**1. Introduction**

The third IPCC Assessment Report on climate change (IPCC 2000) contains an endorsement of the potential for agroforestry to contribute to increase in carbon stock in agriculture lands. Agroforestry can both sequester carbon and produce a range of economic, environmental, and socioeconomic benefits. Trees in agroforestry farms improve soil fertility through control of erosion, maintenance of soil organic matter and physical properties, increase N, help in extraction of nutrients from deep soil horizons, and promotion of more closed nutrients cycling. Agroforestry is an ideal option to increase productivity of wasteland, increase tree cover outside the forest and reduce human pressure on forests under different agro-ecological regions, and is thus a viable option to prevent and mitigate climate change effect [1]. Most, if not all, agroforestry systems have the potential to sequester carbon for a short period, say 6–8 yrs. [2]. With adequate management of trees under agroforestry systems,

a significant fraction of the atmospheric C could be captured and stored in plant biomass and in the soils [2]. An IPCC special report [3] (IPCC 2000) indicates that conversion of unproductive croplands and grasslands to agroforestry have the best potential to soak up atmospheric C. In agroforestry, soil restoration process involves recovery of organic based nutrients cycle through replenishment of soil organic matters, about half of which is C [4]. Removing atmospheric carbon (C) and its storage in the terrestrial biosphere is vital for compensating the emission of greenhouse gases. Agroforestry, a land- use system has an integral relationship with the farm community to supplement fuel, fodder, fruits, fibers and organic fertilizers on one hand and capture abundant amounts of carbon on the other. Agroforestry systems are believed to have good potential to sequester carbon [5] and thus immensely important in the era of climate change. Human activities change carbon stocks in terrestrial ecosystems through rapid land-use transformations [6]. At the moment, agroforestry has generated much enthusiasm as a result of the National Action Plan for Climate Change [7] which, under its Green India mission, has exclusively emphasized the agroforestry interventions. It is proposed that under agroforestry, 0.80 m ha of area would involve improved agroforestry practices on the existing lands under agroforestry and that 0.70 m ha would involve additional lands under agroforestry. There is now consensus that the agroforestry systems and practices hold viable potential to meet the present basic human needs, besides addressing several major agro-ecological, carbon sequestration and socioeconomic issues. Moreover, National Agroforestry Policy 2014 of India has also focused on encouraging fast growing tree species for carbon sequestration and environmental amelioration. The C sequestration potential of agroforestry systems is estimated to be between 12 and 228 Mg, with a median value of 95 Mg. Therefore, based on the earth's area that is suitable for the practice, 1.1–2.2 Pg C could be stored in the terrestrial ecosystems over the next 50 years [8]. Long rotation systems such as agroforestry, home gardens and boundary plantings can sequester sizeable quantities of C in plant biomass and in long-lasting wood products. Soil C sequestration constitutes another realistic option achievable in many agroforestry systems. The potential of agroforestry for CO2 mitigation is well recognized. There are a number of short comings however, that need to be emphasized such as the change in vegetation under agroforestry systems, *etc*. [8] (Albrecht and Kandji 2003). Significance of agroforestry with regard to C sequestration and other CO2 mitigating effects is being widely recognized, but there is still paucity of quantitative data on agroforestry systems with varying altitude in Himalayan region. This study was conducted to determine the carbon stock capacity of different agroforestry system in Indian Himalaya along altitudes.
