Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Ronald J. Kass
    Date: 2001
    Source: In: Maschinski, Joyce; Holter, Louella, tech. eds. Southwestern rare and endangered plants: Proceedings of the Third Conference; 2000 September 25-28; Flagstaff, AZ. Proceedings RMRS-P-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 51-58.
    Publication Series: Proceedings (P)
    Station: Rocky Mountain Research Station
    PDF: Download Publication  (603.79 KB)

    Description

    Wright fishhook cactus (Sclerocactus wrightiae Benson) is a small barrel cactus endemic to the San Rafael Swell in south-central Utah. It was listed as an endangered species in 1979 due to its small population size, threats of over-collecting, and development associated with oil and gas. Demographic monitoring was initiated in 1993 with the following objectives: to establish permanent plots to monitor growth, fecundity, recruitment, and mortality for at least 10 years; to identify habitat factors positively associated with cacti presence; and to identify important insect visitors and predators. Three permanent plots were located throughout the range of S. wrightiae, and 93 individuals were followed from 1993 to 2000. In general, diameter size class was significantly different (P c 0.001) for all three plots. Size classes 3 and 4 (adults) produced the greatest number of flowers and fruits. Size class 3 produced more flowers and fruits by virtue of its higher density, whereas size class 4 produced more flowers and fruits because of its larger diameter. Mortality exceeded recruitment by a 2.5:l ratio for all plots. At Hanksville, 21 cacti (68%) were recorded dead in 1994, and the remaining 10 individuals and 5 recruits were recorded dead in 1995. No new recruits have been recorded since 1995 at Hanksville. Ord's kangaroo rats and white-tailed antelope ground squirrels were primary mortality sources at Hanksville, and the cactus-borer beetle was the primary mortality source at Giles and Mesa Butte.

    Publication Notes

    • You may send email to rmrspubrequest@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Kass, Ronald J. 2001. Demographic monitoring of Wright fishhook cactus. In: Maschinski, Joyce; Holter, Louella, tech. eds. Southwestern rare and endangered plants: Proceedings of the Third Conference; 2000 September 25-28; Flagstaff, AZ. Proceedings RMRS-P-23. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 51-58.

    Keywords

    plant conservation, genetics, demography, reproductive biology, monitoring, endangered species

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/41905