Phytoremediation of a sodic forest ecosystem: plant community response to restoration process.

Abstract

The creation of a new biotope on degraded lands is the focused objective nowadays, on a global level. An attempt was made to rehabilitate sodic waste lands through the establishment of plant cover, with diverse plant communities within Banthra Research Station of the National Botanical Research Institute, Lucknow, India (80degr45min-53degr53min E and 26degr40min- 26degr45min N) for the last three decades. A rehabilitated forest ecosystem developed in this way consists in a number of herbs, shrubs and trees. Derris indica, Dalbergia sissoo, Azadirachta indica, Cassia siamea, Terminalia arjuna, Syzigium cumin were the dominant species in this rehabilitated forest, whereas Sporobolus, Desmostachya and Dactyloctenium were a common genera of grasses /forbs on a barren land. This study showed that species diversity and productivity significantly influenced the soil amelioration process. A comparison of three afforested sites with a varying degree of productivity and diversity indicated that some soil properties were influenced by diversity while others by productivity. Individual effects of diversity and productivity were classified as 42% and respectively 58%, in soil reclamation. A combined effect of both biomass productivity and species diversity contributed about 92% towards amelioration. There was an appreciable reduction in soil pH and ESP (exchangeable sodium percentage) and an increase in organic C and N contents showing that sodicity has receded in the forested soil. This experience can be tried out on similar sites of arid and semiarid regions of the world for the bioreclamation of sodic lands.