waiting to happen: The California Poppy
covers a rangeland hill next to Interstate 5. The
Interior Live and Valley Oaks that formerly covered
these hills were cleared a century ago for grazing.
Areas of erosion can be seen. The large eroded gully
to the right of the center of the photo has been
Posted May 13, 2004 The drive south down
Interstate 5, from Davis, my hometown north of San Francisco,
is a déjà vu. Nearly 30 years ago, in late March
of 1976, I caught a ride to LA for the first leg of my first
journey to Latin America. I was a junior in Agronomy at the
University of California Davis and had landed a small scholarship
to train in the bean program at the Centro Internacional de
Agricultura Tropical (CIAT) in Cali, Colombia. But first I
needed to learn Spanish, so I was heading to Cuernavaca, Mexico
where some of the first Spanish language schools in Mexico
The feeling of trepidation of facing a big unknown, a knot
in the stomach that comes when leaving the security of home,
of knowing that many taxing challenges lie ahead, were the
same today as they were in 1976. Only now I’m 52 years
old, driving a small RV, and wondering if I’m up to
it. It’s one thing to plan the trip with friends over
beers, and another to set out alone, with so many unknowns
the 25 year old Toyota Dolphin RV hold up on the Mexican
and Central American roads? What if I break down late
in the day in the middle of nowhere? How aggressive
will the thieves be?
Will the 25 year old Toyota Dolphin RV (it’s actually
called a mini-RV) hold up on the Mexican and Central American
roads? What if I break down late in the day in the middle
of nowhere? How aggressive will the thieves be in the poor
countries like Guatemala?
The 1976 trip started out difficult – I went through
a bout of acute loneliness in a seedy hotel in the Mexican
border town of Mexicali before boarding the train south. Then,
there was the stressful learning process, without knowing
a word of Spanish, that I needed to bribe the train conductor
in order to get a sleeping bunk for the 3-day trip.
But the six-month sojourn ended up being one of the best
of my life. The I-Ching has a saying that goes something like,
“Difficult beginnings can have great endings.”
I have since made many trips to Latin America, spending some
two years there.
As I drive south, I tell myself the I-Ching saying.
The California Central
Valley: agricultural juggernaut.
The trip down the I-5 highway passes me through one of the
richest agricultural areas in the world, the great Central
Valley, whose agricultural worth is over $25 billion annually.
The Valley’s agriculture produces fully a quarter of
the nation’s food (this is probably either by value
or weight, but definitely not calories) and uses a third of
its pesticides on its 300 crops. I pass almonds, walnuts,
citrus, peaches, apricots, pasture. I smell the enormous feedlot
at Coalinga before I can even see it – a solid square
mile of cattle standing on hills of their own manure.
The only obvious new crop from 30 years ago is pistachio,
which has spread from northern California to the San Joaquin
It is estimated
that as many as 90% of agricultural laborers in California's
Central valley are illegal immigrants, nearly all from
The Central Valley agricultural economy is intimately connected
to Mexico, although this is generally not widely spoken of.
It is estimated that at least 50% and as many as 90% of agricultural
laborers in the valley are illegal immigrants, nearly all
While on the one hand our agricultural economy is totally
dependent on this illegal migrant labor, we demonize the immigrants
when it comes to their relatively small cost to society –
the small percentage of criminals, some public health expenditures,
neglected stepchild: coastal hill rangelands.
The I-5 highway was put on the very west side of the Central
Valley, right at the bottom of the western coastal hills.
The hills have been denuded of 95% of the oaks that formerly
covered them, in order to produce forage for grazing cattle.
My ecology background has made me aware that hilly rangelands
are one of the most unsustainable parts of California’s
agriculture. It is every bit as backwards as many areas I
see in Third World countries, where we send advisors and money
to “develop” them. The amount of money we spend
to help other countries stabilize their rangelands is far
more than we spend on our own.
Trees on hillsides
would take a couple of years of irrigation, a substantial
cost for rangelands, but once established, land values
would increase substantially.
Land slips and gully erosion are evident all over the on
hills I pass.
What land managers don’t seem to realize is that it
just takes a few “perfect storms” over a couple
of centuries before these hills lose most of their soil and
end up looking like the rocky hills of the Mediterranean,
denuded of trees and overgrazed 2000 years ago.
The perfect storm scenario starts with a drought year that
allows only stunted range plant growth. Cattle then graze
to stubble what little pasture gets up. Then in November the
first rains of the season occur as a big two or three day
rainstorm, usually an El Nino year. The storm happens early,
before any plant growth can occur to protect the soil. This
has happened before, and the erosion damage is enormous.
The California native oaks that covered these hills–the
Interior Live and Valley Oaks—are not conducive to producing
cattle, as they are evergreen, throw heavy shade and prevent
growth of range grasses, which are now nearly all Mediterranean
annuals that evolved under heavy grazing and open sun in Europe.
The ecology of California range forages is to get a spurt
of growth at the beginning of the rains in November, when
the temperatures are still fairly warm. During the winter
months, there will be small growth spurts on sunny days. Then
when temperatures warm up in the spring, another growth spurt
occurs before things dry up.
Seventy percent of coastal hill range plant growth occurs
during these fall and spring windows of warmth and wetness.
Early in my graduate career at UC Davis I proposed a study
to look at the potential for putting grazing-friendly trees
on these hills – trees that would also stabilize the
slopes. I found the potential “ideal” agroforestry
tree to be the honey locust (Gleditsia), a common street tree
in California. The honey locust has a nice, open canopy that
lets through a fair amount of light.
Honey locust in California has the unique trait of shedding
its leaves quite early in the fall – the result of an
infestation of a leaf miner insect. This opens the canopy
to sunlight during the critical November period of warmth
and wetness. Honey locust is also a late budder in spring
– which fits with the other growth window, allowing
sunlight penetration while things are warm and still wet.
Honey locust is one of those uncommon legumes that does not
nodulate or fix nitrogen. Nevertheless, it produces copious
amounts of pods which provide additional fodder during late
summer and fall when grasses can be depleted. The shade in
the summer is good for livestock.
The establishment of the trees on hillsides would take at
least a couple of years of intermittent irrigation, a substantial
cost for rangelands, but once established, land values would
Forage-friendly trees would give a multidimensional aspect
to the rangelands. Winter and spring would produce grasses
and forage, summer and fall would have tree shade and pods.
Overall biological diversity would be significantly increased.
|Thinking the gas gauge is broken,
I run out of gas while crossing a busy intersection of
Whittier Boulevard in LA.
Unfortunately, I attempted this research proposal during
the years when the University of California budget was slashed
more drastically than ever before (as is now occurring again),
and it was never funded.
Additionally, there were some concerns amongst the purists
about putting a non-native tree on California rangelands.
Honey locust is native to Tennessee and the eastern Midwest.
However, my view is that the hilly rangeland system is profoundly
unsustainable without its oaks, and a solution is badly needed.
The land owners want something that is going to pay, and they
aren’t going to put in native oaks without hefty subsidization.
California native oaks in the past haven’t allowed profitable
There are millions of honey locust trees in California cities.
All of our agriculture is characterized by introduced plants.
First glitch in the
best laid plans …
The challenges of the journey south start before I even get
to LA. Someone siphoned all of the gas from my full tank during
one of my rest stops. Welcome to southern California (most
of us northern Californians consider it another state and
hardly ever go there). Gas is over $2 a gallon, and my ’79
Toyota has only a flimsy plastic door over the gas cap.
Thinking the gas gauge is broken, I run out of gas while
crossing a busy intersection of Whittier Boulevard in LA.
Believing the problem to be a failed fuel pump, I get towed
to a friend’s house in Whittier. We diagnose the problem,
buy a locking gas cap, and am on my way south to the border.
NEXT INSTALLMENT: First stop in Baja—just
a few miles south of the maquiladora factories on the border,
Don stops to chat with wine grape and olive growers …
then further south for conversations with nopal cactus growers.