After Fire Regenerative Successions in Larch (Larix sibirica Ledeb.) Forests of the Central Khangai in Mongolia
M. Undraa1, K. Kawada2, Ch. Dorjsuren1, T. Kamijo2
1Institute of General and Experimental Biology, Mongolian Academy of Sciences, Zhukov avenue, 77, Ulaanbaatar, 210351 Mongolia
2University of Tsukuba, School of Life and Environmental Sciences, 1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8572 Japan
Keywords: forest fire, succession, regeneration, sapling, seedling, pseudotaiga, forest conservation, detrended correspondence analysis, C. C. Raunkiær life form classification, Tarbagatai Mountain Range, Central Khangai, Mongolia
Abstract
The changes in the composition and the projective cover of understory species and regeneration after fires in 1996 and 2002 in pseudotaiga larch forests of the Central Khangai, Mongolia have been investigated. Descriptions of vegetation and inventory of natural regeneration were carried out in 2007, 2010 and 2012 on permanent sample plots that were established in each of two sites. According to the Detrended Correspondence Analysis (DCA), no drastic changes were observed in species composition of the plant community during 11, 14, 16 years after fire of 1996 and 8, 10 years after fire of 2002. Regarding the plant cover, remarkable change was not observed in vegetation, except in 5 year-old stand. Grasses-herbs community with young larch saplings 10 years after fire of 2002 was formed. Loose herbs community with young larch saplings 16 years after fire of 1996 was established. Moreover plant life forms were identified during the succession years post-fire. By Christen C. Raunkiær life form classification (1937), life forms such as cryptophytes and hemicryptophytes either kept or shared their dominant position following fire. These plants seem to be fire-resistant and have a high ability to recover post-fire. After the fires, natural regeneration was successful. However, grazing may affect negatively to larch regeneration. It can be explained by difference of large saplings in two plots. The number of large saplings per hectare was low despite the long recovery period in one plot.
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