Intra-habitat variability of halophytic flora of north-west India.

Abstract

The growth and ion-accumulating characteristics of different plant species native to saline-arid areas vis-à-vis the ionic status of their rhizospheric soils are important factors to consider when studying the survival of plant species under harsh conditions. A survey of saline areas in Haryana (CCS Haryana Agricultural University and Central Institute for Research on Buffaloes at Hisar) and Rajasthan (Lunkaransar in Bikaner, Sambhar Lake, Jaipur and Gangani-Kaparda at Jodhpur) was done to explore the variability in halophytic species in different arid and saline regions. It was observed that 44 species spread over 16 families of Angiosperms (i.e. Chenopodiaceae, Mimosaceae, Poaceae, Capparidaceae, Portulacaceae, Tamaricaceae, Fabaceae, Caesalpiniaceae, Aizoceae, Asteraceae, Salvadoraceae, Asclepiadaceae, Boraginaceae, Solanaceae, Amaranthaceae and Cyperaceae) were growing across these locations with most species from the Chenopodiaceae family. Among these highly flourishing species were Salsola baryosma, Suaeda fruticosa, S. nudiflora and Saccharum munja, producing the highest biomass per unit area of land. The rhizospheric soil of different locations was saline to highly saline. While exploring the ionic homeostasis, it was found that most ions (e.g. Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl^- and SO₄^2-) were accumulating more in their leaves than in their stems, which may be a survival mechanism of these halophytic species under worse conditions of salinity. In terms of soil habitat across these surveyed regions, the rhizospheric salinity is patchy and supports both facultative halophytes and glycophytes.