Cycad Literature Database

Cycads are highly threatened with extinction worldwide, mostly because of habitat destruction and degradation. Habitat fragmentation is a major threat for these species, but few studies are available about the population biology of cycads in fragmented landscapes. In this paper, I describe the demography of a rainforest cycad in different habitat types within fragmented forests in the Darien region of Colombia. I sampled demes across interior to edge habitats in forest fragments differing in the level of anthropogenic degradation and estimated population density, size distribution, and the population growth rate using integral projection models (IPM) for each habitat. Overall, populations of this cycad appear to be near stable population size in the forest fragments, but demes vary in their population dynamics across habitats within the forests. Edge habitats had higher canopy openness and higher levels of herbivory than interior habitats. Plant density was higher (because of a higher number of seedlings), and there was a higher proportion of seedlings compared to adults in demes from edge habitats. Furthermore, a gradient of higher adult growth, fecundity, and seedling survival in demes from edge to interior resulted in edge habitats demes having the largest population growth rate. Further exploration of the long‐term dynamics of these populations requires extensive demographic census and replication; nevertheless, this study suggests that demographic parameters can vary across habitats within forest fragments and between fragments, which might be important for the long‐term persistence of these cycad populations in anthropogenic landscapes.