Subjects: Biology >> Ecology submitted time 2018-01-05 Cooperative journals: 《中国生态农业学报》
Abstract： To determine the distribution of fine roots of Robinia pseudoacacia mixed forests and pure forest in saline-alkali soils of Yellow River Delta, fine root distributions in Fraxinus velutina and Robinia pseudoacacia mixed forest, Ailanthus altissima and Robinia pseudoacacia mixed forest and Robinia pseudoacacia pure forest were sampled with a soil column method. The vertical distributions of fine roots in different forest stands were analyzed for the distributions of fine root biomass density, fine root surface area density, volume density, root length density and other root parameters. The aim of the study was to clarify differences of roots distribution of different forests and their relationship with soil properties and to provide references for the vegetation recovery and tree species selection in saline soils of the Yellow River Delta. The results showed that fine root biomass, surface area, volume and root length of F. velutina and R. pseudoacacia mixed forest were significantly higher than those of A. altissima and R. pseudoacacia mixed forest and R. pseudoacacia plantations. About 95.77% of fine root biomass of F. velutina and R. pseudoacacia mixed forest was distributed in the 0–60 cm soil layer, 85.37% in the 0–40 cm soil layer for A. altissima and R. pseudoacacia mixed forest and 66.38% in the 0–40 cm soil layer of Robinia pseudoacacia pure forest. Although surface aggregation of fine roots was conducive to reducing the harmful effects of saline-alkaline conditions on the root, fine roots of R. pseudoacacia pure forest were more uniformly distributed in the soil. F. velutina and R. pseudoacacia mixed forest had the highest total fine root biomass (91.56 g in 2500 cm2 of soil), significantly higher than those of other trees stands. Fine root surface area, length and volume densities of F. velutina and R. pseudoacacia mixed forest were significantly higher than that of R. pseudoacacia pure forest. Fine root tips of F. velutina and R. pseudoacacia mixed forest and A. altissima and R. pseudoacacia mixed forest were respectively 2.34 and 1.23 times that of R. pseudoacacia pure forest. Root forks of F. velutina and R. pseudoacacia mixed forest and A. altissima and R. pseudoacacia mixed forest were respectively 6.15 and 1.66 times that of R. pseudoacacia pure forest. There was a significant positive correlation between stand fine root biomass with soil available phosphorus and soil available potassium contents. The correlation between fine root biomass with available nitrogen and organic matter content of F. velutina and R. pseudoacacia mixed forest was also very significant and positive. The research showed that some mixed patterns increased fine root biomass distribution and the ability of roots to absorb soil nutrient. This suggested that proper mixing patterns could increase the adaptability of tree plantations.
Subjects: Biology >> Ecology submitted time 2017-11-29 Cooperative journals: 《中国生态农业学报》
Abstract： To determine the distribution of fine roots of Robinia pseudoacacia mixed forests and pure forest in saline-alkali soils of Yellow River Delta, fine root distributions in Fraxinus velutina and Robinia pseudoacacia mixed forest, Ailanthus altissima and Robinia pseudoacacia mixed forest and Robinia pseudoacacia pure forest were sampled with a soil column method. The vertical distributions of fine roots in different forest stands were analyzed for the distributions of fine root biomass density, fine root surface area density, volume density, root length density and other root parameters. The aim of the study was to clarify differences of roots distribution of different forests and their relationship with soil properties and to provide references for the vegetation recovery and tree species selection in saline soils of the Yellow River Delta. The results showed that fine root biomass, surface area, volume and root length of F. velutina and R. pseudoacacia mixed forest were significantly higher than those of A. altissima and R. pseudoacacia mixed forest and R. pseudoacacia plantations. About 95.77% of fine root biomass of F. velutina and R. pseudoacacia mixed forest was distributed in the 0–60 cm soil layer, 85.37% in the 0–40 cm soil layer for A. altissima and R. pseudoacacia mixed forest and 66.38% in the 0–40 cm soil layer of Robinia pseudoacacia pure forest. Although surface aggregation of fine roots was conducive to reducing the harmful effects of saline-alkaline conditions on the root, fine roots of R. pseudoacacia pure forest were more uniformly distributed in the soil. F. velutina and R. pseudoacacia mixed forest had the highest total fine root biomass (91.56 g in 2500 cm2 of soil), significantly higher than those of other trees stands. Fine root surface area, length and volume densities of F. velutina and R. pseudoacacia mixed forest were significantly higher than that of R. pseudoacacia pure forest. Fine root tips of F. velutina and R. pseudoacacia mixed forest and A. altissima and R. pseudoacacia mixed forest were respectively 2.34 and 1.23 times that of R. pseudoacacia pure forest. Root forks of F. velutina and R. pseudoacacia mixed forest and A. altissima and R. pseudoacacia mixed forest were respectively 6.15 and 1.66 times that of R. pseudoacacia pure forest. There was a significant positive correlation between stand fine root biomass with soil available phosphorus and soil available potassium contents. The correlation between fine root biomass with available nitrogen and organic matter content of F. velutina and R. pseudoacacia mixed forest was also very significant and positive. The research showed that some mixed patterns increased fine root biomass distribution and the ability of roots to absorb soil nutrient. This suggested that proper mixing patterns could increase the adaptability of tree plantations.
Subjects: Biology >> Ecology submitted time 2018-06-09 Cooperative journals: 《生态学报》
Abstract：为探讨黄河三角洲刺槐白蜡混交对土壤细菌群落结构及多样性的影响，通过高通量测序技术分析比较了刺槐白蜡混交林及刺槐纯林、白蜡纯林土壤细菌群落结构及多样性。结果表明：①混交林与两种纯林土壤细菌群落共36门。酸杆菌门、变形菌门、放线菌门（相对丰度大于10%）为刺槐白蜡混交林与两种纯林土壤中共有的优势菌群；硝化螺旋菌门为刺槐纯林土壤中的优势菌群。不同人工林土壤中各门细菌相对丰度差异显著。②混交改变了土壤细菌群落结构，提高了细菌多样性。刺槐白蜡混交林土壤细菌物种数、Chao1指数、Shannon指数分别为1934.5、2629.1、9.1，显著高于两种纯林。③相关性分析表明，土壤含水量与放线菌门细菌呈显著正相关；pH与芽单胞菌门细菌呈极显著正相关，与酸杆菌门细菌呈显著负相关。细菌多样性与土壤含水量呈显著正相关，与速效钾、有机质含量呈显著负相关。研究表明，刺槐白蜡混交林土壤细菌群落结构与两种纯林之间有一定差异，多样性差异显著，刺槐白蜡混交改变细菌群落结构，提高细菌多样性。
Subjects: Biology >> Ecology submitted time 2017-11-01 Cooperative journals: 《生态学报》
Abstract：为探讨盐分环境下，磁化作用对土壤和植株养分特征的影响，以欧美杨I-107为试材，采用磁化和非磁化微咸水灌溉处理，通过对土壤和植物组织中微量元素和碳氮磷含量的测定，以揭示土壤-植物的养分供求关系。研究发现：（1）微咸水灌溉处理中叶片和根系Fe含量均下降；叶片Zn、Mn和Cu含量提高，根系Mn和Zn含量降低、Cu含量提高。叶片和根系中总碳含量均提高，全氮和全磷含量均降低；叶片C/N下降，根系C/N和C/P则提高。（2）磁化微咸水灌溉处理叶片和根系中Fe、Zn、Cu含量均提高，Mn含量降低；叶片C、P及C/N提高，N含量下降；根系C、C/N和C/P含量提高。（3）微咸水灌溉土壤中Fe、Mn、Zn和Cu微量元素全量均降低，有效态含量均提高；OC和N、C/P和N/P下降，全磷和C/N提高。（4）磁化微咸水灌溉中土壤Fe、Mn和Zn全量提高，Cu降低； Fe、Mn、Zn和Cu有效态含量提高；OC和N、C/P和N/P提高。可见，磁化作用有利于调节植株对微量元素的吸收和分配，提高土壤的固氮能力以及对植株的碳供应能力。此外，盐分环境下，植物体通过提高元素Fe含量以及C/N比值维持光合作用的正常进行，以满足植株正常生长发育的需要。
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