Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, Zhejiang, China.
Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, Zhejiang, China; College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, China.
Sci Total Environ. 2024 Nov 20;952:175940. doi: 10.1016/j.scitotenv.2024.175940. Epub 2024 Aug 30.
Microplastics are heterogeneously distributed in soils. However, it is unknown whether soil microplastic heterogeneity affects plant growth and root foraging responses and whether such effects vary with plant species and microplastic types. We grew each of seven herbaceous species (Platycodon grandiflorus, Trifolium repens, Portulaca oleracea, Medicago sativa, Taraxacum mongolicum, Perilla frutescenst, and Paspalum notatum) in heterogeneous soil (patches without microplastics and patches with 0.2 % microplastics) and homogeneous soil (patches with 0.1 % microplastics). Three microplastic types were tested: polypropylene (PP), polyacrylonitrile (PAN), and polyester (PET). P. frutescens showed no response to soil microplastic heterogeneity. For P. grandiflora, microplastic heterogeneity tended to decrease its biomass (total, shoot and root) when the microplastic was PAN and also shoot biomass when it was PET, but had no effect when it was PP. For T. repens, microplastic heterogeneity promoted biomass when PAN was used, decreased total and root biomass when PET was used, but showed no effect when PP was used. Microplastic heterogeneity increased biomass of P. oleracea and decreased that of M. sativa when PET was used, but had no effect when PP or PAN was used. For T. mongolicum, microplastic heterogeneity reduced biomass when the microplastic was PAN, tended to increase total and root biomass when it was PP, but showed no effect when it was PET. For P. notatum, microplastic heterogeneity increased biomass when the microplastic was PP, decreased it when PET was used, but had no effect when PAN was used. However, biomass of none of the seven species showed root foraging responses at the patch level. Therefore, soil microplastic heterogeneity can influence plant growth, but such effects depend on species and microplastic types and are not associated with root foraging. Our findings highlight the roles of soil microplastic heterogeneity, which may influence species interactions and community structure and productivity.
土壤中的微塑料呈不均匀分布。然而，目前尚不清楚土壤微塑料的异质性是否会影响植物的生长和根系觅食反应，以及这种影响是否因植物物种和微塑料类型而异。我们在不均匀土壤（无微塑料斑块和 0.2%微塑料斑块）和均匀土壤（0.1%微塑料斑块）中种植了 7 种草本植物（桔梗、三叶草、马齿苋、紫花苜蓿、蒲公英、紫苏和雀稗）。测试了 3 种微塑料类型：聚丙烯（PP）、聚丙烯腈（PAN）和聚酯（PET）。P. frutescens 对土壤微塑料的异质性没有反应。对于 P. grandiflora，当微塑料为 PAN 时，微塑料的异质性往往会降低其生物量（总生物量、地上部分生物量和根生物量），当微塑料为 PET 时，也会降低地上部分生物量，但当微塑料为 PP 时，没有影响。对于 T. repens，当使用 PAN 时，微塑料的异质性促进了生物量，当使用 PET 时，降低了总生物量和根生物量，但当使用 PP 时，没有影响。当使用 PET 时，微塑料的异质性增加了 P. oleracea 的生物量，降低了 M. sativa 的生物量，但当使用 PP 或 PAN 时，没有影响。对于 T. mongolicum，当微塑料为 PAN 时，微塑料的异质性降低了生物量，当微塑料为 PP 时，生物量有增加的趋势，但当微塑料为 PET 时，没有影响。对于 P. notatum，当微塑料为 PP 时，微塑料的异质性增加了生物量，当使用 PET 时，降低了生物量，但当使用 PAN 时，没有影响。然而，七种植物中的任何一种的生物量都没有表现出在斑块水平上的根系觅食反应。因此，土壤微塑料的异质性会影响植物的生长，但这种影响取决于物种和微塑料类型，与根系觅食无关。我们的研究结果强调了土壤微塑料异质性的作用，它可能会影响物种间的相互作用、群落结构和生产力。
