The natural regeneration of desert ecosystem vegetation at the 2013 crash site of a Proton-M launch vehicle, Republic of Kazakhstan

Abstract Restoration of vegetation at the crash sites of space launch vehicles (LV) and chemical effect of rocket propellant on ecosystems are understudied. We investigated the restoration of vegetation at the crash site of LV Proton-M (Baikonur Cosmodrome, the Republic of Kazakhstan) since launch failure in 2013. Crash area was subdivided into zones defined by differences in the character and intensity of technogenic disturbance. Detailed geobotanical assessments were carried out in 2014 and 2017. We have found that communities dominated by annual species of Salsola have colonized the zone of total destruction of vegetation following the detoxification of spilled rocket fuel and the removal of topsoil, which resulted in specific edaphic conditions. Species-poor communities of Ceratocarpus arenarius on clay loams and relatively species-rich communities of clump-forming grasses ( Agropyron fragile, Stipa hohenackeriana ) on sandy loams were formed within the zone of pyrogenic transformation of phytocenoses. The zones of an irregular mosaic of mechanical disturbances and weak mechanical disturbances of phytocenoses were occupied by Artemisia terrae-albae communities that showed no significant differences from the background phytocenoses. Only zone of total destruction of vegetation and zone of pyrogenic transformation still demonstrate high levels of phytocenoses modification. The discussion offers a best interpretation of the observed trends and findings given certain unavoidable uncertainties.