Eleventh-century shift in timber procurement areas for the great houses of Chaco Canyon

Well-preserved plant remains in packrat middens chronicle vegetation change in Chaco Canyon over the past 11,000 years. Early Holocene evidence of communities dominated by Douglas fir, Rocky Mountain juniper, and limber pine in the San Juan Basin calls for revision of traditional constructs based on fossil pollen. Middle and late Holocene vegetation in the canyon was pinyon-juniper woodland up until Anasazi occupation between 1000 and 800 years ago. Instead of climate, Anasazi fuel needs may explain the drastic reduction of pinyon and juniper after 1230 years ago. The lack of pinyon-juniper recovery over the past millennium has implications for contemporary forest and range ecology.