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Liu X, Wang X, Wang D. Assessment of tree-ring mercury radial translocation and age effect in Masson pine: Implications for historical atmospheric mercury reconstruction. J Environ Sci (China) 2024; 138:266-276. [PMID: 38135394 DOI: 10.1016/j.jes.2022.10.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/13/2022] [Accepted: 10/16/2022] [Indexed: 12/24/2023]
Abstract
The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury (Hg) trends, but with the large knowledge gaps in the reliability. In this study, we comprehensively evaluated the Hg source, radial translocation and age effect of Masson pine (Pinus massoniana) tree ring at Mt. Jinyun in Chongqing, to assess the suitability of such tree ring as the archive of atmospheric Hg. Results showed that distinct variabilities among Masson pine tree-ring Hg concentration profiles. The Hg concentration significantly increased along with stem height (P < 0.05), indicating the Hg in tree rings mainly derived from foliage uptake atmospheric Hg. We found a distinct age effect that the tree ring of young trees had the higher Hg concentration. Besides, we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree rings. The modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in Chongqing. We finally suggest that in further Hg dendrochemistry, better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.
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Affiliation(s)
- Xu Liu
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Xun Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing 400715, China.
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2
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Yin M, Mi J, Wang X, Xing C, Wan X, Zhang F, Yang H, He F, Hu H, Chen L. Interspecific variations in growth, physiology and Cd accumulation between Populus deltoides and P. × canadensis in response to Cd pollution under two soil types. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 271:115951. [PMID: 38211512 DOI: 10.1016/j.ecoenv.2024.115951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 01/13/2024]
Abstract
Both acid and alkaline purple soils in China are increasingly affected by Cd contamination. The selection of fast-growing trees suitable for remediating different soil types is urgent, yet there is a severe lack of relevant knowledge. In this study, we conducted a controlled pot experiment to compare the growth, physiology, and Cd accumulation efficiency of two widely recognized poplar species, namely Populus deltoides and P. × canadensis, under Cd contamination (1 mg kg-1) in acid and alkaline purple soils. The objective was to determine which poplar species is best suited for remediating different soil types. Our findings are as follows: (1) the total biomass of both poplars remained largely unaffected by Cd pollution in both soil types. Notably, under Cd pollution, the total biomass of P. deltoides in acid purple soil was 1.53 times greater than that in alkaline purple soil. (2) Cd pollution did not significantly induce oxidative damage in the leaves of either poplar species in both soil types. However, in acid purple soil, Cd contamination led to a 21% increase in NO3- concentration and a 44% increase in NH4+ concentration in P. × canadensis leaves, whereas in alkaline purple soil, it led to a 59% increase in NH4+ concentration in P. deltoides leaves. (3) Cd concentrations in all root orders of P. × canadensis were significantly higher than those in P. deltoides, especially in the first three root orders, under alkaline purple soil. The total Cd accumulation by P. × canadensis in Cd-polluted alkaline purple soil was 2.18 times higher than that in Cd-polluted acid purple soil, a difference not observed in P. deltoides. (4) redundancy analysis indicated that the sequestration effect of higher soil organic matter on Cd availability in acid purple soil was more pronounced than the release effects caused by lower pH. In conclusion, P. × canadensis is better suited for remediating alkaline purple soil due to its higher capacity for Cd uptake, while P. deltoides is more suitable for remediating Cd-contaminated acid purple soil due to its better growth conditions and greater Cd enrichment capability.
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Affiliation(s)
- Man Yin
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Jiaxuan Mi
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Xue Wang
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Cailan Xing
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China
| | - Xueqin Wan
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu 611130, China
| | - Fan Zhang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu 611130, China
| | - Hanbo Yang
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu 611130, China
| | - Fang He
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu 611130, China
| | - Hongling Hu
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu 611130, China
| | - Lianghua Chen
- College of Forestry, Sichuan Agricultural University, Chengdu 611130, China; National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu 611130, China.
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Chu Z, Zhou Y, Liu M, Lin H, Cheng M, Xie H, Yuan L, Zhang Z, Zhang Q, Li C, Chen Y, Guo Y, Chen L, Wang X. Large-Scale Observations Support Aboveground Vegetation as an Important Biological Mercury Sink in the Tibetan Plateau. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17278-17290. [PMID: 37919873 DOI: 10.1021/acs.est.3c05164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Mercury, a pervasive global pollutant, primarily enters the atmosphere through human activities and legacy emissions from the land and oceans. A significant portion of this mercury subsequently settles on land through vegetation uptake. Characterizing mercury storage and distribution within vegetation is essential for comprehending regional and global mercury cycles. We conducted an unprecedented large-scale aboveground vegetation mercury survey across the expansive Tibetan Plateau. We find that mosses (31.1 ± 0.5 ng/g) and cushion plants (15.2 ± 0.7 ng/g) outstood high mercury concentrations. Despite exceptionally low anthropogenic mercury emissions, mercury concentrations of all biomes exceeded at least one-third of their respective global averages. While acknowledging the role of plant physiological factors, statistical models emphasize the predominant impact of atmospheric mercury on driving variations in mercury concentrations. Our estimations indicate that aboveground vegetation on the plateau accumulates 32-12+21 Mg (interquartile range) mercury. Forests occupy the highest biomass and store 82% of mercury, while mosses, representing only 3% of the biomass, disproportionally contribute 13% to mercury storage and account for 43% (2.5-1.4+3.0 Mg/year) of annual mercury assimilation by vegetation. Additionally, our study underscores that extrapolating aboveground vegetation mercury storage from lower-altitude regions to the Tibetan Plateau can lead to substantial overestimation, inspiring further exploration in alpine ecosystems worldwide.
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Affiliation(s)
- Zhaohan Chu
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yunzhuo Zhou
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Maodian Liu
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
- School of the Environment, Yale University, New Haven, Connecticut 06511, United States
| | - Huiming Lin
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Menghan Cheng
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Han Xie
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Liuliang Yuan
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Zhihao Zhang
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Qianru Zhang
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Chengcheng Li
- Modern Chinese Literature, Department of Chinese Language and Literature, Peking University, Beijing 100871, China
| | - Yuang Chen
- Institute for Data, Systems, and Society, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Yanpei Guo
- Institute of Ecology, Key Laboratory for Earth Surface Processes and College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Long Chen
- Key Laboratory of Geographic Information Science, Ministry of Education, East China Normal University, Shanghai 200241, China
| | - Xuejun Wang
- Ministry of Education Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
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Zeng S, Li X, Yang L, Wang D. Understanding heavy metal distribution in timberline vegetations: A case from the Gongga Mountain, eastern Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162523. [PMID: 36870262 DOI: 10.1016/j.scitotenv.2023.162523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 02/24/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
To quantify impacts of vegetation and topographic factors on heavy metal accumulation in montane forests, we assessed the spatial distribution and determined the sources of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu) and zinc (Zn) in timberline forests of Gongga Mountain. Our results show that vegetation type has little impact on the soil Hg, Cd and Pb concentrations. The soil concentrations of Cr, Cu and Zn are controlled by litter return, moss and lichen biomass, and canopy interception, with the highest concentrations in shrub forest. In contrast to other forests, the soil Hg pool in coniferous forest is significantly high due to the elevated Hg concentration and greater biomass production in litter. However, the soil pool sizes of Cd, Cr, Cu and Zn show a distinct increase along the elevation, which are attributed to the elevated heavy metal inputs from litter and moss, as well as the greater cloud water-induced atmospheric heavy metal depositions. The highest Hg concentrations of the aboveground parts of plant are in the foliage and bark, while the concentrations of Cd, Pb, Cr, Cu and Zn in the branch and bark are the highest. The decreased biomass density leads to a downward trend in the total vegetation pool sizes of Hg, Cd, Pb, Cr, Cu and Zn by 0.4-4.4 times with increasing elevation. The statistical analysis finally suggests that Hg, Cd and Pb mainly originate from anthropogenic atmospheric deposition, whereas Cr, Cu and Zn are mainly from natural sources. Our results highlight the importance of vegetation types and terrain conditions on distribution patterns of heavy metal in alpine forests.
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Affiliation(s)
- Shufang Zeng
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Xianming Li
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Luhan Yang
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing 400715, China; Interdisciplinary Research Centre for Agriculture Green Development in Yangtze River Basin, Department of Environmental Sciences and Engineering, Southwest University, Chongqing 400716, China.
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5
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Shi X, Wang S, He W, Wang Y. Lead accumulation and biochemical responses in Rhus chinensis Mill to the addition of organic acids in lead contaminated soils. RSC Adv 2023; 13:4211-4221. [PMID: 36760272 PMCID: PMC9892687 DOI: 10.1039/d2ra07466d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
Adding organic acid is an effective approach to assist phytoremediation. The effects of organic acids on phytoremediation efficiency are unknown in Rhus chinensis. This study aimed to evaluate the effect of citric acid (CA) and oxalic acid (OA) on the lead phytoremediation potential of R. chinensis with significantly inhibited growth in Pb-contaminated soil. The experimental pot culture study evaluated the long-term physiological response and metal accumulation patterns of R. chinensis grown in varying Pb-treated soil, and examined the effects of 0.5 and 1.0 mmol L-1 CA and OA on the growth, oxidative stress, antioxidant system, and Pb subcellular distribution of R. chinensis grown in pots with 1000 mg kg-1 Pb. Compared with the control, the biomass, leaf area, root morphological parameters, and chlorophyll concentration of R. chinensis decreased, whereas the carotenoid, malondialdehyde, H2O2, and O2˙- concentrations, and superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activity increased under Pb stress. A copious amount of Pb was taken up and mainly stored in the cell walls of the roots. The application of CA and OA increased plant growth. The highest shoots and roots biomass increase recorded was 44.4 and 61.2% in 1.0 mmol L-1 OA and 0.5 mmol L-1 CA treatment, respectively. The presence of CA and OA increased SOD, POD, and CAT activities and decreased the H2O2, O2˙- and malondialdehyde content. A concentration of 0.5 mmol L-1 CA significantly increased the Pb concentration in the organs. The other organic acid treatments changed root Pb concentrations slightly while increasing shoot Pb concentrations. The translocation factor values from organic acid treatments were increased by 38.8-134.1%. Our results confirmed that organic acid could alleviate the toxicity of stunted R. chinensis and improve phytoremediation efficiency.
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Affiliation(s)
- Xiang Shi
- Research Institute of Subtropical Forestry, Key Laboratory of Tree Breeding of Zhejiang Province, Chinese Academy of Forestry Hangzhou 311400 China
| | - Shufeng Wang
- Research Institute of Subtropical Forestry, Key Laboratory of Tree Breeding of Zhejiang Province, Chinese Academy of Forestry Hangzhou 311400 China
| | - Wenxiang He
- Research Institute of Subtropical Forestry, Key Laboratory of Tree Breeding of Zhejiang Province, Chinese Academy of Forestry Hangzhou 311400 China .,State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University Hangzhou 311300 China
| | - Yangdong Wang
- Research Institute of Subtropical Forestry, Key Laboratory of Tree Breeding of Zhejiang Province, Chinese Academy of Forestry Hangzhou 311400 China
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6
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Ghosh S, Othmani A, Malloum A, Ke Christ O, Onyeaka H, AlKafaas SS, Nnaji ND, Bornman C, Al-Sharify ZT, Ahmadi S, Dehghani MH, Mubarak NM, Tyagi I, Karri RR, Koduru JR, Suhas. Removal of mercury from industrial effluents by adsorption and advanced oxidation processes: A comprehensive review. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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8
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Yuan W, Wang X, Lin CJ, Wu F, Luo K, Zhang H, Lu Z, Feng X. Mercury Uptake, Accumulation, and Translocation in Roots of Subtropical Forest: Implications of Global Mercury Budget. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:14154-14165. [PMID: 36150175 DOI: 10.1021/acs.est.2c04217] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Plant roots are responsible for transporting large quantities of nutrients in forest ecosystems and yet are frequently overlooked in global assessments of Hg cycling budgets. In this study, we systematically determined the distribution of total Hg mass and its stable isotopic signatures in a subtropical evergreen forest to elucidate sources of Hg in plant root tissues and the associated translocation mechanisms. Hg stored in roots and its isotopic signatures show significant correlations to those found in surrounding soil at various soil depths. The odd mass-independent fractionation (MIF) of root Hg at a shallow soil depth displays a -0.10‰ to -0.50‰ negative transition compared to the values in aboveground woody biomass. The evidence suggests that root Hg is predominantly derived from surrounding soil, rather than translocation of atmospheric uptake via aboveground tissues. The cortex has a more negative mass-dependent fractionation (MDF) of -0.10‰ to -1.20‰ compared to the soil samples, indicating a preferential uptake of lighter isotopes by roots. The similar MDF and odd-MIF signals found in root components imply limited Hg transport in roots. This work highlights that Hg stored in plant roots is not a significant sink of atmospheric Hg. The heterogeneous distribution of Hg mass in roots of various sizes represents a significant uncertainty of current estimates of Hg pool size in forest ecosystems.
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Affiliation(s)
- Wei Yuan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Xun Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Che-Jen Lin
- Center for Advances in Water and Air Quality, Lamar University, Beaumont, Texas 77710, United States
| | - Fei Wu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kang Luo
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Hui Zhang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Zhiyun Lu
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China
| | - Xinbin Feng
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
- Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an 710061, China
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Zeng S, Wang X, Yuan W, Luo J, Wang D. Mercury accumulation and dynamics in montane forests along an elevation gradient in Southwest China. J Environ Sci (China) 2022; 119:1-10. [PMID: 35934454 DOI: 10.1016/j.jes.2021.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 10/06/2021] [Accepted: 10/11/2021] [Indexed: 06/15/2023]
Abstract
Understanding atmospheric mercury (Hg) accumulation in remote montane forests is critical to assess the Hg ecological risk to wildlife and human health. To quantify impacts of vegetation, climatic and topographic factors on Hg accumulation in montane forests, we assessed the Hg distribution and stoichiometric relations among Hg, carbon (C), and nitrogen (N) in four forest types along the elevation of Mt. Gongga. Our results show that Hg concentration in plant tissues follows the descending order of litter > leaf, bark > root > branch > bole wood, indicating the importance of atmospheric Hg uptake by foliage for Hg accumulation in plants. The foliar Hg/C (from 237.0 ± 171.4 to 56.8 ± 27.7 µg/kg) and Hg/N (from 7.5 ± 3.9 to 2.5 ± 1.2 mg/kg) both decrease along the elevation. These elevation gradients are caused by the heterogeneity of vegetation uptake of atmospheric Hg and the variation of atmospheric Hg° concentrations at different altitudes. Organic soil Hg accumulation is controlled by forest types, topographic and climatic factors, with the highest concentration in the mixed forest (244.9 ± 55.7 µg/kg) and the lowest value in the alpine forest (151.9 ± 44.5 µg/kg). Further analysis suggests that soil Hg is positively correlated to C (r2 = 0.66) and N (r2 = 0.57), and Hg/C and Hg/N both increase with the soil depth. These stoichiometric relations highlight the combined effects from environmental and climatic factors which mediating legacy Hg accumulation and selective Hg absorption during processes of organic soil mineralization.
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Affiliation(s)
- Shufang Zeng
- College of Resources and Environment, Southwest University, Chongqing 400715, China
| | - Xun Wang
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Wei Yuan
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Ji Luo
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences & Ministry of Water Conservancy, Chengdu 610041, China
| | - Dingyong Wang
- College of Resources and Environment, Southwest University, Chongqing 400715, China.
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Cao C, Yang Y, Kwan MP, Ma ZB, Karthikeyan R, Wang JJ, Chen H. Crop selection reduces potential heavy metal(loid)s health risk in wastewater contaminated agricultural soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:152502. [PMID: 34995610 DOI: 10.1016/j.scitotenv.2021.152502] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 11/25/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Abstract
Vegetable crops have varied heavy metal(loid)s accumulation rates from soils to their edible tissues. However, crop selection has been seldom evaluated as a strategy for reducing the health risks of ingesting vegetables grown in soils contaminated by treated wastewater (TWW) irrigation. We cultivated twenty commonly grown vegetables using soils with an approximately 50-year history of TWW irrigation, and their ingestion risks were evaluated by the health risk index (HRI). Results showed that twenty vegetable species had varied abilities in accumulating heavy metal(loid)s from soils to their edible parts (e.g., >100 times of difference for Cd). We found higher potential health risks (HRI > 1) due to As, Cd, and Pb for adults ingesting few vegetable species and all the studied vegetables had negligible health risks (HRI < 1) for Cr, Cu, and Zn. These results suggest that remediation strategies should be targeted towards As, Cd, and Pb removal in agricultural soils in this region. Total HRI > 5 was obtained for ingesting spinach, Chinese lettuce, and Chinese chives, suggesting a high potential of severe health risks. Negligible risks (total HRI < 1) were found for tomato, kidney bean, potato, and cabbage. Our study highlights crop selection as a feasible strategy for ensuring food safety in TWW contaminated farmlands.
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Affiliation(s)
- Chun Cao
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, Gansu, China; Key Laboratory of Resource Environment and Sustainable Development of Oasis, Lanzhou 730070, Gansu, China
| | - Ying Yang
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, Gansu, China; Key Laboratory of Resource Environment and Sustainable Development of Oasis, Lanzhou 730070, Gansu, China
| | - Mei-Po Kwan
- Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China; Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, Hong Kong 999077, China; Department of Human Geography and Spatial Planning, Utrecht University, 3584 CB Utrecht, The Netherlands
| | - Zhen-Bang Ma
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
| | | | - Jun-Jian Wang
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Huan Chen
- Department of Environmental Engineering and Earth Science, Clemson University, SC 29634, United States.
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Cao C, Zhang P, Ma ZP, Ma ZB, Wang JJ, Tang YY, Chen H. Coupling sprinkler freshwater irrigation with vegetable species selection as a sustainable approach for agricultural production in farmlands with a history of 50-year wastewater irrigation. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125576. [PMID: 34030418 DOI: 10.1016/j.jhazmat.2021.125576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/28/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Soil contamination and crop risks of heavy metal(loid)s are widely reported after the long-term irrigation of treated wastewater, causing an adverse influence on agricultural sustainability. Here, we collected soils after 50 years of wastewater irrigation to cultivate cabbage (Brassica pekinensis L.), rape (Brassica chinensis L.), carrots (Daucus carota L.), and potatoes (Solanum tuberosum L.), using surface and sprinkler irrigation with freshwater and wastewater. In general, we found the statistically insignificant influence of short-term freshwater irrigation on the soil and vegetable metal(loid) concentrations. Most of the vegetables had potential adverse health risks with the relatively lower risks in carrots and potatoes, and most of the risks were contributed by As and Cd. Nevertheless, we observed negligible health risks for all studied metal(loid)s in potatoes under the freshwater irrigations. Besides, compared to wastewater irrigations, freshwater irrigations produced lower Cd health risks in all four vegetable species. Sprinkler irrigation with freshwater was a favorable approach for reducing the uptake of metal(loid)s from soils and the metal(loid) concentrations in aboveground parts. Our study highlights the possibility of reducing vegetable metal(loid) risks in contaminated farmlands via a combined approach of coupling the short-term decrease in their levels in irrigation water with vegetable species selection.
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Affiliation(s)
- Chun Cao
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
| | - Peng Zhang
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
| | - Zhen-Ping Ma
- Fifth of Qinghai Institute of Geology Exploration, Xining 810012, China
| | - Zhen-Bang Ma
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China
| | - Jun-Jian Wang
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yuan-Yuan Tang
- Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Huan Chen
- Department of Environmental Engineering and Earth Science, Clemson University, SC 29634, United States.
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Hao L, Chen L, Zhu P, Zhang J, Zhang D, Xiao J, Xu Z, Zhang L, Liu Y, Li H, Yang H, Cao G. Sex-specific responses of Populus deltoides to interaction of cadmium and salinity in root systems. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110437. [PMID: 32193020 DOI: 10.1016/j.ecoenv.2020.110437] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 06/10/2023]
Abstract
More research about branch order-specific accumulation of toxic ions in root systems is needed to know root branch-related responses in growth and physiology. In this study, we used Populus deltoides females and males as a model to detect sex-specific differences in physiology, biochemistry, ultrastructure of absorbing roots and distribution of toxic ions in heterogeneous root systems under Cd, salinity and combined stress. Healthy annual male and female plants of P. deltoides were cultivated in soils including 5 mg kg-1 of Cd, 0.2% (w/w) of NaCl and their combination for a growth season. Our results are mainly as follows: (1) females suffered more growth inhibition, root biomass decline, root viability depression, and damage to distal root cells, but lower ability to scavenge reactive oxygen species (ROS) than the males under all stresses; (2) In both sexes, salinity adopted in the present study caused more significant negative effects on growth and organelles integrity than Cd stress, while interaction treatment did not induced a further depression in growth or more impairments in root cells of both sexes in comparison to salinity, indicating influence of combined stress was not equal simply to a superposition of the effects caused by single factors; (3) Cd and Na accumulation in root systems is highly heterogeneous and branch order-specific, with lower-order roots containing more Cd2+ but less Na+, and higher-order roots accumulating more Na+ but less Cd2+. Besides, it is noteworthy that females accumulated more Cd2+ in 1-2 order roots and more Na+ in 1-3 order roots than males under the interaction treatment. These results indicated that strategies in toxic ions accumulation in heterogeneous root systems of P. deltoides was highly branch order-specific, and may closely correlate with sex-specific root growth and physiological responses to the interaction of Cd and salinity.
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Affiliation(s)
- Linting Hao
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Lianghua Chen
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China.
| | - Peng Zhu
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Jian Zhang
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Danju Zhang
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Jiujin Xiao
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Zhenfeng Xu
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Li Zhang
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Yang Liu
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Han Li
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Hanbo Yang
- Institute of Ecological Forestry, Sichuan Agricultural University, Chengdu, 611130, China; Forestry Ecological Engineering in the Upper Reaches of Yangtze River Key Laboratory of Sichuan Province, Chengdu, 611130, China
| | - Guoxing Cao
- College of Forestry, Sichuan Agricultural University, Chengdu, 611130, China
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Yang Y, Yanai RD, Driscoll CT, Montesdeoca M, Smith KT. Concentrations and content of mercury in bark, wood, and leaves in hardwoods and conifers in four forested sites in the northeastern USA. PLoS One 2018; 13:e0196293. [PMID: 29684081 PMCID: PMC5912732 DOI: 10.1371/journal.pone.0196293] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 04/10/2018] [Indexed: 11/19/2022] Open
Abstract
Mercury (Hg) is deposited from the atmosphere to remote areas such as forests, but the amount of Hg in trees is not well known. To determine the importance of Hg in trees, we analyzed foliage, bark and bole wood of eight tree species at four sites in the northeastern USA (Huntington Forest, NY; Sleepers River, VT; Hubbard Brook, NH; Bear Brook, ME). Foliar concentrations of Hg averaged 16.3 ng g-1 among the hardwood species, which was significantly lower than values in conifers, which averaged 28.6 ng g-1 (p < 0.001). Similarly, bark concentrations of Hg were lower (p < 0.001) in hardwoods (7.7 ng g-1) than conifers (22.5 ng g-1). For wood, concentrations of Hg were higher in yellow birch (2.1-2.8 ng g-1) and white pine (2.3 ng g-1) than in the other species, which averaged 1.4 ng g-1 (p < 0.0001). Sites differed significantly in Hg concentrations of foliage and bark (p = 0.02), which are directly exposed to the atmosphere, but the concentration of Hg in wood depended more on species (p < 0.001) than site (p = 0.60). The Hg contents of tree tissues in hardwood stands, estimated from modeled biomass and measured concentrations at each site, were higher in bark (mean of 0.10 g ha-1) and wood (0.16 g ha-1) than in foliage (0.06 g ha-1). In conifer stands, because foliar concentrations were higher, the foliar pool tended to be more important. Quantifying Hg in tree tissues is essential to understanding the pools and fluxes of Hg in forest ecosystems.
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Affiliation(s)
- Yang Yang
- Department of Forest and Natural Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States of America
| | - Ruth D. Yanai
- Department of Forest and Natural Resources Management, State University of New York College of Environmental Science and Forestry, Syracuse, NY, United States of America
| | - Charles T. Driscoll
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, United States of America
| | - Mario Montesdeoca
- Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, United States of America
| | - Kevin T. Smith
- USDA Forest Service, Northern Research Station, Durham, NH, United States of America
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14
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Cao C, Liu SQ, Ma ZB, Lin Y, Su Q, Chen H, Wang JJ. Dynamics of multiple elements in fast decomposing vegetable residues. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 616-617:614-621. [PMID: 29100695 DOI: 10.1016/j.scitotenv.2017.10.287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/27/2017] [Accepted: 10/27/2017] [Indexed: 05/20/2023]
Abstract
Litter decomposition regulates the cycling of nutrients and toxicants but is poorly studied in farmlands. To understand the unavoidable in-situ decomposition process, we quantified the dynamics of C, H, N, As, Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, and Zn during a 180-d decomposition study in leafy lettuce (Lactuca sativa var. longifoliaf) and rape (Brassica chinensis) residues in a wastewater-irrigated farmland in northwestern China. Different from most studied natural ecosystems, the managed vegetable farmland had a much faster litter decomposition rate (half-life of 18-60d), and interestingly, faster decomposition of roots relative to leaves for both the vegetables. Faster root decomposition can be explained by the initial biochemical composition (more O-alkyl C and less alkyl and aromatic C) but not the C/N stoichiometry. Multi-element dynamics varied greatly, with C, H, N, K, and Na being highly released (remaining proportion<20%), Ca, Cd, Cr, Mg, Ni, and Zn released, and As, Cu, Fe, Hg, Mn, and Pb possibly accumulated. Although vegetable residues serve as temporary sinks of some metal(loid)s, their fast decomposition, particularly for the O-alkyl-C-rich leafy-lettuce roots, suggest that toxic metal(loid)s can be released from residues, which therefore become secondary pollution sources.
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Affiliation(s)
- Chun Cao
- College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, Gansu, China
| | - Si-Qi Liu
- Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Zhen-Bang Ma
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
| | - Yun Lin
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843, United States
| | - Qiong Su
- Water Management & Hydrological Science, Texas A&M University, College Station, TX 77843, United States
| | - Huan Chen
- Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, SC 29442, United States.
| | - Jun-Jian Wang
- School of Environmental Science and Engineering, Guangdong Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology of China, Shenzhen, Guangdong 518055, China.
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15
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Arnold J, Gustin MS, Weisberg PJ. Evidence for Nonstomatal Uptake of Hg by Aspen and Translocation of Hg from Foliage to Tree Rings in Austrian Pine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:1174-1182. [PMID: 29232509 DOI: 10.1021/acs.est.7b04468] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
To determine whether trees are reliable biomonitors of air mercury (Hg) pollution concentrations were measured in bark, foliage, and tree rings. Data were developed using 4-year old Pinus and Populus trees grown from common genetic stock in Oregon and subsequently transferred to four air treatments differing in gaseous oxidized mercury (GOM) chemistry and total gaseous Hg (TGM) concentrations. Soil of a subset of trees was spiked with HgBr2 in solution to test for root uptake. Results indicate no significant effect of the soil spike or GOM compounds on tree tissue Hg concentrations. TGM treatment had a significant effect on Pinus and Populus foliage, and Pinus year 5 growth ring concentrations. Populus foliar Hg concentrations were highest in the exposure where 24 h TGM concentrations were highest, indicating the importance of the nonstomatal pathway for uptake. Pinus tree ring concentrations were correlated to day time TGM concentrations suggesting Hg accumulation into tree rings is by way of the stomata and subsequent translocation by way of phloem. Populus leaves and Pinus rings can be used as biomonitors for TGM concentrations over space. However, the use of trees as temporal proxies requires further investigation due to radial translocation observed in active sapwood tree rings.
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Affiliation(s)
- Jennifer Arnold
- Department of Natural Resources and Environmental Science University of Nevada-Reno Reno, Nevada 89557, United States
| | - Mae Sexauer Gustin
- Department of Natural Resources and Environmental Science University of Nevada-Reno Reno, Nevada 89557, United States
| | - Peter J Weisberg
- Department of Natural Resources and Environmental Science University of Nevada-Reno Reno, Nevada 89557, United States
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16
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Antoniadis V, Shaheen SM, Boersch J, Frohne T, Du Laing G, Rinklebe J. Bioavailability and risk assessment of potentially toxic elements in garden edible vegetables and soils around a highly contaminated former mining area in Germany. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 186:192-200. [PMID: 27117508 DOI: 10.1016/j.jenvman.2016.04.036] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 05/19/2023]
Abstract
Although soil contamination by potentially toxic elements (PTEs) in Europe has a history of many centuries, related problems are often considered as having been dealt with due to the enforcement of tight legislations. However, there are many unsolved issues. We aimed to assess PTE levels in highly contaminated soils and in garden edible vegetables using human health risk indices in order to evaluate the availability and mobilization of arsenic (As), copper (Cu), manganese (Mn), mercury (Hg), lead (Pb), and zinc (Zn). In four gardens in Germany, situated on, or in the vicinity of, a mine dump area, we planted beans (Phaseolus vulgaris ssp. nanus), carrots (Daucus sativus) and lettuce (Lactuca sativa ssp. capitata). We examined soil-to-plant mobilization of elements using transfer coefficient (TC), as well as soil contamination using contamination factor (CF), enrichment factor (EF), and bioaccumulation index (Igeo). In addition, we tested two human health risk assessment indices: Soil-induced hazard quotient (HQS) (representing the "direct soil ingestion" pathway), and vegetable-induced hazard quotient (HQV) (representing the "vegetable intake" pathway). The studied elements were highly elevated in the soils. The values in garden 2 were especially high (e.g., Pb: 13789.0 and Hg: 36.8 mg kg-1) and largely exceeded the reported regulation limits of 50 (for As), 40 (Cu), 400 (Pb), 150 (Zn), and 5 (Hg) mg kg-1. Similarly, element concentrations were very high in the grown vegetables. The indices of CF, EF and Igeo were enhanced even to levels that are rarely reported in the literature. Specifically, garden 2 indicated severe contamination due to multi-element deposition. The contribution of each PTE to the total of measured HQS revealed that Pb was the single most important element causing health risk (contributing up to 77% to total HQS). Lead also posed the highest risk concerning vegetable consumption, contributing up to 77% to total HQV. The presence of lead in both cases was followed by that of As, Mn and Hg. We conclude that in multi-element contamination cases, along with high-toxicity elements (here, Pb, As and Hg) other elements may also be responsible for increasing human health risks (i.e., Mn), due to the possibility of adverse synergism of the PTEs.
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Affiliation(s)
- Vasileios Antoniadis
- School of Agriculture, University of Thessaly, Fytokou Street, GR-384 46, Greece.
| | - Sabry M Shaheen
- University of Kafrelsheikh, Faculty of Agriculture, Department of Soil and Water Sciences, 33 516 Kafr El-Sheikh, Egypt; University of Wuppertal, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
| | - Judith Boersch
- University of Wuppertal, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany
| | - Tina Frohne
- University of Wuppertal, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
| | - Gijs Du Laing
- Laboratory of Analytical Chemistry and Applied Ecochemistry, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, Ghent, Belgium
| | - Jörg Rinklebe
- University of Wuppertal, Soil- and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany.
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17
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Cao C, Chen XP, Ma ZB, Jia HH, Wang JJ. Greenhouse cultivation mitigates metal-ingestion-associated health risks from vegetables in wastewater-irrigated agroecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 560-561:204-211. [PMID: 27101456 DOI: 10.1016/j.scitotenv.2016.04.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 06/05/2023]
Abstract
Wastewater irrigation can elevate metal concentrations in soils and crops and increase the metal-associated health risks via vegetable ingestion in arid and semiarid northwestern China. Here, we investigated the As, Cd, Cr, Cu, Ni, Pb, and Zn concentrations in four vegetable species from Dongdagou and Xidagou farmlands in Baiyin, Gansu, China. We evaluated the effects of irrigation type (Dongdagou: industrial wastewater; Xidagou: domestic wastewater) and cultivation mode (open field and greenhouse) on the vegetable metal concentration, metal partitioning, soil-to-plant bioconcentration factor (BCF), and the health risk index. All stream waters, soils, and vegetables were found most severely polluted by As and Cd, with higher severity in the industrial-wastewater-irrigated Dongdagou than the domestic-wastewater-irrigated Xidagou. All vegetables had higher or, at least, comparable metal mass allocated in the shoot than in the root. Greenhouse cultivation could reduce metal-ingestion-associated health risks from edible vegetable biomass by decreasing the soil to plant bioaccumulation (BCF) and the metal concentration. This effect was always significant for all vegetables within Xidagou, and for carrot within Dongdagou. This mitigation effect of greenhouse cultivation could be attributed to the metal sorption by a higher level of soil organic matter and faster growth rate over metal uptake rate in greenhouses compared to open fields. Such mitigation effect was, however, insignificant for leafy vegetables within Dongdagou, when much more severely polluted water for irrigation was applied in greenhouses compared to open fields within Dongdagou. The present study highlights greenhouse cultivation as a potential mitigating approach to providing less-polluted vegetables for residents in the severely polluted area in addition to the source pollution control.
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Affiliation(s)
- Chun Cao
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China; College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, Gansu, China
| | - Xing-Peng Chen
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
| | - Zhen-Bang Ma
- College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
| | - Hui-Hui Jia
- State High-Tech Industrial Innovation Center, Shenzhen 518057, Guangdong, China
| | - Jun-Jian Wang
- Department of Physical and Environmental Sciences, University of Toronto, Toronto M1C 1A4, Canada.
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18
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Bigham G, Liang L, Balouet JC, Chalot M. Phytoscreening-based assessment of mercury in soil. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:19285-19291. [PMID: 26490933 DOI: 10.1007/s11356-015-5604-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
This study was conducted to determine whether phytoscreening techniques could be used to characterize the distribution of Hg in soil at the South River, VA. An estimated 500 to 1000 kg of Hg was released to the South River in the 1930s and 1940s from a synthetic fiber manufacturing plant located in Waynesboro, contaminating the floodplain downstream. Under background conditions (soil Hg <0.03 μg/g), phytoscreening sample Hg concentrations ranged from 1.9 to 3.9 ng/g. With soil Hg concentrations ranging from 0.1 to 94 μg/g in the top 30.5 cm of nearby soil, phytoscreening sample Hg concentrations ranged from 5.0 to 145 ng/g. The variability of Hg concentrations in soil solution over the scale of the entire rhizosphere of the large trees sampled was likely high. Furthermore, the mean depth of water uptake and the exact proximity of the soil profile samples for each tree could not be determined. Nevertheless, the phytoscreening results of this study could be used to reliably provide a qualitative delineation of Hg-contaminated soil.
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Affiliation(s)
- Gary Bigham
- Exponent, Inc., 15375 SE 30th Place, Suite 250, Bellevue, WA, 98007, USA
| | | | | | - Michel Chalot
- Laboratoire Chrono-environnement UMR6249, Université Bourgogne Franche-Comté/CNRS, F-25211, Montbéliard, France.
- Faculté des Sciences et Technologies, Université de Lorraine, Boulevard des Aiguillettes, BP 70239, F-54506, Vandoeuvre-les-Nancy, France.
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19
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Chen ZX, Ni HG, Jing X, Chang WJ, Sun JL, Zeng H. Plant uptake, translocation, and return of polycyclic aromatic hydrocarbons via fine root branch orders in a subtropical forest ecosystem. CHEMOSPHERE 2015; 131:192-200. [PMID: 25863163 DOI: 10.1016/j.chemosphere.2015.03.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 03/20/2015] [Accepted: 03/22/2015] [Indexed: 06/04/2023]
Abstract
Fine roots of woody plants are a heterogeneous system differing markedly in structure and function. Nevertheless, knowledge about the plant uptake of organic pollutants via fine roots is scarce to date. In the present study, plant uptake, translocation, and return of polycyclic aromatic hydrocarbons (PAHs) via fine roots in a subtropical forest ecosystem were investigated. Levels of Σ15PAHs in different fine root branch orders of Michelia macclurei, Cryptocarya concinna, Cryptocarya chinensis, and Canthium dicoccums varied from 5072±1419 ng g(-1) to 6080±1656 ng g(-1), 4037±410 ng g(-1) to 6101±972 ng g(-1), 3308±1191 ng g(-1) to 4283±237 ng g(-1), and 3737±800 ng g(-1) to 4895±1216 ng g(-1), respectively. Overall, concentrations of low-molecular-weight PAHs with 2-3 aromatic rings were higher than high-molecular-weight PAHs with 4-6 aromatic rings in all fine root branch orders. There were obvious translocations of PAHs between adjacent branch orders and a net accumulation of PAHs may occur in the fourth- and fifth-order roots. The storage of PAHs in the fine root system showed an obvious increasing trend along the branch orders ascending for all tree species. The return flux of PAHs via fine roots mortality showed an obvious decreasing trend with the branch orders ascending across the four tree species. Lower order roots contributed greatly to the total PAHs return flux. Our results indicated that fine roots turnover is an effective pathway for perennial tree species to remove environmental toxicants absorbed into them.
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Affiliation(s)
- Zheng-Xia Chen
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Hong-Gang Ni
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Xin Jing
- Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Wen-Jing Chang
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Jian-Lin Sun
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
| | - Hui Zeng
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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20
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Wang JJ, Tharayil N, Chow AT, Suseela V, Zeng H. Phenolic profile within the fine-root branching orders of an evergreen species highlights a disconnect in root tissue quality predicted by elemental- and molecular-level carbon composition. THE NEW PHYTOLOGIST 2015; 206:1261-1273. [PMID: 25858344 DOI: 10.1111/nph.13385] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/24/2015] [Indexed: 06/04/2023]
Abstract
Fine roots constitute a significant source of plant productivity and litter turnover across terrestrial ecosystems, but less is known about the quantitative and qualitative profile of phenolic compounds within the fine-root architecture, which could regulate the potential contribution of plant roots to the soil organic matter pool. To understand the linkage between traditional macro-elemental and morphological traits of roots and their molecular-level carbon chemistry, we analyzed seasonal variations in monomeric yields of the free, bound, and lignin phenols in fine roots (distal five orders) and leaves of Ardisia quinquegona. Fine roots contained two-fold higher concentrations of bound phenols and three-fold higher concentrations of lignin phenols than leaves. Within fine roots, the concentrations of free and bound phenols decreased with increasing root order, and seasonal variation in the phenolic profile was more evident in lower order than in higher order roots. The morphological and macro-elemental root traits were decoupled from the quantity, composition and tissue association of phenolic compounds, revealing the potential inability of these traditional parameters to capture the molecular identity of phenolic carbon within the fine-root architecture and between fine roots and leaves. Our results highlight the molecular-level heterogeneity in phenolic carbon composition within the fine-root architecture, and imply that traits that capture the molecular identity of the root construct might better predict the decomposition dynamics within fine-root orders.
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Affiliation(s)
- Jun-Jian Wang
- The Belle W. Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
| | - Nishanth Tharayil
- School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Alex T Chow
- The Belle W. Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA
| | - Vidya Suseela
- School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Hui Zeng
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
- College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
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21
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Sun JL, Wang YB, Zeng H, Ni HG. Parent and halogenated polycyclic aromatic hydrocarbons in farmed cockroaches and implications for human exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2015; 111:256-262. [PMID: 25450942 DOI: 10.1016/j.ecoenv.2014.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 06/04/2023]
Abstract
Medicinal insects have been widely used to cure human diseases for ages. Nevertheless, knowledge about the toxic chemicals accumulated in medicinal insects and their effects on human health was insufficient. In the present study, sixteen priority polycyclic aromatic hydrocarbons (PAHs) and nine halogenated PAHs (HPAHs) were determined in farmed medicinal cockroaches to address this issue. Total concentrations of PAHs in young nymphs, old nymphs, and adults ranged from 162 to 1025, 252 to 967, and 267 to 1168 ng/g, respectively. Levels of the sum of HPAHs varied from 0.84 to 9.17, 1.86 to 5.21, and 1.01 to 8.60 ng/g for young nymphs, old nymphs, and adults, respectively. The daily intake and excess cancer risk of PAHs and HPAHs were calculated for people who take cockroach-related drugs. Our results indicated that females and children have slightly higher exposure levels from the perspectives of gender and age, respectively. The estimated excess cancer risk of PAHs and HPAHs were both lower than the priority risk level (10(-4)), indicating a low potential carcinogenic risk with the medicinal cockroach consumption.
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Affiliation(s)
- Jian-Lin Sun
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Yan-Bing Wang
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China
| | - Hui Zeng
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China; Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Hong-Gang Ni
- Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
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Acquisition of ephemeral module in roots: a new view and test. Sci Rep 2014; 4:5078. [PMID: 24865985 PMCID: PMC4035572 DOI: 10.1038/srep05078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 05/06/2014] [Indexed: 11/22/2022] Open
Abstract
The terminal root branch orders composed mainly of primarily-developed tissues are increasingly recognized as an ephemeral module specialized for resource absorption. This root module is crucial in driving a range of ecosystem processes such as belowground productivity, carbon and nutrient cycling. Traditionally, acquisition of the ephemeral root module is achieved by separating these primarily-developed branch orders with forceps. However, obtaining this root segment with forceps approach is labor-intensive which may not be applicable for studies with an appreciable amount of root samples. To address this challenge, we developed a new idea to obtain the ephemeral root module. In this new view, root samples were tenderly kneaded by hand and the detached roots are considered as the ephemeral root module. To test this idea, four species with contrasting growing environment were selected and a range of chemicals were determined including C, N, P, Ca, S, Mg, Ba, Zn, Mn, Pb, Cu, V and Li. We found no or little difference of these chemicals in roots by hand-kneading approach from roots by forceps approach. These results suggested that hand-kneading method could be a convenient way to acquire ephemeral root module.
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Guo YY, Wang JJ, Kong DL, Wang W, Guo DL, Wang YB, Xie QL, Liu YS, Zeng H. Fine root branch orders contribute differentially to uptake, allocation, and return of potentially toxic metals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:11465-11472. [PMID: 24044549 DOI: 10.1021/es4012405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Growing evidence has revealed high heterogeneity of fine root networks in both structure and function, with different root orders corporately maintaining trees' physiological activities. However, little information is available on how fine root heterogeneity of trees responds to environmental stresses. We examined concentrations of seven potentially toxic metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) within fine root networks and their correlations with root morphological and macro-elemental traits in six Chinese subtropical trees. The contributions of different orders of roots to fine-root metal storage and return were also estimated. Results showed no consistent pattern for the correlation among different metal concentration against root traits. Unlike root metal concentration that generally decreased with root order, root metal storage was commonly lowest in middle root orders. Root senescence was at least comparable to leaf senescence contributing to metal removal. Although the first-order roots constituted 7.2-22.3% of total fine root biomass, they disproportionately contributed to most of metal return fluxes via root senescence. The two distinct root functional modules contributed differentially to metal uptake, allocation, and return, with defensive (lower-order) roots effectively stabilizing and removing toxic metals and bulk buffering (higher-order) roots possessing a persistent but diluted metal pool. Our results suggest a strong association of physiological functions of metal detoxification and metal homeostasis with the structural heterogeneity in fine root architecture.
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Affiliation(s)
- Ying-Ying Guo
- School of Urban Planning and Design, Peking University , Shenzhen 518055, China
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24
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Lodenius M. Use of plants for biomonitoring of airborne mercury in contaminated areas. ENVIRONMENTAL RESEARCH 2013; 125:113-23. [PMID: 23472606 DOI: 10.1016/j.envres.2012.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 10/03/2012] [Accepted: 10/13/2012] [Indexed: 05/26/2023]
Abstract
Biological methods provide a wide variety of possibilities to monitor mercury pollution in the environment. E.g., mosses and lichens give a good picture of the spatial distribution of mercury around pollution sources. On regional or global scale the accuracy is smaller and interpretation of the results more difficult. One reason for this is the long life-time and low reactivity of gaseous elemental mercury (Hg(0)). At least temperature, light, concentration in air, speciation and biological factors affect the net deposition to or emission from vegetation. Different methods for estimating mercury fluxes between atmosphere and vegetation give different results. At contaminated sites the reaction types and fluxes most probably differ from those at uncontaminated sites. There are many pathways for mercury fluxes as well as physicochemical and biochemical reactions between different mercury species which makes it difficult to assess the fluxes in detail. Environmental conditions like temperature, light and humidity affect these fluxes. Compared to mechanical collectors biological monitors most probably give a more realistic picture of especially dry deposition but a lot of work has still to be done before we have accurate and reliable quantitative estimates of the deposition.
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Affiliation(s)
- Martin Lodenius
- Department of Environmental Sciences, FIN-00014, University of Helsinki, Helsinki, Finland.
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Long Y, Kong D, Chen Z, Zeng H. Variation of the linkage of root function with root branch order. PLoS One 2013; 8:e57153. [PMID: 23451168 PMCID: PMC3581569 DOI: 10.1371/journal.pone.0057153] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 01/17/2013] [Indexed: 11/18/2022] Open
Abstract
Mounting evidence has shown strong linkage of root function with root branch order. However, it is not known whether this linkage is consistent in different species. Here, root anatomic traits of the first five branch order were examined in five species differing in plant phylogeny and growth form in tropical and subtropical forests of south China. In Paramichelia baillonii, one tree species in Magnoliaceae, the intact cortex as well as mycorrhizal colonization existed even in the fifth-order root suggesting the preservation of absorption function in the higher-order roots. In contrast, dramatic decreases of cortex thickness and mycorrhizal colonization were observed from lower- to higher-order roots in three other tree species, Cunninghamia lanceolata, Acacia auriculiformis and Gordonia axillaries, which indicate the loss of absorption function. In a fern, Dicranopteris dichotoma, there were several cortex layers with prominently thickened cell wall and no mycorrhizal colonization in the third- and fourth-order roots, also demonstrating the loss of absorptive function in higher-order roots. Cluster analysis using these anatomic traits showed a different classification of root branch order in P. baillonii from other four species. As for the conduit diameter-density relationship in higher-order roots, the mechanism underpinning this relationship in P. baillonii was different from that in other species. In lower-order roots, different patterns of coefficient of variance for conduit diameter and density provided further evidence for the two types of linkage of root function with root branch order. These linkages corresponding to two types of ephemeral root modules have important implication in the prediction of terrestrial carbon cycling, although we caution that this study was pseudo-replicated. Future studies by sampling more species can test the generality of these two types of linkage.
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Affiliation(s)
- Yingqian Long
- The Key Laboratory of Science and Technology of Urban Environment, Peking University Shenzhen Graduate School, Shenzhen, People’s Republic of China
| | - Deliang Kong
- The Key Laboratory of Science and Technology of Urban Environment, Peking University Shenzhen Graduate School, Shenzhen, People’s Republic of China
- School of Life Sciences, Henan University, Kaifeng, People’s Republic of China
| | - Zhengxia Chen
- The Key Laboratory of Science and Technology of Urban Environment, Peking University Shenzhen Graduate School, Shenzhen, People’s Republic of China
| | - Hui Zeng
- The Key Laboratory of Science and Technology of Urban Environment, Peking University Shenzhen Graduate School, Shenzhen, People’s Republic of China
- Department of Ecology, College of Urban and Environmental Sciences and the Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, People’s Republic of China
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