Mid‐term effects on ecosystem services of quarry restoration with Technosols under Mediterranean conditions: 10‐year impacts on soil organic carbon and vegetation development

Abstract

The use of Technosols for the restoration of limestone quarries overcomes the usual “in situ” scarcity of soil and/or its poor quality. The use of mine spoils, improved with mineral and/or organic amendments, could be an efficient and environmentally friendly option. Properly treated sewage sludge from urban wastewater treatment plants could be a suitable organic amendment and fertilizer (rich in N and P) whenever its pollutant burden is low (heavy metals and/or organic pollutants). Its appropriate use could improve essential soil physical and chemical properties and, therefore, promote key ecosystem services of restored areas, such as biomass production and carbon sequestration, as well as biodiversity and landscape recovery. However, the mid‐term impacts of these restoration practices on soil functioning and their services have rarely been reported in the available literature. In this study we assess the mid‐term effects (10 years) of the use of sewage sludge as a Technosol amendment on soil organic carbon (SOC), nutrient status, and plant development in several restored quarries. Soils restored using sewage sludge showed a threefold increase in SOC compared to the corresponding unamended ones, despite the moderate sludge dosage applied (below 50 tonnes/ha). Plant cover was also higher in amended soils, and recruitment was not affected by sludge amendment at these doses. This study demonstrates that, used at an appropriate rate, sewage sludge is a good alternative for the valorization of mine spoils in quarry restoration, improving some important regulatory ecosystem services such as carbon sequestration, without compromising woody plant encroachment.

Effects of Sewage Sludge Application on Plant Growth and Soil Characteristics at a Pinus sylvestris var. mongolica Plantation in Horqin Sandy Land

“…As expected, this finding could be related to the higher rates of organic matter, TN, and TP in SS (Table 1). Similar results have been reported by Chen et al [69] and Carabassa et al [70], who observed that SS addition showed increases in the contents of SOC, TN, and TP, and thus positively improved the soil fertility. Sardans et al [71] pointed out that inputs of C, N, and P are the major processes that decide the stoichiometry of these nutrient elements in various ecosystems.…”

Nitrogen recovery in reclaimed mine soil under different amendment practices in tandem with legume and non‐legume revegetation: A review

“…Ten years of limestone quarry restoration under Mediterranean climatic conditions using municipal sewage sludge‐amended technosols boosted the vegetation cover to 80% with a higher frequency of ruderal species than 62% (control). Moreover, differences in N status were even greater with more than three times the N concentration in sludge‐amended technosols (1800 mg kg −1 ) compared with an un‐amended technosol extremely poor in N (500 mg kg −1 ) (Carabassa et al, 2019). The authors recommended moderate doses of organic amendment (sewage sludge) at 45 Mg ha −1 with technosols for maximum benefits and fast recovery of mine‐degraded lands.…”

Mining and Industrial Landscapes of Podillia as Potential Structural Elements of the Regional Eco-Network

“…It is possible to preserve the newly formed topography as a secondary or replacement habitat for species, but these areas may become an ecological trap (Salguiero et al, 2020). To stabilise soil conditions, it is proposed to introduce engineering solutions for strengthening or constructing new artificial slopes (Wang et al, 2018), implementation of identification of water erosion processes by remote sensing (Padro et al, 2022) and filling with additional materials to protect groundwater (Semeraro et al, 2019), improvement of the organic component by sewage sludge (Carabassa et al, 2020) or carrying out transplanting of soil and plant litter from undisturbed areas (Benetkova et al, 2020). In the case of a slow succession, it is advisable to perform a biological stage of reclamation, provided that the ecological plant species inherent in the region are selected (Sampaio et al, 2021).…”