Microecology and floristic diversity of seasonal wetlands of a lateritic plateau of South India

Abstract

An analysis of the microecology and floristic diversity of the seasonal pools on the Madayippara lateritic plateau, located in Kannur District of Kerala, South India, was conducted. Temporary wetlands of varying sizes are formed during the rainy season, supporting a large number of habitat-specific flowering plants, a greater number of which are endemic, and a few belong to various threat categories. The seasonal pools vary in their size, soil cover and texture, and are subjected to extreme diurnal changes in temperature due to the high surfaceto-volume ratio. They are characterised by high variation in soil temperature and water pH between pools and between seasons, extreme variation of water temperature in different seasons and in different hours of a day, and also hold maximum moisture content with extreme variation in different seasons. The soil type in most of the seasonal pools is sandy loam, and is the richest with respect to soil nutrients. The occurrence of high diversity of carnivorous plants in these nutrient-rich habitats is ascribed to the limitation in nutrient absorption, resulting from factors such as low pH, inundation and low phosphorus levels. Seasonal pools are highly specialised microhabitats active only in the monsoon period to support several specialised species showing a high degree of endemism owing to their characteristic microecology.