Page 19 - 《广西植物》2024年第7期
P. 19
7 期 覃慧婷等: 近自然化改造对马尾松人工林土壤团聚体有机磷组分含量变化的影响 1 2 1 9
1 1 1 1 1
QIN Huiting ꎬ YAN Jinliu ꎬ HUANG Haimei ꎬ LI Jiajun ꎬ XIANG Mingzhu ꎬ
1 1ꎬ2 1 1ꎬ2∗
LI Changhang ꎬ HUANG Xueman ꎬ ZHAO Lijun ꎬ YOU Yeming
( 1. College of Forestryꎬ Guangxi Universityꎬ Guangxi Key Laboratory of Forest Ecology and Conservationꎬ Guangxi Colleges and Universities
Key Laboratory for Cultivation and Utilization of Subtropical Forest Plantationꎬ Nanning 530004ꎬ Chinaꎻ 2. Guangxi Youyiguan
Forest Ecosystem National Observation and Research Stationꎬ Youyiguan Forest Ecosystem Observation
and Research Station of Guangxiꎬ Pingxiang 532600ꎬ Guangxiꎬ China )
Abstract: Organic phosphorus (Po) is an important part of soil phosphorus reservoir. In order to investigate the effects
of soil aggregate Po distribution properties in Pinus massoniana plantations after close ̄to ̄nature transformationꎬ the pure
P. massoniana plantations ( PP ) and P. massoniana ̄broad ̄leaved mixed plantations ( CP ) after close ̄to ̄nature
transformation were investigated in southern subtropical China. Soil samples collected from 1-10 cm were screened into >
2 mmꎬ 0.25- 2 mm and < 0.25 mm three ̄part aggregates using the dry ̄sieving method. The Po fractionꎬ microbial
biomass phosphorus (MBP) content and acid phosphatase (ACP) activity in the bulk soil and aggregates were measured
to understand the distribution of the Po fraction and its drivers. The results were as follows: (1) Soil Po fractions
changed in CP compared to PPꎬ with highly recalcitrant organic phosphorus (HRO ̄P) and moderately labile organic
phosphorus (MLO ̄P) significantly greater in the bulk soil and soil aggregates than in PP (P< 0.05)ꎬ while labile
organic phosphorus (LO ̄P) and moderately recalcitrant organic phosphorus (MRO ̄P) were not significantly different in
CP and PP. In additionꎬ there was no consistent pattern of change in Po fractions in the bulk soil and soil aggregates
between PP and CP. (2) The size of the proportion of each form of Po in PP was HRO ̄P>MRO ̄P>MLO ̄P>LO ̄Pꎬ
while CP was HRO ̄P>MLO ̄P>MRO ̄P>LO ̄P. (3) The MBP content and ACP activity in CP were significantly greater
than that of PP in the bulk soil and soil aggregatesꎬ and there was a tendency for the ACP activity to increase with the
decrease in the size of aggregates. ( 4) Redundancy analysis revealed that soil available phosphorus ( AP )ꎬ soil
aggregate mean weight diameter (MWD)ꎬ MBP and total nitrogen (TN) were the main drivers of soil Po fractions. In
conclusionꎬ the close ̄to ̄nature transformation is beneficial to the accumulation and transformation of soil phosphorus in
P. massoniana plantation. This study provides a theoretical reference for the improvement of soil quality and productivity
in P. massoniana plantations.
Key words: Pinus massoniana plantationsꎬ soil aggregatesꎬ organic phosphorus fractionsꎬ close ̄to ̄nature
transformationꎬ subtropics
土壤磷是植物生长与土壤发生的关键元素ꎬ 磷的生物有效性取决于植物吸收的无机磷和作为
在生 物 地 球 化 学 循 环 过 程 中 发 挥 着 重 要 作 用 土壤可溶性磷库的有机磷含量ꎬ磷组分的测定对
(Vitousek et al.ꎬ 2010ꎻ Costa et al.ꎬ 2016)ꎮ 土壤 于判 断 土 壤 磷 的 有 效 性 至 关 重 要 ( Redel et al.ꎬ
磷的有效性在大多数陆地生态系统中普遍较低ꎬ 2008ꎻ Williams et al.ꎬ 2013)ꎮ 在 森 林 生 态 系 统
许多陆地生 态 系 统 往 往 受 到 磷 限 制 ( Vitousek et 中ꎬ有机磷来源于有机质的输入( 如凋落叶)、微生
al.ꎬ 2010)ꎮ 在 土 壤 高 度 风 化 的 热 带、 亚 热 带 地 物生物量和土壤有机磷库( Vincent et al.ꎬ 2010)ꎬ
区ꎬ土壤中许多可利用性磷和土壤粘粒、铁铝氧化 可占总磷的 20% ~ 80%( Dalaiꎬ 1977)ꎮ 矿化后的
物等粒 子 结 合 紧 密ꎬ 导 致 植 物 难 以 吸 收 和 利 用 有机磷可作为植物和微生物可利用的磷源ꎬ尤其
(Fan et al.ꎬ 2019)ꎬ并且特殊的雨热同期气候导致 是在热带和亚热带等高度风化的土壤中( Vincent
土壤磷更易被淋溶从而加剧对植物生长的限制作 et al.ꎬ 2010)ꎮ 然而ꎬ长期以来并没有直接的方法
用ꎮ 因此ꎬ土壤对磷的固持能力以及土壤磷有效 量化土壤中的有机磷ꎬ或由于分析上的局限性ꎬ对
性的增加有利于改善人工林土壤质量、提高土地 有机磷的研究少于无机磷( Turner et al.ꎬ 2005)ꎮ
生产力ꎬ最大化地促进生态服务功能ꎮ 生物介导的磷转化ꎬ如胞外磷酸酶引起的磷矿化ꎬ
土壤中的磷以无机磷和有机磷的形式存在ꎮ 对植 物 获 得 磷 尤 其 重 要 ( Liu et al.ꎬ 2021 )ꎮ