Characteristics of soil phosphorus fractions under different thinning intensities in Larix principis-rupprechtii plantation and the affecting factors.
מילות מפתח
תַקצִיר
Thinning is an important plantation management strategy. Phosphorus (P) is one of the limiting nutrients in forest ecosystems. The impacts of thinning on soil P remain unclear. In this study, we investigated the characteristics of soil P fractions in topsoil (0-10 cm) of Larix principis-rupprechtii plantation in Taiyue Mountain, Shanxi Province under different thinning intensity (control, CK, 0%; low thinning, LT, 15%; moderate thinning, MT, 35%; high thinning, HT, 50%) and the affecting factors. The soil P fractions were measured using Tissen modified Hedley P fractionation method. The results showed that the total inorganic P content in soil was significantly higher in stands subjected to moderate thinning than in control. The soil acid phosphatase activity (APA) and the contents of Resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and microbial biomass phosphorus (MBP) were significantly increased in LT and MT compared with CK, but the content of NaOH-Po showed an opposite trend. Thinning had no significant effect on soil total P, total organic P, non-available P and residual-P. Soil moisture, organic matter, MBP and APA were the important factors affecting soil P availability. Our results demonstrated that MT could enhance soil P availability in Larix principis-rupprechtii plantation.