Traffic-related metal(loid) status and uptake by dominant plants growing naturally in roadside soils in the Tibetan plateau, China.
To understand traffic-related metal(loid) status and uptake by dominant plants growing naturally in roadside soils in the Tibetan plateau, China, aboveground parts and root samples of three dominant plant species (Kalidium slenderbranch, Stipa purpurea, Kobresia pygmaea) were collected along the Qinghai-Tibet highway, and were analyzed for concentrations of traffic-related metal(loid)s such as chromium (Cr), zinc (Zn), copper (Cu), cadmium (Cd), arsenic (As), and lead (Pb). The results indicated that concentrations of metal(loid)s in plant tissues varied greatly among plant species and sites. Tissue distribution of metal(loid)s was significantly related to distance and demonstrated variability as an exponential function of traffic proximity. It was deduced that Cd in Kalidium slenderbranch and Cu and Zn in S. purpurea were mainly derived from soil; Kalidium slenderbranch and Kobresia pygmaea absorbed Zn, and S. purpurea absorbed Cd, mainly through stomata, from atmospheric deposition; enrichments of Pb and As in S. purpurea presented similar characteristics to those of Cd and Pb in Kobresia pygmaea and were affected by both soil and atmospheric deposition. After excluding the effects of the traffic, the highest value obtained for metal(loid)-translocation capacity (7.51 for translocation factor, TF) was observed for S. purpurea collected from Tuotuohe, while the lowest value for metal(loid)-uptake capacity (0.015 for bioaccumulation factor, BF) was for Kalidium slenderbranch collected from Golmud. The three plant species showed limited soil-to-root transfer of metal(loid)s, possibly due to the high soil pH along the Qinghai-Tibet highway, but demonstrated great potential for metal(loid) transfer from roots to aboveground parts.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resource Research, Chinese Academy of Sciences, Beijing 100101, China; Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China.
Hua
H
Zhang
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resource Research, Chinese Academy of Sciences, Beijing 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China.
Yili
Y
Zhang
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resource Research, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: wangzf@igsnrr.ac.cn.
Zhaofeng
Z
Wang
Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China.
Mingjun
M
Ding
Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China.
Yinghui
Y
Jiang
Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang 330022, China.
Zhenglei
Z
Xie
D004784:Environmental Monitoring / Q000379:methods*; D058955:Metalloids / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D035261:Plant Components, Aerial / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*; D018609:Tibet; D001335:Vehicle Emissions / Q000032:analysis*
D058955:Metalloids; D019216:Metals, Heavy; D012989:Soil Pollutants; D001335:Vehicle Emissions
Distribution; Dominant plant; Qinghai–Tibet highway; Traffic-related metal(loid)s