Indian Journal of Agroforestry

The forest and tree cover of the Bihar state, based on interpretation of satellite data is 9, 45, 500 ha. In terms of forest canopy density classes, the state has 23, 600 ha-very dense forest, 2, 43, 000 ha-moderately dense forest and 1, 99, 700 ha-open forest. The estimated tree cover in the state is 2, 16, 400 ha, which is 2.52% of the geographical area of the state. The forest and tree outside forests are managed for a number of purposes like timber harvesting, wilderness, habitat and recreation but arguably their most important output is water. Precipitation is cycled through vegetation and soil, and ultimately some is delivered as stream flow to receiving bodies of water. In this way, permanent vegetal cover process nearly two-thirds of the freshwater supply in the Bihar state. Demand for water in the state is increasing and forest managers today are asked to provide higher quantities and qualities of water. Water supply is becoming more difficult day by day because of elevated water demand or with changes in climate. How to manage forests and sustain water supplies will be a primary challenge in this century. To ascertain this, an experiment was conducted in chawnia block of R.A.U., Pusa in 1988. Soil temperature, soil moisture, water holding capacity and infiltration rate were estimated in Bauhinia variegata, Acacia lenticularis, Eucalyptus tereticornis, Swietenia mahogany, Tectona grandis, Bombax ceiba, Albizia procera, Dalbergia sissoo, Terminalia arjuna, Ceiba pentendra, Pongamia pinnata and Cassia siamea based cyclical agroforestry system of North Bihar. It was observed that water holding capacity, infiltration rate and soil moisture in increasing trend in cyclical agroforestry system was key factor or solid foundation of general principles that describe how water is connected to and moves through trees/forests. On the principles of forest hydrology, new forest hydrology research can fill information gaps in the coming decades. It is incumbent upon scientists, policy makers, land and water managers and citizen to use the lesson of the past and apply emerging research, technology and partnerships to protect and sustain water resources from forested/farm forest landscapes.