From: Alan McGowen <alanm@igc.apc.org>
Newsgroups: sci.environment
Date: 11 Nov 92 22:54 PST
Subject: Re: Ecosystem "Services" or Functions?
Nf-ID: #R:hpindda.cup.hp.com:149180048:cdp:1466601904:000:8849
Nf-From: cdp.UUCP!alanm    Nov 11 22:54:00 1992


I wrote:

>   The crucial point is that Steinn tacitly orders the functions in 
>   terms of some scale of "importance" -- anthropocentric utility --
>   and compares two different ecosystems with different lists of
>   functions on this scale of "importance". No ecologist would ever
>   do that, for a few reasons: 1) the functions that are subjectively
>   "important" are coevolved with functions that are subjectively 
>   "unimportant", 2) we don't know all the interdependencies, so we don't
>   in fact know all the functions which it objectively takes to support
>   the ones that are subjectively important, and 3) biology doesn't 
>   revolve around human values any more than the heavens do -- using
>   what's subjectively important to humans as a yardstick for what's
>   actually important for keeping an ecosystem running isn't likely to 
>   lead to improved understanding. 

Steinn:
>
>Alan, you miss the point, it is clear than in general changing the
>nature of an environment will affect the inhabitants of that
>environment, the problem here is that the objections are raised
>because certain inhabitants will lose services 

That isn't *my* objection, and in fact it's the sort of objection 
which is more consistent with an animal rights philosophy than 
with ecocentrism. My objection is that the *ecosystem* is losing
function. Loss of services to "inhabitants" however defined is a 
possible result of loss of function, but as I warned this line of 
argumentation can be coopted by economic imperialists -- which I 
strongly suspect is what is afoot in Steinn's response.

>without any
>consideration of the fact that there is some gain for other
>inhabitants.... 
>Currently
>anthropocentric concerns dominate the decision making process in
>anthropogenic changes, if you want other factors to be rationally
>taken into consideration you must have some way of evaluating them and
>ranking their importance, you _cannot_ simply say we must do
>nothing because we know not what we do. 

Nor do I. This is either a misunderstanding or a misrepresentation 
of everything I have written in this group for the past year and 
more. 

>If ecologists really want
>some ecocentric basis for human actions they have to rank the
>priorities, there will be changes in natural systems and they will
>be influenced by humans. You must explain not only why the loss
>of something is bad, but also why what replaces it is not good enough
>to compensate for the loss  - if you don't loke the current metric,
>come up with your own and show why it is better.

Rather than attempting some program to extend economic 
utilitarianism to all the species that make up an ecosystem 
(which might be an amusing long-term project, but is not likely 
to prove useful in the foreseeable future), existing measures of 
diversity can be used to identify the most valuable areas -- the 
biodiversity "hotspots" -- and give them the top priority 
for protection. Next in importance are rare ecosystem types -- even 
if small -- to preserve ecosystem-level diversity -- and lands 
which can be restored to provide increased habitat area for 
groups which are in decline as a result of habitat loss.    

The object is to protect diversity at all levels -- intrapopulation,
interpopulation, intraecosystem (species and habitat diversity) 
and interecosystem (biogeographic diversity). As a crude rule of 
thumb, the greater the diversity, the more valuable because the
greater the investment of evolutionary time required to produce
it: rainforests and wetlands tend to win on that measure. But 
there are other considerations -- a lower diversity, low 
productivity region such as a desert can also be important on 
grounds of uniqueness. Still, I don't know of any ecologists who 
object to restoration of the Sahara, for example. Despite 
Steinn's misunderstanding, the objection is *not* to *any* 
anthropogenic change whatsoever -- it's to those that produce 
degradation, including the slow degradation of reduced speciation 
potential and loss of adaptation resulting from range 
restriction.   

>   [What would astronomers make of the idea that our subjective sense of 
>   the stability of the Earth should be the first consideration in 
>   cosmology? Just as we have found it necessary to reeducate our subjective
>
>Actually, it is a primary consideration in cosmology, any cosmology

I was thinking of the anti-Copernican argument offered 400 years 
ago to the effect that the earth can't possibly be moving because 
we would feel it if it were. Fortunately at least some 
astronomers then were able to see that this subjective sense of 
stability should not be the first concern of their science. 
Likewise, the human subjective sense of their own ecological centrality 
is mistaken and cannot be the starting point for conservation 
biology. This is another argument to eschew the economics-
centered "services" talk.

I wrote:
>
>   Consequently, though biologists (I think beginning with Ehrlich)
>   often speak of "ecosystem services" to convey to the public that many 
>   of these functions are important to humans, there is the deadly danger 
>   that the economic analogy will be pushed too far, as Steinn has done
>   here: the idea that we can pick and choose economic services and
>   intersubstitute them at will doesn't apply here, because *these* 
>   "services" go to make up living systems. With ecosystems, if you like 
>   *some* of what they do, you had better leave their species inventories
>   pretty much alone. (What is the exact Aldo Leopold quote? "If evolution, 

Steinn:

>To be quite brutal, this is not true in general, while Alan makes much
>of the limited knowledge that ecologists have of ecosystem dynamics,
>and in particular the danger that the wrong action can lead to a
>catastrophic collapse of ecosystem function, 

Actually, I've made a great deal more of gradual degradation -- 
though there are plenty of examples of cases where loss of 
keystone species have caused rapid loss of diversity through a 
whole community. One classic example was removing most of the 
sea otters along the California coast, which led to a low-
diversity shelf community dominated by sea urchins. There are 
many others.

>the converse is 
>usually the case, ecosystems are generally robust and can adapt to large
>perturbations, 

This sweeping generalization is basically nonsense. Ecosystems 
tend to be "robust" (technically, *resiliant*) with respect to 
the disturbance regime they evolved under. Much of the ability to 
recover arises from the potential for recolonization of the 
disturbed area from nearby undisturbed areas -- this potential 
deteriorates as the overall area is diminished and fragmented. I 
devoted one of the ECOCENTRALs to different senses of the words 
"stable", "unstable, "robust" etc. for ecosystems. Perhaps I 
should repost it.  

>further, ecosystems do substitute, if conditions become
>hostile to a particular ecosystem, it is generally replaced by a
>different ecosystem, often one with a different functionality but
>then Alan argues that we cannot declare that any less important
>than the one replaced - by Alan's own argument a desert ecology
>is just as important as that of wetlands or grassland, so why
>bother saving the wetlands? 

This is flagrant sophistry. The top priority is to preserve 
enough of all levels of diversity for all ecological and 
evolutionary processes to continue on the earth as a whole -- not 
necessarily on every single spot. [As with Dietz' "concerns" 
about the ecosystem destruction when a hut is built.] But we 
have already lost more than 40% of the wetlands in this country 
and even the outgoing administration paid lip service to a policy 
of "no net loss" of remaining wetlands (while trying to foist on us a 
politically-motivated redefinition of "wetland"). The need to 
protect wetlands is not in question except among the most extreme 
ideologues of the right, and their uninformed technocratic 
running-dogs. [Whee! I have to get back in practice after a 
twelve-year hiatus. :-)]

Steinn is right about one thing -- there is a great need to 
prioritize the regions most in need of conservation efforts. This 
requires amassing an immense amount of information about the 
organisms in each region. It may shock readers to learn that we 
have only sketchy knowledge of the biodiversity and the processes 
which support it even in the United States outside of the more 
conspicuous groups of organisms. 

This prioritization would be one of the functions of the National 
Institutes of Biodiversity, which may be established by the next 
Congress. For more about this idea, and the topic of 
biodiversity, I'd again urge the reader to find a copy of Edward 
O. Wilson's new book _The Diversity of Life_.

------------
Alan McGowen