Litter production and decomposition from shrubs of Protea repens growing in sand plain lowland and mountain fynbos, south-western Cape

Abstract

Litter production and decomposition of mature shrubs of Protea repens (L.) L. growing in coastal and mountain fynbos, south-western Cape, were studied during 1981 – 1983. Mean annual litter production under the canopies ranged from 200 to 450 g m–2. Leaf fall accounted for 50 – 87% of the total with floral bracts being the next dominant category. November – January was the main period of litter release. Winter (June – August) leaf litter contained the lowest soluble carbohydrates and highest lignin levels. The phosphorus and nitrogen concentrations of freshly fallen litter were less than that of attached leaves and the decline ranged from 33 to 66% and 3 to 25% respectively. Leaf litter decomposition was not seasonal and no differences were encountered in the decay of dry mass, lignin, cellulose and soluble carbohydrates in the decomposing leaf litter from the two study areas. Leaf litter decomposition turnover times of P. repens are longer than those of sclerophyllous shrubs of other mediterranean-type ecosystems.