Изменение общего проективного покрытия фитоценоза долголетнего

Abstract

On the basis of the experiment, founded in 1946 with a seven-component, traditional at that time grass mixture, consisting of tall grass, low-grass and legumes, the effect of fertilizers on the productivity and botanical composition of the herbage was studied. In the first years of use, the herbage completely corresponded to the sown species. With long-term use, depending on fertilizers and meteorological conditions, the composition of the herbage has changed. In place of short-term types of cereals, self-renewing low-grass ones have been penetrate — red fescue, thin bent grass. Against the background of increased doses of fertilizers, the participation of tall grass species increased — meadow foxtail and awnless brome. Along with the determination of the botanical composition of the phytocenosis of long-term haymaking, from 1999 to 2002, a geobotanical assessment of the abundance of plants was carried out, which made it possible to more fully study the alternation over time of some types of phytocenosis with others and determine their participation. The abundance of plants was determined by their projective cover (PC) in three groups: grasses, legumes, motley grass, and it is represented by the total projective cover (TPC).Studies have shown the dynamics of changes in the types of phytocenosis depending on fertilizers and meteorological conditions of the growing season. In moisture-rich years, the total projective coverage reaches 80–95%, in dry years it decreases to 70–84%. The lack of moisture most strongly affects the creeping clover, the abundance of which has decreased to 0.2–0.1% in dry years.