Functional traits differences of Cyclosorus afer (Christ) Ching. in some wetlands: a potential invasive fern

Abstract

Invasive plants are known to possess significant morphological and physiological traits which influence their impacts and disruption of ecosystem processes, even in the presence of natives. In this study, we assessed the functional traits of a potential invasive tropical fern Cyclosorus afer which has colonized most wetlands in some parts of Nigeria. We selected three wetlands of 500 m × 500 m and separated by 1000 m from each other. In each site, we determined the functional trait differences using 10 consecutive 1.5 m by 1.5 m quadrants located at 10 m intervals along a single 200 m transect at the peak of the growing season. These traits including whole plant, foliar and stipe traits explain its potential for efficient resource acquisition and usage in the habitats. Principal component analysis with varimax rotation was carried out on the traits to determine axis of specialization/drivers of its invasion in the wetlands. The results revealed that C. afer utilize different functional traits as its drivers in the three wetlands. Leaflet fresh weight, plant height, number of leaflets and leaf dry matter content (LDMC) are drivers in site 1; leaflet fresh weight, LDMC and plant height in site 2; leaflet fresh weight, SLA and number of leaflets in site 3. These traits are indicators of its high competitive ability, low inflammability and efficient acquisition and usage of resources. The possession of underground rhizome by this plant has also been observed as aiding its rapid horizontal expansion in unfavourable seasons.