For a long time I have considered the term "food chains" a misnomer as what really happens in nature is ongoing series of nutrient cycles.What does anyone else think?
Food chains are just one strand in a food web. To identify a food web you start off by linearly ordering each "chain" of consumption, starting with the bottom (a producer organism) and ending with the top consumer. e.g. seed -> bird -> cat; grass -> worm -> bird -> bigger bird -> cat; and so on. Now start connecting all of your chains, e.g. seed -> bigger bird or worm -> bigger bird. When you have all these connections you have identified the food web. The food web only represents the "living" part of the overall nutrient cycles. Once an organism dies, decomposers digest the bodies for us and nutrients such as nitrogen and carbon are returned to the soil or atmosphere into their respective cycles. Here they are taken in by photosynthesizing plants (the producers), which brings those nutrients back into the food web. So I guess I don't agree. The common use of the term Food Chain may be a misnomer, but in its actual definition its not. Sorry if this answer sounds smart-assish.
Its different to a nutrient cycle. A nutrient cycle is a way given chemicals are cycled in nature. A food chain is a way of structuring an ecological system based on diets of component species of flora and fauna. The only link I can see is that a step in a nutrient cycle can be carried out via a step in a food chain.
Of course you're right. There are different nutrient cycles, e.g. for carbon, nitrogen, phosporous. These cycles are the paths these nutrients take through the atmosphere, soil, rocks, and flora and fauna. During the time the chemical is contained in the biota, it is being cycled through a food web as well. So just like you said, the food web is on part of the nutrient cycle. Note, I'm not saying that any one atom of carbon, for example, enters a food chain and cylces all the way through. I dropped a big load of carbon this morning in the toilet. Those carbon molecules (or the poop housing them) are by now at the waste water treatment plant, being digested and returned into the atmosphere as CO2.
