中文摘要：

红树林生态系统的重金属污染是滨海湿地研究的重要课题之一。为揭示中国红树林天然分布北缘区（福建省福鼎市）秋茄红树林生态系统中重金属空间分布与污染情况，采用样地取样与内业实验相结合的方法，比较分析了我国红树林天然分布北缘区（福建省福鼎市）不同起源（天然林和人工林）秋茄红树林湿地沉积物重金属（Zn、Pb、Cd、Cu）元素水平和垂直空间分布特征. 结果表明：（1）天然林湿地沉积物对重金属的吸收富集能力高于人工林，天然林和人工林均有较高的Zn、Pb含量，Cd、Cu含量相对较低；（2）从水平分布上看，4种重金属元素含量在天然林和人工林湿地沉积物中水平变化规律各异，但在林内深处均有明显下降. 林缘或林缘附近4种重金属含量普遍存在显著性差异（P＜0.05），不同起源秋茄林内均存在明显的边缘效应. （3）天然林和人工林中林内湿地沉积物中4种重金属含量垂直分布总体呈现随着深度增加而减小的规律，其中Cd最为明显，Cu次之，Zn和Pb变化则平缓中有波动. 4种重金属元素在湿地沉积物30-60 cm深度处含量普遍存在明显波动现象，推测该深度区间可能对重金属的积累起着特殊作用. （4）林内（林内15 m、林内50 m）重金属含量与土壤沉积物理化性状的相关性明显高于林外光滩. 因此，红树林天然分布北缘地区天然秋茄林生态系统对重金属的吸附能力高于秋茄人工林生态系统，不同起源（天然林和人工林）秋茄林湿地沉积物重金属含量水平和垂直空间分布规律一致.

英文摘要：

For a comprehensive understanding of spatial distribution for heavy metals of Kandelia candel ecosystem in the north marginal region of natural mangrove wetlands, horizontal and vertical spatial distribution characteristics of contents of heavy metals （Zn, Pb, Cd, and Cu） were analyzed for mangrove sediments of different origins （plantation and natural forest）. The absorption for heavy metals in natural forest was stronger than in plantation. In both plantation and natural forest, Zn and Pb had high contents, while Cd and Cu had low contents. Though the horizontal distribution of contents of the 4 types of heavy metals varied differently between the plantation and natural forest, there was a uniform declining trend in both for all 4 types deep in the forest. The contents of all 4 heavy metals showed significant differences at or near the forest edge. An edge effect existed generally between natural forest and plantation. With increase of the depth, the contents of the four heavy metals firstly increased and then decreased, especially for Cd and Cu. The distinct fluctuation in the depth of 30-60 cm suggested a special mechanism of heavy metal accumulation there. Correlations between the physiochemical properties of sediments and contents of heavy metals in 15 m and 50 m inside-forest were much higher than those in 100 m outside-forest, suggesting a stronger absorption for heavy metals by natural Kandelia candel forest than plantation in the north marginal region of natural mangrove wetlands. However, the distribution law of mangrove sediments was the same in horizontal and vertical spaces regardless of the origin.