So an ecosystem can't support as many carnivores as herbivores.

Over any length of time, no ecosystem will support that.

"This leads to anomalies, such as food web calculations determining that an ecosystem can support one half of a top carnivore, without specifying which end."

Among other benefits, riverine ecosystems create breeding grounds for commercial fisheries, carry nutrients to them and support multimillion-dollar recreational activities.

These ecosystems support a great nutritional pyramid important to marine animals, birds, and surrounding human settlements.

"The whole ecosystem of cameramen, producers and executives won't support them if they do."

The exact drug used depends on what the particular ecosystem a given tribe lives in can support, and are typically found growing wild.

Dr. Curtin said scientists had generally concluded that only some ecosystems could support long-term grazing.

This arid, mountain ecosystem supports a surprising biodiversity and a high proportion of plant endemics.

The fragile ecosystem of the Thar supports a unique and varied wildlife.