稀土对杉木、杨树幼林生长的影响

Effect on the Young Trees′ Growth of Cunninghamia lanceolata and Populus Treated by the Rare earth Solution

对杉木 [Cunninghamia L anceolata (Lamb) Hook]、杨树 (Populuscv.‘Lux’)施用稀土后幼树的根系吸收等指标进行的观测结果表明 ,用不同浓度的稀土处理苗木 ,其单株幼树根系的总吸收面积、活跃吸收面积差异显著 ,根系的比表面差异不显著。杨树以 50 0 mg/kg的稀土溶液浸根时根系的吸收指标最高 ,杉木以 80 0 mg/kg浓度叶面喷施最高。经不同浓度稀土处理后 ,与对照相比 ,杉木、杨树在同时期所测得的高生长量、地径生长量。

Applied the rare earth solution to Cunninghamia lanceolata and Populus ,the indexes about their roots assimilating rare earth were investigated. The observed results show that the average square differences on the total assimilating surfaces and the active assimilating surfaces of the young trees' roots are remarkable, but the average square differences on the rates between the surface area and the volume of assimilating roots are not remarkable. When soaked by the rare earth solution of 500 mg/kg, the index of Populus roots assimilating rare earth is the highest; correspondingly, when sprayed by the rare earth solution of 800 mg/kg, the index of Cunninghamia lanceolata′s roots assimilating rare earth is the highest. Comparing to the CK, the growth of the height and the bottom diameter of the young tree and the dry weight of the root increased after treated by the rare earth solution.