Plant species diversity in the riparian forests of the Moyar River in southern India

Abstract

Riparian forests are among the most rapidly disappearing vegetation types throughout the world. River Moyar cascades through gorges and links the Western Ghats with the southernmost segments of the Eastern Ghats. Considering the relatively well-preserved state of the Moyar riparian vegetation and being amongst the least explored forests in southern India, an assessment of angiosperm diversity was undertaken. The study used an array of belt transects along and perpendicular to the river course so that the entire elevation gradient of the gallery could be covered. A total of 172 species representing 126 genera belonging to 47 families, including 100 monotypic genera and 17 monotypic families, were recorded from both the transects in the study area. 131 woody angiosperm species representing 100 genera in 41 families were recorded along the river. The perpendicular gallery transects recorded 111 woody angiosperm species representing 86 genera in 36 families. Thirteen monotypic families were found in both transects, and 70 species were found in both transects. The dominant families with the maximum species were Fabaceae, Rubiaceae and Phyllanthaceae. Shannon diversity index ranged between 2.0 to 3.27 along the river transects and 1.51 to 2.67 along the galleries. The study concludes that Moyar riparian zone merits high conservation value as it supports significant species diversity, including red-listed species and habitat-specific plants, and functions as a vital wildlife corridor in the landscape.