Abstract
Microplastics are increasingly recognized as a factor of global change. By altering soil inherent properties and processes, ripple-on effects on plants and their symbionts can be expected. Additionally, interactions with other factors of global change, such as drought, can influence the effect of microplastics. We designed a greenhouse study to examine effects of polyester microfibers, arbuscular mycorrhizal (AM) fungi and drought on plant, microbial and soil responses. We found that polyester microfibers increased the aboveground biomass of Allium cepa under well-watered and drought conditions, but under drought conditions the AM fungal-only treatment reached the highest biomass. Colonization with AM fungi increased under microfiber contamination, however, plant biomass did not increase when both AM fungi and fibers were present. The mean weight diameter of soil aggregates increased with AM fungal inoculation overall but decreased when the system was contaminated with microfibers or drought stressed. Our study adds additional support to the mounting evidence that microplastic fibers in soil can affect the plant-soil system by promoting plant growth, and favoring key root symbionts, AM fungi. Although soil aggregation is usually positively influenced by plant roots and AM fungi, and microplastic promotes both, our results show that plastic still had a negative effect on soil aggregates. Even though there are concerns that microplastic might interact with other factors of global change, our study revealed no such effect for drought.
Highlights
Microplastic is becoming increasingly recognized as a factor of global change (Rillig, 2012; Machado et al, 2018a; Ng et al, 2018), owing to the fact that these materials are ubiquitously found in various environmental compartments
These include (i) that we do not know how any such responses depend on key plant mutualists, including arbuscular mycorrhizal (AM) fungi; (ii) that microplastic might interact with other factors of global change, such as drought; and (iii) how these interrelated factors modulate plant, microbial and soil responses
All investigated root traits were affected by drought (Fig. 2, Table 1); i.e., specific root length and surface area decreased while the root average diameter and tissue density increased under drought conditions
Summary
Microplastic is becoming increasingly recognized as a factor of global change (Rillig, 2012; Machado et al, 2018a; Ng et al, 2018), owing to the fact that these materials are ubiquitously found in various environmental compartments. These include (i) that we do not know how any such responses depend on key plant mutualists, including arbuscular mycorrhizal (AM) fungi; (ii) that microplastic might interact with other factors of global change, such as drought; and (iii) how these interrelated factors modulate plant, microbial and soil responses. To target these limitations in our knowledge, we designed the current study
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call