【摘要】 为了解旱区荒漠生物结皮的养分效应及其同植被灌丛间的关系,研究以毛乌素沙地广泛分布的苔藓、藻结皮为对象,选取4类典型植被样地,深入探讨了植被对生物结皮及其下伏土壤的养分分布的影响。结果表明:(1)沙蒿植被冠层下的藻结皮及其下伏土壤的全氮、全磷、有机质含量显著高于植被冠层间,沙柳、柠条群落则为植被冠层下的相应值显著低于植被冠层间(p<0.05)。(2)沙蒿、沙柳、柠条3种群落的生物结皮及下伏土壤养分含量均随土层加深逐渐降低,而草地则表现为5—10 cm土层的土壤养分显著高于上层土壤;苔藓结皮的全氮、有机质表现为:柠条>草地>沙柳>沙蒿,苔藓结皮的全磷以及藻结皮的养分含量均表现为:草地>柠条>沙蒿>沙柳。(3)总体上,各类型植被下的苔藓及藻结皮均能够显著增加表层0—10 cm土壤的养分含量,且苔藓结皮的养分富集作用优于藻结皮。更多还原

【Abstract】 In order to understand the nutrient effect of desert soil biocrusts and its relationship with shrub vegetation, this study focused on moss and algal crusts widely distributing in the Mu Us Sandland. Typical plots of four types of vegetation were selected and the effects of vegetation types on the distribution of nutrients of biocrusts and underlying soil were discussed in detail. The results showed that:(1) nutrients in algae crusts and underlying soil under the canopy of Artemisia ordosica were higher than those between the canopy, the corresponding values under the canopy of the Salix and Caragana communities were significantly lower than those between the canopies of the vegetation types(p<0.05);(2) soil nutrients in biocrusts of Salix psammophila, Artemisia ordosica and Caragana gradually decreased as soil depth increased, it indicated that soil nutrients in 5—10 cm soil were significantly higher than that in upper soil in grassland; the distribution of total nitrogen and organic matter in moss crust decreased in the order: Caragana korshinskii>grassland>Salix>Artemisia, the total phosphorus content of mossy crust and the nutrient content of algae crust decreased in the order: grassland>Caragana>Artemisia annua>Salix;(3) moss and algae crusts of each vegetation could significantly increase the nutrient contents in the 0—10 cm soil layer, and the nutrient enrichment of moss crusts was better than those of algae crusts.更多还原