Abstract Detail

Ecology

Wolkis, Dustin [1], Salywon, Andrew [2].

A comparison of mid-elevation ciénega (wetland) plant communities in southern Arizona, U.S.A.

Landscape-wide investigations are essential to inform efforts to conserve rare vegetation types. Groundwater-dependent wetlands of the American Southwest, regionally called ciénegas, are imperiled, yet floristic effects of losing any single ciénega remain unknown. To determine the relative significance of each ciénega to regional diversity, we asked, 1) How similar are their plant communities? To understand the role of environment in shaping their communities, we asked 2) What factors influence species richness and composition? To put ciénega conservation in broader perspective, we asked, 3) How regionally distinct are ciénega floras? We selected six study ciénegas, spanning a 1000-m elevation gradient within the Santa Cruz watershed of Arizona, and sampled vegetation and soils in 30 quadrats, three times. The plant communities of all were composed of the same functional type (clonal herbaceous perennials), but the predominant species differed among sites. Floristic overlap was low. Each ciénega supported a distinct suite of imperiled species. Species richness was greatest at sites with low salinity, high elevation, and large wetland area; at the quadrat-level, moisture was negatively related to species richness. Differences in composition among ciénega is attributable in part to differences in salinity and canopy cover. Assessment of ranges and floristic province affiliation show that ciénegas have a distinct regional floristic signature, with one fourth of species restricted to the American Southwest. Our results highlight the high variability of ciénega wetlands, the rare species they harbor, and their regional distinctiveness make these vanishing communities high priority for conservation.

1 - National Tropical Botanical Garden, Science & Conservation, 3530 Papalina Rd, Kalaheo, HI, 96741, United States
2 - Desert Botanical Garden, 1201 N Galvin Parkway, Phoenix, AZ, 85008, United States

Keywords:
Arid
rare plants
Ciénega
Species Richness
Wetland.

Presentation Type: Oral Paper
Session: ECO3, Ecology 3: Vegetation, Community and Restoration Ecology
Location: Tucson A/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 1:30 PM
Number: ECO3001
Abstract ID:280
Candidate for Awards:None