西南喀斯特区域不同植被恢复阶段土壤磷主要来源及其季节变化  

Main sources of soil phosphorus and their seasonal changes across different vegetation restoration stages in karst region of southwest China

作　　者：刘家齐 梁燕 肖凡 韩依晴 胡传星 韦柳红 段敏 LIU Jiaqi;LIANG Yan;XIAO Fan;HAN Yiqing;HU Chuanxing;WEI Liuhong;DUAN Min(Ministry of Education Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection,Guangxi Normal University,Guilin 541006,Guangxi,China;Guangxi Key Laboratory of Landscape Resources Conservation and Sustainable Utilization in Lijiang River Basin,Guilin 54i006,Guangxi,China;Library of Guangxi Normal University,Guilin 541006,Guangxi,China)

机构地区：[1]广西师范大学珍稀濒危动植物生态与环境保护教育部重点实验室,广西桂林541006 [2]广西漓江流域景观资源保育与可持续利用重点实验室,广西桂林541006 [3]广西师范大学图书馆,广西桂林541006

出　　处：《应用生态学报》2023年第12期3313-3321,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42067023);广西漓江流域景观资源保育与可持续利用重点实验室主任基金(LRCSU21Z0208);广西研究生教育创新计划项目(YCSW2023129);自治区级大学生创新创业训练计划项目(S202210602030)资助。

摘　　要：探究西南喀斯特区域不同植被恢复阶段土壤磷主要来源及其季节变化特征,有助于深入认识喀斯特区域植被恢复过程中土壤磷循环过程,为该区域石漠化治理提供科学参考。本研究以广西桂林典型喀斯特区域处于不同植被恢复阶段的生态系统为对象,设置植被恢复10年(R10)、30年(R30)和50年(R50)3个处理,开展为期1年的野外试验。在试验期间根据降水情况采集雨水,每个季节采集土壤、新鲜凋落物和植物根系样品,测定雨水全磷(TP)、土壤TP和速效磷(AP)含量以及新鲜凋落物和植物根系TP含量,结合现存凋落物磷储量和微生物生物量磷(MBP),分析不同磷来源对土壤磷输入的差异。结果表明:土壤TP含量随植被恢复时间先增加后降低,随季节变化表现为秋季>夏季>春季>冬季;土壤AP含量在所有处理中均较低,并且夏、冬季含量高于春、秋季;土壤MBP随植被恢复时间呈增加趋势,随季节变化表现为春季>秋季>夏季>冬季。雨水全年磷输入量为0.78 kg·hm^(-2),春季高于其他3个季节之和。R10、R30和R50处理新鲜凋落物全年磷输入量分别为2.42、10.64和5.03 kg·hm^(-2),现存凋落物磷储量分别为1.23、5.32和3.45 kg·hm^(-2),植物根系全年磷输入量分别为5.18、12.65、5.96 kg·hm^(-2),均表现为R30处理最高。相关性分析表明,土壤TP含量与植物根系磷输入量呈显著正相关,而土壤AP含量与雨水磷输入量呈显著负相关。综上,西南喀斯特区域不同植被恢复阶段不同来源磷输入对土壤磷库的贡献存在差异,植物根系是土壤磷的主要来源,其次为凋落物,通过磷湿沉降进入到土壤中的磷素非常有限,土壤微生物对土壤磷库也有一定贡献。Investigating the main sources of soil phosphorus and their seasonal variations across different vegetation restoration stages in karst region of southwest China can deepen our understanding of soil phosphorus cycling during vegetation restoration, and provide scientific reference for the controlling of rocky desertification. Taking the typical karst ecosystems at different vegetation restoration stages in Guilin, Guangxi as the research objects, we conducted a one-year field experiment with three treatments: vegetation restoration for about 10 years(R10), 30 years(R30) and 50 years(R50). We collected rainfall based on precipitation frequency, as well as soil, fresh litter and root samples in each season to measure the concentrations of total phosphorus(TP) in rainfall, the contents of TP and available phosphorus(AP) in soil, and the contents of TP in fresh litter and roots. In combination with litter phosphorus storage and soil microbial biomass phosphorus(MBP), we analyzed the contributions of phosphorus input to soil from different phosphorus sources. The results showed that soil TP content increased initially and then decreased with vegetation restoration, with a seasonal pattern of autumn > summer > spring > winter. Soil AP content was low in all treatments, with higher levels in summer and winter than in spring and autumn. Soil MBP content increased with vegetation restoration, with a seasonal variation pattern of spring >autumn > summer > winter. The annual phosphorus input from rainfall was 0.78 kg·hm^(-2) with the highest value in spring. The annual phosphorus input from fresh litter in the R10, R30, and R50 treatments was 2.42, 10.64 and 5.03 kg·hm^(-2). Phosphorus storage in litter was 1.23, 5.32 and 3.45 kg·hm^(-2). The annual phosphorus input from plant roots was 5.18, 12.65, and 5.96 kg·hm^(-2), respectively. The highest levels of the above parameters always occurred in the R30 treatment. There was a significant positive correlation between soil TP content and plant root phosphorus input, and a

关 键 词：喀斯特区域 植被恢复 土壤磷来源 雨水-凋落物-根系-土壤 微生物生物量磷 

分 类 号：S153.6[农业科学—土壤学]