Estimating Growth Rate of Bryum coronatum, Barbula lambarenensis and Hyophila involuta in the Guinea Savanna Ecological Zone of Nigeria

Abstract

Mosses are non-vascular plants that occur on a wide range of habitats. Many species of mosses grow naturally in Nigeria, but there is a paucity of studies on their growth rate. This study investigated the growth rate of three acrocarpous mosses: Bryum coronatum Schwaegr; Barbula lambarenensis (Hook) Jaeg; and Hyophila involuta (Hook) Spreng in Ejiu-Ayegunle and AraromiOpin, Ekiti Local Government Area of Kwara State. Mosses were randomly collected from their natural habitats at different locations in the study area and taken to the laboratory at two weeks interval for a period of six months where they were identified and used for growth study. The shoot heights were measured fortnightly for a period of 6 months by placing the stems on a clean slide and a thread stretched over each shoot from the base of rhizoid to the apex of the shoot and the measurements were later extrapolated on metre rule. Leaves were detached into a drop of water on a microscope slide with a scalpel and forceps and positioned on the slide, before counting under a dissecting microscope at 40x magnification. The results showed that moss shoot heights ranged between 1mm and 4mm and the growth rate varied among the species and habitats. Of the three species, Bryum coronatum recorded the highest mean incremental shoot height of 0.9±0.42mm3.5±1.13mm per season followed by Barbula lambarenensis (0.2±0.04mm-2.1±1.60mm) and Hyophila involuta (0.2±0.07mm-1.4±0.14mm) during the period of study. The species also showed a variation in the number of leaves per plant and differed significantly in leaf blade length and blade width. The study concluded that the growth potential of a species determines its degree of success in a particular environment.