Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size: a response to Smith et al (this issue)

Authors: Davies, Kirk; Boyd, Chad; Bates, Jonathan - Jon; HULET, APRIL - University Of Idaho

Submitted to: International Journal of Wildland Fire
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2016
Publication Date: 3/3/2016
Publication URL: http://handle.nal.usda.gov/10113/62583
Citation: Davies, K.W., Boyd, C.S., Bates, J.D., Hulet, A. 2016. Winter grazing decreases the probability of fire-induced mortality of bunchgrasses and may reduce wildfire size: a response to Smith et al (this issue). International Journal of Wildland Fire. 25:489-493. doi: 10.1071/WF15209.

Interpretive Summary: A recent commentary by Smith et al. (2016) attempted to discount the findings of our study (Davies et al. 2016) on winter grazing effects on fire. Smith et al. claimed that our study contained methodological errors and lacked the data necessary to support our conclusions; in particular that winter grazing may reduce the likelihood of fire-induced mortality of bunchgrasses. These comments resulted from Smith et al. not carefully reading Davies et al. (2016) and relevant literature and a basic misunderstanding of the methodology we employed. In this manuscript, we detailed where Smith et al. misinterpreted Davies et al. (2016) and relevant literature that supported our methodology and conclusions.

Technical Abstract: A recent commentary by Smith et al. (this issue) attempted to discount the findings of our study (Davies et al. this issue) by claiming that our study contained methodological errors and lacked the data necessary to support our conclusions, in particular that winter grazing may reduce the probability of fire-induced mortality of bunchgrasses. Smith et al. (this issue) further insist that we should have had a more thorough discussion on effects of grazing on rangelands. We believe these comments resulted from not carefully reading Davies et al. (this issue) and relevant literature. Most notably, Smith et al. (this issue) argue that thermocouples placed in the air have no correlation to temperatures experienced by shrub-grass vegetation. However, we clearly state in the methods that thermocouples were placed in the center of meristematic crowns of bunchgrasses, not in the air. Duration of elevated temperatures has been linked repeatedly to an increased risk of fire-induced mortality of vegetation in the literature. The conclusion that winter grazing may decrease the likelihood of perennial bunchgrass mortality was not solely based on the data collected in this experiment, but also Davies et al. (2009) where post-fire bunchgrass density and production in ungrazed areas were less than half of grazed areas. If Smith et al. (this issue) had diligently evaluated prior literature they would have realized that we had thoroughly discussed the various effects of grazing on sagebrush rangelands in our prior article (Davies et al. 2015).