【作者】 李国辉；

【导师】 安韶山； 郑粉莉；

【作者基本信息】 西北农林科技大学 ， 水土保持与荒漠化防治， 2010， 硕士

【摘要】 研究不同植被类型根际与非根际间的土壤性质差异性,对指导植被建设有重要的理论和实践意义。本文选取黄土丘陵区草原带和森林带中16种典型植物,采用野外调查与室内分析相结合的方法,通过研究不同植物根际与非根际土壤性质的差异性,阐明典型植物根际对土壤化学性质和微生物功能多样性的影响,揭示植物根际对土壤质量作用的机理,以期为改善土壤质量、提高土壤养分资源利用效率和保护生态环境等提供重要科学依据。主要研究结论如下:（1）在黄土丘陵区的草原带和森林带,16种不同典型植物之间的根际土壤和非根际土壤化学性质（有机质、全氮、铵态氮、硝态氮、全磷、速效磷、速效钾）、土壤酶活性（蔗糖酶、脲酶、碱性磷酸酶、脱氢酶）、微生物生物量（微生物生物量碳、微生物生物量氮、微生物生物量磷）、基础呼吸以及土壤微生物功能多样性（微生物活性AWCD、微生物多样性指数、均匀度指数）均存在不同程度的差异。对不同植物而言,草原带的冷蒿植物根际土壤4种酶活性、微生物生物量碳、微生物生物量氮、基础呼吸和微生物功能多样性各指标都较高,其中碱性磷酸酶活性和脱氢酶活性分别为84.53 mgP2O5.kg^-1.h^-1和24.97 ulH+.g^-1.h^-1,皆极显著的高于其他植物;达乌里胡枝子植物的根际和非根际土壤化学性质、酶活性、微生物生物量皆较低,其根际和非根际土壤有机碳含量分别为8.14和5.53 g.kg^-1,皆极显著的低于其他植物。森林带的白羊草植物根际土壤大部分土壤性质指标都比其他植物高,其有机碳含量为20.59 g.kg^-1,全氮含量为2.71 g.kg^-1,微生物量碳含量为547.61 mg.kg^-1,脱氢酶活性为32.27 ulH+.g^-1.h^-1,皆极显著的高于其他植物。铁杆蒿、冷蒿、辽东栎的根际土壤微生物活性AWCD、土壤微生物多样性指数和均匀度指数都很高,这三种植物根际土壤微生物代谢强度高于其他植物。（2）大多数植物的根际土壤化学性质、酶活性、微生物生物量和微生物功能多样性各指标都大于非根际土壤,而全磷在各个植物根际土壤与非根际土壤之间的含量很接近。草原带细辛植物的根际土壤速效磷、脲酶、碱性磷酸酶、脱氢酶、微生物生物量碳、微生物生物量磷含量或活性皆小于非根际土壤,而其它12个土壤性质指标表现则为根际土壤大于非根际土壤;森林带刺槐的各个土壤性质指标在根际土壤与非根际土壤之间的差异上无明显规律,其中刺槐的根际土壤碱性磷酸酶活性比非根际土壤小38.43 mgP2O5.kg^-1.h^-1,两者差异明显;对白羊草而言,大部分指标在根际土壤与非根际土壤之间的差异上都较大。（3）典型草原带各种植物根际土壤微生物的主要碳源利用类型是羧酸类、氨基酸类;非根际土壤微生物的主要碳源利用类型是羧酸类、胺类、氨基酸类。典型森林带各种植物根际土壤微生物的主要碳源利用类型是羧酸类、氨基酸类,非根际土壤微生物的主要碳源利用类型是糖类和羧酸类。（4）在不同植物的根际和非根际土壤中,有机碳、全氮、蔗糖酶、微生物生物量碳、微生物生物量氮之间存在显著或极显著相关关系;不同植物土壤微生物功能多样性中的微生物活性AWCD、微生物多样性指数、微生物均匀度指数之间均具有显著或极显著相关性,与其他指标的相关性规律不明显;其余指标在不同植物之间的相关关系表现不一。（5）对草原带9种典型植物根际与非根际土壤的18个指标进行主成分分析,结果表明,有机碳、全氮、蔗糖酶、碱性磷酸酶、微生物生物量碳、微生物生物量氮、基础呼吸、微生物多样性指数、均匀度指数这9个指标能大体上反映草原带9种典型植物土壤的化学和微生物学性质,对评价土壤质量有重要意义。与草原带有所不同,有机碳、全氮、硝态氮、全磷、速效磷、速效钾、蔗糖酶、脲酶、碱性磷酸酶、微生物生物量碳、微生物活性AWCD、微生物多样性指数、均匀度指数这13个指标能大体上反映森林带7种典型植物土壤的化学和微生物学性质。更多还原

【Abstract】 The degradation of soil quality by vegetation deterioration in the loess hilly region has threatened the ecological environment and agriculture sustainable development. Therefore, improving soil quality and speeding up the process of vegetation restoration is one of important goals in ecological rehabilitation project of loess hilly region. 16 typical species of plants were chosen from two representative regions （grassland zone and forest zone） in the loess hilly region, to study the difference of soil chemical properties and soil microbial functional diversity between the rhizosphere and non-rhizosphere by using field sampling and laboratory analysis. The resaech results will provide scientific evidence for preserving or improving soil quality, increasing soil fertility, and use efficiency of nutrient resources, protecting ecological environment. The main research results were as follows:（1） Soil chemical properties （organic C, total N, ammonium N, nitrate N, total P, availabel P, available K）, soil enzyme activity （invertase, urease, alkaline phoshpatase, dehydrogenase）, soil microbial biomass （Cmic, Nmic, and Pmic）, basal respiration and soil microbial functional diversity （AWCD, soil microbial diversity index and uniformity index） are different whether rhizosphere soil or non-rhizosphere soil among 16 species of plant in grassland zone and forest zone in the loess hilly region. In grassland area, all kinds enzymes and Cmic、Nmic、basal respiration in the rhizosphere soil of Artemisia frigida was higher than other plants, alkaline phoshpatase activity was 84.53 mgP2O5.kg^-1.h^-1, dehydrogenase activity was 24.97 ulH+.g^-1.h^-1, they were significant higher than other plants; the main trend of chemical properties、soil enzyme activity、soil microbial biomass in the rhizosphere and non-rhizosphere soil of Lespedeza bicolor Turcz was lower; content of organic C were 8.14 and 5.53 g.kg^-1 respectivety in the rhizosphere soil and non-rhizosphere soil, they were significant lower than other plants; In forest area, major indicators in the rhizosphere soil of Bothriochloa ischcemum was higher than others plants. content of organic C was 20.59 g.kg^-1, content of total N was 2.71 g.kg^-1, content of Cmic was 547.61 mg.kg^-1, dehydrogenase activity was 32.27 ulH+.g^-1.h^-1, they were significant higher than other plants; the rhizosphere soil microbial activity（AWCD）, soil microbial diversity index and uniformity index of A. sacrorum, A. frigida, and Quercus liaotungensis Koidz were high, shown that rhizosphere soil microbial metabolic intensity in these three plants are fiercer than others.（2） Soil chemical properties, soil enzyme activity, soil microbial biomass and soil microbial functional diversity in rhizosphere soil were higher than in non-rhizosphere soil for most of plants,and the difference of total P in all kinds plant is not significant between rhizosphere soil and non-rhizosphere soil. In grassland area, for Asarum sieboldii Miq, the content or activity of availabel P, urease, alkaline phoshpatase, dehydrogenase , Cmic, and Pmic in the rhizosphere soil was lower than in the non-rhizosphere soil, but the remaining indicators in the rhizosphere soil was higher than in the non-rhizosphere soil; In forest area, there was no significant law among indicators of Robinia Pseudoacacia between rhizosphere soil and non-rhizosphere soil, alkaline phoshpatase of Robinia Pseudoacacia in rhizosphere soil was lower than in non-rhizosphere soil 38.43 mgP2O5.kg^-1.h^-1, there was apparent difference. For Bothriochloa ischcemum, there were apparent difference between rhizosphere soil and non-rhizosphere soil for most indicators.（3） In grassland area, the major carbon sources of all species of plants’rhizosphere soil microbe were carboxylic acid sort and amino acids sort, and in non-rhizosphere soil were carboxylic acid sort, amine sort, and amino acids sort. In forest area, the major carbon sources of all species of plants’rhizosphere soil microbe were carboxylic acid sort and amino acids sort, and in non-rhizosphere soil were carbohydrate and carboxylic acid sort.（4） There were significant correlations between organic C, total N, invertase, Cmic, and Nmic in rhizosphere and non-rhizosphere soil under different plants. There were significant correlation between different species of plants’Soil microbial activity （AWCD）, soil microbial diversity index, and uniformity index, but the correlation of soil microbial activity （AWCD）, soil microbial diversity index, and uniformity index to other indicators were not obvious. The rest of indicators’s correlation is different.（5） By principal components analysis, in all indicators among 9 species of plants in typical grassland area, organic C, total N, invertase, alkaline phoshpatase, Cmic, Nmic, basal respiration, soil microbial diversity index, and uniformity index can be used as the indices to evaluate soil quality. Unlike grassland zone, organic C, total N, nitrate N, total P, availabel P, available K, invertase, urease, Alkaline phoshpatase, Cmic, AWCD, soil microbial diversity index, and uniformity index can general reflect soil chemical and microbial properties under 7 species of typical plants in forest zone.更多还原