Soil under stress: effects of (micro)plastic pollution on soil life

Soil: home of organisms performing key soil functions 

Soils are a complex mixture of minerals, organic matter and a network of pore spaces. This habitat is the home of soil organisms performing key soil processes and functions. The most dominant players are the microorganisms, who contribute to key biological processes by interacting with their surroundings, other soil organisms, and plants.

Soil under stress

Soil processes are carried out by a variety of microorganisms so the loss of a few species is assumed to have limited impact on the soil system. Over time, human-induced changes however, have led to the modification of soil structure and physicochemical properties, resulting in tremendous changes in the microbial community composition and diversity, which in turn alters the dynamics of the soil food web. The soil and the soil microbiome are therefore under continuous pressure by the changing climate and pollution due to human activities.

A new stressor in the field: plastic pollution

Since the 1950’s, the production rate of plastic has grown to over 300 million tons per year. The widespread use of plastics has led to plastic pollution in nearly every conceivable environment. Most of the plastic particles found in aquatic environments originate from land; terrestrial plastic pollution is therefore expected to be 4- to 23-fold larger than that of marine environments. Agricultural soils alone may contain more (micro)plastics than oceanic basins. 

 

Marine versus terrestrial ecosystem: mind the gap

Despite these expectations of intense plastic pollution on land, only limited research has been performed on plastic contamination in soils. The current focus on microplastics in marine environments however, leaves an enormous knowledge gap regarding microplastic pollution in other ecosystems. In this review, the authors state human-caused pollution, of which plastic is the most common, will disrupt the microbial community as well. They therefore urge the research community to focus on terrestrial and not exclusively marine microplastic pollution, and to focus on the effect of microplastics pollution on the microbial community in future experiments. 

The review “Soil under stress: The importance of soil life and how it is influenced by (micro)plastic pollution” (by L. Joos & C. De Tender) can be found here.