Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Functional Aquatic Ecotoxicology, Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany.
Glob Chang Biol. 2021 Sep;27(17):3969-3986. doi: 10.1111/gcb.15724. Epub 2021 Jun 13.
Microplastic (plastic particles measuring <5mm) pollution is ubiquitous. Unlike in other well-studied ecosystems, for example, marine and freshwater environments, microplastics in terrestrial systems are relatively understudied. Their potential impacts on terrestrial environments, in particular the risk of causing ecological surprise, must be better understood and quantified. Ecological surprise occurs when ecosystem behavior deviates radically from expectations and generally has negative consequences for ecosystem services. The properties and behavior of microplastics within terrestrial environments may increase their likelihood of causing ecological surprises as they (a) are highly persistent global pollutants that will last for centuries, (b) can interact with the abiotic environment in a complex manner, (c) can impact terrestrial organisms directly or indirectly and (d) interact with other contaminants and can facilitate their transport. Here, we compiled findings of previous research on microplastics in terrestrial environments. We systematically focused on studies addressing different facets of microplastics related to their distribution, dispersion, impact on soil characteristics and functions, levels of biological organization of tested terrestrial biota (single species vs. assemblages), scale of experimental study and corresponding ecotoxicological effects. Our systematic assessment of previous microplastic research revealed that most studies have been conducted on single species under laboratory conditions with short-term exposures; few studies were conducted under more realistic long-term field conditions and/or with multi-species assemblages. Studies targeting multi-species assemblages primarily considered soil bacterial communities and showed that microplastics can alter essential nutrient cycling functions. More ecologically meaningful studies of terrestrial microplastics encompassing multi-species assemblages, critical ecological processes (e.g., biogeochemical cycles and pollination) and interactions with other anthropogenic stressors must be conducted. Addressing these knowledge gaps will provide a better understanding of microplastics as emerging global stressors and should lower the risk of ecological surprise in terrestrial ecosystems.
微塑料（粒径<5mm 的塑料颗粒）污染无处不在。与其他研究充分的生态系统（例如海洋和淡水环境）不同，陆地系统中的微塑料相对研究较少。必须更好地理解和量化它们对陆地环境的潜在影响，特别是造成生态惊喜的风险。当生态系统的行为与预期的行为发生巨大偏差时，就会发生生态惊喜，这通常会对生态系统服务产生负面影响。陆地环境中微塑料的特性和行为可能会增加它们造成生态惊喜的可能性，因为它们：(a) 是高度持久的全球性污染物，将持续数百年；(b) 可以以复杂的方式与非生物环境相互作用；(c) 可以直接或间接影响陆地生物；(d) 与其他污染物相互作用并促进其运输。在这里，我们汇集了以前关于陆地环境中微塑料的研究结果。我们系统地关注了与微塑料分布、分散、对土壤特性和功能的影响、测试的陆地生物群的不同组织层次（单一物种与组合）、实验研究的规模以及相应的生态毒理学效应相关的研究。我们对以前的微塑料研究的系统评估表明，大多数研究都是在实验室条件下对单一物种进行的，暴露时间较短；很少有研究是在更现实的长期野外条件下进行的，或者是针对多物种组合进行的。针对多物种组合的研究主要考虑了土壤细菌群落，并表明微塑料可以改变重要的营养循环功能。必须进行更具生态意义的陆地微塑料研究，包括多物种组合、关键生态过程（如生物地球化学循环和授粉）以及与其他人为胁迫的相互作用。解决这些知识空白将更好地理解微塑料作为新兴的全球胁迫因素，并降低陆地生态系统发生生态惊喜的风险。
