Soil-Quality Effects of Grassland Degradation and Restoration on the Qinghai-Tibetan Plateau
Soil-Quality Effects of Grassland Degradation and Restoration on the Qinghai-Tibetan Plateau
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DOI：
10.2136/sssaj2012.0092
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发表时间：
2012-11-01
影响因子：
2.9
通讯作者：
Li, X. Y.
中科院分区：
文献类型：
--
作者：
Dong, S. K.;Wen, L.;Li, X. Y.
在中国的青藏高原，高山草原及其生长的土壤正在退化，以期为不断增长的全球人口增加食物和饲料产量。我们的目标是利用土壤质量评价来量化3个深度增量(0~4、4~10、10~20 cm)土壤理化性质的变化，从而确定土壤与植被变化之间的联系、限制高寒地区草地恢复的土壤元素(S)以及通过重建草地恢复土壤肥力的能力。对中度退化草地(MDG)、重度退化草地(HDG)和重度退化草地(SDG)以及不同年限的恢复草地(5年恢复草地、7年恢复草地和9年恢复草地)的土壤和植被进行了比较研究。结果表明：(1)随着植被盖度的降低，土壤持水能力降低，土壤硬度增加；(2)土壤有机碳(OC)和全氮(TN)降低，土壤全钾含量增加；(3)人工草地的建立不能恢复退化草地土壤质量和养分储量；(4)不同深度土壤性质随草地退化程度的变化有显著的年际变化。土壤理化参数的显著变化可能归因于表层土壤的流失以及植被组成和土壤质地的变化。土壤质量可以用来评价高寒地区草地退化和恢复情况。总之，要恢复青藏高原退化的高寒草地，需要更好的土壤管理。
Alpine grassland and the soil on which it is growing in the Qinghai-Tibetan Plateau (QTP) of China is being degraded in an attempt to increase food and feed production for an increasing global population. Our objective was to use soil quality assessment to quantify changes in soil chemical and physical properties at three depth increments (0 to 4, 4 to 10, and 10 to 20 cm) and thus determine the linkages between soil and vegetation changes, the soil element(s) limiting grassland restoration in alpine region, and the ability to restore soil fertility by reestablishing grasslands. The soil and vegetation were sampled in the different types of degraded grasslands, that is, moderately degraded grassland (MDG), heavily degraded grassland (HDG) and severely degraded grassland (SDG) as well as in the reestablished grasslands at different ages, that is, 5-yr restored grassland (5yRG), 7-yr restored grassland (7yRG), and 9-yr restored grassland (9yRG) for comparative study. The results show: (i) decreased water holding capacity and increased soil hardness as vegetative cover declined, (ii) decreased soil organic carbon (OC) and total nitrogen (TN) and increased total soil potassium, (TK) (iii) the establishment of artificial grassland did not restore soil quality or nutrient stocks within degraded grassland soils, and (iv) yearly variations in soil properties at different depths were significant along the degree of grassland degradation. Significant variations of soil physical and chemical parameters might be attributed to loss of the top soil and changes of vegetation composition and soil and textures. Soil quality can be used to assess grassland degradation and restoration in the alpine region. In conclusion, better soil management is needed for restoring the degraded alpine grasslands on the QTP.