Fabrice, An interesting and evocative question and dilemma! I should really think on it over time and reply in depth...but some thoughts of the top instead...
I agree with other repliers that the definition really does not exclude humans per se...unless we focus on the "special" aspect of your ID of humans as "special animals". So I think the CBD definition is OK in the broadest sense of all animals. But I also agree that humans are special animals...so what could we change? My core idea of ecosystem as I remember Tansley to have originally coined it mentioned and emphasized "reciprocal" influence between the abiotic and biotic realms. And I think it a reasonable extension to also suggest the definition so far includes a sense of a balanced reciprocity...not necessarily equilibrium, stasis, homeostasis or simple stability...but still in general a kind of equal weighting, value, importance, dominance, or causal driving by the biotic and abiotic realms. If we tried to address what is special about humans as animals, in this context of ecosystem as a functional biotic-abiotic unit...what to emphasize? One option would be to say that when humans enter the integrated functional whole of an ecosystem, the relationship is no longer reciprocal or balanced between biotic and abiotic realms. This does not necessarily have to mean that this change is "bad", just that it is different from ecosystems without humans. The change would be compatible with the idea of the anthropocene era in which humans are the main driving force of change...even geologic, atmospheric, biogeochemical, species extinctions, etc. changes...on the planet. Another very general analogy would be to say that without humans the organisms and communities within ecosystems (biotic) adapt themselves mainly to survival needs as defined by abiotic changes, but humans (biotic) adapt (alter) the abiotic (and biotic) environment to our own needs. This is grossly general...and not even a clearly separable difference between humans and other species, especially those studied as "ecosystem engineers", but it is a rough start. So...a revised approach would be to leave the definition of ecosystem as it is (or one of the other classic or widely used versions by Odum and others), but to add some modifier to another term or type of ecosystem and define that one differently. This might be "coupled human-natural ecosystems" or "human-dominated ecosystems" or "human ecosystems" or "ecosystems with humans". But I think you open a can of worms that has to remain fuzzy and open-ended, because I think it an open question as to whether we humans can continue this lopsided relationship and continue to alter the environment to our needs and wishes. If the pendulum swings back as we reach the environmental limits of the planet, then the old and original ecosystem definition may be fine. If we find some way to transcend these planetary limits or "boundaries"...then we humans really are special enough to require an expanded definition of ecosystem. Some thoughts...would be fun to discuss more... Dan -- Dan Fiscus Assistant Professor Biology Department Frostburg State University 308 Compton Science Center Frostburg, MD 21532 USA 301-687-4170 [email protected] -----Original Message----- From: Ecological Society of America: grants, jobs, news on behalf of Fabrice De Clerck Sent: Fri 6/25/2010 11:20 AM To: [email protected] Subject: [ECOLOG-L] Humans in the definition of ecosystems Dear Friends, An environmental economist colleague of mine is disappointed with the CBD definition of ecosystems which gives the impression that only pristine areas are ecosystems. Can anyone point us to a more recent definition of ecosystems that explicitly includes humans as an integral part of the definition? Here is the original question: The CBD defines ecosystems as a dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit. I find this boring, as it leaves us humans, as special animals, out of the picture. When you read it, it is easy to think of pristine environments. Has there been any reaction or correction of this definition? I need an authoritative quote that balances the CBD´s All reactions welcome, and citations welcome! Fabrice ******************************************************** Fabrice DeClerck PhD Community and Landscape Ecologist Division of Research and Development CATIE 7170, Turrialba, Costa Rica 30501 (506) 2558-2596 [email protected] Adjunct Research Scholar Tropical Agriculture Programs The Earth Institute at Columbia University ********************************************************
