Category: Ecological Research
Title: Fire history of a mixed conifer forest on the Mogollon Rim, northern Arizona, USA
Author: * Huffman, D.W., Zegler, T.J., Fule, P.Z.
Subject: Fire history, Mixed Conifer, Mongollian Rim
Abstract: It has been suggested that large, high-severity fires historically structured warm–dry mixed conifer forests in the American South-west. To test this, we reconstructed fire regime characteristics of an 1135-ha (11.3 km2) mixed conifer landscape in northern Arizona using complementary approaches. We analysed composite fire intervals, point fire intervals, natural fire rotation, landscape characteristics and forest age structure. Composite analysis of cross-dated fire scars from 133 trees indicated a mean fire interval (MFI) of 2.0–8.5 years between 1670 and 1879. Frequent fires halted abruptly after 1879. Mean point fire interval (MPFI) was 11.8 years and ranged 2–61 years. Mean fire rotation was 14.4 years. Density of most occurring tree species increased dramatically after fire regime disruption, with south-western white pine (Pinus strobiformis) and white fir (Abies concolor) showing large numerical gains. Tree establishment patterns compared with widespread fire dates did not suggest historical high-severity fires at the site level. Although strong evidence of high-severity fire at finer scales was lacking, spatial locations of ‘young’ plots suggested the possibility of historical high-severity disturbances #25 ha in size. The historical fire regime on this landscape was one of highfrequency, low-severity fires. Current conditions call for restoration of forest structure and function.
Source: International Journal of Wildland Fire
Publisher: CSIRO Publishing