The U.S. Fish & Wildlife Service (FWS) is proposing to list the acuna cactus (Echinomastus erectocentrus var. acunensis) as an endangered species and establish critical habitat for it in Arizona. Will such a listing and critical habitat actually have a positive effect on the cactus?
As described by FWS, the Acuna cactus is a small, spherical cactus, usually single-stemmed, that can be up to 16 inches tall and 3.5 inches wide. Rose, pink, or lavender flowers which are produced in March. The fruits are pale green and contain small, black seeds. This cactus occurs in valleys and on small knolls and gravel ridges of up to 30 percent slope in the Arizona Upland subdivision of the Sonoran Desert scrub at 365 to 1,150 m (1,198 to 3,773 ft) in elevation.
In a press release, FWS says, “Current evidence suggests that the acuña cactus and Fickeisen plains cactus are in danger of becoming extinct in the foreseeable future.” The Arizona Daily Star puts it more dramatically: “Small cactus in Organ Pipe National Monument faces extinction.”
Let’s look at the threat assessment according to FWS (from Federal Register vol. 77, no. 192):
Urbanization near Ajo and Florence may have direct or indirect effects on the cactus, but these areas comprise “less than 21 percent of known living acuna cactus individuals.” “The majority of the range in the United States is protected from urban development because populations are on Federal lands, where little or no development will take place. In addition, most populations of the acuna cactus are relatively remote or otherwise protected from the effects of urbanization. We conclude that urban development and site degradation is not currently a threat to any entire population of the acuna cactus.”
About 65 percent of acuna cactus occur in National Parks or National Monuments and are thus protected from cattle grazing. Cattle grazing is not a threat.
About 78 percent of known living acuna cactus live along or near the U.S.-Mexican border. FWS concludes that “cross-border violators” are a threat the cactus habitat.
Throughout the Sonoran Desert invasive species such as bufflegrass, red brome, and Lehmann’s love grass “have altered nutrient regimes; species composition and structure; and fire frequency, duration, intensity, and magnitude.” However, FWS is not aware of any effect on populations of acuna cactus and concludes that invasive species pose no threat.
FWS says, “We are aware of no acuna cactus populations that are currently impacted by active mining.” “We conclude that current and future mining activity is not a threat to the acuna cactus and its habitat.”
Drought and Climate Change:
After a very long discussion, FWS concludes that “drought and the effects of climate change, combined with insect predation, rise to a rangewide level threat.”
Disease or predation:
FWS concludes “that predation is a threat that is resulting in significant population impacts to the acuna cactus, and this threat is expected to continue into the future.”
To summerize, FWS says that the cactuses are threatened by “border activities,” climate change, and by predation or disease.
Listing the cactus as endangered and establishing critical habitat will only make the “border activity” problem worse because it will limit enforcement activities.
I do not see how the endangerment listing and establishment of critical habitat could have any impact on the effects of climate change, predation by animals, or upon disease.
The conclusion, therefore, is that the acuna cactus should not be listed; it’s just a waste of time, money, and resources.