Hohokam Impacts on the Vegetation of Canal System Two, Phoenix Basin

In 1850, the Phoenix Basin had been uninhabited for about 350 to 400 years. It was visited occasionally by hunting, fishing, or gathering parties from the Pima, Pee Posh, Yavapai or Apache, but the last people to have cleared farming fields, excavated canals, and built villages in the lower Salt River valley had been the Hohokam, and they had abandoned the area sometime between A.D. 1450 and 1500. This timeline is important to archaeologists because it means that the desert vegetation in the lower Salt River valley had had more than three centuries to return towards a natural climax that was only minimally affected by human intervention. (In some places the abandoned canals continued to have a relict affect on vegetation as discussed below.) Archaeological evidence suggests that the composition and approximate distribution of plant communities in 1850 resembled those that had last existed in the basin at around A.D. 300 to 400, when the Hohokam were just beginning to grow in population size.1850年时，菲尼克斯盆地（Phoenix Basin）已有约350至400年无人定居。彼时皮马人（Pima）、皮波什族群（Pee Posh）、亚瓦派人（Yavapai）与阿帕奇人（Apache）的狩猎、捕鱼或采集小队，会偶尔到访此地；但曾在下盐河谷（lower Salt River valley）开垦农田、开挖运河并建造村落的最后一批先民，是霍霍坎人（Hohokam），他们于公元1450年至1500年之间的某个时期放弃了该区域。 这一时间线对考古学家而言具有重要意义，因为它意味着下盐河谷的荒漠植被拥有了超过三个世纪的时间，得以恢复至几乎未受人类活动干预的自然顶极群落（natural climax）状态。（如后文所述，部分区域的废弃运河仍会对当地植被产生残留影响。）考古证据显示，1850年该区域植物群落的组成与大致分布，与公元300年至400年左右该盆地内的群落形态高度相似——彼时霍霍坎人刚刚开始实现人口规模的增长。