The field survey method based on typical points was used to conduct the sampling of soil,air and leaves of 28 tree species along three transects (100,600 and 1 200 m away from pollution source separately) in chemical zone of northern Jiaxing and non-polluted area (8 000 m away from pollution source) to analyze the horizontal variation of sulfur (S) and fluorine (F) contents within Soil-Plant-Atmosphere Continuum (SPAC) in this area.The results showed that soil S mass fraction decreased with increasing horizontal distance while soil F mass fraction increased firstly and then decreased.The S mass fraction reached the highest level in topsoil while F mass fraction came to the maximum at 20 cm depth profile.Meanwhile leaf S concentrations for arbor,small arbor and shrub decreased with increasing horizontal distance,but F concentrations increased firstly and then decreased.Moreover leaf S concentrations for the arbor were higher than that of small arbors and shrubs on each transect,while leaf F concentrations were comparatively close to each other.Particularly horizontal variations of leaf S and F concentrations of the shrub were both greater than that for arbors and small arbors.And the peak of SO2 concentration appeared at the 100 m's transect and continued to decrease with increasing horizontal distance,but HF appeared at the 600 m's transect,which showed different horizontal variation characteristics.Through correlation analysis on S and F contents among soil,tree leaves and air it illustrated that the SO2 and HF in air might be the main source of soil S and F while litters contributed secondarily.Overall,the horizontal variation characteristics of S and F within SPAC were basically synchronous in the test area,and the three media jointly regulated the dynamic balance of S and F within SPAC system The deeper understandings on horizontal variation characteristics of S and F contents within SPAC system is helpful to better control S and F pollution in urban industrial areas,and to take corresponding soil and plant remediation measures to create a much more beautiful urban ecological environment for residents.%采用典型设点调查法对嘉兴市北部化工区污染源正西方向上3条样带(分别距污染源100、600和1 200 m)和无污染区(距污染源8 000 m)的土壤、28种绿化树种叶片和空气进行取样分析,以明确该区域土壤-植物-大气连续体(SPAC)硫、氟含量在水平方向上的变异特征.结果表明:土壤硫质量分数随水平距离增加而减少,而土壤氟质量分数先增加后减少;表层土壤硫质量分数最高(0.036％),而20 cm深处土壤氟质量分数最高(35.7 mg·kg-1).乔木、小乔木和灌木叶片硫浓度均随水平距离增加而降低,但叶片氟浓度先增加后降低;各样带上乔木叶片硫浓度均高于小乔木和灌木,而氟浓度则比较接近,灌木叶片硫、氟浓度在水平方向上的变异均大于乔木和小乔木.空气中SO2质量浓度峰值(0.176 mg·m-3)出现在100m样带上,随水平距离增加而持续减小,但HF质量浓度的峰值(1.487 μg·m-3)出现在600m样带上,二者浓度呈现不同的水平变异特征.对土壤、树木叶片和空气硫、氟含量的相关性分析表明:空气中的SO2和HF可能是土壤中的硫和氟的主要来源,凋落物的贡献次之.总体上,研究区SPAC系统硫、氟含量水平变异特征是统一的,3种介质通过相互作用共同调节SPAC系统硫、氟的动态平衡.对于SPAC系统硫、氟含量水平变异特征的认识有利于更好地控制城市工业区硫、氟污染,采取相应的土壤和植物修复措施,营造更加美好的城市生态人居环境.
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