Aspects Of The Water Relations Of Five Mosses From Savanna Area Of Upper Ogun, Southwest Nigeria

Abstract

Aspects of the water relations of five mosses growing in a savanna area of southwest Nigeria were studied. Experiments were conducted using Archidium acanthophyllum Snider, Bryum coronatum Schwagr., Calymperes erosum Mull.Hal., Stereophyllum conterminum Cardot. (=Entodontopsis nitens (Mitt.) W.R.Buck & Ireland and Thuidium gratum (P. Beauv.) A. Gaeger. The water content at field capacity (WC_FC) significantly higher (P <0.05) in C. erosum and T.gratum than in other mosses and subsequently WC_FT was lower. The RWC (% dry wt) was significantly higher  (P<0.05) in C. erosum (376%) and B. coronatum (351%). After the short term exposure (48 h) to preset relative humidity (RHs), WC was lower in all the taxa except for T. gratum that was significantly higher (P <0.05) at 80% RH. During the long term exposure (8 days) to preset RHs the WC of each tested taxon remained constant after 2 days of exposure. The rate of water loss peaked at 4 h of exposure in all taxa and afterward declined. The rate of decline in A. acanthophyllum was significantly higher (P <0.05) than in other taxa. Conclusively, mosses in drier areas survived dehydration through morphological characters while those in wetter areas survived through physiological process.

 Keywords: Archidium acanthophyllum, Bryum coronatum, Calymperes erosum, Inselberg, Stereophyllum conterminum, Thuidium gratum