Soil Functions and Ecosystem Services: A Literature Review (Part 2/2)

Rapport, 2021

Soils are a non-renewable resource and comprise a key component of the world's stock of natural capital. Due to industrialisation, urbanisation and other patterns of unsustainable development, widespread land degradation in the form of contamination, soil sealing, compaction, etc. has impaired the capacity of soils to perform their essential functions and provide humans with vital ecosystem services. Brownfields are typically urban or peri-urban sites that have been affected by the former uses of the site, are or are perceived to be contaminated, and require intervention to bring them back to beneficial use. They also constitute an important and underutilised land and soil resource to provide ecosystem services in urban areas as an element of green infrastructure through the use of nature-based solutions such as gentle remediation options (GRO). Within the scope of the Ph.D. project " Enhancing ecosystem services by innovative remediation using gentle remediation options (ECO-GRO)", an in-depth but inexhaustive literature review has been carried out to build a theoretical understanding of soil functions and ecosystem services for the overall research project. This literature review report (part 2 of 2) will present a compilation of the main findings by continuing with E) core concepts of soil biology, functioning and linkages to ecosystem services including how they can be delivered in healthy soils by functional assemblages of soil biota; then, F) methods for assessing soil quality are reviewed including potential physical, chemical and biological indicators, how they can be selected using a logical sieve approach, which standardised analyses exist to measure certain parameters as well as how they can be interpreted to give an indication of the status of certain aspects of soil functioning; G) quantitative, semi-quantitative and qualitative methods for assessing ecosystem services are also discussed, primarily within the context of urban or brownfield soils, and noteworthy examples are presented at some length as well as considerations for economic valuation of ecosystem services; and finally H) broader implications for land management and planning are considered in terms of managing soils to improve their quality and adaptive management and monitoring approaches to iteratively evaluate soils for their capacity to function and deliver ecosystem services over time. Also, how the breadth of information presented in this report can be transferred and applied at contaminated sites and marginal land to improve soil quality and provide much-needed ecosystem services, particularly in urban areas, is discussed.