Reintroduction is a crucial step in the conservation efforts aiming to restore ecosystems and protect threatened species. However, studies that incorporate and evaluate the effect of plant reintroduction are scarce. A study on a population of Cephalocereus polylophus, a vulnerable cactus endemic to the southern Chihuahuan Desert, allowed us to evaluate the effect of seedling reintroduction on the viability of this population. An integral projection model was used on a 5-year dataset to forecast population size over a century, and to simulate scenarios of seedling survival and protection. The study revealed an asymptotic population growth rate (λ) of 0.97 (95% CI = 0.96 – 0.99). Simulating the seedling survival and an increase in the seedling bank translated into a λ that showed only a slight increase, but remained below one, mainly because the recruitment and survival of small individuals were insufficient to compensate for the population decline. Protecting seedlings against herbivores and increasing their survival to 96.5% resulted in a larger population size (~ 5% average increase) and delayed extinction, in comparison with a no intervention and 60% survival rate scenario. This demonstrates that increasing seedling survival rates through protection and reintroduction efforts can only be conceived as a complementary conservation strategy to those focused on preserving existing individuals. Effective reintroduction strategies can help delay the extinction of the population of this cactus, but the conservation of the current population and its habitat is pivotal for its future survival.

Globally, around half of all tropical forests are secondary communities which are recovering from previous disturbances. In these communities, dominant pioneers play a critical role in the successional dynamics due their ability to modify the environment, and thus to facilitate or hinder the performance of other species. In this study, we examined the population dynamics of the dominant pioneer species, Mimosa acantholoba var. eurycarpa, in a tropical dry forest during the process of secondary succession. We collected data from permanent plots over a period of 13 years and used integral projection models to analyze the vital rates and changes in population size. Most vital rates were negatively related to successional age, with resprouting, survival and recruitment of individuals responding more strongly, and individual growth rate more weakly. These vital-rate trends translated into significant variation of population size over succession, with a maximum size at year four and a rapid decline thereafter. Overall, our findings suggest that this species benefits from its ability to display a large number of resprouts in very early stages of succession, contributing to the rapid increase in population density. However, as succession unfolds, a lack of resprouting and a decline in survival reduce its population size, to the point of local extinction. These results highlight the importance of resprouting in the early dynamics of tropical dry forest communities recovering from disturbance.