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为了解不同植被覆盖对沙地土壤生物结皮及其下层土壤的影响,于2006年调查了科尔沁沙地冷蒿、小红柳、杨树和樟子松等植被封育区土壤生物结皮及结皮下0～5cm土壤的理化特性.结果表明:经过15年的封育保护和植被建设,科尔沁沙地天然植被和人工植被下流动沙地大部分被生物结皮所覆盖,其结皮覆盖度可达60%～80%,厚度1～2cm;在调查的几种植被中,小红柳植被区的土壤结皮厚度、硬度、粘粉粒、有机质和养分含量最高,其次是樟子松林地,杨树林地和冷蒿植被区相对较差;几种植被区的苔藓结皮的结皮厚度、硬度、粘粉粒、有机质和养分含量均优于地衣结皮;与流动沙地相比,结皮下0～5cm土壤的理化特性有明显改善,改善程度苔藓结皮强于地衣结皮,小红柳和樟子松植被区强于杨树林地和冷蒿群丛;土壤结皮及结皮下表土理化特性的变化既受植被覆盖类型的影响,也受制于土壤结皮的发育.由于枝叶繁茂的中、高植被有利于降风滞尘和产生较多的凋落物,因而更能促进沙地结皮发育和土壤改良,而苔藓结皮较地衣结皮更有利于其下层土壤理化特性的改善.
In order to understand the effect of different vegetation cover on the soil biological crusts and the underlying soils of sandy soils, soil crusts and crusts in the enclosing areas of Artemisia frigida, Castanopsis titumen and Pinus sylvestris var. Mongolica in Horqin sandy land were investigated in 2006 ~ 5cm soil.The results showed that after 15 years of enclosure protection and vegetation construction, the natural vegetation in Horqin Sandy Land and the mobile sandy land under artificial vegetation were mostly covered by biological crusts with the crust coverage of up to 60 % ~ 80% and 1 ~ 2 cm in thickness. Among the surveyed vegetation, the thickness, hardness, sticky grain, organic matter and nutrient content of soil crust in the Tamarix erectus vegetation area were the highest, followed by Pinus sylvestris var. Mongolica, poplar woodland And the Artemisia frigida community were relatively poor. The crust thickness, hardness, sticky grain, organic matter and nutrient content of moss crust in several vegetation areas were better than that of lichen crust. Compared with the mobile sandy land, The physical and chemical properties of 5 cm soil were significantly improved. The improvement degree of moss crust was stronger than that of lichen crust. The vegetation area of Castanopsis nephrolepis and Pinus sylvestris var. Mongolica was stronger than that of poplar woodland and Artemisia frigida. The changes of physicochemical properties of soil surface and crust Both affected by the type of vegetation cover, Subject to the development of soil crust.Due to the lush foliage and medium and high vegetation is conducive to wind and dust and produce more litter, which can promote the development of sand crust and soil improvement, and moss crust more than lichens Skin is more conducive to the improvement of physical and chemical properties of the underlying soil.