investigation of weed community diversity in forage crop fields in different provinces of iran

in order to evaluate the weed diversity in forage crop fields such as alfalfa (medicago sativa l.), clover (trifolium sp.) and sainfoin (onobrychis spp.) in different provinces of iran, a study was conducted by using data from reports of plant protection organization, ministry of agriculture during 2008. after evaluation of weed species and definition of weed family, these species classified based on functional diversity in four groups such as life cycle, growth type, photosynthetic pathway and persistence degree. the results indicated that the number of weed species and plant families were 37 and 18, respectively, in alfalfa fields. most diverse families of monocotyledonous and dicotyledonous weeds were poaceae and asteraceae, respectively. nine species of five different families were observed in sainfoin fields that among these weed families, the highest species diversity was in poaceae family. in addition, in clover fields of different provinces, 20 species of 11 plant families were observed. the highest species diversity obtained in poaceae family with six species and brassicaceae family with four species. the highest similarity index for alfalfa fields (100%) was observed between west azerbaijan- ardabil, west azerbaijan- zanjan, west azerbaijan- kordestan, ardabil- kordestan, zanjan- kordestan, zanjan-gilan, kordestan - gilan, west azerbaijan- gilan and ardabil- gilan. the highest similarity for sainfoin fields (0.60) was between east azerbaijan- west azerbaijan and west azerbaijan- fars. also, in clover fields, the highest similarity index was obtained between fars and isfahan provinces.