Pneumatopteris afra (Christ) Holttum Invasion: Impact on Species Diversity and Soil Seed-Bank Richness in Lafia, Nigeria

Gbenga Festus Akomolafe; Paul Tersoo Terna; Saudat Musa.

Invasive species are a threat to the conservation of natural ecosystems as they compete with crops and natural vegetation, potentially reducing food quality and quantity. A study was carried out to investigate the impact of invasion by the wetland tropical fern Pneumatopteris afra (Christ) Holttum on species diversity and soil seed-bank richness in Lafia, North-Central Nigeria from 2020 to 2021. Community characteristics were computed from data of species sampled from three invaded and uninvaded plots, using ten 1 m x 1 m quadrats, and five 30 m line transects. Soil seed-bank richness was evaluated using the seedling emergence method. Community characteristics of plant species, such as number of species, number of individuals, Simpson Index, Evenness Index, Margalef Index, and Fisher Alpha Index, were higher in the uninvaded sites, and differed significantly from the P. afra-invaded sites (p<0.05). Seed-bank obtained from uninvaded plots contained higher species composition (n=14), compared to the uninvaded plots (n=4). The study showed that invasion by P. afra poses serious threats to species diversity, and the regenerative ability of invaded plant communities. Therefore, measures aimed at controlling the dominance and eventual take-over of native vegetation by invasive P. afra are required to preserve the species richness and diversity in the region.

KEYWORDS: P. afra; Species diversity; Invasive species; Native species; Seed-bank.



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