荒漠草原人工柠条林重建的土壤养分效应  

Soil Nutrient Effect of Desert Steppe Reconstructed by Artificial Caragana Microphylla Stand

作　　者：宋乃平[1,2] 杨新国[1,2] 何秀珍[1,2] 何彤慧[1,2] 李勇 刘孝勇[1,2] 

机构地区：[1]西北土地退化与生态恢复国家重点实验室培育基地,宁夏银川750021 [2]西北退化生态系统恢复与重建教育部重点实验室(宁夏大学),宁夏银川750021

出　　处：《水土保持通报》2012年第4期21-26,共6页Bulletin of Soil and Water Conservation

基　　金：国家重点基础科学(973)研究发展计划前期专项"北方农牧交错典型脆弱区生态环境变化过程及驱动力研究"(2009CB426304);国家自然科学基金项目(30960075)

摘　　要：采用时空互代方法,构建了由天然草地和7,12,27a柠条林组成的序列,对其下土壤有机质、全氮、碱解氮、有效磷进行了研究。结果表明:(1)0—200cm土壤剖面上的有机质含量由草地、幼龄林、中龄林、老龄林依次增加,有机质含量增加的显著程度随着林龄的增加在更深土层上体现。(2)全氮含量由草地到幼龄林阶段显著增加,由幼龄林到中龄林再到老龄林依次减少。幼龄林、中龄林、老龄林之间全氮含量减少的最大幅度随林龄增加向土壤深层移动。碱解氮与全氮具有一致的规律。(3)整个土壤剖面上有效磷含量依次为:老龄林<幼龄林<中龄林<草地。(4)3个不同林龄的柠条林的有机质、全氮、有效磷在柠条行内和行间的空间差异均不显著。柠条行内与行间的有机质和全氮相关程度很高,有效磷相关性不显著。Using spatiotemporal substitution method, we constructed a sequence which was formed by natural grassland and Caragana microphylla stands of 7（young）, 12（intermediately aged） and 27（old） years old. In addition, we measured and analyzed the variations of the soil nutrients including organic matter, total nitro- gen, alkali-hydro nitrogen, and available phosphorus. The results show that： （1） The soil organic matter contents within 0--200 cm displayed an ascending order of the cover as meadows〈 young stand〈intermedi- ately aged stand.old stand; the increasing trend of organic matter was more significant in the deeper layers. （2） The grassland soil had lower total nitrogen contents than the soil of young Caragana microphylla stand. The total nitrogen contents in the soils decreased with the increase of the forests age, as the biggest differ- ence was found between the young and intermediately aged stands. Alkali-hydro nitrogen showed the exactly same trend as total nitrogen. （3） The available phosphorus content in the whole soil profile is： aged forests ~young forests〈middle-aged forests〈meadows. （4） The spatial variability of all the variables in the three differently aged Caragana microphylla forests was not significant in the rows and between the rows. The degree of correlation was found high between organic matter and total nitrogen, and low between alkali-hydro nitrogen and available phosphorus.

关 键 词：人工柠条林 土壤养分效应 荒漠草原 

分 类 号：S157.5[农业科学—土壤学]