Geography Reference
In-Depth Information
existence of many other species. Similarly, both pikas and prairie dogs have been targets
of eradication and control by governments responding to livestock interests, largely under
the assumptions that the small, wild species competed with the large domestic ones, and
that their mere presence foretold doom to grassland health. A more nuanced view has
recently become accepted among scientists, recognizing that high densities of pikas (in
western China) or prairie dogs (in western North America) are more likely a response to
range degradation than its cause; although once established, the animals and the range
condition act symbiotically to reinforce each other, and competition among the wild and
domestic species is a legitimate management issue.
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Chinese scientists have altered their thinking from earlier days and have recently
begun emphasizing integrated control for pikas and zokors, admitting that while lethal
control may be necessary to begin with, pika management ultimately requires that the
source of grassland change (usually excessive livestock grazing) be addressed. Tracking
this evolution of consciousness among Chinese scientists makes for fascinating reading,
and not only among documents written in English for an international audience. For
example, writing in the mid-1980s in
Economic Animals of Qinghai
, Li Dehao and col-
leagues characterized pikas as “among the most harmful mammals in Qinghai. . . . They
are very destructive of grassland vegetation and compete with livestock for forage. They
lead to grassland degradation and increase the grassland's sandy nature. We recommend
energetic and scientific prevention and elimination.”
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Contrast this with the following, published in 2002 by a team from the State Ministry
of Agriculture (which one might expect to be less sympathetic to arguments favoring
biodiversity as a value in its own right and instead to maintain an instrumentalist attitude):
“Natural grassland ecosystems are basically in a type of dynamic balance. Rodents are
an indispensable part of this system. Their position within grassland ecosystems comes
about through their position in trophic food webs, as well as their burrowing and feeding
activity,”
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and later in the same topic, this conclusion to the “cause or effect” debate,
taking a view of nature's balance that
Through a long history of biological evolution, rodents have formed a very harmo-
nious relationship with their surrounding environment as well as with other animal
species. Each species, including those currently so-called “most harmful rodent
pests,” even as they attempt to increase their numbers, are ultimately controlled by
multiple factors such as predators, disease and nutritional resources. As a result,
they generally cannot become large-scale or serious grassland pests. Even the
most numerous grassland rodent pests, while one cannot say they lack the intrinsic
potential to become harmful, are ultimately controlled by such natural biological
factors as predators and abiotic factors such as weather, as well as pressures from
their own population abundance. Regardless of whether or not people are aware of it,
natural regulation is always the main path toward preventing rodents from becoming
pests. Regrettably, in irresponsibly increasing our living standards, we humans have
often been greedy in using natural resources (for example, continuously exceeding
grazing capacity). The basic conclusion of Chinese research on rodent pests makes
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