DEMOUTIONAL AND INVASIVE PROCESSES OF LAYLANDS IN THE STEPPE ZONE OF THE REPUBLIC OF KHAKASSIA
The research objective was the assessment of speed of demoutional and invasive processes of arable lands in the steppe zone of the Republic of Khakassia subjected to spontaneous preservation. The research was conducted according to the standard techniques on the arable lands which are spontaneously preserved within 13 years. On the transects trial platforms were put and geobotanical description according to A.G. Voronov carried out, vital condition of seed renewal of Ulmus pumila according to V.A. Alekseev. It is defined that restoration of primary virgin vegetation proceeds slowly, the demutation belonged to root stage. Ulmus pumila L. it is actively settled and naturalized on laylands in bor- ders of forest shelter belts (FSB). The speed of the pro- cess of distribution of Ulmus pumila was shown by the seeds as in weak and strong degree (category "intro- duction" and "capture"). Overgrowing of interband fields Ulmus pumila happened unevenly. Overgrowing of the fields located with edge of system of FSB was referred to the category "introduction" where the density of elm crown of interband field on all territory, averaged less than 0.3. Overgrowing remote from influence of the dominating winds of an interband field referred to the category "capture" where all area was occupied with Ulmus pumila phytocenosis. On the sites with the cate- gory "introduction" middle-aged individuals were pre- sented small and not forming the top circle, on the terri- tory with the category "capture" formed the top circle with crowns density 0.2-0.5. Vital condition of middle- aged plants was estimated as weakened or drying out. Vital condition of young growths was good. Obtained data can be used at return of laylands to agricultural turn in the conditions of active moving of an elm stocky.