and reproductive capacity of Tribulus terrestris |
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| Authors: | A M C VERDÚ & M T MAS |
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| Institution: | Escola Superior d'Agricultura de Barcelona, DEAB-Universitat Politècnica de Catalunya, Av. Canal Olímpic s/n, Castelldefels, Barcelona, Spain |
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| Abstract: | Knowledge of the population biology of the summer annual Tribulus terrestris can provide valuable information for managing the risk of its colonising crop fields. Because of spring‐summer crop management practices, fields can exhibit bare ground in late April and early May. In this situation, four cohorts in 2000 and three cohorts in 2001 were censused and monitored throughout the vegetative and reproductive season, in order to evaluate the relationship between time of emergence, survival, vegetative growth and plant reproductive capacities. To a great extent, seedling survivorship depended on emergence timing; the earlier the emergence of the seedlings, the higher was the proportion of survivorship (64% and 4%, for early and late emergences). The time of emergence also influenced plant development; in both years, surviving individuals of the first cohorts presented significantly greater plant biomass and larger numbers of reproductive structures (60.5 fruits per plant) than those of later cohorts (0.8 fruits per plant). Reproductive meristem allocation was also highest in the earliest cohorts. Results showed that T. terrestris can increase its population size in fields if gaps of bare soil surface are available from mid spring to early summer. |
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| Keywords: | Tribulus terrestris seedling emergence survival plant growth plant reproduction |
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