Early colonization of constructed Technosols by macro-invertebrates

Abstract

Purpose Anthropogenic activities lead to soil degradation and loss of biodiversity, but also contribute to the creation of novel ecosystems. Pedological engineering aims at constructing Technosols with wastes and by-products to reclaim derelict sites and to restore physico-chemical functions. Materials and methods The biological (dynamics of soil and epigeic macroinvertebrate assemblages) and physical (chemical and physical fertility) properties have been studied in two constructed Technosols under grassland during 4 years after their implementation. Results and discussion The soils exhibited a moderate chemical fertility (high organic matter and calcium carbonate contents, low nitrogen content) and a good physical fertility that only slightly evolved over the monitored period. Macro-invertebrates have colonized these soils. This colonization was characterized by an increasing number of individuals and species over time. The diversity and abundance values fell within those quoted in the literature for similar natural soils. Epigeic invertebrates presented a succession, indirectly linked to changes in soil parameters. No succession was recorded for soil invertebrates. However, the proportion of soil detritivores, an important functional group for soil evolution, grew consistently. Questions about soil invertebrates' functional complementarity/redundancy emerge in such artificially created ecosystem. Conclusions The constructed Technosol, on which a meadow was sown and well-established after 4 years, can host numerous soil invertebrates. In addition, an increase in diversity was monitored throughout the duration of the study.

Tree growth and macrofauna colonization in Technosols constructed from recycled urban wastes

“…The macrofauna density in constructed Technosols was in the same range to less disturbed meadows in the North West region of France(Hedde et al, 2019). The diversity was similar to constructed soils with non-hazardous construction and demolition wastes (11.6 ± 4 family groups,Vincent et al, 2018) Hedde et al (2019). andMathieu et al (2005) found similar rapid colonization of respectively a constructed Technosols in a rural landscape of France and of deforested plots by soil macrofauna in Amazonia respectively.…”

“…neighbouring woods and meadows. The macrofauna density in constructed Technosols was in the same range to less disturbed meadows in the North West region of France(Hedde et al, 2019). The diversity was similar to constructed soils with non-hazardous construction and demolition wastes (11.6 ± 4 family groups,Vincent et al, 2018) Hedde et al (2019).…”

Early colonization of constructed technosol by microarthropods

“…Studies conducted on the nematode community (Villenave et al, 2018) have shown the rapid colonization of Technosols, with a succession of nematode communities established during the study. In other studies, macroinvertebrates, which were absent at the beginning of monitoring, rapidly colonized the Technosols after construction (Hedde et al, 2018).…”

“…12 Colonization of an ecological system is a process influenced by a variety of abiotic and biotic factors, but also depends on interspecific interactions and stochastic effects (Melbourne and Hastings, 2009;Clobert et al, 2012). This results in community assemblage dynamics that shift from random associations to interspecific interactions, ultimately reaching a steady state or a dynamic equilibrium within the community (Hedde et al, 2018). Our analysis of the microarthropod community (Fig.…”

“…The experimental design we implemented and the soil properties are described in detail in several publications (Hafeez et al, 2012;Hedde et al, 2018;Villenave et al, 2018). In summary, the Technosol was constructed using three distinct technogenic parent materials: paper-mill sludge (PS), thermally treated industrial soil (TIS), and green-waste compost (GWC).…”