The Relationship of the Soil Microbial and Enzymes Changes with Soil Nutrition Stoichiometry in Artificial Vegetation Restoration in Honghe Dry-Hot Valleys

PurposeThe relationship between soil chemical stoichiometry of nitrogen, phosphorus and potassium and soil microbial and enzymes in the artificial restoration of vegetation in Honghe dry-hot valley is explored. In order to provide theoretical basis and reference for the influence of different vegetation restoration patterns on soil characteristics in dry-hot valley.

MethodThe relationship between soil chemical properties, enzymes and microbial of two pure plantations, Schleichera oleosa and Cassia siamea, and savanna with Woodfordia fruticosa as the main vegetation types in Honghe dry-hot valley, was analyzed by field sample investigation and indoor control experiments.

Result There were significant differences in the contents of organic matter, total nitrogen, hydrolytic nitrogen, available phosphorus, available potassium, slow-acting potassium, protease, urease, bacteria and fungi between root system and non-root system soil of three communities (P<0.05), while there was no significant difference in the contents of actinomycetes between root system and non-root system soil of different vegetation communities (P>0.05). There was no significant difference in acid phosphatase content between three communities (P>0.05). The activity of root system soil was higher than that of non-root system soil in both artificial restoration vegetation communities and sparse shrubs and grasslands. Redundancy analysis (RDA) showed a positive correlation with bacteria, fungi and actinomycetes. Slow-acting potassium, available potassium and acid phosphatase were negatively correlated with only protease. The main factors driving community variation were slow-acting potassium, followed by available phosphorus, organic matter and acid phosphatase.

ConclusionThe community environment and soil physicochemical properties can be improved by artificial vegetation restoration in Honghe dry-hot valley, compared with the savanna community, the soil nutrients of artificial vegetation restoration can be utilized more efficiently and the quantity and structure of soil microbial community can be improved, which provides a basis for revealing the material cycle of the forest ecosystem in the dry-hot valley.