Biology Reference
In-Depth Information
story emerging from Carly's work was that the maned wolves were selecting croplands for
hunting rodents, partly because the hunting was easy and efficient. But there was more. Carly
had discovered that the cropland wolves had higher levels of cortisol, indicating that the Ag
land was also more stressful for that species to live in. So the soy fields may be an ecologic-
al trade-off for this elegant animal. Abundant food awaits in the soy, but so does the stress
of leaving its natural habitat and venturing into the human landscape, where perhaps it feels
more exposed and vulnerable.
We compared notes about how natural landscapes were being transformed in the places
we had been working. I mentioned the vast plantations of oil palm and acacia (cultivated
for pulp) I had just seen on Borneo and Sumatra. “Remember the soy plantation we walked
through looking for wolf scat?” Carly interjected. “In one year, it changed over to sugarcane.”
Does it matter to rare grassland mammals if the agricultural expansion involves sugarcane,
soy, tapioca, or cacao? To the Cerrado trio, the answer is yes. The conversion of low-growing
soy to sugarcane will shake things up ecologically, Carly explained. With the soy, there is
a relatively welcoming landscape matrix for the wild animals in the region. “But when con-
verted to sugarcane, it becomes inhospitable to an open vegetation-adapted species like my
wolves.” Compared with soy, sugarcane is a longer-growing crop between harvest periods,
and it forms tall, dark stands, which entails loss of the open-landscape qualities mimicked
by soy fields that are conducive to species such as the maned wolf. Sugarcane also requires
more manual cultivation, and factories may be built to handle the cane on-site, so it could
become a magnet to draw in workers. Carly didn't sound hopeful. “I see conflict as animals
try to avoid humans, and as poachers seek out the wildlife that wanders into the Ag.”
In Sumatra, I had spoken to David McLaughlin, an agricultural expert for the World Wild-
life Fund who had worked in tropical agriculture all over the world. I asked him how agribusi-
ness can maintain, year after year, the commodities we use without tropical nature evolving
innovative pathogens and leaf pests to attack the widespread cultivated plants. Every crop
plant has legions of pests, some minor, some fatal if not controlled, he replied. “For your oil
palm, it's lethal spear rot, found in South America in the 1980s but not yet present in South-
east Asia. Cacao trees have all sorts of things that can hit them. And tropical soy needs con-
stant vigilance against fungi and herbivores.”
“So,” I continued, “you mean if some careless biologist introduced a pathogen into a soy
or oil palm plantation, it could wipe out the whole place and native vegetation would return?”
David eyed me suspiciously. What Carly had observed around Emas foreshadowed his an-
swer. “Remember, commodity production can turn on a dime. Even if a crop pest attacked
soy, farmers could shift immediately to growing sugarcane for biofuels. And if the sugar-
cane succumbed, they might go back to cattle ranching or corn.” The point is that land once
converted to agriculture will likely never go back to native vegetation but rather will be con-
verted to the next big monoculture. The same holds true in the vast oil palm developments
