Termites in Ecosystems

Abstract

Termite assemblages are considered as complex systems containing species with several modes of feeding and nesting, which have a major though not necessarily dominant role in decomposition and C mineralization processes, and which influence soil properties and structure. Sampling methods for species richness, abundance and biomass and the estimation of food consumption rates are reviewed; transect methods are recommended for biodiversity surveys as they are efficient and have acceptable accuracy. Biases introduced by sampling methods which focus on mounds only and by consumption assays based on baits lead to underestimates of assemblage diversity, abundance and ecological impact. The range of abundance and biomass of termites in major ecosystems and biogeographical regions is discussed and representative data are tabulated. In savanna systems, the turnover of organic matter by termites is roughly comparable to that of mammalian herbivores and bush fires, and as much as 20% of C mineralization may be directly attributed to termites. In forests, absolute C fluxes through populations are generally larger, owing to higher termite biomass, but the relative contribution to C turnover is less. Functional group heterogeneity rather than species richness per se is considered the key link between termite biodiversity and ecosystem functions.