青藏高原高寒草地土壤磷含量对围栏管理的响应

Effect of fence management on soil phosphorus content in the Alpine grassland in Qinghai-Xizang Plateau

围栏是一种广泛使用的草地管理措施。磷是植物生长发育不可或缺的营养元素,研究围栏管理对土壤磷含量的影响和驱动,对高寒草地生态系统修复和适应性管理具有重要意义。然而,目前缺乏系统的围栏管理对土壤磷含量的影响研究。本文基于Web of Science核心数据库和中国知网(CNKI)检索平台,筛选了101篇文献开展Meta分析,探究不同高寒草地土壤全磷(STP)与速效磷(SAP)含量对围栏管理措施及围栏年限(短期1~4年,中期5~8年和长期9~30年)的响应。结果表明:1)总体而言,围栏显著提升了STP、SAP、全氮(STN)、有机碳(SOC)、速效氮(SAN)和含水量(SM)(P<0.001),却导致了pH和容重显著降低(P<0.01)。2)围栏对高寒草原STP和SAP的正效应显著高于其对高寒草甸磷含量的影响(P<0.001)。3)针对围栏年限,发现中长期围栏对草甸STP具有极显著的正效应(P<0.001),同时短期围栏能够极显著促进草原STP(P<0.001),中长期围栏则会导致草原STP降低;围栏始终有利于提升SAP,且中期围栏对草原SAP的效应最大。4)围栏管理下STP、STN和SOC的效应值存在协同变化规律,且围栏对STP的效应值随气温的升高而显著增加,但土壤pH的降低促进了围栏对STP的效应值的显著增加。此外,围栏对STN与SAP的效应值呈显著正相关关系。本研究揭示了合理的围栏管理有利于提高高寒草地生态系统的土壤磷含量,结果可为高寒草地管理提供理论参考。

Fences are widely used in grassland management practices,and phosphorus is an essential nutrient for plant growth.It is crucial to investigate the impact and drivers of fence placement on soil phosphorus cycling to evaluate the dynamics of phosphorus in alpine grassland ecosystems.Moreover,there is a lack of systematic research on fence management and soil phosphorus content.To bridge this knowledge gap,101 articles were selected for a meta-analysis,based on the Web of Science core database and the China Knowledge Network search platform,to explore the responses of soil total phosphorus(STP)and soil available phosphorus(SAP)in different alpine grasslands to fence management measures and fencing years(short-term 1~4 years,medium-term 5~8 years,and long-term 9~30 years).The results showed that:1)Generally,fencing significantly increased STP,SAP,total nitrogen(STN),organic carbon(SOC),available nitrogen(SAN),and moisture(SM)levels(P<0.001)but decreased pH and bulk density(P<0.01).2)The positive effect of fencing on STP and SAP in the alpine steppe was significantly higher than that on phosphorus content in the alpine meadow(P<0.001).3)According to the years of fencing,medium-term and long-term fencing exerted a significant positive effect on STP(P<0.001),short-term fencing significantly promoted steppe STP,and medium-term and long-term fencing resulted in a decrease in steppe STP.Fencing helped to improve SAP,and medium term exerted the greatest effect of fencing on steppe SAP.4)The effects of fencing on STP,STN,and SOC varied synergistically.However,soil acidification significantly increased the effect of fencing on STP.The effect of fencing on STP increased significantly with an increase in temperature.In addition,the effects of fencing on SAP and STN were significantly correlated.Our study revealed that reasonable fencing improves soil phosphorus content in alpine grassland ecosystems,and the results provide a theoretical reference for the scientific management of alpine grasslands.