| Editor's
Note: This is the first of a two-part series
on the work done at the U.S. Department of Agricluture's
Jornada Experimental Range in Las Cruces, N.M.
The first time I heard Dr. Kris Havstad
give a presentation on desert ecology he began his talk
in the back of the room – literally.
His point was figurative as well as literal
– that for too long scientists were most comfortable
in the back of the room, listening attentively, but
politely disengaged from the controversies surrounding
natural resource management in the West.
The reasons for this detachment, he noted,
included a concern about incomplete knowledge, a fear
of getting dragged into politics, an aversion to conflict,
and even a certain shyness.
As Havstad said these things he walked slowly
to the front of the room.
This was also meant to illustrate a point
– that it was time for science to be out front,
to be engaged, to be useful. In Havstad's opinion the
main role of scientists, especially government scientists,
such as those who work under his supervision at the
U.S. Department of Agriculture's Jornada Experimental
Range (JER) in Las Cruces, N.M., is to deliver their
knowledge in ways that have impact in the real world.
"If we're not relevant," Havstad said recently,
"then the public should bag us."
It is a typical statement from a man who
has gained a well-earned reputation as an articulate
spokesperson both for the role of science in society
and for explaining how arid ecosystems work. An opportunity
to combine the two was one of the reasons Havstad left
a professorship at Montana State University and took
the job as the boss of the JER in 1994.
"If we're not relevant
– Dr. Kris Havstad, Supervisor
USDA Jornada Experimental Range
Eight years ago, when Havstad began walking
the talk, which included becoming a founding board member
of The Quivira Coalition, the idea of relevant science
was somewhat radical, especially the holistic (meaning
‘whole systems') approach exercised by the JER
scientists.
Moreover, the tenor of the times was not
exactly ripe for thoughtful analysis. The political
climate was confrontational, the struggle between ranchers
and environmentalists had reached a crescendo, and anti-federalist
feelings in rural counties ran high.
It's no wonder scientists felt safe in the
back of the room.
It took some courage, therefore, for the
JER researchers not only to step forward but also to
find creative ways to break down old stereotypes. Fortunately,
Havstad had help, including Dr. Jeff Herrick, a soil
scientist who led the effort to rethink monitoring protocols,
and Dr. Ed Frederickson, an animal scientist who has
taken the JER's traditional focus on cattle in new directions.
Perhaps the best way to explain this new
approach is to repeat a phrase I heard Havstad use often,
with acknowledged irony, when opening a meeting with
ranchers and other private citizens at the time:
"We're from the government and we're here
to help."
Old School
It is almost a cliché to say that
summarizing the complexity of rangeland science at the
start of the 21st century is as difficult as summarizing
the desert itself.
The more we learn, it seems, the more we
realize how little we know. And if the goal of achieving
ecological understanding isn't enough, add to it the
job of communicating this knowledge to growing and diversifying
lay audiences and you have a recipe for a tall order.
Adding to the difficulty is the changing
nature of rangeland research itself. Until recently,
useful science at the JER meant research that supported
agricultural aims, specifically the goal of raising
cattle in an arid environment.
In fact, the principal reason the 190,000-acre
Jornada Ranch, located north of Las Cruces, became government
property in 1911 was so scientists could study the damage
done by overgrazing in the desert and consider mitigation
strategies.
There was a lot to consider. The Boom Years
(1880-1920) of the livestock industry, characterized
by large numbers of animals and few controls, had decimated
the range across the Southwest. Throw in periodic drought,
and you had a serious problem.
Widespread alarm at the time over soil erosion,
loss of vegetative cover, and other grazing-related
maladies prodded the federal government to take remediative
action, including the creation of the old Soil Conservation
Service (now the National Resource Conservation Service)
to assist private landowners. It also set researchers,
such as those at the new Jornada station, to work on
the problem of deducing a ‘better way' to raise
livestock in the desert.
They're still deducing.
What changed in the intervening years was
the rise of ecology. However, in the beginning this
young discipline was directed to maintain focus on livestock,
especially on the issue of increasing forage production.
But there was an unintended consequence – new
knowledge began to rub against old thinking.
"We tried various silver bullets over the
years to solve certain problems – herbicide, Lehman's
lovegrass, prescribed burning," said Havstad, "but research
revealed that if it isn't done right, it may be a waste
of time."
"Rangelands involve thousands of variables
and millions of interactions among those variables,"
said Havstad. "They don't ‘behave' in predictable
ways, they defy easy, quick, simplistic solutions or
responses and they challenge specific blueprints for
their management. That's the conundrum. We need years
of scientific study, but the land manager is expected
to provide quick, correct, and practical answers."
"That means today we should:
– Dr. Kris Havstad
One significant change brought about by
ecological understanding has been the broad shift within
the science community from the idea of a ‘balance
of nature' – where natural forces are engaged
in a constant effort to maintain equilibrium –
to the idea of the ‘flux of nature' – where
the role of disturbance, or ‘pulses of energy'
such as fire, wind, and animal impact, is seen as key
to the maintenance of land health.
This shift in thinking led the JER researchers
to shift the definition of useful science.
"It's not about creating more forage for
cattle anymore," said Havstad. "Our mission is to improve
our knowledge of ecosystem processes as a basis for
management and remediation of desert rangelands."
Teachable Moments
Believing that a basic understanding of
ecological processes is a prerequisite for prudent decisions
by land managers, the researchers at the JER started
over, in a sense, at the level of soil, grass, and water.
"What we've learned since the 1950s," said
Havstad, who like many scientists, tends to talk in
lists, "is a better understanding of ecological principles,
the mechanisms that drive ecological change, and the
characteristics of ecological sites. That means today
we should: one, understand the ecological processes
in specific environments; two, know local conditions
that modify those processes; three, monitor to evaluate
responses; and four, adjust management."
In a nutshell: adaptive management.
The tools that the JER, in cooperation with
many other researchers, has helped to develop include:
-
(1) Ecological Site Descriptions
– which help communicate how ecological processes
vary over time, climate, and soils in particular
places;
-
(2) State-and-Transition models
– which summarize how particular
processes combine to produce reversible and irreversible
changes; and
-
(3) Rangeland Health Indicators
– a qualitative assessment protocol which
enables land managers to evaluate actions, including
approaching potential thresholds.
They also helped to develop a quantitative
monitoring system that precisely measures watershed
function over time.
By going back to basic ecological processes,
these tools are designed to answer real-life questions
– what is the land capable of supporting? What
is the system lacking? What management strategy is appropriate?
And indirectly, but no less importantly:
who will do the work?
"Repetitive behaviors on a landscape that
are a function of soils, topography, aspect, climate,
and organisms, create capacities and potentials," said
Havstad. "Understanding those repetitive behaviors is
the key to management."
So is communicating those behaviors. The
trick, according to Havstad, is finding "teachable moments"
– when and where you can actually have an impact.
One of the researchers on the front lines
of finding these moments is Jeff Herrick, one of the
principal authors of the new rangeland health monitoring
and assessment protocols.
"It's all about better understanding the
land and how our actions might affect it, and then communicating,"
said Herrick. "You can develop the best tools, but if
you can't communicate them then you aren't helping."
Jeff does his part by leading a great deal
of training, mostly on the assessment system these days,
for government land managers, conservationists, ranchers,
and other landowners.
"The point of the training, and really of
all our work," said Herrick, "is the assumption that
what we value from land, such as livestock use or recreation
or hunting, depends on three attributes: soil and site
stability, hydrologic function, and biotic integrity.
Without that healthy foundation you'll never reach true
sustainability."
In other words, useful science-based land
management, according to Herrick, Havstad and others,
means:
-
(1) defining the ecological
potential of particular piece of land;
-
(2) assessing the current
status of that land relative to its potential; and
-
(3) monitoring to document
changes over time, especially in response to management
activities.
It all starts with soil, grass, and water.
Value
One of the messages that Kris Havstad voiced
when he walked from the back of the room to the front,
years ago, was that from a scientific perspective the
"debate" over livestock grazing in the Southwest was
largely over.
In November 1999, Kris Havstad summarized
this message in an issue of The Quivira Coalition's
newsletter:
"We now know that many of our rangelands
have been overgrazed, that some areas remain in degraded
states despite adequate rainfall, and that some rangelands
shouldn't be grazed by livestock. Yet, we also know
fairly clearly that livestock grazing of rangelands
can be a sustainable practice for many sites, for many
seasons, and for many years.
Extensive experimentation has illustrated
that grazing can be managed and the integrity of rangelands
ecosystems, in terms of their ability to produce, capture
and store nutrients and to conserve soil resources,
can be maintained."
In other words, the ecological function
of rangelands, if maintained, can support a societal
value – livestock production. That was settled.
The next step, he wrote, was to explore the ecological
processes in more detail in order to provide the basis
for their proper management.
According to Havstad, however, what could
not be done was provide a ‘silver bullet' for
livestock management in arid environments. He compares
it to the science of raising a child:
"There is no clear scientific basis supporting
a specific ‘blueprint' for a parent to follow
in rearing a child…a single methodology derived
from hypothesis-based scientific experimentation that
services all possible combinations of parents, children,
and environments does not exist."
"Like the science of children," he continued,
"we have an impressive knowledge base for rangelands.
Yet, like human nature, there does not exist a single
science-based blueprint for how we interact with our
environment."
This is important for two reasons: first,
it demonstrates that rangeland management, like parenting,
will always be more art than science.
In other words, science can inform, but
not dictate, our decisions. Second, since these decisions
will always be based primarily on societal values –
culture, politics, economics – useful science
means making as clear as possible the functions that
supports these values – much the way medicine
and psychology are used to raise healthy children.
For example, the JER recently began to focus
on another societal value: sustainability. Achieving
this value, which Havstad defines as "the maintenance
of ecological integrity over time," is especially important
not only if we intend to continue to use arid landscapes
into the future, but also for wider issues involved
in the human/nature relationship. Therefore, the goal
of sustainable use in the desert is immediately relevant.
"Sustainable use can be defined as an appropriation
of production, such as biomass used by grazing livestock,
for instance," said Havstad, "that allows for natural
processes to replace appropriated materials."
In other words, we must give back what we
take, either by letting it happen naturally, through
photosynthesis for example, or through restoration activities,
if possible. In either case, it means that levels of
use – all use – must be gauged by the natural
limits of an ecosystem.
That's the theory – the practice is
more complicated. Useful science along these lines is
difficult to achieve because while ecosystems exist
at tremendous scales, both in time and space, we tend
to view them, for obvious reasons, at human-friendly
scales. This means the tools available to land managers
are limited to only a few components of a landscape.
Such as plants.
"There is much we can't control, but we
can control plants," said Havstad, "and we know a great
deal about plants. Water too, especially the water cycle
in arid environments. We can base our management actions
on how we impact properties of these landscapes that
are related to these key processes."
And that's where livestock grazing comes
in – as a tool for the maintenance of key ecological
processes. It is, in fact, one of the few tools land
managers have, along with fire, rest, and certain forms
of technology, to ensure the maintenance of these processes
over time. We could ‘leave well enough alone'
too – let nature take its course. But that's not
an option in many places on the planet anymore.
For example, take desertification –
a sustainability concern for one-third of the globe.
It is characterized by the unnaturally rapid loss of
soil's protective plant cover, resulting in erosion
by wind and water, which threatens the very processes
that sustain life.
If we are to reverse desertification –
and many people think we need to – then we have
to think about plants, as well as the proper use of
land management tools that encourage their health, including
well-managed livestock grazing.
In sum, function and value – ecological
integrity and human use – are now inseparably
intertwined, especially under the spreading threat of
global climate change.
Coming next week: How Jornada
researchers are working to reduce the impact of livestock
on the range by using a specific breed of cattle.
|
Courtney White writes