Plants Found Along the Effluent Dominated Stretch of the Middle Santa Cruz River

摘要

Water was sustainably harvested from the Santa Cruz River before European settlement by the native Hohokam peoples in what is now southern Arizona for hundreds of years. These people cultivated edible crops utilizing carefully engineered mud lined irrigation canals (Logan 2002). During this time the Santa Cruz River ran perennially and supported an abundant and vast riparian ecosystem. This riparian forest system contained such regionally extinct species as the muskrat, wild turkey, beaver as well asa variety of native fish. In addition its waters supported abundant and vast cottonwood, mesquite, and willow forests. Unsustainable water harvesting, deforestation, overgrazing, introduction of plant cultivars and their accompanying insect communities,erosion, and desertification begun in the middle 1800's by new Spanish urban settlers marked the start of the decline of the Santa Cruz River ecosystem (Logan 2002). By 1940 groundwater pumping from the Tucson basin's aquifers had lowered water tables past the reach of even the great cottonwood's massive root systems and the river's remaining riparian vegetation began to die.