Take a basic meal for instance, steak, potatoes, peas and fruit cobbler for desert. It is easy to imagine that only four or five organisms were involved, maybe if you really think about it, grain and grazing pasture for the steer and bees to pollinate the fruit trees. Think that is it? Not even close, we are forgetting the host of AMF fungi that are necessary for most plants to be productive enough to have harvest-able growth. But why stop there, almost nothing would grow with out nitrogen fixing bacteria, and what about the birds and bats that keep insect pests in check, or detritivores that allow for nutrients to be converted from waste.
The point is, we have never and will never take a bite of food or breath a single lungful of air that didn't come to us through the complex interactions of hundreds if not millions of organisms. Like it or not we all deeply depend on natural land and water ecosystems. Researchers at Stanford University have taken the first step towards quantifying the value of these complex systems. InVEST is a GIS based modeling tool that can be used to quantify data from biological field experiments among its myriad of uses.
We have the tools now to place a concrete value in economic terms to natural resources without having to resort to "aesthetic appeal". In the right hands, this has immense potential to change the way we look at natural resources. From water resource management, to farming, and even city planning. Best of all (through the link above) the program is free. But you do have to purchase the accompanying GIS software package (second link) if you do not already have it.
Better than any "cap and trade" model for environmental stewardship, this could revolutionize economic policy to actually account for the systems now taken entirely for granted. It is better than learning the hard way, like when we found out after installing a dam that NW cedar forests require the input of salmon to maintain a viable nutrient store.
As always, I welcome comments and criticism, and will not edit or omit anything.