Ee Ling Ng

An overview of microplastic and nanoplastic pollution in agroecosystems

Microplastics and nanoplastics are emerging pollutants of global importance. They are small enough to be ingested by a wide range of organisms and at nano-scale, they may cross some biological barriers. However, our understanding of their ecological impact on the terrestrial environment is limited. Plastic particle loading in agroecosystems could be high due to inputs of some recycled organic waste and plastic film mulching, so it is vital that we develop a greater understanding of any potentially harmful or adverse impacts of these pollutants to agroecosystems. In this article, we discuss the sources of plastic particles in agroecosystems, the mechanisms, constraints and dynamic behaviour of plastic during aging on land, and explore the responses of soil organisms and plants at different levels of biological organisation to plastic particles of micro and nano-scale. Based on limited evidence at this point and understanding that the lack of evidence of ecological impact from microplastic and nanoplastic in agroecosystems does not equate to the evidence of absence, we propose considerations for addressing the gaps in knowledge so that we can adequately safeguard world food supply.

Biochar Effects on Ecosystems: Insights From Lipid-Based Analysis

Abstract To reflect the microbial ecology techniques being applied currently, this chapter aims to explore how the phospholipid fatty acids can be used to determine how biochar affects the structural, compositional, and functional capacities of microbial communities in different soil ecosystems. Used in combination with natural isotope or radioisotope ( 13 C or 14 C)-labeled substrates, it has the potential to determine soil organic matter cycling rate, monitor C flows from plants to soil microbes, and identify below-ground trophic relationships. Insights into biochar effects on soil phospholipid fatty acids, alternatives to data analysis, its limitations, and knowledge gaps are highlighted.