It’s no secret that wetlands have dramatically declined in the arid and semiarid American West, yet the small number of wetlands that persist provide vital ecosystem services. Ciénega is a term that refers to a freshwater arid-land wetland. Today, even in areas where ciénegas are prominent they occupy less than…
It’s no secret that wetlands have dramatically declined in the arid and semiarid American West, yet the small number of wetlands that persist provide vital ecosystem services. Ciénega is a term that refers to a freshwater arid-land wetland. Today, even in areas where ciénegas are prominent they occupy less than 0.1% of the landscape. This investigation assesses the distribution of vascular plant species within and among ciénegas and address linkages between environmental factors and wetland plant communities. Specifically, I ask: 1) What is the range of variability among ciénegas, with respect to wetland area, soil organic matter, plant species richness, and species composition? 2) How is plant species richness influenced locally by soil moisture, soil salinity, and canopy cover, and regionally by elevation, flow gradient (percent slope), and temporally by season? And 3) Within ciénegas, how do soil moisture, soil salinity, and canopy cover influence plant species community composition? To answer these questions I measured environmental variables and quantified vegetation at six cienegas within the Santa Cruz Watershed in southern Arizona over one spring and two post-monsoon periods. Ciénegas are highly variable with respect to wetland area, soil organic matter, plant species richness, and species composition. Therefore, it is important to conserve the ciénega landscape as opposed to conserving a single ciénega. Plant species richness is influenced negatively by soil moisture, positively by soil salinity, elevation, and flow gradient (percent slope), and is greater during the post-monsoon season. Despite concerns about woody plant encroachment reducing biodiversity, my investigation suggests canopy cover has no significant influence on ciénega species richness. Plant species community composition is structured by water availability at all ciénegas, which is consistent with the key role water availability plays in arid and semiarid regions. Effects of canopy and salinity structuring community composition are site specific. My investigation has laid the groundwork for ciénega conservation by providing baseline information of the ecology of these unique and threatened systems. The high variability of ciénega wetlands and the rare species they harbor combined with the numerous threats against them and their isolated occurrences makes these vanishing communities high priority for conservation.
Located directly south of Pima County, Arizona, there is a culturally rich community known as Santa Cruz County, Arizona. Santa Cruz County is a smaller community being home to an estimated 47,000 people. Santa Cruz County has a rich history given its proximity to the United States-Mexico border. One example…
Located directly south of Pima County, Arizona, there is a culturally rich community known as Santa Cruz County, Arizona. Santa Cruz County is a smaller community being home to an estimated 47,000 people. Santa Cruz County has a rich history given its proximity to the United States-Mexico border. One example of this rich history can be found at the Tumacacori National Historical Park (NHP) with the attractive and unique ruins. The Tumacacori NHP was once an active Spanish mission that oversaw the religious expansion and communal resources. While the Tumacacori NHP no longer operates in this manner, it does serve an important role in providing visitors with a diverse and immersive look into the history of the region and the Tumacacori mission. While the Tumacacori NHP is meant to be a place for all people to visit, most visitors are not from the local community. The reason for this stems from a lack of educational and engagement opportunities between the Tumacacori NHP and the community youth, mainly due to community members being unaware of the park’s existence or the programs that are offered. This project analyzes and uncovers this disconnect as well as the barriers between the Tumacacori NHP and the Santa Cruz County youth through a research study and the use of children’s literature.
