Weed Flora, Spatial Distribution and Diversity Indexes in Afforestation of Around of Karaj

This investigation was conducted in afforestation around Karaj in order to determine flora and spatial distribution patterns description and weed density in 2012. The studied region was divided into 50×50 meters grids, then weeds were identified, counted and recorded in a 1×1 quadrates. Fiftysix weed species belonging to 18 families were identified: Four species with average numbers of more than 5 plants/m2 Consisting Avena fatua, Hordeum murinum, Chondrilla juncea and Aegilops ovate with 19.566, 18.080, 6.190 and 5.677 plants/m2 were dominant species. Asteraceae, Poaceae, Fabaceae, Apiaceae and Lamiaceae families with 13, 10, 6, 5, and 4 species have maximum species number of weeds. Weed infestation maps generated by geostatistics showed that the dominant species formed infestation spots with the oradius of more than 50 m diameter. The result of experiment about diversity indexes showed that studied region had high variety as diversity indexes. The results of this study can be useful to improve decision making and efficient control of weeds.