Climate drives fire synchrony but local factors control fire regime change in northern Mexico

Abstract

Abstract. The occurrence of wildfire is influenced by a suite of factors ranging from "top-down" influences (e.g., climate) to "bottom-up" localized influences (e.g., ignitions, fuels, and land use). We carried out the first broad-scale assessment of wildland fire patterns in northern Mexico to assess the relative influence of top-down and bottom-up drivers of fire in a region where frequent fire regimes continued well into the 20th century. Using a network of 67 sites, we assessed (1) fire synchrony and the scales at which synchrony is evident, (2) climate drivers of fire, and (3) asynchrony in fire regime changes. We found high fire synchrony across northern Mexico between 1750 and 2008, with synchrony highest at distances <400 km. Climate oscillations, especially El Niño-Southern Oscillation, were important drivers of fire synchrony. However, bottom-up factors modified fire occurrence at smaller spatial scales, with variable local influence on the timing of abrupt, unusually long fire-free periods starting between 1887 and 1979 CE. Thirty sites lacked these fire-free periods. In contrast to the neighboring southwestern United States, many ecosystems in northern Mexico maintain frequent fire regimes and intact fire-climate relationships that are useful in understanding climate influences on disturbance across scales of space and time.

Wind speed and relative humidity influence spatial patterns of burn severity in boreal forests of northeastern China

“…The spatial patterns of burn severity are products of several interacting controls, which are generally categorized as Btop-down^(external to ecosystems) and Bbottom-up^(internal to ecosystems) controls (Kent et al 2017). The Fig.…”

Dendrochronological reconstruction of fire history in coniferous forests in the Monarch Butterfly Biosphere Reserve, Mexico

“…It is important to point out that short fire return intervals have been documented in high-elevation mountain coniferous forests of northern (Yocom et al 2017) andcentral Mexico (Ortega-Jiménez 2012;Yocom and Fulé 2012;Cerano-Paredes et al 2016). Furthermore, a latitudinal gradient in the range of fire return intervals has been proposed, with lower intervals in tropical areas (SCF 2001;Sommers et al 2011).…”

“…The scarcity of studies documenting fire return intervals or any of the other attributes associated with current fires regimes in montane tropical coniferous forests contrasts with a greater number of fire chronologies developed in northern Mexico, where coniferous forests, in general terms, experience frequent surface low-severity fires ). Most of these forests have synchronous fire return intervals that are strongly associated with ENSO oscillations, and, in some places, fire regimes have changed by local processes such as forest management and fire suppression (Yocom et al 2017). Most sites in northern Mexico, however, did not experience fire suppression or reduction of fire return intervals until the second half of the twentieth century, when logging became an important activity after the formation of the ejidos in 1936 (Heyerdahl and Alvarado 2003).…”

Response of Arizona cypress (Hesperocyparis arizonica) to the Horseshoe Two Megafire in a south-eastern Arizona Sky Island mountain range

“…The frequency of high-severity fires is increasing in the South-west USA (Westerling et al 2006;Dennison et al 2014;Abatzoglou and Williams 2016;Kent et al 2017). Given the fire sensitivity of Arizona cypress, frequent, repeated highseverity fires could pose a threat to the long-term viability of these populations by preventing trees from reaching sexual maturity during inter-fire intervals, the positive effects of fire on establishment notwithstanding.…”

“…Further research on the response of this species to fire is especially important given the ongoing changes in fire regimes in the American South-west and northern Mexico. The past three decades have seen a dramatic increase in wildfire severity and area burned across southwestern North America, caused both by a build-up in fuels from more than a century of fire suppression and by hotter, drier conditions in the uplands on both sides of the US-Mexico border (Westerling et al 2006;Dennison et al 2014;Abatzoglou and Williams 2016;Kent et al 2017). We know little about how Arizona cypress will respond to the changing fire regime, especially with respect to predicted regional increases in wildfire frequency and severity (Liu et al 2013).…”