Food chains, also called food webs, food networks and/or trophic networks, describe the feeding relationships between species to another within an ecosystem. Organisms are connected to the organisms they consume by arrows representing the direction of biomass transfer. Typically a food chain or food web refers to a graph where only connections are recorded, and a food network or ecosystem network refers to a network where the connections are given weights representing the quantity of nutrients or energy being transferred.

In some areas of the world, up to 63 percent of all the energy produced by plants - energy that would normally fuel native ecosystems - has been pressed into service for humankind.

In the light of "The Great Chinese Pet Food Scare" Is the FDA allowing too much free reign on just what corporations are allowed to do and introduce into our ecosystem and food chain?

Life as we know it, from the most basic microbes to our human neighbors, is carbon based. By investigating how carbon cycles through ecosystems, scientists can learn valuable information about food chains, nutrient cycling, and productivity. An accurate global carbon budget is needed to address climate change.

Algae, at the base of the food chain, for example, rely on fish to cycle back into the water such nutrients as nitrogen and phosphorus, which are otherwise locked up in animal or plant cells. Fish excrete dissolved nutrients back into the water, making them available to algae, which need them to grow.

Breaking up is hard to do, y'all, especially when you're part of a rich ecosystem of plant and animals that thrive under the frozen surface of the Antarctic sea. Evidence shows that ice plays a major role in the marine ecology by reducing light penetration to the waters beneath.