Results of elimination and pioneer trials with tree species in West Azerbayjan province

This paper presents the results of four elimination and two pioneer(growth) trials with 22 tree species and provenances in un-irrigated plantation conditions inNorth-west Iran. The studied areas are characterized as semi-arid zone with very cold winters(Fig.1). The summer drought lasts between 111 and 132 days andfrost days between 97 and 115 days(Tab. 4). The geology is basically formed of sedimentary limestone. The degree of alkalinity and salinity is high and the organicmatter is often at a very low level. The results(Tables 6, 8, 10, 12, 14) showed that the most promising species include: Elimination trials Pioneer(growth) trialsUromieh:  Celtis australis Eleagnus angustifolia Fraxinus xanthoxyloides  Fraxinus pseudoacaia  Robinia pseudoacaia  Fraxinus rotudifolia  Eleagnus angustifolia  Robinia pseudoacacia   Khoy: Eleagnus angustifolia Cercis siliguastrum   Maku(only promissing species): Pyrus syriaca Eleagnus angustifolia Robinia pseudocaiaFraxinus rotundifolia