摘要
为探究近自然改造措施对热带雨林区土壤的修复机制,以海南热带雨林国家公园内4种典型人工林(马占相思林、杉木林、加勒比松林、桉树林)及天然次生林为研究对象,对比分析人工林对照样地及其近自然改造(环剥、择伐)对0—20cm和20—40cm土层土壤理化性质的影响。结果表明:(1)与天然次生林相比,马占相思林、加勒比松对照样地显著提高表层土壤全钾(TK)含量,但马占相思对照同时显著提高0—40cm土壤全磷、速效钾(AK)及TK含量(TK增幅9.8—11.9倍)。杉木对照样地显著提高各土层TK,但深层AK含量显著降低;桉树对照样地明显呈现土壤养分退化,pH降低的趋势。(2)相较于人工林对照,马占相思近自然改造深层TK含量显著增加,土壤机械组成(砂粒降低、粉粒增加)及深层大团聚体比例显著提高;杉木近自然改造显著提升深层土壤TK含量以及大团聚体质量占比;而桉树择伐则显著加剧了土壤酸化,且团聚体稳定性显著降低(平均重量直径降低55.8%)。(3)冗余分析表明,黏粒含量、碱解氮、有效磷是团聚体稳定性的核心驱动因素;大团聚体占比与团聚体稳定性呈极显著正相关。综上,马占相思林近自然改造、加勒比松林和杉木林对照样地均有助于改善土壤质量并趋向天然次生林状态;桉树林改造则伴随土壤酸化和钾素流失风险。研究结果为海南热带雨林国家公园人工林转型改造及可持续经营提供科学依据。
With the focus on four typical plantation forests(Acacia mangium,Chinese fir,Caribbean pine,and Eucalypt)and natural secondary forests within Hainan Tropical Rainforest National Park,this study investigates the restoration mechanisms of close⁃to⁃nature transformation measures on soil in tropical rainforest regions.A comparative analysis was conducted between control plots of plantation forests and their close⁃to⁃nature transformation plots(ring girdling and selective logging)to examine changes in soil physicochemical properties at 0—20 cm and 20—40 cm depths.The results indicate that:(1)Compared to natural secondary forests,surface soil total potassium(TK)content in the control plots of Acacia mangium and Caribbean pine was significantly higher.Specifically,the Acacia mangium control plot also showed significant increases in total phosphorus(TP),available potassium(AK),and TK content across 0—40 cm soil depth(with TK increasing by 9.8 to 11.9 times).In Chinese fir control plots,TK content was significantly elevated in all layers,while deep-layer AK content markedly decreased.Conversely,the Eucalyptus control plots exhibited clear signs of soil nutrient degradation and reduced pH levels.(2)Compared to the control plots,the close⁃to⁃nature transformation of Acacia mangium significantly increased deep-layer TK content,improved soil mechanical composition(evident by decreased sand and increased silt content),and significantly raised the proportion of large aggregates.For Chinese fir,close⁃to⁃nature transformation notably enhanced deep soil TK content and the mass proportion of large aggregates.However,selective logging in Eucalyptus plantations significantly accelerated soil acidification and decreased aggregate stability(with mean weight diameter reducing by 55.8%).(3)Redundancy analysis revealed that clay content,alkaline nitrogen(AN),and available phosphorus(AP)are major driving factors for aggregate stability.There is a highly significant positive correlation between the proportion of large aggregates and aggregate stability.In summary,the close⁃to⁃nature transformation of Acacia mangium,as well as the control plots of Caribbean pine and Chinese fir,contribute positively to soil quality improvement,aligning it more closely with the state of natural secondary forests.In contrast,the transformation of Eucalyptus poses risks of soil acidification and potassium loss.These findings provide scientific evidence for the transformation and sustainable management of plantation forests in Hainan Tropical Rainforest National Park.
作者
王小燕
王如
廖立国
雷金睿
张碧嘉
段左俊
黄士绮
吴彪
羊子科
WANG Xiaoyan;WANG Ru;LIAO Liguo;LEI Jinrui;ZHANG Bijia;DUAN Zuojun;HUANG Shiqi;WU Biao;YANG Zike(Hainan Academy of Forestry(Hainan Academy of Mangrove),Haikou 571100,China;Key Laboratory of Tropical Forestry Resources Monitoring and Application of Hainan Province,Hainan Academy of Forestry,Haikou 571100,China;Jianfengling Branch Bureau of Hainan Tropical Rain Forest National Park Service,Ledong 572542,China)
基金
海南省省属科研院所技术创新项目(KYYSLK2023-012)。
关键词
热带雨林
人工林
近自然改造
土壤理化性质
团聚体
tropicalrainforest
plantation
close-to-naturetransformation
soilphysicochemicalproperty
aggregate
