黄土丘陵区油松根系化感效应研究

通过生物测定法研究油松根系对不同物种的化感效应,为油松林的乔灌草复合提供科学依据。设定油松根系化感效应研究中浸提液的质量浓度为0.5、1.0、3.0、5.0、7.0、10.0mg/mL,测定油松根系提取液在不同浓度下对油松、刺槐、侧柏、胡枝子、绣线菊、冰草、紫花苜蓿发芽、生长的影响。研究结果显示:在所有研究浓度下,油松根系浸提液对刺槐、冰草、紫花苜蓿发芽和生长的综合影响呈抑制效应,并且随浓度加大抑制效应不断加强;在所有研究浓度下,对侧柏的综合影响呈促进效应;对油松、胡枝子、绣线菊的综合影响呈现低促高抑的情况,在1mg/mL时,对油松、绣线菊的影响由促进转为抑制。因此,从油松根系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、冰草、紫花苜蓿,选择复合胡枝子、绣线菊时应注意油松林间伐以及间作的密度。 

Allelopathic effect of Pinus tabuliformis root in loess hilly area

This research aimed to provide a scientific basis for the construction of compound arbor-shrub-herb vegetation in Pinus tabuliformis forest by studying the allelopathic effect of P. tabuliformis root on varied plant species. The allelopathic effects of P. tabuliformis root aqueous extract ( RAE) on the germination and growth of seven plants ( P. tabuliformis, Robinia pseudoacacia, Platycladus orientalis, Lespedeza bicolor, Spiraea salicifolia, Agropyron cristatum, and Medicago sativa) were investigated with different concentrations of P. tabuliformis RAE, i. e. , 0.5, 1.0, 3.0, 5.0, 7.0, and 10.0 mg/mL. The results showed that P. tabuliformis RAE inhibited the growth of R. pseudoacacia, A. cristatum, and M. sativa, and such effect increased with the increase of RAE concentration. P. tabuliformis RAE promoted only the growth of P. orientalis at each concentration. At low concentrations, the P. tabuliformis RAE promoted the growth of P. tabuliformis, L. bicolor and S. salicifolia, while it inhibited at high concentrations;at 1 mg/mL the promoting effects changed into inhibiting. We suggest that when constructing compound arbor-shrub-herb vegetation in P. tabuliformis forest, we should give priority to P. orientalis, and carefully choose R. pseudoacacia, A. cristatum, and M. sativa. When choosing L. bicolor and S. salicifolia, we should control the thinning and intercropping density of P. tabuliformis forest.