Population Size, Reproductive Ecology, and Threat Assessment of Cycas thouarsii in the Freshwater Swamp Forests of Akwa Ibom State

Cycas thouarsii is a cycad species found in restricted freshwater swamp forest habitats in Akwa Ibom State, South South Nigeria, and is considered threatened by habitat loss, yet quantitative population data and reproductive ecology information are entirely absent from the scientific record. This study assessed population size, age-class structure, reproductive parameters, and threats facing Cycas thouarsii at three freshwater swamp forest sites in Akwa Ibom State: Itu, Eket, and Oron Local Government Areas. All cycad individuals within systematically demarcated plot areas (total survey area: 5.6 ha) were counted and classified by developmental stage (seedling, juvenile, immature, reproductive female, and reproductive male). Reproductive parameters including coning frequency, seed set, germination rate, and seedling survival were assessed through observation and experimental seed germination trials. Threat scores were assigned following the Rapid Vulnerability Assessment protocol. The total population recorded across all three sites was 847 individuals. Population age-class structure was skewed toward juveniles and immatures, with adults comprising only 18% of all individuals. The sex ratio of reproductive individuals was 1.4 males per female. Mean seed set per female cone was 12.4 seeds. Germination rate under nursery conditions was 61%. Habitat disturbance from logging and oil palm plantation expansion was identified as the primary threat at all three sites. The study concludes that Cycas thouarsii populations in Akwa Ibom State are viable but declining, and recommends immediate habitat protection and ex-situ conservation in botanical garden living collections.

Keywords: Cycas thouarsii, cycad, population ecology, reproductive biology, Akwa Ibom State