T.W. Swetnam Craig D. Allen E.Q. Margolis 2007 <p>Dendroecological techniques were applied to reconstruct stand-replacing fire history in upper montane forests in northern New Mexico and southern Colorado. Fourteen stand-replacing fires were dated to 8 unique fire years (1842–1901) using four lines of evidence at each of 12 sites within the upper Rio Grande Basin. The four lines of evidence were (<i>i</i>) quaking aspen (<i>Populus tremuloides</i> Michx.) inner-ring dates, (<i>ii</i>) fire-killed conifer bark-ring dates, (<i>iii</i>) tree-ring width changes or other morphological indicators of injury, and (<i>iv</i>) fire scars. The annual precision of dating allowed the identification of synchronous stand-replacing fire years among the sites, and co-occurrence with regional surface fire events previously reconstructed from a network of fire scar collections in lower elevation pine forests across the southwestern United States. Nearly all of the synchronous stand-replacing and surface fire years coincided with severe droughts, because climate variability created regional conditions where stand-replacing fires and surface fires burned across ecosystems. Reconstructed stand-replacing fires that predate substantial Anglo-American settlement in this region provide direct evidence that stand-replacing fires were a feature of high-elevation forests before extensive and intensive land-use practices (e.g., logging, railroad, and mining) began in the late 19th century.</p> application/pdf 10.1139/X07-079 en NRC Research Press A stand-replacing fire history in upper montane forests of the southern Rocky Mountains article