Studies on the Vegetation of Mauritius: III. The Structure and Development of the Upland Climax Forest

Abstract

The upland climax forest of Mauritius was studied by measuring all trees 10 cm. diam. and above in ten 1000 sq.m. random plots. The individuals were sorted into 14 diam. classes, and size class frequency curves prepd. Abnormalities in age distribution were exhibited by certain spp. of top canopy trees. The number of trees per hectare was > 1700. Further data required for stratification and floristic composition were obtained from a 1000 sq.m. plot in which all woody plants above 50 cm. high were charted to scale; this plot contained 1726 individuals. 4 strata were recognized (i) a-mesophanerophytes > 15 m. high forming open canopy with Sapotaceae dominant, (ii) [beta]-mesophanerophytes 8-15 m. high forming closed stratum of complex floristic composition, (iii) microphanero-phytes 2-8 m. high of scattered undertrees, and (iv) nano-phanerophytes up to 2 m. high mostly Rubiaceae. Stratification is illustrated by tables and a profile drawing. For the development of the forest, 1000 sq.m. plots in different stages of the sere were used; the spp. were listed and species/area curves prepd. The forest appears to have developed from a sheath associes. The formation is related to the "subtropical Rain-forest of the lower Montane regions in the tropics" of Schimper. Comparative data are given for climate, plant density, and stratification in the following regions: Mauritius, Southern Nigeria, Sarawak, and British Guiana.