Spatial Variation in Decomposition Rate of Carex Rostrata Leaves on a Swedish Mire

Abstract

(1) The litter bag method was used to study the decomposition rate of Carex rostrata leaves on a central Swedish mire. (2) The leaves used were of two types, one originating from an area influenced by spring water and one from an intermediate fen area. The decomposition rates of both types were studied in the spring and intermediate fen area. A 14% loss in weight due to initial leaching was determined under laboratory conditions. (3) Despite the distance between the two areas being only 30 m, the loss of weight from the leaves after twelve months exposure differed significantly between the areas. Also, the decomposition rate of leaves originating from the spring area was significantly greater in each case. (4) Loss of weight from leaves collected from the spring area was correlated with initial contents of P and K, while loss of weight from leaves collected in the intermediate fen area was correlated with initial contents of N and K. (5) The loss of weight over a twelve-month period ranged from 81 0/o in the spring area to 44% in the intermediate fen area. A small-scale spatial difference caused a large-scale variation in decomposition rates.