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以塔克拉玛干沙漠南缘策勒绿洲西部过渡带为研究区,选取植被盖度为30%、15%~20%、10%、<5%的4个典型样地,对各样地的柽柳(Tamarix ramosissima)灌丛沙堆-丘间地系统典型部位0~10cm和10~20cm土壤进行系统采样,测定土壤pH值及总盐、Cl~-、Na~+、K~+、SO_4~(2-)、Ca~(2+)、Mg~(2+)、CO_3~(2-)、HCO_3~-含量,从风沙地貌的角度探讨过渡带沙漠化进程中土壤盐分分异规律。结果表明:随着植被总盖度的降低,0~10cm层土壤pH值及总盐、Cl~-、K~+、Na+含量总体呈先升高后降低的趋势;土壤SO2-4和Ca~(2+)含量呈先降低后升高的变化趋势;Mg~(2+)含量随着植被盖度的变化没有明显的变化规律。灌丛下→沙堆边缘→丘间地→风影区,总盐、Cl~-、K~+、Na~+、SO_4~(2-)、Ga~(2+)、Mg~(2+)含量呈先减小后增大的变化规律,最大值均位于灌丛下,最小值位于丘间地;pH值和HCO_3~-含量大体呈先升高后降低的趋势,最小值位于灌丛下,最大值多位于丘间地,二者存在中度相关(r=0.644)。与0~10cm土层相比,10~20cm总盐、Cl~-、K~+、Na~+含量明显增加,SO_4~(2-)、HCO_3~-、Ga~(2+)含量降低,Mg~(2+)含量和pH值没有明显的变化。两土层各盐分含量随植被盖度的梯变呈相对一致的变化趋势。在不同的环境条件下,以蒸腾作用、泌盐作用和根系的选择性吸收作用等为主的生物积盐作用与地下水蒸发聚盐以及地表风蚀强度等非生物因素之间的平衡关系,应该是影响绿洲沙漠过渡带柽柳灌丛沙堆盐岛效应强弱的关键因素。
Taking the transition zone of the western Cele Oasis in the southern Taklimakan Desert as the study area, four typical plots with vegetation coverage of 30%, 15% -20%, 10% and <5% ramosissima) were collected from 0-10 cm and 10-20 cm soil layers in a typical site of shrub sand-mound intercropping system to determine the effects of soil pH and total salts, Cl ~ -, Na ~ +, K ~ +, SO_4 ~ (2- ), Ca2 +, Mg2 +, CO3- and HCO3- in the desertification process of the transitional zone were discussed. The results showed that with the reduction of total vegetation cover, the soil pH value and total salt, Cl ~ -, K ~ +, Na + content in 0 ~ 10cm layer increased firstly and then decreased; soil SO2-4 and Ca ~ (2+) content decreased firstly and then increased; Mg 2+ content did not change obviously with the change of vegetation coverage. Under shrubs → edge of sand bank → inter-mound area → wind shadow area, total salt, Cl ~ -, K ~ +, Na ~ +, SO 4 2-, Ga 2+, Mg 2+ ) Content decreased first and then increased. The maximum values were all under the shrubs and the minimum values were located at the inter-mound site. The contents of pH and HCO_3 ~ - increased first and then decreased, and the minimum values were located in the shrubs , The maximum value is more in the intercostal space, there is a moderate correlation between the two (r = 0.644). Compared with 0 ~ 10cm soil layer, the contents of Cl ~ -, K ~ +, Na ~ + in 10 ~ 20cm total salt increased obviously while the content of SO_4 ~ (2 -), HCO_3 ~ Mg 2+ content and pH value did not change significantly. The soil salt content of the two soil layers showed a relatively consistent trend with the vegetation coverage. Under different environmental conditions, the balance between biosorption effects such as transpiration, salt secretion and selective root absorption is related to non-biological factors such as groundwater evaporation poly-salt and surface wind erosion intensity. Key Factors Affecting the Effect of Salt Island Effect in Tamarix Saplings of Oasis Desert Transitional Zone.