Effects of fires on vascular plant and microalgae communities of steppe ecosystems

The article is focused on a hypothesis verification: the higher plants, microalgae and cyanobacteria may be used in bioindication of steppe ecosystem restoration dynamics after fires. On territory Askania Nova biosphere reserve (Ukraine) 4 stationary polygons were investigated: SP1 – area which had not been exposed to fire for 20 years preceding our study, as well areas where single fires occurred 2001 (SP2), 2005 (SP3), site 2004 (SP4). investigation revealed height projected vegetation according seasons during two (2010 2011), abundance biomass cyanoprokaryotes soil layer by depth 15 cm. It was found that effects pyrogenic load remain evident several fires, manifesting decrease herbage, number algae soil, especially 5 Multivariate general linear models test significance dependence quantitative characteristics vegetation, microalgae, environmental predictors (season, year, layer, fire). In model, 75.2% grass variability 91.6% could explained under consideration. series → SP2 SP3 SP4 decreased. differences stand most spring. model 89.1% variation Bacillariophyceae. Bacillariophyceae greater upper than lower decreased with depth. this group at depths 0–5 5–10 Changes abundances Chlorophyta, Streptophyta, Heterokontophyta (Xanthophyceae Eustigmatophyceae) equaling 47.6% also model. greatest layer. maximum recorded Polygon minimum SP3. Within 48.0% predictors. trend coherent population trend. A special feature there significant increase 10–15 cm compared other able explain 61.8% 66.7% biomass. highest polygon SP1. Somewhat numbers SP4, lowest turn, particularly pattern group. research results confirmed (height area) (abundance biomass) post-pyrogenic processes ecosystems.