【目的】了解粤西地区不同林分类型土壤重金属的含量特征及污染情况，为其生态风险评价提供理论依据。【方法】以粤西地区桉树Eucalyptus urophylla人工林、马尾松Pinus massoniana人工林、杉木Cunninghamia lanceolata人工林、相思Acacia spp.人工林和阔叶混交林5种林分类型为研究对象，分析不同林分0~20 cm土层土壤中Cu、Zn、Pb、Cd和Ni的含量，并采用单项污染指数(Pi)法、内梅罗综合污染指数(PN)法和Hakanson潜在生态风险指数(RI)法对各林分土壤重金属污染情况进行污染评价及潜在生态风险评价。【结果】各林分土壤重金属含量均以Zn最高，Cd最低，但均未超过广东省土壤背景值；土壤pH为3.62~6.42，呈酸性。马尾松人工林土壤中Cu质量分数(16.06 mg·kg–1)及桉树人工林土壤中Pb质量分数(12.37 mg·kg–1)均显著高于阔叶混交林土壤中相应重金属的质量分数(9.21和6.87 mg·kg–1)；人工林土壤重金属含量间的相关性显著。5种林分土壤重金属Pi均小于1，污染等级均为清洁；土壤重金属Pi及PN均表现为：马尾松人工林 > 杉木人工林 > 桉树人工林 > 相思人工林 > 阔叶混交林，除马尾松人工林外，其余林分的综合污染等级均为安全。单一及多种重金属的潜在生态风险评价结果均为轻微风险，单一重金属潜在生态风险系数(Ei)表现为Cd最大，Zn最小，多种重金属RI表现为马尾松人工林最高，阔叶混交林最低。【结论】Hakanson潜在生态风险指数法能更综合地反映土壤受重金属污染情况；本研究评价结果表明，防止和减少森林土壤中人为的重金属输入仍是一项需要长久坚持的必要举措。
【Objective】 To understand heavy metal content characteristics and pollution conditions in different forest soils in west Guangdong, and provide a theoretical basis for their ecology risk assessments.【Method】 Eucalyptus urophylla plantation, Pinus massoniana plantation, Cunninghamia lanceolata plantation, Acacia spp. plantation and broad-leaved mixed forest in West Guangdong were chosen to investigate heavy metal (Cu, Zn, Pb, Cd and Ni) contents in soil at the 0-20 cm depth. Single pollution index (Pi), Nemerow index (PN) and Hakanson potential ecological risk index (RI) methods were used to assess heavy metal pollution conditions and potential ecological risks in different forest soils.【Result】 Cd content was the lowest while Zn content was the highest in all studied forest soils, but they were all below soil background value of Guangdong Povince. The values of pH ranged from 3.62 to 6.42, presenting acidic. Both Cu content (16.06 mg·kg–1) in P. massoniana plantation soil and Pb content (12.37 mg·kg–1) in E. urophylla plantation soil were significantly higher than those in broad-leaved mixed forest soil (9.21 and 6.87 mg·kg–1). The correlations among five heavy metal contents in plantations were significant. All Pi values in five forests were lower than 1, indicating no contamination. Both Pi and PN ranks in five forests were as follows: P. massoniana plantation>C. lanceolata plantation>E. urophylla plantation>Acacia spp. plantation>broad-leaved mixed forest. Except P. massoniana plantation, the pollution levels of all other forests were safe. The potential ecological risk assessment results of single and multiple heavy metals were slight risk. The potential ecological risk coefficients (Ei) of single heavy metal showed that Cd had the highest value while Zn had the lowest value. The results of RI showed that P. massoniana forest had the highest value and broad-leaved mixed forest had the lowest value.【Conclusion】 The Ei method can more comprehensively reflect the soil heavy metal contamination. According to its assessment results, it is still a long-term and necessary measure to prevent and reduce heavy metal pollution caused by human.