摘要
以陕西省神木县六道沟小流域为研究区域,探讨了植被恢复对土壤有机质(SOM)和氮含量的影响。结果表明,研究区不同植被恢复模式表层(0-20 cm)SOM和全氮(TN)的变化顺序为:天然草地>灌丛>人工草地>弃耕地>农田,但是相互间统计差异不显著(p>0.05),意味着不同模式对促进土壤质量恢复均有一定的作用,但效果并不明显,因此考虑到研究区水分的限制性,建议植被恢复模式以草地为主。植被恢复阶段对SOM和TN的影响表现为前期(<14 a)降低而后期稳定增加的趋势,但对矿质氮(Nmin)则无显著影响。坡向比较结果表明,南坡(背风坡)SOM,TN以及矿质氮均显著高于北坡(迎风坡),这与其它地区的研究结果恰恰相反,这一特征意味着土壤沙化导致土壤肥力退化的机理可能在于土壤沙化因增强SOM的矿化消耗而降低了土壤养分的累积。
The impacts of vegetation recovery on soil organic matter （SOM） and nitrogen （N） were studied in a small catchment of Liudaogou, which located in Shenmu County. Results showed that SOM and total N （TN） for surface soil 0-20 cm for different vegetation recovery models varied in the following order： natural grassland 〉 scrubland 〉 artificial grassland 〉 abandoned farmland〉 farmland, however, the differences are non-significant （P〉0.05）. This implied that the vegetation recovery is effective in some certain though non-significant in soil quality improvement among different patterns. So, considering water shortage in the studied area, grassland should be as the main vegetation recovery patterns. The impacts of vegetation recovery period on SOM and TN changed in the following patterns： decreased before 14 yrs and continuously increased since then. However, the change in mineral N was negligible except for a sharp reduction in Nal in the initial period. Comparison between slope aspects showed that SOM and N concentrations were higher in south-facing （leeward） slope than those in north-facing （windward） slope, which is conflict to results in other areas. This suggested that the mechanism of soil degradation in fertility derived from desertification is probably associated with the strengthening in SOM mineralization and subsequent reduction in soil nutrient accumulation.
出处
《水土保持学报》
CSCD
北大核心
2009年第5期10-15,29,共7页
Journal of Soil and Water Conservation
基金
国家自然科学基金重大项目(90502006)
国家重点实验室基金项目(10501-197)
关键词
黄土高原
水蚀风蚀交错带
植被恢复与重建
土壤恢复
土壤有机质
土壤氮
the Loess Plateau
cross area of wind-water erosion
vegetation recovery and restoration
soil organic matter
soil nitrogen.
