磴口县引种胡杨的生长规律及其评价

胡杨是优良的绿化树种和荒漠地区主要造林树种,多年来许多地方引种栽培,但成林不多。为探究内蒙古磴口县引种胡杨的生长状况,采用树干解析和模型模拟方法研究了引种胡杨的树高、胸径和材积等生长规律,以此对磴口县乃至巴彦淖尔盟胡杨引种工作进行客观评价。结果表明,磴口县的胡杨长势良好,树高、胸径和材积等呈现慢-快-慢的"S"型曲线。树高速生期早于胸径与材积,树干形数随年龄增加逐渐减小。比较发现,引种胡杨第16年后树高开始超过额济纳天然胡杨的平均树高,但胸径小于额济纳同龄天然胡杨。引种胡杨的材积速生期多出现在第10年以后,较天然胡杨出现时间至少晚5a,其成熟期也晚于额济纳天然胡杨。研究认为磴口县乃至巴彦淖尔盟的气候环境适合胡杨生长,其生长状态优于额济纳天然林。

Growth Regularity and Evaluation of Populus euphratica Introduced in Dengkou County

Populus euphratica is an excellent and main afforestation species in desert area.It has been introduced to many places over years,but the forest establishment is poor.In order to explore the growth regularity of P.euphratica in Dengkou County,Inner Mongolia,this paper used the trunk analysis and model simulation method to study the growth regularities of tree height,diameter at breast height (DBH) and volume of P.euphratica,then to make an objective evaluation.The results showed that P.euphratica in Dengkou County grew well.The tree height,DBH,volume and other parameters all presented “S” curve trends:slow,fast,and slow.The fast growing period of the tree height was earlier than DBH and volume.The number of stem form gradually decreased with age.Moreover,it was found that after planted for 16 years,the height began to exceed the height of natural P.euphratica in Ejina,while the DBH of the planted tree was smaller than natural one.The rapid growing period of planted P.euphratica appeared at the 10 th year after planted,at least 5 years later than that of natural one.It was concluded that the climatic environment of Dengkou County and Bayannaoer was suitable for the growth of P.euphratica,and its growth status was better than natural forest in Ejina.