民勤西沙窝自然植被与土壤肥力性状相关分析

甘肃民勤西沙窝属阿拉善地块南缘凹陷带,自然植被稀疏,植物种类贫乏,组成以灌木、小灌木为主的荒漠植被,该荒漠植被可以分为4个植被型,10个群系组,19个群系。植物群落对土壤理化性状及土壤养分转化的影响都很显著。苦豆子+芦苇群落,胡杨林和盐爪爪+红砂群落,植物体吸收营养元素量和土壤肥力呈强反相关,r=-0.9986,y=5.376-0.785x;白刺群落、红柳群落和沙蒿+沙米群落的土壤母质都是流沙,植物体吸收营养元素量和土壤肥力呈强正相关,r=0.7556,y=1.0706+0.7059x,白刺对氮素的吸收量,土壤中累积的全氮量,0～30厘米土层氮元素矿化率以及磷、钙、钾、镁元素分别较红砂、沙蒿要高0.63～2.70倍。

The Correlation Analyses Between the Natural Vegetation and Soil Fertility in Western Sandland of Minqin

The western sandland in Minqin County is within the hollow belt of the southern Arasan region. The sparse natural vegetation and a few plant species show desert vegetation form consisting of the shrub and small shrub. All vegetation are divided into 4 vegetation forms, 10 formation groups and 19 formations. Plant community has a great influence upon the physicochemical properties of soil and nutrient inversion. Foxtail-like Sophora (Sophora alopecuroides)+Common Reed (Phragmites communis) community, Diversifolious Poplar (Populus diversifolia ) community, Slenderbranch Kalidium (Kalidium gracile)+Songory Reaumuria (Reaumuria soongrica) community show inverse correlation between the nutrient absorption and soil fertility, r=-0.9986, y=5.376-0.785x. Siberian Nitrarian (Nitraria sibirica) community, Branchy Tamarisk (Tamarix ramosissima) community and Roundhead Wormwood (Artemisia sphaerocephala)+Squarrose Agriophyllure (Agriophyllum squarrosura) community are distributed on the fluid sand dune, so the positive correlation is presented between the nutrient absorption and soil fertility, r=0.7556, y=1.07506+0.7059x, The nitrogen absorption amount, the total nitrogen mineralizing rate in 0～30 cm soil horizon and phosphorus, calcium, potassium, magnesium content of the Nitraria community are about 0.63～2.70 times higher than those of Songory Reaumuria and Roundhead wormwood community.