摘要：Meadow and pasture weed flora in Serbia is surveyed and ecological analysis provided.The acquired data show a very high participation of weed species in grassland areas.Weeds accounted for over 50% of overall floristic composition of the analyzed meadow and pasture plant communities (48),which belong to the classes Phragmitetea,Molinio-Arrhenatheretea,Festuco-Brometea,Festucetea vaginalcae,Nardo-Callunetea and Juncetea trifidi.The lowest participation of weeds was 50.7% in the class Fcstuco-Brometea,while the highest reached as much as 91.3% in the class Phragmitetea.Viewed from the phytocoenological aspect,weed plants are equal with other (beneficial) coenobions in grassland areas.However,viewed from the aspect of grassland utilization they belong to an undesirable group of plants.Depending on the degree of harmfulness,grassland weeds may be differentiated into several groups: 1.plants of low forage value,consumed by livestock but only reluctantly (e.g.Nardus slricta);2.prickly plants (with thorns,hooks and emergance growths) such as Carduus sp.,Cirsium sp.,Ononis spinosa,Eryngium campestre,etc.,which may cause injury to the mouth,throat,stomach or intestines;and 3.poisonous species such as Aristolochia clematitis,A tropa belladonna,Colchicum autumnale,Conium maculatum,Euphorbia sp.,Hyosciamun niger,Veratrum album and many others,which may cause disorders of some sort in animals and even produce fatal result when consumed in large amounts.
