Abstract: To explore the changes in soil physicochemical properties of Nitraria tangutorum shrub sand dunes under different succession stages in the Ulanbuhe Desert.,the N. tangutorum shrubs were classified into the developmental stage (mortality rate 10%~30%,coverage 20%~40%),stabilization stage (mortality rate ≤ 10%,coverage 40~60%),and decline stage (mortality rate ≥ 50%,coverage ≤ 20%) according to the mortality rate and coverage. Three relatively independent N. tangutorum shrub sand dunes were selected for each succession stage to study the changes in soil nutrients and soil particle size. The results showed that the surface soil nutrient of the N. tangutorum shrub sand dune with different slope aspects showed a decreasing trend with the succession of the sand dune. The organic matter,available nitrogen,and available phosphorus contents in the leeward slope of development stage were 164.58%,144.44%,and 215.93% higher than the decline stage,respectively. The organic matter,available nitrogen,and available phosphorus content in the windward slope of the development stage was 107.95%,200%,and 45.64% higher than the decline stage,respectively. The succession stage had a significant impact on the nutrient and particle size composition of the N. tangutorum shurb sand dunesoil on the windward slope (P<0.05). In summary,the soil nutrient enrichment in the surface soil of shrub sand dunes is significant at different successional stages,but there are differences in the physical and chemical properties of the same successional hrub sand dunes soil at different slopes.

Key words: Desert, Desert vegetation, Nitraria tangutorum, Physical and chemical properties of soil

摘要： 为探究乌兰布和沙漠不同演替阶段下白刺灌丛沙堆土壤理化性质的变化特征。本研究按照白刺灌丛枯死率和盖度划分不同演替阶段,分别为发育阶段(枯死率10%~30%,盖度20%~40%)、稳定阶段(枯死率 ≤ 10%,盖度40%~60%)和衰退阶段(枯死率 ≥ 50%,盖度 ≤ 20%),每个演替阶段选取3个相对独立的白刺灌丛沙堆作为研究对象,研究土壤养分和土壤粒径的变化特征。结果表明:不同坡向白刺灌丛沙堆表层土壤养分含量随着沙堆演替呈下降趋势。背风坡发育阶段有机质、速效氮和速效磷含量分别较衰退阶段高164.58%,144.44%和215.93%,而迎风坡发育阶段有机质、速效氮和速效磷含量分别较衰退阶段高107.95%,200%和45.64%。演替阶段对迎风坡处白刺沙堆灌丛土壤养分含量和粒径组成产生显著影响(P<0.05)。综上所述,不同演替阶段白刺灌丛沙堆表层土壤养分富集现象明显,但不同坡向相同演替白刺灌丛沙堆土壤理化性质存在差异。

关键词: 荒漠, 荒漠植被, 白刺, 土壤理化性质