Abstract:
Old-growth forests host a rich diversity of invertebrate assemblages. Among them, saproxylic insects play a fundamental role in the nutrient cycle and ecosystem functioning. In these environments, coevolution between insect and plants have reached a stable equilibrium over millions of years. These delicate ecosystems are threatened mainly by habitat loss and fragmentation, and to date, they have to face the new \"plastic threat.\" Plastics are widespread in all biomes and ecosystems accumulating throughout the years due to their low degradation rate. Once accumulated, large pieces of plastics can be degraded into smaller particles, the latter representing a great threat to biodiversity and ecosystem health, producing detrimental effects on biota. Since the effects of plastics on terrestrial systems remain largely unexplored, this study aimed at contributing to increasing the knowledge on the interaction between plastics and terrestrial biota. We put our emphasis on the novel and broad topic of plastic degradation by saproxylic beetle larvae, describing how they fragmented macroplastics into microplastics. To investigate whether saproxylic cetonid larvae could degrade expanded polystyrene, we performed an experiment. Thus, we put larvae collected in the field in an expanded polystyrene box. We observed that larvae dug in the thickness of the box fragmenting macroplastics into microplastics and producing a total of 3441 particles. Then, we removed the larvae from the EPS box and isolated them in glass jars filled with natural substrate. The substrate was checked for EPS microplastics previously ingested and now egested by larvae. Additionally, we pointed out that plastics remained attached to cetonid larvae setae, with a mean number of 30.7 ± 12.5 items. Although preliminary, our results highlighted that microplastics attached to saproxylic cetonid larvae might be transported into habitats and transferred along the food web. In conclusion, plastic pollution might affect vulnerable species and ecosystem services representing a risk also for human health.
摘要:
古老的森林拥有丰富的无脊椎动物组合。其中,腐生昆虫在营养循环和生态系统功能中起着重要作用。在这些环境中,昆虫和植物之间的协同进化在数百万年中达到了稳定的平衡。这些脆弱的生态系统主要受到栖息地丧失和碎片化的威胁,到目前为止,他们必须面对新的“塑料威胁”。“塑料广泛存在于所有的生物群落和生态系统中,由于其降解率低,多年来一直在积累。一旦积累,大块的塑料可以降解成更小的颗粒,后者对生物多样性和生态系统健康构成了巨大威胁,对生物群产生有害影响。由于塑料对陆地系统的影响仍未被探索,这项研究旨在增加对塑料和陆地生物群相互作用的认识。我们把我们的重点放在新的和广泛的主题塑料降解的腐熟甲虫幼虫,描述了他们如何将大型塑料分解成微塑料。为了研究seproxylic鲸蜡幼虫是否可以降解膨胀聚苯乙烯,我们做了一个实验。因此,我们把收集在野外的幼虫放在一个膨胀的聚苯乙烯盒子里。我们观察到幼虫在盒子的厚度中将大型塑料碎裂成微塑料,总共产生3441个颗粒。然后,我们从EPS盒中取出幼虫,并将它们隔离在装有天然基质的玻璃罐中。检查基材中是否有先前摄入的EPS微塑料,现在已被幼虫抛弃。此外,我们指出,塑料仍然附着在鲸蜡幼虫刚毛上,平均数量为30.7±12.5项。虽然是初步的,我们的研究结果强调,附着在蛇形细胞幼虫上的微塑料可能会被运输到栖息地并沿着食物网转移。总之,塑料污染可能会影响脆弱的物种和生态系统服务,这也对人类健康构成风险。