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 revegetated.
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 ahead.
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
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 Valley.
It is estimated that
as many as 90% of agricultural laborers in California's Central
valley are illegal immigrants, nearly all from Mexico.
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 from Mexico.
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, etc.
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
Land slips and gully erosion are evident all over the on hills
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
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 increase
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
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 grazing.
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.