Arvind Bijalwan^1,, Manmohan J. R. Dobriyal²

This study narrates geometry, distribution and regeneration pattern of traditional agroforestry systems viz. Agrisilviculture (AS), Agrisilvihorticulture (ASH) and Agrihorticulture (AH) systems in the Upper Yamuna region of Uttarkashi district in Uttarakhand, India. The study spread in different altitudinal ranges from 1000-1500m, 1500-2000m, 2000-2500m with two aspects (northern and southern) to observe the diversity of agroforestry along altitude and aspects. In this study, tree geometry deals with arrangement and orientation of trees on farm land in different traditional agroforestry systems. It was found that the tree geometry have not shown particular pattern in location of trees occurring on agriculture field. The positions of trees depended on the nature (forest tree/ fruit tree), use of tree species, origin of occurrence (naturally grown/planted), nature of field crop and interaction with the intercrops (positive/negative interactive effect). The maximum numbers of trees were recorded on bunds followed by other places and on middle of agricultural field in AS system. In AH system the more number of trees was recorded on middle followed by other places and on bund whereas no regular pattern of tree geometry was recorded in ASH system. In diversity studies, the number of tree species ranged from 7 to 13, 4 to 16 and 1 to 8 in AS, ASH and AH respectively. The tree diversity recorded to be highest in ASH and lowest in AH, however higher number of tree species recorded in lower elevation compared to higher. The regeneration status dealt with presence of trees, saplings and seedlings under different traditional agroforestry systems. The minimum number of seedling and sapling were observed in AH followed by AS and ASH. With respect to elevation, comparatively higher numbers of seedlings and saplings presence were recorded in 1000-1500m and minimal presence in 2000-2500m inferred poor regeneration in higher elevation. Similarly seedlings and saplings presence is recorded lower in southern aspect compared to northern aspect. The tree structure in AS and AH systems recorded more number of trees under 20-30 cm diameter class and ASH in 10-20 diameter class, similarly more trees were recorded in AS, AH under 10-15m height class and ASH under 5-10m height class. The overall representation of trees in above mentioned agroforestry systems recorded reciprocal relationship i.e. higher number in lower elevation (1000-1500m) and lower in higher elevation (2000-2500m).

tree geometry, orientation, diversity, traditional agroforestry, altitude, aspect, diameter class, height class, regeneration pattern