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Soil‐Quality Effects of Grassland Degradation and Restoration on the Qinghai‐Tibetan Plateau
Author(s) -
Dong S. K.,
Wen L.,
Li Y. Y.,
Wang X. X.,
Zhu L.,
Li X. Y.
Publication year - 2012
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2012.0092
Subject(s) - grassland , environmental science , soil fertility , grassland degradation , soil quality , vegetation (pathology) , soil biodiversity , soil carbon , agronomy , soil water , soil retrogression and degradation , soil organic matter , nutrient , soil science , ecology , biology , medicine , pathology
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.