PARENT SESSION
Poster Session #33: Rare, Threatened, and Endangered Species.
Wednesday, August 7. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC
30
Huachuca water umbel monitoring - a disturbance adapted endangered wetland plant in Arizona.
Zuhlke, Amber*,1, Titus, Priscilla1,2, Titus, Jonathan1, 1 Columbia University's Biosphere 2 Center, Oracle, AZ2 SWCA, Inc., Environmental Consultants, Tucson, AZ
ABSTRACT- Huachuca water umbel (Lilaeopsis schaffneriana ssp. recurva) is a federally-listed endangered plant currently known to occur only in southeastern Arizona and northern Sonora, Mexico. Huachuca water umbel inhabits cienegas, marshes, rivers, and other wetlands, generally in perennial, shallow and slowly flowing waters. Recently, a hitherto unknown population of Huachuca water umbel was documented at Bingham Cienega Preserve, which is owned by Pima County Flood Control District. The population is of special interest because it was discovered one year after a fire reduced interspecific plant competition in the marsh. In fall of 2001, six permanent 1 m2 monitoring plots were established within the water umbel population and seed bank samples were collected. In three of the plots all aboveground portions of competing plant species were removed. All Huachuca water umbel leaves were counted and measured in each of the plots for four consecutive weeks during fall 2001. The number of leaves increased in all plots over the four-week period, but increases were greater among smaller leaf size-classes in all six plots, and leaf number increased more in treatment plots. Seedbank samples contained water umbel seeds. Monitoring is ongoing; we seek to define management strategies and increase our understanding of the basic ecology of this species.
KEY WORDS: endangered species , wetlands, Arizona, Huachuca water umbel