Introduction Conclusions References

The availability and cycling of nutrients is determined by an interaction of physical, chemical, and biological processes in an ecosystem. This interaction of processes, collectively known as biogeochemistry, is important as it determines the forms, transformations, and ultimate fate of nutrients in a given system. This chapter focuses on biogeochemical processes in springs and spring runs with...

An adequate and balanced supply of elements necessary for life, provided through the ecological processes of nutrient cycling, underpins all other ecosystem services. The cycles of several key elements—phosphorus, nitrogen, sulfur, carbon, and possibly iron and silicon—have been substantially altered by human activities over the past two centuries, with important positive and negative consequen...

Ecologists are increasingly recognizing the importance of consumers in regulating ecosystem processes such as nutrient cycling. Ecologists have recently made considerable progress in understanding nutrient cycling and trophic interactions in pelagic systems by application of a new concept, ecological stoichiometry, to consumer-driven processes. In this paper we synthesize these conceptual advan...

Wetlands host complex microbial communities including bacteria, fungi, protozoa and viruses. The size and diversity of microbial communities are related directly to the quality and quantity of the resources (i.e., nutrients, energy sources) available in the system. Microbial biomass and activity is highest in habitats where these resources are concentrated, including periphyton mats, plant detr...

Context The rates and pathways of nutrient cycling through ecosystems depend on interactions between both bottom-up forces, including the chemical characteristics of biomass that influence its decomposition and consumption by higher trophic levels, and top-down forces, such as the nutritional requirements andmetabolic efficiencies of consumers and decomposers that influence their feeding and ex...

Variable-charge (v-c) and permanent-charge (p-c) soils differ fundamentally with regard to many nutrient-cycling processes. Variable-charge soils are more common in the tropics than in temperature zones because their formation requires desilication, which proceeds fastest in warm, moist climates. The dynamics of nutrient mobility tend to be more complex in v-c than in p-c soils. For example, th...

Animals can be important in modulating ecosystem-level nutrient cycling, although their importance varies greatly among species and ecosystems. Nutrient cycling rates of individual animals represent valuable data for testing the predictions of important frameworks such as the Metabolic Theory of Ecology (MTE) and ecological stoichiometry (ES). They also represent an important set of functional ...