Dynamics of fine and coarse roots and nitrogen mineralization in a humid subtropical forest ecosystem of northeast India
- First Online:
- Cite this article as:
- Upadhaya, K., Pandey, H.N., Law, P.S. et al. Biol Fertil Soils (2005) 41: 144. doi:10.1007/s00374-004-0827-2
- 119 Downloads
The present study was carried out to understand whether fine root growth and N mineralization are synchronized in such a manner that helps to conserve N in the humid subtropical forest ecosystem, and to assess whether or not these processes are influenced by human disturbance. The study was conducted in two pairs of undisturbed and disturbed stands of subtropical humid forest in the Jaintia hill district of Meghalaya, northeast India. The amount of fine root (540–754 g m−2) and coarse root (307–387 g m−2) mass in the protected stands was higher than those recorded (fine root 422–466 g m−2, coarse root 247–305 g m−2) in the unprotected stands. The total annual root production was also higher in the protected stands (1,102–1,242 g m−2) than the unprotected stands (890–940 g m−2). The mean concentration of NH4+–N and NO3−–N was higher in the protected stands than in the unprotected stands. The inorganic-N (NH4+–N and NO3−–N) concentration was markedly high during the dry period and low during the wet period in all the stands. Inorganic-N concentration, nitrification and N mineralization rates were significantly (P<0.01) higher in the surface (0–10 cm) than the subsurface (10–20 cm) layer. The low and high N mineralization rates observed during the dry and wet periods, respectively, coincided with the lean and peak periods of fine root mass. Disturbance in the forests caused a reduction in fine root mass as well as in N mineralization.