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生态学杂志 ›› 2023, Vol. 42 ›› Issue (12): 2828-2835.doi: 10.13292/j.1000-4890.202312.005

• 重金属污染与修复专栏 • 上一篇    下一篇

中亚热带4种类型森林叶片非生物重金属元素重吸收及累积动态

彭清清1,张耀艺1,张慧玲1,彭艳1,2,倪祥银1,2,吴福忠1,2*


  

  1. 1福建师范大学湿润亚热带生态-地理过程教育部重点实验室, 福州 350007; 2福建三明森林生态系统国家野外科学观测研究站, 福建三明 365002)

  • 出版日期:2023-12-10 发布日期:2024-06-10

The resorption and accumulation of abiotic heavy metal elements in leaves from four types of forests in mid-subtropical China.

PENG Qingqing1, ZHANG Yaoyi1, ZHANG Huiling1, PENG Yan1,2, NI Xiangyin1,2, WU Fuzhong1,2*#br#

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  1. (1The Key Laboratory of Humid Subtropical Eco-Geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China; 2Fujian Sanming Forest Ecosystem National Field Scientific Observation and Research Station, Sanming 365002, Fujian, China).

  • Online:2023-12-10 Published:2024-06-10

摘要: 非生物重金属元素的累积可能会对植物生长发育产生不利影响,但林木叶片在衰老过程中是否对这些重金属元素具有重吸收作用尚不清楚。因此,选择中亚热带以米槠为建群种的天然林和次生林以及米槠人工林和杉木人工林4种不同类型森林为研究对象,在一个生长季(4—10月)同步分析林木成熟叶片和新鲜凋落叶片铬(Cr)、镉(Cd)和铅(Pb)的含量变化,探讨不同森林叶片非生物重金属元素的重吸收和累积规律。结果表明: 4种森林叶片表现出对3种非生物重金属元素明显的选择性重吸收作用,其重吸收率受森林类型、元素和时间的显著影响。天然林在4月和7—10月对Cr元素重吸收(4月重吸收率最高,达67.8%),在4月和6月对Cd元素重吸收,仅在4月对Pb元素重吸收,其余月份表现出累积特征。次生林在4月(最高达62.5%)、5月和10月对Cr元素重吸收,在4月和10月对Cd和Pb元素重吸收,其余月份表现出累积特征。米槠人工林在整个生长季节中Cr元素均在衰老叶中累积,在8月和9月对Cd元素重吸收,在4月、7—8月和10月对Pb元素重吸收,其余月份表现出累积特征。杉木人工林在4月和10月对Cr元素重吸收,整个生长季节Cd元素均在衰老叶中累积,在10月对Pb元素重吸收,其余月份表现出累积特征。总体来看,天然林和次生林对Cr和Cd元素的重吸收显著高于人工林,而对Pb元素的重吸收特征表现相反。另外,在4种类型森林中,Cr与Pb元素在新老叶片中的变化动态呈显著正相关,并随降水的增加而增加,随气温升高而降低,但Cd与Cr和Pb元素呈显著负相关。这些结果表明,相对于人工林,米槠天然林和次生林对含量较高的Pb元素具有较好的避害能力,为区域森林营建和可持续经营提供了理论依据。


关键词: 重金属, 人工林, 天然林, 重吸收率, 成熟叶片, 衰老叶片

Abstract: The accumulation of abiotic heavy metal elements may adversely affect plant growth. However, whether forest leaves resorb these heavy metals during senescence is not fully understood. We analyzed the changes of chromium (Cr), cadmium (Cd), and plumbum (Pb) contents in mature and senescent leaves during the growing season (from April to October) to elucidate resorption or accumulation efficiency of heavy metals in four types of mid-subtropical forests. The results showed obvious leaf resorption of Cr, Cd and Pb in four types of forests, although the resorption efficiency significantly varied across forest types, elements, and sampling months. The Castanopsis carlesii natural forest displayed Cr resorption in April and from July to October with the highest resorption rate of 67.8% in April, and Cd resorption in April and June, but Pb resorption only in October, while the elements showed accumulation in senescent leaves in other months. In contrast, the C. carlesii secondary forest displayed Cr resorption in April (the highest resorption rate of 62.5%), May, and October; it also showed Cd and Pb resorption in April and October, but the elements exhibited accumulation in senescent leaves in other months. Cr was accumulated in senescent leaves throughout the growing season in C. carlesii plantation, although Cd was resorbed in August and September, and Pb was resorbed in April, from July to August and October. Moreover, Cunning hamia lanceolata plantation showed Cr resorption in April and October, and Pb resorption in October, but Cd was accumulated in senescent leaves throughout the growing season. The resorptions of Cr and Cd were significantly higher in natural and secondary forests than those in plantations, while Pb showed an opposite pattern. In addition, the dynamics of Cr and Pb in mature and senescent leaves were significantly positively correlated with precipitation and negatively with temperature in four types of forests, whereas the changes of Cd were negatively correlated with the Cr and Pb. These results indicated that the natural and secondary forests are more efficient in avoiding Pb toxicity than plantations, which provides a new insight for forest establishment and sustainable management.


Key words: heavy metal, plantation forest, natural forest, resorption efficiency, mature leaf, senescent leaf.