Reforestation role of fire in Central Yakutia

The article brings the results of research concerning the role of forest fires in Central Yakutia for reforestation. Natural specifics of Central Yakutia, i.e. combination of permafrost with insufficient atmospheric moistening and arid climate, caused natural reasons for emergence and spreading of fire forests. Central areas of Yakutia, as compared to other regions, were characterized by high fire rating of forests for a long historic time, which is connected not only with arid conditions and high population density but also with economic trends in these regions. In recent years, the human role in appearance and spreading of fires is increasing. Information on the fire impact on forest vegetation has been brought in the publications of researchers since the early 20 century, where they indicate that larch role increases in the post-fire period and there is a relatively good revegetation of the original type of forests. It is thought that supremacy of larch forests in NE Asia is conditioned, foremost, by biological species features obtained in the process of evolution and is one of the mechanisms for decreasing the effect of fire influence on natural ecosystems. Larch forests are mostly of pyrogenic origin, which is proved by very good larch regeneration after fires. Research made by authors from different regions (Scherbakov et al, 1979; Tsvetkov, 1993, 2004 et al) evidence that the larch has the properties of "pyrophyteness". Studies related to the role of fire in reforestation of Central Yakutia are conducted near Matta vil., Megino-Kangassky Ulus. Burn-sites of different post-fire periods (6, 16, 20, 65yrs) served the targets of the research; the larch with growing Vaccinium vitis-idaea was a control site. Natural reforestation was carried out by tried and tested practices according to P.A. Tsvetkov (2004), A.V. Pobedinsky (1966) with laying 25 plots for each burned-out site. The undergrowth was classified according to groups of heights (lower than 10, 10 to 50, 50 to 100, 100 to 300 and higher than 300 cm) including vitality (vigorous, weakened, drying out, dry wood). DP was performed according to V.A. Alexeyev (1989) and P.A. Tsvetkov (2004) techniques in Excel computer program. It has been established that the share of sound undergrowth of larch makes 87-100% at early and mid-stages of succession and the one of all larch trees is 59-60% at late stages of succession and in the forest. Starting from the age of 16-20 the proportion of frail, wilt and dry larch trees increases. The vital power of post-fire larch cenopopulations (with vitality index 98.1-99.9%) is more wholesome and sound as compared to young larches growing in the forest (77.6%).

Keywords

Authors

References