The Short-Term Effects of a High Severity Forest Fire on Moth Communities in New Mexico

Abstract

A comparative survey of moth communities in burned and unburned coniferous forests in the Valles Caldera National Preserve of Northern New Mexico was used to assess the short-term effects the Las Conchas fire, a high severity wildfire that decimated large portions of the VNCP in June, 2011. Specifically, we set out to test the independent and interactive strengths of three variables acting on moth communities in the VNCP: forest type (Mixed-conifer or Ponderosa pine), treatment type (burned or unburned) and collection period (June, July, or August). We tested the two-sided hypothesis that there would be a difference between treatment types by performing blacklight trappings in 16 variant forest sites over the course of the summer (June-August, 2012). In total, 9624 moths from 257 species were collected. The sole variable of treatment type (burned versus unburned) yielded the most significant results, with decreased abundance (F=14.53, df=1,12, P=0.0025; Table 6) and richness (F=11.13, df=1,12, P=0.0059; Table 6) in the burned sites. There was no difference in species richness or abundance based solely on forest type. Species assemblages differed significantly by time of collection period (Figure 7). The interactive strengths of variables proved insignificant. Individually, only 17 species (with >20 individuals) showed significant differences in density based on treatment type; only 3 of these species had higher abundances in burned plots. Moths are integral components of a healthy forest ecosystem. Our study verified that fire decreases moth species richness and abundances the summer following a high-severity fire event. In light of the increasingly frequent and severe disturbance events, we suggest that monitoring moth species in disturbed habitats is an essential tool for deepening our understanding of fire.