—We studied nutrient-reserve dynamics of female Greater Scaup (Aythya marila) to quantify intraspecific strategies of nutrient acquisition for egg production, particularly in relation to the seasonal timing of reproduction (i.e., date of initiation of rapid follicle growth [RFG]). We collected female Greater Scaup on the Yukon-Kuskokwim Delta, Alaska, from arrival through clutch formation durin...

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...

We developed a stoichiometrically explicit computer model to examine how heterotrophic uptake of nutrients and microbial mineralization occurring during the decay of leaves in streams may be important in modifying nutrient concentrations. The simulations showed that microbial uptake can substantially decrease stream nutrient concentrations during the initial phases of decomposition, while miner...

A simple food chain which consists of nutrient, prey and predator in which nutrient is growth limiting at low concentrations but growth inhibiting at high concentrations is investigated in this study. It is assumed that the nutrient concentration is separated into internal and external nutrient concentration and only the internal nutrient level is capable of catalyzing cell growth. It is shown ...

Insects represent a dominant component of biodiversity in most terrestrial ecosystems yet they have largely been neglected in studies on the role of biodiversity in nutrient cycling, or, more generally, the functioning of ecosystems. The scarcity of manipulative studies on the role of insects in ecosystem processes contrasts with the expert knowledge and large body of research already available...

Primary production and uptake rates of ammonium, nitrate and silicic acid were measured during the 1996 spring bloom in the Oslofjord, southern Norway, using isotope methodology (14C, 15N and 32Si). Chlorophyll a (chl a) standing stock peaked at 38 mg chl a m–3. Diatoms, especially Thalassiosira nordenskioeldii, dominated the plankton community. The diatom bloom followed a sigmoid growth patter...

The term agroecology refers to ecosystems. Ecosystems are characterised by aspects such as nutrient cycling, population regulation, energy flows and a dynamic equilibrium. These characteristics apply to natural ecosystems, and, in a much altered form, also to manmade or agricultural ecosystems. The magnitude of the differences between natural and agricultural ecosystems depends mainly on the hu...

Introduction Conclusions References