Their ability to maintain homeostasis differs. Negative feedback systems maintain homeostasis. Organisms allocate limited energy supplies to different needs, including the maintenance of homeostasis. In temperate and polar zones, day length is more reliable than weather as an indicator for seasonal cycles. The flow of energy drives the cycling of nutrients.
Organisms use oxidation-reduction reactions to gain and transfer energy.
The carbon cycle is most closely associated with the flow of energy through ecosystems. Most nitrogen conversions are performed only by prokaryotes. Phosphate has a limited local cycle and a long-term geological cycle. Biological productivity may be limited by the energy source, by nutrient availability, and by inefficiencies in biochemical conversions. Net production at higher levels in the food web is smaller than at the lower levels.