Influence of microarthropod abundance and climatic factors on weight loss and mineral nutrient contents of Eucalyptus leaf litter during decomposition

Abstract

Densities of the different taxa of microarthropods per gram of litter in litter bags varied widely from the rainy to the dry season. Collembola and Acarina constituted more than 86% of the total microarthropods, and occurred in significantly greater numbers in the coarse-mesh bags than the fine-mesh bags. There were no fauna in the litter of suspended bags. The average weight loss was greater in the coarse-mesh bags (50.4%) than in the fine-mesh bags (44.5%), and the suspended bags (7.4%). Similarly, the concentrations of N and Ca were greater in the litter of coarse-mesh bags compared to that of the fine-mesh bags. In contrast, the concentrations of P and K were comparatively lower in coarse-mesh bags. The mass loss of litter showed a negative linear correlation with the total Collembola and with litter temperature. The N concentrations in the litter in both the mesh bags showed negative correlations with the abundance of total Collembola, and with that of Lepidocyrtus sp. and Sminthuridae, and rainfall. The N concentration in the litter in the coarse-mesh bags was positively correlated with the total number of arthropods but, surprisingly, was negatively correlated with the total number of Acarina. The concentration of Ca showed negative correlations with rainfall and litter moisture only. The P concentration showed positive correlations with total Collembola, with Lepidocyrtus sp. and Sminthuridae in both the mesh bags, with rainfall in the fine-mesh bags, and with total microarthropods in the coarse-mesh bags.