These are forests of the Mascarene Archipelago in the Indian Ocean. The main islands include Mauritius, Reunion and Rodriguez. In Mauritius there is a pronounced dry season in the lowlands between May and November. Consequently these forests are markedly different from their wetter upland counterparts in both composition and structure. They are less species rich and the number of woody plants per 25 sq. m diminishes from an average of 60 in the upland climax forest to no more than about 20 in the lowland forest. The canopy, which reaches heights of up to 15m, is closed but with the decreased density of trees much more light can penetrate to the forest floor than in upland forests. The stratification is also less discernable. However, only remnants of these native forest remain, but what can be gleaned from these suggests that most of the dominant trees were endemic species such as Diospyros tesselaria (Ebenaceae), Elaeodendron orientale (Celastraceae), Foetidia mauritiana (Foetidiaceae), Poupartia pubescens (Anacardiaceae) and Stadtmannia sideroxylon (Sapindaceae), although most of these are now very rare. Other endemic trees not necessarily confined to these forests include Protium obtusifolium (Burseraceae) and Ochna mauritiana (Ochnaceae). Probably resulting from the increased light level the shrub layer is well developed with species such as the two endemics Pittosporum senacia (Pittosporaceae) and Quivisia ovata (Meliaceae). At ground level there are fewer ferns than in the upland forests together with other floristic differences. The most conspicuous species is the gregarious Nephrolepis biserrata; while other common species include Asplenium rhizophorum and A. viviparum. Bryophytes are also few in number and mainly represented by Frullania affinis, Rhacopilum praelongon and the two endemic species Hymenostomum ayresii and Sematophyllum schimperi.

References

Baker, J. G. 1999. Flora of Mauritius and the Seychelles. (reprint of 1877 edition). Asian Educational Services, India.

Balgooy, Van. M. M. J. 1969. A study of the diversity of island floras. Blumea, 17: 139-178.

Wiehe, P. O. 1949. The vegetation of Rodrigues Island. The Mauritius Institute Bulletin, 2: 280-304.

Renvoize, S. A. 1979. The origins of Indian Ocean Island floras. In: Plants and Islands. Ed. D. Bramwell. Academic Press.

Vaughan, R. E. 1937. Studies on the vegetation of Mauritius. I. A preliminary survey of the plant communities. Journal of Ecology, 25: 289-343.