Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Oversowing or resowing of subalpine grassland appointed after the dynamics of floristic composition.

Abstract

In the summer of 1995 on a semi-natural grassland invaded by Nardus stricta located at 1,800 m altitude in the Bucegi Mountains, a scientific trial aimed of improving them was placed. After the destruction of the grassy carpet degraded by Nardus stricta with the glyphosate herbicide we performed oversowing and resowing, chemical fertilization or organic fertilization by calcium oxide and floral observations were made annually in addition to the usual production and feed quality determinations. Fertilization with NPK chemical fertilizers and organic fertilization were repeated in 2004 and 2011 on the same grassland sown by the two methods. Among the species sown Phleum pratense lasts for 21 years, Festuca pratensis between 12 and 19 years old, Lolium perenne between 3-5 years old, Trifolium hybridum between 9 and 11 years old and Lotus corniculatus up to 8 years, all lasting more years than those in the plain area. Of the spontaneous flora, only Agrostis capillaris and Trifolium repens are kept for 21 years, the rest of the species appear later as follows: Agrostis rupestris immediately up to 5 years, Festuca nigrescens immediately up to 7 years, Poa media immediately grow up to 8 years old, Poa pratensis barely after 6-20 years depending on the factors of improvement. Overgrazing and sheepfold stimulates sown species and prolongs their life in the grassy carpet. As a general conclusion, the species of perennial grasses and grasses sown at 1,800 m altitude that can not be multiplied by seeds as a number of years are 2-3 times longevive than those sown at 100-200 m altitude. It can be argued that the sum of the vegetation periods in the mountains is equal to the sum of the vegetation periods from the plain, the existence of the component species in the sown meadows.