Effects of fire on production and destruction processes in steppe phytocenoses of Burtinskaya Steppe, Orenburg Nature Reserve

Abstract

The paper deals with the production and destruction process in burned and unburned (control) steppe phytocenoses. The fire occurred in August 2014, after which a monitoring network consisting of 6 sites was laid out. During two vegetation seasons (2015 – 2016), we surveyed above-ground and below-ground phytomass stocks and on their basis production and destruction amounts in phytocenoses were calculated. Comparative analysis of control and burned communities revealed higher production and destruction of above-ground phytomass components in both years. With the general tendency for most phytocenoses to reduce above-ground production and increase litter in the second year of the survey, the first process was more intense in burned phytocenoses that were exposed to anthropogenic load in the past, and the second process occurred in almost all burned communities. In the below-ground sphere, mineralization processes were more intense during the entire survey period on control sites, and an increase in the mass of living and dead below-ground organs was more determined by the phytocenoses specifics, rather than their damage by fire.