Oh? You think that humans are at the top? Well, if we were charting the one organism with the power for the most destruction to the planet, then yes. Yes, that would definitely be us! However, if we were charting the one group upon which all other groups depend for their existence, then that would not be us. It would be plants.
Plants, with their ability to change sunlight into food, are the PRODUCERS. All green plants turn carbon dioxide and water into carbohydrates and oxygen, using the light energy trapped in chlorophyll. This is called photosynthesis. So plants make the oxygen that we need in order to breathe. I’d say that should make them number one.
Animals (including us) survive by eating plants, or other animals that eat plants, or other animals that eat animals who eat plants. [Our food sources all go back to a plant eventually.] Animals are the CONSUMERS. Producers don’t need consumers, but consumers sure as hell need producers. That ought to make animals number two.
Now we come to an often overlooked group, the DECOMPOSERS. They consume dead plants and dead animals. This is important to be sure, but they wouldn’t exist without the other two groups. I suppose this puts them in third place.
In nature, the varieties and quantities of plants in any one particular area determine the group of consumers and producers. Removing any one species from the community threatens the survival of the whole. This is why we can’t really number the three groups according to importance. Everything is intertwined.
There is wise saying attributed to Chief Seattle of the Squamish Native American tribe that states this perfectly. “The Earth does not belong to man, man belongs to the Earth. Man did not weave the web of life; he is only a strand in it. Whatever he does to the web, he does to himself.”
|Iron Eyes Cody|
A connection also exists between the size of the food resources and the species population. In other words, the small food sources must be the most productive and the most plentiful. The food consumers must be smaller in number. (Think of Plankton versus Whales.)
|Microscopic view of Green Algae|
Each summer, when the ocean’s water warms up, tiny plants and algae called plankton bloom. They in turn feed tiny animals called zooplankton (krill and other small crustaceans). Fish, shellfish and whales feed on these. Seabirds and seals eat the fish and shellfish. Polar bears eat the seals. The timing of this harvest of plankton is programmed into the reproductive cycles of these animals.
So, you can see that any disruption of this cycle of plankton production – such as global warming - can have devastating effects upon the rest of the planet’s species. Each living thing, no matter where it fits in the food chain, fills a place. Each has a job to do.
Lastly, in one community, no two creatures can fill the same position. You can’t have two consumers needing the same food source. One of them is going to die because there will not be enough to go around. (Think of Neanderthals and Cro-Magnon.)
You can’t have an over abundance of plants without enough animals to consume them either.
When there are too many plants in an ecosystem competing for the same resources, the superior competitors do not always win because herbivores may only eat one plant. If there is no one higher up on the food chain to prey upon them, that population will increase and will eat the preferred plant to extinction. When that happens they will, of course , die and the inferior plant will thrive.
Do you recognize humanity's fate in that last paragraph? What with the diversity of our natural food crops being replaced by genetically designed foods, our increasing dependence upon fewer and fewer food sources, and the overpopulating of the planet, can we last much longer as a species without making changes?
Bill Bryson, author of A Walk in the Woods says this about Mankind. “We have been chosen…by fate or providence, or whatever you wish to call it. As far as we can tell, we are the best there is. We may be all there is! It’s an unnerving thought that we may be the living universe’s supreme achievement …and its worst nightmare simultaneously.”
Books of Interest
The Food of a Younger Land by Mark Kurlansky
Earth: A visitor's guide to the human race by Jon Steward
On Thin Ice:The Changing World of the Polar Bear by Richard Ellis
Designer Genes: A new era in the evolution of man by Steven S. Potter
What Darwin Never Knew DVD Videorecording