Driving Factors for Forest Fire Occurrence in Durango State of Mexico:A Geospatial Perspective

Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide.Identifying the driving factors and understanding the contribution of each factor are essential for the management of forest fire occurrence.The objective of this study is to identify variables that are spatially related to the occurrence and incidence of the forest fire in the State of Durango,Mexico.For this purpose,data from forest fire records for a five-year period were analyzed.The spatial correlations between forest fire occurrence and intensity of land use,susceptibility of vegetation,temperature,precipitation and slope were tested by Geographically Weighted Regression(GWR) method,under an Ordinary Least Square estimator.Results show that the spatial pattern of the forest fire in the study area is closely correlated with the intensity of land use,and land use change is one of the main explanatory variables.In addition,vegetation type and precipitation are also the main driving factors.The fitting model indicates obvious link between the variables.Forest fire was found to be the consequence of a particular combination of the environmental factors,and when these factors coexist with human activities,there is high probability of forest fire occurrence.Mandatory regulation of human activities is a key strategy for forest fire prevention.

Contrasting climate drivers of seasonal growth in western vs. eastern Mexican mountain conifer forests

Hydroclimate affects the radial growth responses of trees, but the drivers of their spatial and population variability are not sufficiently understood. We addressed this issue by sampling several conifer populations located at the same latitude, but at different longitude and elevation in western(W) and eastern(E) Mexican regions. We used dendroecology to disentangle how earlywood width(EW), latewood width(LW) and adjusted LW(LWadj),i.e. the residuals after removing EW influences on LW, responded to climate variables(temperature and precipitation), climate indices(Southern Oscillation Index, SOI, Nino 3.4, Pacific Decadal Oscillation, PDO) and a drought index(Standardised Precipitation-Evapotranspiration Index, SPEI). The W species(Pinus herrerae Martinez, Pinus durangensis Martinez, Abies durangensis Martínez and Cupressus lusitanica Mill.) showed lower growth rates than the E species(Pinus hartwegii Lindl., Picea mexicana Martinez, Pseudotsuga menziesii(Mirb.) Franco and Abies vejari Martinez). Growth in W benefits mostly from high precipitation in the prior winter and current spring and it is limited by high temperatures in spring, whereas growth in the E showed similar but weaker responses.Furthermore, positive(negative) correlations were found in radial growth with the Nino 3.4(SOI) and the PDO from the prior to current autumns, which were again stronger in absolute terms in the W than in the E regions,excepting SOI in summer. In the W, P. durangensis and C. lusitanica were the least and most responsive species to spring drought, respectively;whilst P. menziesii and A. vejari were very responsive to spring drought compared to P. hartwegii in the E. Our results suggest greater responsiveness to hydroclimate and atmospheric patterns in the W than in the E region. These findings allow better interpretations of future changes in growth and composition in Mexican conifer forests, considering that climate models forecast warmer spring conditions and increased water shortage.