基于^(13)C脉冲标记法探究种植密度对侧柏幼苗生长及光合碳分配的影响  

Effect of planting density on photosynthetic carbon distribution of Platycladus orientalis seedlings based on ^(13)C pulse labeling method

作　　者：孔玉华[1] 朱庆征 曲安然 朱龙飞 杨小燕 KONG Yuhua;ZHU Qingzheng;QU Anran;ZHU Longfei;YANG Xiaoyan(College of Forestry,Henan Agricultural University,Zhengzhou 450002,China;China Construction Seventh Bureau Building Decoration Engineering Co.,Ltd,Zhengzhou 450000,China)

机构地区：[1]河南农业大学林学院,河南郑州450002 [2]中建七局建筑装饰工程有限公司,河南郑州450000

出　　处：《甘肃农业大学学报》2022年第1期131-138,共8页Journal of Gansu Agricultural University

基　　金：国家自然科学基金项目(41501331)。

摘　　要：【目的】通过盆栽试验定量研究侧柏光合碳在地上部分、地下部分及土壤中的分配规律,探索人工林生态系统中植物-土壤的碳周转情况。【方法】以树龄1 a的侧柏幼苗为研究对象,设置3个种植密度水平(低密:1株/盆,中密:3株/盆,高密:5株/盆),两个处理(^(13)C脉冲标记处理和未标记处理),采集地上部分、地下部分及根际土壤样品,对比分析植株生物量、^(13)C、全碳(TC)和全氮(TN)含量以及根际土壤理化性质的变化。【结果】随种植密度的提高,侧柏幼苗地上部分生物量、地下部分生物量和总生物量均呈递增的趋势,高种植密度显著提高了根际土壤溶解性有机碳和硝态氮的含量(P<0.05)。3个种植密度下植物-土壤系统各组分固定的^(13)C含量均表现为地上部分>地下部分>根际土壤(P<0.05)。种植密度显著影响了光合^(13)C含量在各组分的分配比例,且随种植密度的提高,分配在地上部分的比例呈递增趋势,变化范围为61.95%~64.92%;分配在地下部分的比例呈递减趋势,变化范围为38.04%~35.07%;而分配在土壤中的比例无显著差异(0.01%~0.02%)。【结论】种植密度显著影响侧柏幼苗的生长及光合碳在地上部分、地下部分和土壤中的分配比例,高密度种植提高了植株及土壤的碳固定,但也可能造成了种间竞争作用,使光合碳优先分配在植株的地上部分,而减少了向地下部分的转运。【Objective】To study the distribution of photosynthetic carbon in aboveground,underground and soil of Platycladus orientalis,and to explore the carbon turnover of plant-soil in the artificial forest ecosystem.【Method】Through the simulation experiment of pot planting,one-year-old seedlings of P.orientalis were selected as research objects.3 kinds of planting density levels(low density,1 plant/pot;medium density,3 plants/pot;high density,5 plants/pot)and 2 treatments(^(13)C pulse mark and unmarked group)were set up.Aboveground and underground of the seedlings as well as rhizosphere soil samples were collected.The biomass,^(13)C,total carbon(TC)and nitrogen(TN)contents of each tissue part of the seedling,as well as the root morphological indexes and the physicochemical properties of the rhizosphere soil were determined.【Result】With the increase of planting density,the aboveground and underground biomass of P.orientalis seedlings all showed an increasing trend,but did not reach a significant level.High planting density significantly increased soil dissolved organic carbon and nitrate nitrogen contents(P<0.05).The fixed^(13)C content of each component of the plant-soil system under the 3 planting densities was all tended as follows:aboveground>underground>rhizosphere soil.The planting density changed the distribution ratio of photosynthetic^(13)C content in each component.With the increase of planting density,the proportion of its distribution in aboveground showed an increasing trend,and the range of variation was 61.95%~64.92%.While it showed a decreasing trend in underground ranged by 38.04%~35.07%.There is no significant difference in soil,ranged by 0.01%~0.02%.【Conclusion】Planting density was significantly affected the growth and the distribution ratio of photosynthetic carbon of P.orientalis seedlings.High density of planting increased the TC sequestration in plants and soil,but may leaded to interspecific competition,which promoted the preferential distribution of photosynthetic carbon to the abo

关 键 词：^(13)C脉冲标记 种植密度 侧柏幼苗 光合碳分配 碳周转 

分 类 号：Q945[生物学—植物学] S714[农业科学—林学]