Habitat preferences in Acroporium (Sematophyllaceae) and related taxa in Peninsular Malaysia

Abstract

Habitat preferences and habitat differentiation were studied among species of Acroporium (Sematophyllaceae) and related taxa between 140-2,000 m a.s.l. in Peninsular Malaysia (02.92°-04.87°N, 100.80°-101.83°E). Canonical Correspondence Analysis was used to reveal how species data were related to 16 environmental factors that represent geographical, physical environmental, chemical, and substrate type components. We found some geographical variation, but this explained little of the species distribution patterns. A minimum model based on automaticforward selection suggested that elevation, the substrate peaty soil, and pH explain 57% of the variation in the species data, and variation partitioning suggests that much of the variation in the latter is explained by several factors in combination. Light availability and the substrate mineral soil were of moderate importance in explaining species data distribution, whereas other variables influenced the variation less and mainly along the third and fourth ordination axes. Trichosteleum and Papillidiopsis species occurred mainly at low elevations, Acroporium secundum (Reinw. & Hornsch.) M. Fleisch., A. diminutum (Brid.) M. Fleisch., and A. stramineum (Reinw. & Hornsch.) M. Fleisch, var. stramineum were found at relatively high pH values, and A. convolutum (Sande Lac.) M. Fleisch and Radulina hamata (Dozy & Molk.) W. R. Buck & B. C. Tan at low pH values. Acroporium procerum (Müll. Hal.) M. Fleisch., A. strepsiphyllum (Mont.) B. C. Tan, and probably A. rigens (Dixon) Dixon showed a preference for peaty soil, whereas Papillidiopsis malayana (Dixon) B. C. Tan was the only species found on thin mineral soil over rocks.