Fertilization and irrigation effects on the Geranium-Hedysarum Meadows, Northwestern Caucasus, Russia

We investigated the response of an alpine highly productive plant community to soil nutrient addition and irrigation. A 10-year experiment, including additions of calcium, phosphorus, nitrogen, phosphorus + nitrogen, and irrigation—was conducted in the northwestern Caucasus, Russia, at 2800 m above sea level. We found out that aboveground biomass did not change significantly. But the biomass increased by 25% in the case of the treatment with calcium addition compared with the control, also the floristic richness in this treatment was not changed. Biomass of the main dominant Geranium gymnocaulon doubled in Ca and NP. Campanula tridentata, Carum meifolium, Euphrasia ossica, and Matricaria caucasica increased in Ca; Geranium gymnocaulon in Ca and NP; Gagea fistulosa in NP; Agrostis vinealis in N and NP; Carex atrata, Nardus stricta in N; Phleum alpinum in P; Leontodon hispidus in irrigation treatment. Sedges had a positive response to N. Legumes had a negative response to NP, N, and Ca.