Jian Zunji, Zeng Lixiong, Lei Lei, Liu Changfu, Shen Yafei, Zhang Jiajia, Xiao Wenfa, Li Mai-He
Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China.
Front Plant Sci. 2024 Jun 25;15:1416852. doi: 10.3389/fpls.2024.1416852. eCollection 2024.
Forest management changes the physical environments and nutrient dynamics and then regulates the forest productivity. Soil phosphorus (P) availability is critical for productivity in tropical and subtropical forests. However, it was still poorly understood how soil P content and fraction respond to various forest management practices in these regions. Here, we measured the soil total P, available P, and Hedley's P fractions, including inorganic and organic P (Pi and Po), in subtropical pine plantations treated with understory removal (UR), non-dominant species thinning (NDST) and dominant species thinning (DST) after nine years. Compared to plantations without management (CK), treatments such as UR, NDST, and DST decreased soil total P at 0-10 cm and soil available P at 0-10 cm and 10-20 cm. Increases in resin-Pi, NaOH-Pi, and C.HCl-Pi resulted in a higher total Pi in 0-10 cm ( < 0.05) in treated plots (UR, NDST, and DST) than in CK plots. UR, NDST, and DST treatments increased NaHCO-Po and NaOH-Po ( < 0.05) but decreased C.HCl-Po at a depth of 0-10 cm. Regardless of management treatments, soil total P, available P, and P fractions in 0-10 cm showed higher contents than those in 10-20 cm. There were positive relationships between total P and total Po ( < 0.01) and between available P and total Pi. There were also positive relationships between total P, available P, NaHCO-Pi, and NaOH-Pi ( < 0.05). In conclusion, forest management such as UR, NDST, and DST decreased soil total P and available P, and transforming soil P fractions to available P will meet the P demand following management in the pine plantations of subtropical China.
森林管理改变了物理环境和养分动态，进而调节森林生产力。土壤磷（P）有效性对于热带和亚热带森林的生产力至关重要。然而，这些地区土壤磷含量和组分如何响应各种森林管理措施仍知之甚少。在此，我们测定了亚热带松树林地在进行林下清除（UR）、非优势树种疏伐（NDST）和优势树种疏伐（DST）九年后的土壤总磷、有效磷以及Hedley磷组分，包括无机磷和有机磷（Pi和Po）。与未进行管理的林地（CK）相比，UR、NDST和DST等处理降低了0 - 10厘米土层的土壤总磷以及0 - 10厘米和10 - 20厘米土层的土壤有效磷。处理地块（UR、NDST和DST）中树脂态磷、氢氧化钠提取态磷和盐酸提取态磷的增加导致0 - 10厘米土层的总无机磷含量高于CK地块（P < 0.05）。UR、NDST和DST处理增加了0 - 10厘米土层的碳酸氢钠提取态有机磷和氢氧化钠提取态有机磷（P < 0.05），但降低了盐酸提取态有机磷。无论管理措施如何，0 - 10厘米土层的土壤总磷、有效磷和磷组分含量均高于10 - 20厘米土层。总磷与总有机磷之间存在正相关关系（P < 0.01），有效磷与总无机磷之间也存在正相关关系。总磷、有效磷、碳酸氢钠提取态无机磷和氢氧化钠提取态无机磷之间也存在正相关关系（P < 0.05）。总之，UR、NDST和DST等森林管理措施降低了土壤总磷和有效磷，在中国亚热带松树林地管理后，将土壤磷组分转化为有效磷能够满足磷需求。
