POST-PYROGENIC REFORESTATION OF SUBTAIGA LIGHT CONIFEROUS GEOSYSTEMS OF THE TUNKINSKAYA DEPRESSION, SOUTH-WESTERN CISBAIKALIA (THE STUDY OF PINE FORESTS OF THE BADARY UROCHISHCHE)

Abstract

We analyzed the post-pyrogenic demutation processes in pine forests of the Badary urochishche in the Tunkinsky National Park, which are periodically exposed to wildfires. The research was based on the geobotanical monitoring in two burnt-out areas, differing in the degree and area of damage due to a creeping fire in 2010. We studied the species composition of the stand, shrub layer and plant communities at different time periods between 2014 and 2020. The emergence of the first shoots of undergrowth and new growth was noted; the size of the projective cover and the abundance dynamics of the species of all forest layers were established. The analysis of the dynamics of natural reforestation revealed the similarity of the main geobotanical indicators. Pine (Pinus sylvestris) sprouts dominated in the undergrowth of the sites under consideration, and only a small percentage fell to the share of silver birch (Betula pendula). The shrub layer consisted of prickly wild rose (Rosa acicularis); daurian rhododendron (Rhododendron dauricum) was noted there only at the late observation stages. In the herbaceous layer, meadow species with a small participation of forest species made up the largest share. There were revealed differences in the time of emergence of the first sprouts of undergrowth and new growth, as well as in the size of the projective cover of species in all forest layers. The first sprouts of pine on a heavily burnt-out key plot were noted a year earlier than on the less transformed area. Nevertheless, the height increment and the projective cover of the undergrowth were significantly greater within the burnt-out area with the medium-degree damage. On the territory heavily damaged by wildfire, we observed pine seedlings planted by the staff of the National Park. Satisfactory survival rate of the seedlings at the initial stage and further deceleration of growth parameters were noted. The results obtained indicate the reforestation success and, therefore, a favorable forecast for post-fire recovery of light coniferous forests in the Badary urochishche.