Grasslands comprise the majority of agricultural lands, and harvest the
water required for many urban areas. However, we can't sell the water we
harvest so the economic return is considered to be less significant than
more intensive agriculture. The sustainability question also has a
different slant, at least in the US. Instead of a dichotomy between "Green
Revolution agriculture" and Sustainable agriculture we have a dichotomy
between "environmentalist" and "ranchers". From and ecological and social
perspective, however, these dichotomies are based on different kinds of
foundations. In cropping systems it is primarily a difference in criteria
of choosing tools, whereas in the grazing lands it is more a difference in
human uses -- recreation and/or animal production. (Obviously there are
many other differences, and I choose these to allow other thoughts to be
more clearly compared.)
If we consider livestock to be management tools, instead of forms of
production, and water instead of animal products the economic output of the
land, we see something much more similar to croping systems and the
agriculture we have been primarily discussing. For the moment, let us
assume this fantasy. The differences in production of water now may be
shifted to a dichotomy of capture and storage above ground (analogous to
Green Revolution) or below ground (sustainable). A sustainable system will
tend more toward storage of water below ground, where evaporation and
pollution are reduced and where the ecosystem is more stable, dynamic,
productive, autocatalytic, etc. In our experience appropriate use of the
animals and other tools can increase infiltration with better ground cover
and root systems. There is a transition where water catchments tend to go
dry, but as the water table rises, streams and springs flow more. However,
the application of any tool is a local matter for skillful use, and general
"rules" that fit the statistical average only lead to disaster. The
indicators of movement toward success defined by the goal include such
responses as spacing between perennial non-woody plants, frequency of deep
rooted perennial grass, diversity of forbs, amount of organic matter in the
soil, activity of soil macrofauna (eg. dung beetles and earthworms), animal
health and performance, and,-- arguably an improvement -- more organized
management and planning time required of the managers. Other indicators
are added that relate to the goal or the processes that seem to be critical
at the time. For example, native plants or animals may be important, or
financial return may be important. I am working on indicators that may be
evaluated by remote sensing and incorporated into a GIS. I hope the
technology can be developed so that it is available for short management
decisions as well as longer term monitoring.
However, as with cropping system agriculture, we have certain theoretical
models that are both useful and handicaps to creative thinking and
effective management. Among these are concepts of "succession" and
"restoration". Tools affect ecological processes, which are interrelated
and highly non-linear, as many aspects of the discussion in this conference
address. It is impossible to affect only one or a few processes, but our
focus on "problems" tends to focus our attention on THE cause, which is
usually just another symptom. The tools devised to address such simple
minded interpretations actually affect many processes that aren't
associated with their design, and we get unexpected results. Often the
results become a record of a comedy of errors, which isn't very funny since
it may take decades to recognize, and much more to illicit an effective
response. In the meantime, ecosystem changes are possibly produced that
begin to lead to new states of quasi-stability, such as desertification. A
common reaction of shocked observers is to condemn the tools without
understanding the underlying processes. (It's like regulating hammers
because I hit my thumb.) Of course, in all honesty, one can't point at
"environmentalists" who are guilty of this oversimplified reaction without
simultaneously admitting we still don't know much more about the effects of
tools on processes than they do. We know mostly about tools, and not how
they affect the ecosystem processes (ALL of them, not just those we
associate the tool with by design or accident).
I'll drop the discussion here, realizing we could begin the conference anew
with a focus on non-cropping agriculture. But wouldn't it make more sense
if grazing were considered to be management of a watershed to harvest
water, more than simply a form of animal production? If so, we need some
new legal definitions of ownership (or capture rights) and economic
incentives so that the management will become "Agriculture" rather than
only "agriculture," and the choice and management of tools would become
whatever works for a sustainable savannah ecosystem.
I might add, as the conference is winding down, that I have found it to be
highly stimulating, and I feel that I have gotten to know a number of you
much better as individuals, even though we would not recognize one another
face to face. In this sense, this conference has been time very well spent,
although it is not a substitute for having lunch together.
=========================================================================
R. H. (Dick) Richardson * (512) 471-4128 (w)
Zoology Department * (512) 471-9651 (FAX)
University of Texas * (512) 476-5131 (h)
Austin, TX 78712 * dickr@utxvm.cc.utexas.edu