State of Desert Phytocenoses in the Republic of Kazakhstan at Crash Sites of Launch Vehicles

摘要

The article describes the vegetation cover that formed at three crash sites of launch vehicles fueled by toxic unsymmetric dimethylhydrazine 4-12 years after the accident. A launch-vehicle crash is accompanied by chemical, mechanical, and thermal (or pyrogenic) effects on the vegetation cover that extend out from the impact site to different distances, thereby forming characteristic, technogenically disturbed areas. The vegetation cover at the three 2006-2013 crash sites of launch vehicles are characterized by geobotanical descriptions that were performed in plots located at different distances from the center of the impact site. A self-restoration feature of the vegetation cover at the studied crash sites is the formation of an annual saltwort community (Climacoptera lanata,Salsola laricina,S. paulsenii, etc.) with a relatively high projective cover on the site of the former impact funnel due to soil subsidence and surface-runoff redistribution. The original vegetation regenerates with distance from the center of the impact site: the proportion of annual plants decreases, while the total projective cover and floristic saturation of the communities increases. According to the most optimistic forecasts, the period of self-restoration of phytocenoses without biological reclamation can be no less than 15 years.