In this work is presented the evolution of the vegetation carpet from some sandy land grassland under the influence of exploitation intensity. The purpose of these researches is to analyse the dynamics of the vegetation in the condition of the improper management, because this is the condition of most of the Romanian grasslands. Also, this research is concerned by the botanical composition of the vegetation carpet, the structure of the vegetation from the point of view of the main plant types (grasses, leguminous, Cyperaceae and Juncaceae, and species from other botanical families) species number, and aspects concerning the biodiversity. The data were collected from 4 grassland surfaces (Lenfin – hayfield, Fürkó, Dihenes and Urkuta – pastures) from the land surface of Valea lui Mihai locality during 2007-2008. The research methods used in this work are the vegetation analysis with square meter method (Daget et Poissonet, 1971) this type of data collecting offering data that can be used in the detailed calculus of biodiversity (Shannon-Weaver) and dominance (Simpson) indexes. The results obtained shows that the greatest biodiversity is found in the case of Lenfin hayfield, and in the case of the pastures the obtained indexes have similar values they showing a medium biodiversity index. For the improvement of the botanical composition of the grasslands from the area of Valea lui Mihai are needed some immediate measures as are: mowing the non-consumed plants to reduce the weed proliferation on the grazed land surfaces (Fürkó, Dihenes and Urkuta); fertilization of the hayfield and of the pastures; the use of the grassland only for grazing (not for deposition of wastes); the elimination of water excess in the case of Urkuta pasture there being  present in a great amount hydrophytes plants species.

sandy-land grassland; dynamics; hayfield; pasture; vegetation

Presentation: oral