This TED lecture from ecologist Jeremy Jackson explains really well what I've been saying about the importance of understanding resources not just economically but as living systems. When "tree huggers" mobilize to save an endangered snail darter, it's not because everyone is so enamored of a little fish. It's because they understand that every living organism plays an important role in that system. Get rid of one component and you throw the whole thing out of balance. No one thought sea urchins were a big deal until they were gone, the seaweed took over the coral reef, and now there's no fish.
It's almost 20 minutes long but well worth it.