| 摘要: |
| 对黄土高原沟壑区林草景观界面（包括林地、草地和林-草界面3种生态系统）土壤的养分（有机质、氮、磷、钾和pH）含量、水分含量和微生物（细菌、真菌和放线菌）数量进行测定，分析比较了其养分、水分和微生物分布特征。结果表明，林草景观界面3种生态系统土壤养分分布不平衡，有机质、全氮、水解氮和速效钾在0～40 cm土层的平均含量为林地〉草地〉林-草界面；全磷平均含量为林地〉林-草界面〉草地；速效磷平均含量为草地〉林地〉林-草界面；全钾平均含量和pH为林-草界面〉草地〉林地；各种养分含量在各生态系统土壤剖面中有明显的层次性，表层0～20 cm土层的养分含量基本上高于20～40 cm土层；不同土层的土壤水分在水平方向上，随着水平距离梯度的变化表现出上升或下降的趋势，草地和林地内水分变化不显著，而在林-草界面内不同距离梯度上的含水量变化极显著；随着土层深度的增加，土壤平均含水量在草地区逐渐升高，在刺槐林地中呈逐渐降低趋势，而在林-草界面区域则表现为先降低后升高的趋势；林草景观界面下土壤中各种微生物数量存在明显差异，在总体数量上均以细菌为主，占微生物总量的98％以上，微生物总数量为林-草界面〉草地〉刺槐林地；微生物数量的垂直动态明显，林-草界面和草地0～20 cm土层数量较20～40 cm土层显著增多，而林地0～20 cm土层微生物数量少于20～40 cm土层。 |
| 关键词: 林-草界面 土壤养分 土壤水分 微生物 |
| DOI： |
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| 基金项目:国家重点基础研究发展规划资助项目（2002CB111506） |
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| Study on soil nutrients and moisture as well as soil microorganism at grassland-forestland interface in gully region of Loess Plateau |
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| Abstract: |
| The content of soil nutrients and moisture as well as microorganisms quantity at the landscape interface of forestland-grassland in gully region of Loess Plateau were studied. The results showed that soil nutrients were unevenly distributed and there was obvious hierarchy characteristics in forestland, grassland and forestland-grassland;with changing horizontal distances, soil mois reducing tendency between different soil layers in horizontal direction, and the forestland and grassland was insignificant but significant at the forestland-gras soil moisture content increased with the increasing of soil depths in grassland while and showed a tendency of increasing first then reducing in grassland-forest ture showed increasing or soil moisture variation in sland boundary; the mean but reduced in forestland land interface ; the populations of soil-inhabiting microorganisms under the interface presented different for different kinds;the total amounts of microorganisms in forestland-grassland were higher than those in forestland and grassland. In addition,the amount of microorganism in 0-20 cm soil layer was significantly much more than that in 20- 40 cm,and the microorganisms amounts changed a lot in vertical distribution. |
| Key words: forestland-grassland soil nutrient soil moisture microorganism |
