‘中潜 3 号’杨树在浙西南山区的适应性试验

Test of Seedling Cultivation by Cutting and Afforestation of Populus×canadensis‘Zhongqian 3’in Longquan City

为了解‘中潜3号’杨树Populus×canadensis‘Zhongqian 3’引种至浙南山区的生产力及适应性表现,以‘中潜3号’杨树为试验材料分别在龙泉市的中山、山垅田、低山缓坡3种立地进行扦插育苗和造林试验,其中扦插育苗密度为6株·m^(-2),造林密度为1650株·hm^(-2)。结果表明,海拔高度、土壤肥力等立地条件对‘中潜3号’杨树苗高生长量影响较大,而地径生长则受土壤肥力条件影响较大,受海拔因素影响较小;不同月份间苗高生长差异极显著(P<0.01),地径生长则相邻月份间不显著而生长期起始月和终止月差异极显著(P<0.01)。其中,在山垅田的育苗效果最好,扦插1年后的优株苗木高为4.6 m,地径为3 cm,平均苗高为3.9 m,地径为3 cm;‘中潜3号’杨树造林宜选择地径2.5 cm以上、苗高300 cm以上的大苗,大苗造林后生长快,造林第2年即可快速生长,其造林后的树高、胸径、冠幅和生物量均优于小苗。以上结果表明,‘中潜3号’杨树在龙泉地区造林前期生长良好。

In March 2019,1-year Populus×canadensis‘Zhongqian 3’seedlings was introduced from Qianjiang of Hubei province in Longquan,Zhejiang province for scion.Seedling cultivation by cuttings of 20-25 cm was carried out in different sample sites with different elevation in 2019,and topped seedlings were afforestated with two specifications in 2020.In November 2021,determinations were implemented on height,DBH and crown diameter,meanwhile,sample trees were selected for biomass detection.The result showed that elevation and soil fertility had great influence on the height growth of seedlings,while the ground diameter growth was greatly affected by soil fertility and less affected by elevation.There was a significant difference in seedling height growth among different months(P<0.01),and there was no significant difference in ground diameter growth between adjacent months,but there was a significant difference between the beginning and ending months of the growth period(P<0.01).The growth of seedling at lower elevation had the best effect with the height and ground diameter of superior seedlings of 4.6 m and 3.0 cm.The average height and ground diameter of seedlings were 3.9 m and 3.0 cm.The experiment demonstrated that the tree height,DBH,crown width and biomass of larger seedlings with ground diameter of more than 2.5 cm and height of more than 300 cm after afforestation were better than that of small ones.