黄土丘陵区油松根际土化感效应研究

通过生物测定法研究油松根际土对不同物种的化感效应,以期为油松林的乔灌草复合提供科学依据。设定油松根际土化感效应研究的质量浓度分别为0.5、1、3、5、7、10 mg/m L,测定提取液对油松、刺槐、侧柏、胡枝子、绣线菊、冰草、紫花苜蓿发芽与生长化感效应。结果显示:在所有研究浓度下,油松根际土对刺槐、紫花苜蓿呈抑制效应,且随浓度的加大抑制效应不断加强;对侧柏起促进作用;油松根际土对油松、胡枝子、绣线菊、冰草的化感效应呈低浓度促进、高浓度抑制。因此,从油松根际土化感效应的角度考虑,在油松林营造乔灌草复合植被时,应优先考虑侧柏,慎重选择刺槐、紫花苜蓿,选择复合胡枝子、绣线菊、冰草时应该注意油松林的间伐以及间作的密度。

Allelopathic Effect of Pinus tabulaeformis Rhizosphere Soil in Loess Hilly Area

The research aimed to provide a scientific basis of arbor-shrub-herb compound vegetation construction in Pinus tabulaeformis Carr forest through studying the potential allelopathic effect of Pinus tabulaeformis rhizosphere soil. The potential allelopathic effects of Pinus tabulaeformis rhizosphere soil on germination and growth were investigated with 7 plants (Pinus tabulaeformis, Robinia pseudoacacia Linn., Platycladus orientalis, Lespedeza bicolor Turcz, Spiraea salicifolia L., Agropyron cristatum Gaertn, Medicago sativa L.), and with different concentrations (0.5, 1, 3, 5, 7, 10 mg/mL). The results showed that: Pinus tabulaeformis rhizosphere soil aqueous extract inhibited the growth of Robinia pseudoacacia Linn, Medicago sativa L., and stimulated the growth of Platycladus orientalis at each study concentrations. Low concentration of Pinus tabulaeformis rhizosphere soil aqueous extract promoted effect on Pinus tabulaeformis, Lespedeza bicolor Turcz, Agropyron cristatum Gaertn and Spiraea salicifolia L. At high aqueous extract, the stimulating effects changed into inhibited. As a result, when arbor-shrub-herb compound vegetation in pine forest is constructed, people should give priority to Platycladus orientalis, carefully choose Robinia pseudoacacia Linn and Medicago sativa L.. When people choose Lespedeza bicolor Turcz, Spiraea salicifolia L. and Agropyron cristatum Gaertn, pine forest intermediate cutting and intercropping density should be noted.