丛枝菌根真菌侵染率对喀斯特坡地坡位与灌木物种的响应

he response of arbuscular mycorrhizal fungi (AMF) colonization percentage to slopeposition and shrub species and the key influencing factors were identified as well in karst slopes,which is the prerequisite for rational utilization of soil AMF to promote karst vegetationrestoration. Based on field investigation of typical shrub communities and environmental variableson slopes of a karst peak cluster depression catchment. The fine root samples of three typicalshrub species (Vitex negundo, Alchornea trewioides and Pyracantha fortuneana) were collectedfrom three positions (upper, middle and lower) along three slopes. The frequency, intensity andabundance of AMF colonization were detected and calculated by the Trypan blue method. Theresults were as follows: (1) The colonization frequency, colonization intensity and abundance of AMF for Vitex negundo and Alchornea trewioides were higher than those for Pyracanthafortuneana in the same slope. The colonization intensity for Vitex negundo and Pyracanthafortuneana in the lower slope was higher than that in the upper or middle slope. The abundance ofAMF for Alchornea trewioides in the middle slope was significantly higher than that in the upperand lower slope (P<0.05). (2) Shrub species had significant effect on the colonization frequency,intensity and abundance of AMF, but slope position only had significant effect on the colonizationintensity of AMF. Slope position and shrub species had significant interactive effect on theabundance of AMF (P<0.05). (3) Soil depth and total potassium content were identified as the twostrongest explanatory factors on AMF colonization according to the redundancy analysis (P<0.05).Therefore, the rational use of soil AMF to promote vegetation restoration in karst areas needs toconsider the choice of terrain and species, and should pay attention to the water and soilconservation.