30 years of post-grazing restoration of the subalpine meadows in the Lagonaki Highlands: evaluation of results on the composition and structure of dominant species complexes (West Caucasus, Russia)

The Lagonaki Highlands are the northwesternmost highland massif of the Greater Caucasus. For a long time, its vegetation was used as pasture. Excessive loads led to a considerable transformation of subalpine meadows, in particular, to an increase in the abundance of poorly palatable and low-growing plants and the replacement of dominant species of primary communities to pasture communities. After the Lagonaki Highlands became part of the Caucasian State Nature Biosphere Reserve, Russia (CSNBR), as a biosphere polygon in 1992, cattle grazing ceased in most of its territory. We assessed the results of 30-year post-pasture restoration of subalpine meadows of this mountain range based on the composition and structure of complexes of dominant species in relatively large visually homogeneous sites of the landscape (sample plots, 1500–2500 m2). In accordance with this approach, within each sample plot, 100–150 accounting plots of 1 m2 were regularly arranged. At each accounting plot, the role of dominant species in the formation of grass stand was assessed using a five-point scale for the projective cover. The total number of sampling plots established in 2023 and 2024 within the recovering vegetation of the Lagonaki Highlands was 24. We additionally established five sampling plots in disturbed communities in the area of the active cattle camp and six in natural communities of the CSNBR core zone. Our studies have shown that the overall dominance frequency of species characteristic for disturbed communities currently does not exceed 5% in most areas of recovering subalpine meadows. Among the primary dominants, Calamagrostis arundinacea is the most common, as in the CSNBR core zone. At the same time, the recovering sites of vegetation cover, compared to natural (slightly disturbed) ones, are characterised by a relatively low frequency of polydominant communities and a higher frequency of sites with a high coverage of dominants. It is assumed that in the future these communities will change towards a decrease in the participation of dominant species (both secondary and primary) and, as a consequence, an increase in the participation of other (associated) species.