I just finished reading chapter 3 Ecosystem Services by Jerry Melillo, PhD and Osvaldo Sala, PhD in the book Sustaining Life. They did a brilliant job describing the complex services ecosystems perform and the myriad players in each system. Life couldn't exist with out these systems functioning around the globe. The Doctors went on to then list threats to ecosystem services. These threats include climate change, deforestation, desertification, urbanization,wetland drainage, pollution, dams and water diversions, and invasive species. I know that I don't have the impressive alphabetical attachments added to my name, nor the nice pieces of paper to go with them, but I think the good doctors missed an important threat.
The point they missed is that all ecosystems are local. They function at a local level, using local resources in their cycles. Yes there is a combined regional and global benefit to the functioning of these systems, and regional and global threats as well. But the greatest threat comes from our trans-locating resources from one system to another. When we pack up the carbon, nitrogen, etc. from a location in the form of corn, or wood, or what ever and ship it elsewhere to be used, those resources are lost to that original system. This weakens the original system. The waste from the use of what ever was shipped is then dumped in a new system and becomes pollution, weakening the new system as well. Ecosystems work by cycling resources in a local community. We do subtle, daily damage to these systems every day with our current system of producing food and energy, and our methods of disposing of waste.