Role of chosen grass species in herb layer structure of all-aged timber pine woods

The present paper depicts the role of selected grass species in all-aged pine woods exploited as production forest. The studies were conducted on permanent plots 32 m x 64 m, placed in tree stands 30, 50, 70, 90, 130 yrs old in western part of the Olkusz Upland. Basic subplot amounted to 2 m2 and within cover-abundance in the scale: 1, 5, 10, 20,... 100% were recorded. Based on obtained data it stated that Deschampsia flexuosa and Festuca ovina play the most significant role in assembly of ground flora of pine forests varying in age. Furthermore frequency of occurrence and abundance of these species changed dependently on age of forest stands. Their role is the highest in the youngest and the oldest tree stands, which owing to them have a "grassy" appearance - one of degeneration forms of forest phytocoenoses