Abstract Detail

Systematics

Coburn, Francis [1].

Flora of the Upper Verde River, Arizona.

The Upper Verde River of central Arizona flows through a landscape of complex geology at the meeting of seven biotic communities and three physiographic provinces. This has resulted in a notably diverse flora and fauna and a hub of rare and endemic plant species. The river has sustained cultures since pre-history, however current regional water use is predicted to diminish streamflow over the next century. Prior to this project, no floristic inventory had been conducted along any section of the Verde. The purpose of this study was to develop a Flora of the Upper Verde River, with the goals of documenting rare and endemic species, the composition and abundance of wetland plants, and the factors shaping plant diversity in the region. I made a total of 1856 collections and reviewed past collections to produce a checklist of 729 vascular plant taxa in 403 genera and 98 families. The flora includes 159 wetland taxa, 47 regional and local endemics, and 26 taxa of conservation concern, eight of which are federally listed. Several new populations were found in these categories and of rarely-collected taxa including one state record, three county records and several range extensions. I report on the status of several endemics, range extensions, wetland taxa with limited distributions, and relict populations of tepary bean (Phaseolus acutifolius) that were likely transported to the region and cultivated by pre-Columbian cultures. I categorize thirteen distinct plant communities, the most abundant being Pinyon/Juniper Woodland, Chihuahuan/Apacherian Scrub, and Riparian Deciduous Forest. Four primary factors influence floristic diversity of the Upper Verde region: its location at the junction of three physiographic and floristic provinces—represented by the co-occurrence of species with affinities to the Sonoran, Intermountain, and Madrean regions, 2) geologic diversity—as distinct groups of species, including several localized endemics, are specific to particular geologic formations, 3) topographic and habitat complexity—allowing species adapted to disparate environments to co-occur, and 4) human introductions—since over 15% of the flora is composed of introduced species and several taxa were introduced to the region and cultivated by pre-Columbian cultures.

1 - Oklahoma State University, Department of Plant Biology, Ecology, and Evolution, 301 Physical Sciences, Stillwater, OK, 74074, USA

Keywords:
Floristics
Endemics
edaphic endemism
Wetlands
ethnobotany
Rare Plants
Southwest
Arizona
flora.

Presentation Type: Oral Paper
Session: 31, Cooley Awards II
Location: 201/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 1:30 PM
Number: 31001
Abstract ID:678
Candidate for Awards:George R. Cooley Award