Comparison of moth communities following clear-cutting and wildfire disturbance in the southern boreal forest

Abstract

Nocturnal macrolepidopteran fauna (moths) of the southern boreal forest of Ontario, Canada, were compared between forests clear-cut or burned by wildfire approximately 5 years previously to assess whether their assemblages differed following disturbance. Moths were light-trapped for 27 days during the summer in three burned and three clear-cut sites that had been formerly mature mixed jack pine (Pinusbanksiana) forest. The dominant species varied throughout the summer (Protorthodes oviducadominated in June, Orthodes cynica in July and Idia americalis in August), but they were similar between disturbance types. Diversity indices were similar although ordinations showed significant differences between the two disturbance types. Nine species were more significantly abundant in burn than clear-cut sites (Callopistra cordata, Cyclophora pendulinaria, Gluphisia septentrionis, Hyppa nr. xylinoides, Nemoria rubrifrontaria, Semiothisa neptaria, Spiramater lutra, and Tacparia detersata), whereas the converse was true for three species (Acronicta innotata, Phyllodesma Americana, and Euxoa comosa). Vegetation composition, disturbance age, percentage of jack pine pre-disturbance, and amount of downed woody debris and snags were the most important environmental correlates of moth community composition. Our study supports that of previous work on the effects of forest disturbance and biodiversity suggesting that clear-cutting may emulate wildfire for some organisms, but not for others. Thus, forest managers must consider multiple aspects of forest structure in attempting to use clear-cuts to mimic fire