بررسي روند احياء طبيعي پوشش گياهي در مناطق آسيب ديده پارك ملي گلستان بعد از آتش سوزيهاي سال 1374

Fire damaged approximately 720 ha of forest area in Golestan National Park during 1995. In this research, vegetation cover was investigated in 3 sub - sectors and plant community types were determined based on their importance value and index of dominance. Fire -damaged area included transient plant communities surrounded by Hyrcanian deciduous forest trees in the north and semi-savanna steppe vegetation of the Irano-Turanian biome in the south . Dominant vegetation type included members of Rosaceae, e.g. Pyrus boissieriana, Crataegus turcomanica, Prunus divaricata and Cotoneaster ovatus. Juniperus excelsa occupied higher mountainous areas. Gramineae were dominant grasses of the forest floor. Pattern of secondary succession of vegetation is discussed in early years after the fire incidence. Results of diversity indices of vegetation types showed a greater variation in fire-damaged zone than those of undamaged forest nearby. Grass species grew denser in fire-damaged zones while regeneration of woody species was tardy. Festuca drymeia community had recovered entirely.