Changes in soil properties with vegetation types in highland grassland of the Loess Plateau, China

Abstract

The response of soil properties to vegetation types is still not well understood and the relationship between vegetation types and soil properties has not been quantified in highland grasslands. A field experiment was conducted in highland grassland of the Loess Plateau in China to study the distribution of soil properties under different vegetation. 22 plant communities totaling 17 species that belong to 8 families were selected and root zone soil samples were collected to measure soil properties. The ability of vegetation to influence soil properties was vegetation type and soil property dependent. Generally, cation exchange capacity, soil organic carbon, labile organic carbon, total nitrogen, alkaline phosphatase, and invertase showed similar distribution trends with vegetation types and were higher in soils under Lilaceae, Leguminosae, Gramineae, Compositae, Solanaceae and Chenopodiaceae than those under Labiatae and Rosaceae. Also, total phosphorus, inorganic, and available phosphorus were higher in soils under Lilaceae, Leguminosae, Solanaceae and Chenopodiaceae than under Gramineae, Labiatae and Rosaceae. Catalase activity was not significantly influenced by vegetation type. Statistical analysis suggested that soil organic carbon has significant direct and indirect influences on soil properties and that the combination of soil organic carbon, total phosphorus, and alkaline phosphatase could be used to represent physico-chemical, nutritional and biological properties under different vegetation. Our results highlighted the role of soil organic carbon in the relationship between vegetation and soil properties and indicated the potential of Leguminosae and Lilaceae to improve soil properties and of Labiatae and Rosaceae to degrade soil properties in highland grassland of the Loess Plateau.

Key words: Soil enzymes, nutrients, organic carbon, vegetation types, root zone soils.