Page 49 - 《广西植物》2023年第2期
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2 期            陈荣枢等: 漓江流域海拔、土壤及植被对土壤养分和酶化学计量比的影响                                            2 4 3

            ( 1. Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protectionꎬ Ministry of Educationꎬ Guangxi Normal Universityꎬ
                  Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 2. College of Environment and Resourcesꎬ Guangxi Normal Universityꎬ Guilin 541006ꎬ Guangxiꎬ
                            Chinaꎻ 3. College of Life Sciencesꎬ Guangxi Normal Universityꎬ Guilin 541006ꎬ Guangxiꎬ China )


                 Abstract: The Lijiang River Basin covers great variation in altitudeꎬ soil and vegetation types. In order to study the
                 characteristics of its soil nutrients and enzymes activitiesꎬ we determined soil nutrient contents and activities of several
                 extracellular enzymes (amylaseꎬ sucroseꎬ ureaseꎬ protease and catalase) of the surface soils (0- 20 cm) of typical
                 vegetation types [natural forestꎬ bamboo (Phyllostachys edulis) forestꎬ Pinus massoniana forestꎬ orchard and rice paddy
                 field] with calcareous soils and acid soils in the Lijiang River Basin. The results were as follows: (1) The soils at high
                 altitude had greater total nitrogen (TN)ꎬ total phosphorus (TP)ꎬ available phosphorus (AP) contents as well as
                 amylaseꎬ sucroseꎬ urease and protease activitiesꎬ whereas the catalase activity was to the contrary. (2) Compared with
                 the acid soilsꎬ the calcareous soils had higher contents of total phosphorus (TP) and available phosphorus (AP). Among
                 the acid soilsꎬ vegetation types had greater impact on soil nitrogen and phosphorus contents. In generalꎬ anthropogenic
                 vegetation resulted in decrease of nitrogen content and increases of phosphorus contentꎻ while the nutrients in the
                 calcareous soils had relatively little variation among different vegetation types. (3) Compared with the natural forest
                 soilsꎬ soils from the anthropogenic vegetation had lower nitrogen related enzyme activitiesꎻ whereas the carbon related
                 enzyme activities was less impacted. The enzymatic stoichiometry revealed that soils of natural forests were nitrogen
                 limited whereas those of anthropogenic vegetation was carbon limited. (4) The results of canonical correspondence
                 analysis ( CCA) showed that soil physiochemical properties in the first and second axes explained 86. 56% of the
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                 variation of soil enzyme activities with the contribution order of TN>pH>NH >AP>TP>NO ꎬ with the first three as the
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                 main impacts. All the above results indicate that acid soils in the Lijiang River Basin have great ecological sensitivitiesꎻ
                 vegetation changes easily result in nutrient imbalanceꎬ thereforeꎬ in order to improve the sustainable utility of landscape
                 resources of the Lijiang River Basinꎬ special attention should be paid to the conservation of soil nutrients and prevention
                 of the loss of soil organic matter. This study provides theoretical base for the scientific conservation and development of
                 local ecosystem.
                 Key words: limestone soilꎬ acid soilꎬ vegetation typeꎬ enzyme activitiesꎬ stoichiometryꎬ the Lijiang River Basin




                土壤酶是土壤中最活跃的组分之一ꎬ主要来                            物化学过程ꎬ从而影响土壤养分和植被类型的分布
            源于动植物、微生物的分泌及残体等ꎮ 土壤酶通                             (Gastonꎬ 2000ꎻ Fierer et al.ꎬ 2013)并导致土壤酶活
            过催化复杂含碳、氮和磷有机化合物的矿化和水                              性的巨大差异ꎮ Margesin 等(2014)对阿尔卑斯山脉
            解等一系列生物化学过程ꎬ促进土壤有机物的分                              研究发现土壤酶活性随着海拔的升高而降低ꎬZuo
            解(Burns et al.ꎬ 2013)ꎬ其活性大小能灵敏地反映                  等(2018)对新疆山脉的研究结果则与其相反ꎮ 而

            土壤生物化学过程的方向和强度( 曹慧等ꎬ 2003ꎻ                         李聪等(2020) 对滇东南典型常绿阔叶林土壤酶的
            Yang et al.ꎬ 2020)ꎮ 植被类型改变所引起的生态                   研究发现ꎬ土壤过氧化氢酶、脲酶和蔗糖酶的活性
            系统特 征 的 变 化ꎬ 如 植 被 群 落 特 征 和 发 育 阶 段               随海拔的升高而增加ꎬ而土壤酸性磷酸酶活性则呈
            ( Feng et al.ꎬ 2019ꎻ 王玉琴等ꎬ 2019)、土壤生物群             现先下降后上升的趋势ꎮ 这表明不同地区或气候
            落的组成(Lauber et al.ꎬ 2013)、土壤水热条件( 杨                带下海拔梯度影响土壤酶活性的关键作用因子有
            曦等ꎬ 2009)等ꎬ对土壤的理化性质产生综合性的                          很大差异ꎬ需要对不同地区进行针对性的研究ꎮ
            影响(Stock et al.ꎬ 2019)ꎬ如土壤 pH、土壤养分及                    土壤酶化学计量比可以反映微生物对养分的

            其化 学 计 量 特 征 ( Zhao et al.ꎬ 2018ꎻ 田 静 等ꎬ           需求与土壤养分限制之间的生物地球化学平衡模
            2019ꎻ 林红玲等ꎬ 2021)和土壤温湿度(江淼华等ꎬ                      式(Hill et al.ꎬ 2012ꎻ 张星星等ꎬ 2018)ꎬ全球尺度
            2018)等ꎬ从而直接或间接地影响土壤酶活性( 段                          上土壤酶化学计量比为 1 ∶ 1 ∶ 1ꎬ在区域尺度上ꎬ
            春燕等ꎬ 2020ꎻ 邵文哲等ꎬ 2022)ꎮ                            土壤微生物活性受到土壤养分影响ꎬ其实际值将
                 不同海拔间温度、湿度的差异强烈影响土壤生                          会偏离 ( Zhao et al.ꎬ 2018ꎻ Zhang et al.ꎬ 2019)ꎮ
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