Recreation
Although once considered a non-consumptive use of the desert
relative to mining, grazing and logging, recreation-related
damage is now considered the second most pervasive impact
upon threatened and endangered species in the Western United
States (Rick Knight pers. Comm.) Off-road vehicle damage of
vegetation, vandalism and illicit collecting of endangered
plants - all incidentally associated with outdoor recreation
- are collectively cited more frequently than any other pressures
on threatened plants in the U.S./Mexico borderlands (Nabhan
et al. 1989).
Ironically, in the Sonoran Desert, the most intensive poaching
of endangered cacti occurs on the public lands where the "conservation
message" of land management agencies is supposedly the
strongest - in National Parks and National Wildlife Refuges,
then less dramatically so, on BLM lands, Indian reservations
and private lands (Bennett et al. 1987). For example, Park
Service biologists recorded a 44% loss of Thornber's fishhook
cactus individuals due to "recreational cactus-poaching"
and trampling by tourists at an intensively-visited site in
Organ Pipe Cactus National Monument.
Similarly, studies in recreational campgrounds in Oak Creek
Canyon at the northern limits of the Sonoran Desert have conclusively
demonstrated that breeding bird density and diversity decline
precipitously once campgrounds are opened for seasonal use
(Aitchison 1987).
We surveyed
managers of Sonoran Desert protected areas about visitation,
growth of visitation, types of recreational use, the detrimental
effects of this use on the natural values of the area, sensitive
species, and management of recreational use. The numbers of
recreationalists, trends in these numbers, and the extent
of certain detrimental visitation effects are often little
known and difficult to quantify, but we did receive some valuable
information (Table 5).
Recorded visitation per year (1996 or 1997) ranged
from about 500 to 2000 in several BLM Arizona Upland/Lower
Colorado River Valley Wilderness areas and reached 200,000
to 400,000 in Organ Pipe National Monument and Saguaro
National Park (Arizona Upland/Lower Colorado River Valley).
Tourists visited these areas for a variety of activities,
from hiking to off-road recreational use.
Not surprisingly, total visitation remains unknown
for most protected areas in Mexico, and unknown for
3 out of 10 protected areas in the U.S. The growth in
visitation over the last quarter century was known in
only 30% of the protected areas.
With regard to detrimental effects of recreational
use, soil erosion was the most frequently cited negative
impact, occurring at 8 of the 10 protected areas surveyed.
It was followed in frequency of disturbance of understory
of vegetation (40%), fuelwood harvesting (30%), disruption
of nesting birds (20%), and disturbance of other landscape
features, including riparian vegetation and dunes.
Almost all areas are attempting to mitigate recreational
impacts by employing various intervention strategies. These
include: advertising of visitation rules, stricter law enforcement,
and even complete closure of sensitive areas. The BLM is completing
an inventory of vehicle routes in the Barry M. Goldwater Air
Force Range in order to close "redundant" ones.
Despite these efforts, only 30% of the surveyed managers thought
that recreational impact management strategies would be adequate
for the protection of the areas in the next 10 years.
From:
Nabhan, Gary Paul and Andrew R. Holdsworth. 1998. State
of the Sonoran Desert Biome: Uniqueness, Biodiversity, Threats
and the Adequacy of Protection in the Sonoran Bioregion.
p.24-25. Tucson, Ariz.: The Wildlands Project.
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