CULM RECRUITMENT, DRY-MATTER DYNAMICS AND CARBON FLUX IN RECENTLY HARVESTED AND MATURE BAMBOO SAVANNAS IN THE INDIAN DRY TROPICS

Culm recruitment, standing crop biomass, net production and carbon flu x were estimated in mature (5 years after last harvest) and recently h arvested bamboo (Dendrocalamus strictus (Roxb.) Nees) savanna sites in the dry tropics. During the 2 study years bamboo shoot recruitment wa s 1711-3182 and 1432-1510 shoots ha(-1) in harvested and mature sites, respectively. Corresponding shoot mortality was 66-93% and 62-69%, re spectively. Total biomass was 34.9 t ha(-1) at the harvested site and 47.4 t ha(-1) at the mature site. Harvesting increased the relative co ntribution of belowground bamboo biomass. Annual litter input to soil was 2.7 and 5.9 t ha(-1) year(-1) at the harvested and mature sites, r espectively The bulk of the annual litterfall (78-88%) occurred in the cool dry season (November to February). The mean litter mass on the s avanna floor ranged from 3.1 to 3.3 t ha(-1); at the harvested site wo od litter contributed 70% of the litter mass and at the mature site le aves formed 77% of the litter mass. The mean total net production (TNP ) for the two annual cycles was 15.8 t ha(-1) year(-1) at the harveste d site and 19.3 t ha(-1) year(-1) at the mature site. Nearly half(46-5 7%) of the TNP was allocated to the belowground parts. Short lived com ponents (leaves and fine roots) contributed about four-fifths of the n et production of bamboo. Total carbon storage in the system was 64.4 t ha(-1) at the harvested site and 75.4 t ha(-1) at the mature site, of which 23-28% was distributed in vegetation, 2% in litter and 70-75% i n soil. Annual net carbon deposition was 6.3 and 8.7 t ha(-1) year(-1) at harvested and mature sites, respectively.