摘要
【目的】通过植物与生物炭联合应用修复土壤镉污染,探究在模拟镉污染土壤中施加不同比例生物炭后北方常见树种栓皮栎和白蜡幼苗的生长生理状况和土壤镉吸附效果差异,为阐明树木对镉污染的响应机制以及提升镉污染治理能力提供参考。【方法】将栓皮栎和白蜡的实生苗在模拟镉污染土壤中进行盆栽试验,向土壤中施加不同比例(0%、2.5%、5%、10%)的生物炭,观察幼树生长、光合及抗氧化生理活性、镉在土壤和苗木中的迁移差异,分析栓皮栎和白蜡的镉吸附效果及生物炭修复作用。【结果】1)5 mg·L^(-1)的镉污染导致:栓皮栎、白蜡土壤pH值分别显著降低10.8%和11.7%;栓皮栎苗木的苗高、地径、生物量分别降低18.5%、15.1%及38.9%;白蜡苗木的苗高和生物量分别提高3.9%和12.6%,但地径降低10.1%;2个树种幼苗的叶片净光合速率、蒸腾速率、气孔导度受到抑制;栓皮栎叶片抗氧化酶活性降低,而白蜡叶片抗氧化酶活性有所提高。2)施加生物炭后,土壤酸性得到改善,土壤镉含量显著降低,可缓解苗木胁迫状态,但生物炭施加比例提高至10%时,苗木生长与生理指标下降。3)栓皮栎和白蜡苗木对土壤中镉的吸附表现不同,白蜡有更高的富集系数,而栓皮栎有更高的转运系数。【结论】施加生物炭比例为2.5%时,植物对土壤中镉的吸附效果最好,土壤中镉含量最低;施加生物炭比例为5%时,能有效提高镉污染下的苗木生长状况,保障苗木稳定生长;白蜡的镉耐受性比栓皮栎高,苗木吸附镉的能力也更强。
【Objective】Through the combined application of plants and biochar to repair soil cadmium pollution,the growth and physiological status of seedlings of two common northern tree species,Quercus variabilis and Fraxinus chinensis,and the differences in soil cadmium adsorption effects were explored after adding different proportions of biochar to simulated cadmium-contaminated soil.【Method】A potted experiment was conducted on Q.variabilis and F.chinensis seedlings grown in simulated cadmium-contaminated soil.Different proportions of biochar(0%,2.5%,5%,and 10%)were added to the soil.The differences in seedling growth and physiological traits such as photosynthesis and antioxidant activities,as well as cadmium migration in the soil and seedlings were observed.The cadmium adsorption effects of Q.variabilis and F.chinensis and the remediation effects of biochar were analyzed.【Result】1)Cadmium contamination at 5 mg·L^(−1) significantly decreased soil pH of Q.variabilis and F.chinensis by 10.8%and 11.7%,respectively.The height,ground diameter,and biomass of Q.variabilis seedlings decreased by 18.5%,15.1%,and 38.9%,respectively.The height and biomass of F.chinensis seedlings increased by 3.9%and 12.6%,respectively,but the ground diameter decreased by 10.1%.The net photosynthetic rate,transpiration rate,and stomatal conductance of leaves of both tree species were inhibited.Antioxidant enzyme activities in Q.variabilis leaves decreased,while those in F.chinensis increased.2)Biochar applications increased soil acidity and significantly reduced soil cadmium content,alleviating seedling stress.However,when the biochar application rate was increased to 10%,the growth and physiological indicators of seedlings decreased.3)Q.variabilis and F.chinensis seedlings exhibited different cadmium adsorption behaviors in soil,with F.chinensis having a higher enrichment coefficient and Q.variabilis having a higher transport coefficient.【Conclusion】When the biochar application ratio is 2.5%,the plants have the best adsorption effect on cadmium in the soil and the cadmium content in the soil is the lowest;when the biochar application ratio is 5%,it can effectively improve the growth of seedlings under cadmium pollution and ensure the stable growth of seedlings.The cadmium tolerance of F.chinensis is higher than that of Q.variabilis,and the seedlings have a stronger ability to adsorb cadmium.
作者
郑志伟
马铭
刘勇
王佳茜
朱雨帆
李国雷
Zheng Zhiwei;Ma Ming;Liu Yong;Wang Jiaxi;Zhu Yufan;Li Guolei(College of Forestry,Beijing Forestry University,Oak Research Center,Beijing Forestry University,Beijing 100083;Academy of Agricultural Planning and Engineering,Ministry of Agriculture and Rural Affairs,Beijing 100125)
出处
《林业科学》
北大核心
2025年第11期14-23,共10页
Scientia Silvae Sinicae
基金
国家自然科学基金项目(32171764)。
关键词
栓皮栎
白蜡
镉污染
生物炭修复
Quercus variabilis
Fraxinus chinensis
cadmium contamination
biochar remediation
