Study On Adaptability And Cultivation Technique Of Ailanthus Altissima Swingle In Hohhot Urban Districts

In order to understand and grasp the adaptability and cultivation technique of Ailanthus altissima Swingle which is introduced species,we can provide the basis for introduced cultivation and nursery.The paper has reseached on the growing development, adaptability in low temperature, nursery and cultivation technique throw phenological observation, growth gauge, fieldwork,nursery trial and other methords.draw the following conclusions:(1) Growth and Development of Ailanthus altissima SwingleThe phenology is late in urban district of huhhot. The infancy is in April20;the leaf stage is from April30to May18;the florescence is from June2to June14;the young fruits appear in June16and ripe by the end of August.The seed quality is good,and the germination rate,germination potentiality are79%,39%.The Ailanthus altissima Swingle keeps fast growing after cultivation.The average height increment in8a is0.97m; the top current annual increment is1.56m;the total increment is7.72m.The average DBH increment in9a is1.56cm; the top current annual increment is2.8cm; the total increment is14.05cm.(2) The adaptabilityof Ailanthus altissima Swingle in low temperatureBecause of the influence of low temperature and microclimate, the preservation rates is significant.The average value is51%,and the highest value in courtyard is93%while the lowest value in street is2%. The overwinter survival rate of center is82%higher than that of edge in urban district of hohhot. The overwinter survival rate is not significant in different green land type and east-west streets. The overwinter survival rate is significant in different age of cultivation;and with the age of cultivation increasing,the overwinter survival rate is increasing too.Compared to the average years,the overwinter survival rate is9%higher than that in extreme low temperature years.The influence of strong wind is obvious,and the overwinter survival rate in a draught is62%higher than that in the lee.(3) The nursery techniqueThe impact of tectorial membrane and storage time on germination rate and seedling growth is significant.Compared to CK,the germination rate,growth increment,ground diameter,height are31.34%、5.0mm、12.7cm higher.The germination rate, ground diameter,height of0.5a storage time are17%、4.3mm and22.7cm higher than that of1.5a storage time. (4) The cultivation techniqueThe growth in doras is better than that in sandy loam, Ailanthus altissima Swingle is suitable to cultivate in sunny leeward region.The cultivation technique is the key to the survival of the introduction. We should take note of depth of planting and other links.After cultivate,we should irrigate reasonably; especially in dry season,we must increase irrigation frequency.The man-made sabotage is critical to Ailanthus altissima Swingle, especially in shops focus on shopping centre. We need to strengthen the prompt and protection.We should strengthen quarantine in introduction and cultivation, and prevent pests and diseases such as Eucryp torrhynchus brandti(Harold).