The dry grasslands (Festuco-Brometea) of the North Caucasus: first data on numerical classification and biodiversity patterns

Vynokurov D., Lysenko T., Dutova Z., Shylnikov D., Doroshina G., Urbanavichene I., Urbanavichus G. & Tsepkova N.
41: 175–201
The North Caucasus is still one of the least studied regions in Europe regarding syntaxonomy. We investigated dry grasslands in the central part of the North Caucasus, namely in the Stavropol Kray region of Russia. We sampled 47 vegetation plots (relevés) of 10 m2 size (3.16 × 3.16 m) at elevations from 470 to 1150 m a.s.l. To determine the scale-dependent species richness patterns, we recorded five nested-plot series of 0.0001 to 100 m² in different dry grassland types (one in xero-mesic, one in xeric, two in rocky grasslands on limestones, one in rocky grasslands on chalk outcrops). To obtain a more comprehensive understanding of higher-level syntaxa, we collected other available data from published sources from the Stavropol Kray and the Northern Caucasus. In total, we collected 392 additional relevés from the Republic of Karachay-Cherkessia, Stavropol Kray, Krasnodar Kray, Republic of Kabardino-Balkaria, Republic of North Ossetia-Alania and Dagestan Republic regions. We analyzed the dataset using Modified TWINSPAN with different settings until we received ecologically meaningful units. This yielded in five main cluster that correspond to the major steppe vegetation types: 1) desert steppes; 2) true steppes; 3) mountain steppes of Dagestan and the intermontane basins of the Central Caucasus; 4) rocky grasslands; 5) semi-dry and dry grasslands on deep soils. Considering that these vegetation types are quite unique and different from those described in previous literature, we describe here a new order of Caucasian and Crimean xerophilous rocky grasslands on calcareous outcrops (Asphodelino tauricae-Euphorbietalia petrophilae), three new alliances (Artemisio chamaemelifoliae-Bromopsion variegatae, Helianthemo buschii-Cephalarion coriaceae, Onosmo caucasicae-Asphodelinion tauricae) and nine new associations.
Saturday, 09 September 2023 01:29