The current state of Polypodium vulgare L. and Ptilium crista-castrensis (Hedw.) De Not. populations on the territory of the nature reserve «Racheyskie Rocks» (Syzran District of the Samara Region)

This paper presents data on the new location of the moss Ptilium crista-castrensis (Hedw.) De Not, which is listed in the Red Data Book of the Samara Region on the territory of the nature reserve «Racheyskie Rocks» in the Syzran district. 10 of its coenopopulation loci have been identified and the exact geographic coordinates are given. For the first time the exact coordinates of 11 coenopopulation loci are also named for the holarctic mountain-forest relict fern Polypodium vulgare L., which is also protected at the regional level, both of these species have a mosaic structure of coenopopulations confined to confluent sandstones as a substrate for growth. It has been revealed that the ecological preferences of these species are very close, however, Polypodium vulgare is more shade-tolerant and it can be called a scioheliophyte, in contrast to the heliophyte Ptilium crista-castrensis. The Polypodium requires more humid and shaded conditions for its normal existence. When growing in the forest-steppe zone, where humidity is often a limiting factor, Ptilium crista-castrensis and Polypodium vulgare can form a significant projective cover (more than 30%) only in the northern and northeastern exposures of the substrate, but only with an enhanced light regime in the phytocoenosis at the density of the stand that is not more than 0,3.