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This reduction, or the area preserved, is the difference between the area actually burned and the counterfactual area that would have burned absent of fire suppression.6 Fire regimes and historical records in North American boreal forests function in a manner that prevents this effect from being detected or estimated directly. 7 In this essay I will examine two different studies that are representative of the dissention within the community of fire suppression. Arguing in support of Ward and Thithecott and a measurable reduction in forest area burned is Cumming; while Miyanishi and Johnson contend the results inferred by Ward and Thithecott.
8 The purpose of this study is a comparative analysis of the competing perspectives on fire suppression in an effort to identify what makes them significant, unique, and similar. A Re-examination of the Effects of Fire Suppression in the Boreal Forest: Miyanishi and Johnson base their study on the foundation that Ward and Thithecott’s report is filled with serious flaws that invalidate the conclusions regarding effects of fire suppression on fire size and fire frequency.9 They argue that because fire-size data from the unprotected zone are censored in small size classes due to detection resolution, comparisons of shapes of the distributions between the protected and unprotected zones do not hold up.
10 Due to lack of uniformity in plotting scales, Miyanishi and Johnson content that the report gives the false appearance of large differences in the number of large fires between the two zones. In addition, the authors argue that change in fire frequency does not infer evidence of fire oppression, and could likely be attributed to climate change.11 In a later study, Ward and Mawdsley draw the conclusion that the landscape-scale impact of fire suppression on the protected zone is that “fire is creating far fewer moderate- and large-sized disturbance patches” than in the unprotected zone.
12 However, as noted by Ward and Tithecott, in the unprotected zone, “detection is biased towards those fires that got large enough to be detected”, and thus underestimating the number of fires in the smaller size classes.13 This bias has led to a significant skewing of data between number of fires in the protected (1,700), and unprotected zones (100). Miyanishi and Johnson contend such significant disparity; citing a failure to detect and record fires in the unprotected zone as the primary factor for inaccuracy.
14 Their second criticism of the study, 15 and with their comparison of the two distributions of fires, is a difference of scales used for plotting the fires that misrepresents what Miyanishi and Johnsons believe to be a little difference between the two zones in the number of moderate- and large-sized fires. They contend this invalidates the shape of the fire distributions due to the unreliably low number of small fires in the data set for the unprotected zone.16 Without an accurate representation of the shape of fire distribution between the protected and unprotected zone, the authors refute Ward and Mawdsley’s conclusion that such data indicate fires are creating “
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