Litterfall, decomposition, and nitrogen release in two age groups of trees in Casuarina equisetifolia plantations in the dry tropical Vindhyan plateau, India

Srivastava, A.K.; Ambasht, R.S.

Litterfall, decomposition, and nitrogen release in two age groups of trees in Casuarina equisetifolia plantations in the dry tropical Vindhyan plateau, India

1996

Srivastava, A.K. | Ambasht, R.S.

Litterfall, decomposition, and N release in 5-year-old and 8-year-old plantations of Casuarina equisetifolia (Forst.) in the dry tropical region of the Vindhyan plateau were studied during 1989-1990. Maximum litterfall occurred in May. The total litterfall ranged from 7.2 to 9.9 t ha-1 year-1 in the 5-year-old stand and from 11.3 to 12.7 t ha-1 year-1 in the 8-year-old stand over the 2-year period. Photosynthetic branchlets contributed 87-95% to the total litter. The relative decomposition rates of litter components of the ash-free mass were highest in the rainy months (4.7 to 9.9 mg g-1 day-1) followed by winter (2.8 to 3.6mg g-1 day-1) and lowest in the summer months (1.7 to 3.0 mg g-1 day-1). Similar patterns were observed for N release. The annual decay constant was highest for cone litter and lowest for photosynthetic branchlets. During decomposition, the photosynthetic branchlets showed N immobilization in November and April, the twig litter in March, and the roots in January and February. N release per unit area (g m-2) was maximum from the photosynthetic branchlets (5.3-6.3) followed by cones (4.4) > roots (3.4) > twigs (2.6-3.2). The combination of the litter C:N ratio, moisture, and temperature with the relative decomposition rate in a multiple regression analysis explained 66-84% of the variability in mass loss and 58-66% of the variability in N release.

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