杉木林分郁闭度对林下黄花倒水莲生长及皂苷含量的影响

Influence of canopy density of Chinese fir stand on the undergrowth and polygalacin content of Polygala fallax

在杉木人工中龄纯林的林冠下,设计5个林分郁闭度(0.1—0.2,0.2—0.4,0.4—0.6,0.6—0.8,0.8—0.9),进行2年生黄花倒水莲苗套种试验,3 a后比较其生长及其根茎远志皂苷的含量。结果表明,不同郁闭度林冠下套种的黄花倒水莲,生长量及根茎远志皂苷含量均以郁闭度0.4—0.6的林分为最高,黄花倒水莲植株平均保存率为85.5%,平均地径达2.15 cm,平均株高达123.0 cm,平均冠幅达92.7 cm,平均根茎总质量(干质量)达99.28 kg/m2,根茎中远志皂苷平均含量达1939.12 mg/kg;郁闭度为0.2—0.4的上述各项指标值次之,低郁闭度(0.1—0.2)及较高郁闭度(0.6—0.9)的各项指标值均显著降低。认为选择郁闭度为0.4—0.6的杉木人工纯林林分套种黄花倒水莲,生长量及根茎药材产量与质量较高。

After planting 2-year-old seedlings of Polygala fallax Hemsl.under the canopy of middle-aged pure Chinese fir plantation,5 canopy densities(0.1—0.2,0.2—0.4,0.4—0.6,0.6—0.8 and 0.8—0.9)were designed to compare their undergrowth and polygalacin content.The results showed that 3 years later,both the growth and rhizome polygalacin content were the highest at the canopy density of 0.4—0.6,that was,the average preservation rate of plants reached 85.5%,average ground diameter reached 2.15 cm,average height reached 123.0 cm,average crown width reached 92.7 cm,and average total rhizome weight(dry weight)reached 99.28 kg/m2 with average rhizome polygalacin content of 1939.12 mg/kg.The above-mentioned indexes followed at the canopy density of 0.2—0.4.All the indexes decreased significantly at low canopy density as 0.1—0.2 or high canopy density as 0.6—0.9.Therefore,the canopy density ranged from 0.4 to 0.6,could be preferent when growing P.fallax Hemsl.under Chinese fir pure plantation as high growth,yield and quality of medicinal materials from rhizomes could be achieved.