Philosophical Transactions of the Royal Society B: Biological Sciences
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Soil-derived Nature's Contributions to People and their contribution to the UN Sustainable Development Goals

Pete Smith

Pete Smith

Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen AB24 3UU, UK

[email protected]

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Saskia D. Keesstra

Saskia D. Keesstra

Soil, Water and Land Use Team, Wageningen University and Research, Wageningen, The Netherlands

Civil, Surveying and Environmental Engineering and Centre for Water Security and Environmental Sustainability, University of Newcastle, Callaghan, Australia

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Whendee L. Silver

Whendee L. Silver

Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA

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Gerlinde B. De Deyn

Gerlinde B. De Deyn

Soil, Water and Land Use Team, Wageningen University and Research, Wageningen, The Netherlands

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Luísa G. Carvalheiro

Luísa G. Carvalheiro

Departamento de Ecologia, Universidade Federal de Goiás, 74001-970, Goiânia, Brazil

Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal

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Phil Renforth

Phil Renforth

Research Centre for Carbon Solutions, Heriot Watt University, Edinburgh, UK

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Kun Cheng

Kun Cheng

College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People's Republic of China

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Patricia M. Saco

Patricia M. Saco

Civil, Surveying and Environmental Engineering and Centre for Water Security and Environmental Sustainability, University of Newcastle, Callaghan, Australia

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Kate Scow

Kate Scow

Department of Land, Air and Water Resources, University of California, Davis, CA, USA

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Jo Smith

Jo Smith

Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen AB24 3UU, UK

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Jean-Claude Morel

Jean-Claude Morel

Tribology and Systems Dynamics Laboratory (LTDS-UMR CNRS 5513), National School of Civil Engineering (ENTPE), University of Lyon, Lyon, France

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Rattan Lal

Rattan Lal

Carbon Management and Sequestration Center, Ohio State University, Columbus, OH, USA

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    Abstract

    This special issue provides an assessment of the contribution of soils to Nature's Contributions to People (NCP). Here, we combine this assessment and previously published relationships between NCP and delivery on the UN Sustainable Development Goals (SDGs) to infer contributions of soils to the SDGs. We show that in addition to contributing positively to the delivery of all NCP, soils also have a role in underpinning all SDGs. While highlighting the great potential of soils to contribute to sustainable development, it is recognized that poorly managed, degraded or polluted soils may contribute negatively to both NCP and SDGs. The positive contribution, however, cannot be taken for granted, and soils must be managed carefully to keep them healthy and capable of playing this vital role. A priority for soil management must include: (i) for healthy soils in natural ecosystems, protect them from conversion and degradation; (ii) for managed soils, manage in a way to protect and enhance soil biodiversity, health and sustainability and to prevent degradation; and (iii) for degraded soils, restore to full soil health. We have enough knowledge now to move forward with the implementation of best management practices to maintain and improve soil health. This analysis shows that this is not just desirable, it is essential if we are to meet the SDG targets by 2030 and achieve sustainable development more broadly in the decades to come.

    This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

    1. Introduction

    Previous studies have examined the role of soils in contributing to ecosystem services, showing that soils have a decisive and positive contribution to many [15]. Other papers in this special issue [620] have considered each ecosystem service in turn, classified according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) Nature's Contributions to People (NCP, [21,22]), thus providing the most comprehensive treatment to date of the role of soils in delivering NCP. Other studies have examined the role of soils in contributing to the UN Sustainable Development Goals (SDGs, [2326]), arguing that soils also play a vital role in delivering the SDGs. In a Forum paper, Keesstra et al. [27] explored the role of soils in delivering the SDGs through a series of short essays focusing on the SDGs related to food security, water scarcity, climate change, biodiversity loss and health threats. They used an approach which mapped the functions provided by soils (table 1) to these five SDGs.

    Table 1. The seven soil functions as defined by the European Commission [28].

    1 biomass production, including agriculture and forestry
    2 storing, filtering and transforming nutrients, substances and water
    3 biodiversity pool, such as habitats, species and genes
    4 physical and cultural environment for humans and human activities
    5 source of raw material
    6 acting as carbon pool
    7 archive of geological and archaeological heritage

    Using a similar approach, Smith et al. [29] examined how soil carbon sequestration as a climate mitigation strategy provides co-benefits and trade-offs to the delivery of all SDGs. Like Keesstra et al. [27], Smith et al. [29] first considered the functions provided by the soils and mapped these to NCP, with the delivery of these NCP then mapped on to the delivery of the SDGs. We use a similar approach here, drawing on the extensive analysis presented in the other papers presented in this issue [620], to examine the role of soils in contributing, positively or negatively, to the UN SDGs.

    2. The impact of Nature's Contributions to People on the UN Sustainable Development Goals

    The IPBES Global Assessment [22] defined 18 NCP as ‘all the contributions, both positive and negative, of living nature (i.e. diversity of organisms, ecosystems and their associated ecological and evolutionary processes) to the quality of life of people’ [21]. NCP and ecosystem services are related, but not precisely parallel concepts [30]. The IPBES authors stressed that NCP is a way to think of ecosystem services, rather than a replacement for the term. As noted by McElwee et al. [31], NCP was proposed to be a broader umbrella to engage a wider range of disciplines, particularly from the social sciences and humanities, and a larger range of values around ecosystems [32]. Unlike ecosystem services described in the earlier Millennium Ecosystem Assessment (MA, [33]), supporting services were no longer considered as separate entities, but many NCP can be mapped onto the MA ecosystem services. Table 2 shows NCP as proposed by IPBES, with the corresponding ecosystem services, as described in the Millennium Ecosystem Assessment, to which they are related.

    Table 2. IPBES NCP, with the corresponding Millennium Ecosystem Assessment (MA) ecosystem services and categories shown.

    NCP category NCP MA category MA ecosystem service
    supporting service soil formation
    supporting service nutrient cycling
    supporting service primary production
    material NCP food and feed provisioning service food
    materials and assistance provisioning service fibre
    energy provisioning service energy
    medicinal, biochemical and genetic resources provisioning service medicinal products, biotechnical approaches and genetic biodiversity
    non-material NCP learning and inspiration cultural service aesthetic values
    supporting identities cultural service spiritual and religious values
    physical and psychological experiences cultural service recreation and ecotourism
    regulating NCP regulation of climate regulating service climate regulation
    regulation of freshwater quantity, flow and timing provisioning service water
    regulation of freshwater and coastal water quality regulating service water purification and waste treatment
    regulation of hazards and extreme events regulating service natural hazard regulation
    habitat creation and maintenance regulating service
    regulation of air quality regulating service air quality regulation
    regulation of organisms detrimental to humans regulating service pest regulation and disease regulation
    pollination and dispersal of seeds and other propagules regulating service pollination
    regulation of ocean acidification regulating service water regulation
    formation, protection and decontamination of soils and sediments regulating service erosion regulation
    cross-cutting NCP maintenance of options

    The UN SDGs were developed under an initiative by the UN aiming to end poverty, protect the planet and improve the lives and prospects of everyone, everywhere by 2030. The 17 goals were adopted by all UN Member States in 2015, as part of the 2030 Agenda for Sustainable Development which set out a 15-year plan to achieve the goals [34]. Table 3 summarizes the SDGs.

    Table 3. The UN SDGs [34].

    SDG goal
    Inline Graphic end poverty in all its forms everywhere
    Inline Graphic end hunger, achieve food security and improved nutrition, and promote sustainable agriculture
    Inline Graphic ensure healthy lives and promote well-being for all at all ages
    Inline Graphic ensure inclusive and equitable quality education and promote lifelong learning opportunities for all
    Inline Graphic achieve gender equality and empower all women and girls
    Inline Graphic ensure availability and sustainable management of water and sanitation for all
    Inline Graphic ensure access to affordable, reliable, sustainable, and modern energy for all
    Inline Graphic promote sustained, inclusive, and sustainable economic growth, full and productive employment, and decent work for all
    Inline Graphic build resilient infrastructure, promote inclusive and sustainable industrialization, and foster innovation
    Inline Graphic reduce inequality within and among countries
    Inline Graphic make cities and human settlements inclusive, safe, resilient, and sustainable
    Inline Graphic ensure sustainable consumption and production patterns
    Inline Graphic take urgent action to combat climate change and its impacts
    Inline Graphic conserve and sustainably use the oceans, seas, and marine resources for sustainable development
    Inline Graphic protect, restore, and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss
    Inline Graphic promote peaceful and inclusive societies for sustainable development, provide access to justice for all and build effective, accountable, and inclusive institutions at all levels
    Inline Graphic strengthen the means of implementation and revitalize the global partnership for sustainable development

    There have been a number of studies that have mapped the relationship between NCP (or other categorizations of ecosystem services) onto the SDGs. Wood et al. [35], for example, assessed the contribution of ecosystem services to the SDGs and specific SDG targets using the ‘The Economics of Ecosystems and Biodiversity’ definitions [36]. Yang et al. [37] used an expert elicitation exercise to assess the contribution of ecosystem services to the SDGs and Anderson et al. [38] used a similar approach to assess the contribution of NCP to the SDGs. Johnson et al. [39] described a modelling toolkit to link ecosystem services described in the InVEST suite of models to delivery of the SDGs. For soils specifically, Keesstra et al. [27] and Smith et al. [29] used ecosystem services and NCP framings, respectively, to examine the role of soils, or soil carbon sequestration specifically in the case of Smith et al. [29], in contributing to the delivery on the SDGs.

    Of the studies described above, the matrix of NCP and SDGs is based on Anderson et al. [38] since they specifically focused on the NCP categorization on ecosystem services. Table 4 shows a matrix of NCP and SDGs, with an associated relationship indicated if over 50% of expert respondents in Anderson et al. [38] identified a relationship. We use the relationships identified by Anderson et al. [38], supplemented with other well-defined relationships, to map soil-derived NCP onto the SDGs.

    Table 4. Relationship between NCP and SDGs. A relationship is shown (in blue) only to those interactions indicated by over 50% of expert respondents in Anderson et al. [38]. Note: impacts where a relationship was not identified by Anderson et al. [38], but where the relationship is well-documented elsewhere are shown (in green). These are the impact of habitat creation and maintenance [40], and the impact of regulation of air quality [41] on SDG3, the impact of regulation of ocean acidification on SDG13 through enhanced mineral weathering [42] and the impact of regulation of organisms detrimental to humans on SDGs 2, 12 and 15 [14].

    Inline Graphic

    3. Soil-derived Nature's Contributions to People and their contribution to the UN Sustainable Development Goals

    Each paper in this issue [620] has presented evidence for the contribution of soils to NCP. Table 5 summarizes the potential positive, negative and context-specific contributions of soils to NCP arising from these papers.

    Table 5. Summary of the potential positive, negative and context-specific contributions of soils to NCP arising from papers in this issue. Note, these impacts are illustrative rather than comprehensive. SOC, soil organic carbon.

    NCP positive impacts provided by soils negative impacts provided by soils mixed impacts provided by soils
    1) food and feed (material NCP; [20]) nutrients to sustain life, physical environment to support plant growth, supports biota that contribute to plant growth insufficient nutrient concentrations to sustain life, toxic elements and compounds, physical environment inhibits plant growth or supports pests and pathogens that inhibit plant success; inequitable distribution of nutrients through trade chemical stoichiometries and physical conditions that favour some plants over others
    2) materials and assistance (material NCP [16]) cheap construction materials; healthy indoor air quality in earthen architecture; low-carbon construction materials; construction materials fulfilling the circular economy (no waste); reduced energy in use for well-designed earthen architecture may lead to a shortage of soil for agriculture in some places; if extracted from a quarry --> related environmental impacts depending on the architecture some of the positive impacts may be withdrawn, e.g. if stabilized with cement, may not any longer be a low-carbon construction material
    3) energy (material NCP; [15]) soils (peats) can be burnt to provide energy; soils contribute nutrients and water to grow energy crops burning of peats releases large stores of carbon so soils increase greenhouse gas emissions; energy crops may occupy areas that could otherwise be used for food production, so soils provide less food; energy crops encourage disturbance of permanent land use, which results in loss of soil carbon, so soils release carbon; use of organic wastes for energy reduces carbon inputs to soils, which results in reduced carbon storage in soils (soils increase greenhouse gas emissions); if wind turbines or hydro schemes are located on deep peats, changes to the hydrological regime can result in large emissions of soil carbon to the atmosphere (so soils increase greenhouse gas emissions)
    4) medicinal, biochemical and genetic resources (material NCP; [18]) soils with their ecosystem services are indispensable for intact ecosystems, clean water, healthy food in general as well as the provision of substances, enzymes and organisms for medicinal and technical purposes soil dust, nutrient depletion and contamination may have direct or indirect adverse effects on human health the genetic and biochemical resources of soil are still largely unexplored
    5) learning and inspiration (non-material NCP; [17]) soils provide an opportunity for formal and informal study; inspiration leading to art and literature, and sources of biomimicry and design; indigenous knowledge around soils is rich and widespread, contributing to better management around fertility and erosion in particular none none
    6) supporting identities (non-material NCP; [17]) soil has been metaphorically and linguistically linked to human identities in major world languages and religions; concepts of a 'land ethic' shape farmer and other identities, as well as gendered experiences of soil; cultural identities often expressed through the use of soil in housing and food metaphorical concepts of 'native soil' and 'blood and soil' have been used to justify exclusion/violence against others access to the benefits of soils for identities can be limited by environmental injustices or unfair blame for the degradation
    7) physical and psychological experiences (non-material NCP; [17]) green spaces and gardening allow for physical and mental benefits of being in nature; recreation, tourism and sport all depend on, and can bring financial benefits to, good soil management recreation and tourism can be bad for soils; compaction and damage reported in some tourist sites none
    8) regulation of climate (regulating NCP; [19]) restoration of soil functionality and enhancement of SOC concentration in the root zone has numerous environmental and economic co-benefits; in addition to creating climate-resilient soil and agriculture, through adaptation and mitigation of climate change, restoration of soil health through sequestration of SOC is also pertinent to improving soil and environmental quality soils of agricultural and other managed ecosystems contain lower carbon stocks than natural vegetation because of the long-term land use and degradation (i.e. erosion) induced depletion of SOC stock; soils are also a major contributor to greenhouse gases like CH4 and N2O that has an important role in climate change feedback and elemental cycling adoption of restorative management practices, which conserve soil and water and strengthen elemental cycling, can create a positive soil/ecosystem carbon budget and sequester atmospheric carbon; understanding and predicting the impact of climate change on soil microbiomes is a grand challenge for our planet
    9) regulation of freshwater quantity, flow and timing (regulating NCP; 10]) healthy soils have high infiltration capacity that increases green water (for crop production and nature) and regulates blue water (less floods and droughts); soils also function as a filter for pollutants unhealthy soils can form crusts and increase the risk of floods and droughts; soil may be eroded and clog up waterways, reservoirs and infrastructure downstream high infiltration rates may also cause a lack of water in the riverine system in (semi) arid system; plants will make use of this water on the hillslopes in summer, but as a consequence, rivers run dry
    10) regulation of freshwater and coastal water quality (regulating NCP; [11]) natural soils and constructed wetlands provide water purification by absorbing pollutants water pollution caused by non-point source pollution in farmland with overused chemicals positive and negative water quality impacts depend on soil environmental capacity
    11) regulation of hazards and extreme events (regulating NCP; [13]) healthy soils attenuate floods by storing and slowly releasing stormwater, and this ability to store water in the soil profile during wet periods is also important to mitigate droughts, which is used by plants during drought periods; healthy soils can sustain vegetation with a root system that directly reduces erosion potential, landslide risk, and negative impacts associated with windstorms degraded soils or those with poor drainage or under intensive irrigation are prone to water logging conditions that increase risks for flood, severe erosion, and landslides; soils that do not support healthy vegetative cover result in reduced infiltration, increased evaporation and reinforcement of drought conditions and soil loss via windstorms while soils with commercial crops can have some beneficial effects on hazards, agricultural management practices must be carefully chosen to balance productivity with hazard protection
    12) habitat creation and maintenance (regulating NCP; [6]) soils are a habitat for many species, including plants and species with aboveground life stages; soils store and provide nutrients, water and shelter; soils have a buffering capacity for perturbations, enabling resilience of ecosystems soil loss proceeds faster than soil formation; specific interactions of soil biology, chemistry and physics required for adequate functioning which makes soil restoration difficult; opaqueness of soils precludes non-destructive in situ observations of soil life and its functioning plant-soil feedbacks promote certain habitat conditions over others; this can be beneficial when desired ecosystem development is promoted or detrimental when an undesired state is promoted (e.g. increased expansion of invasive species); propagules stored in the soil can promote or counteract habitat creation depending on the identity and functioning of the species
    13) regulation of air quality (regulating NCP; [8]) sink for airborne pollutants; biofiltration of gaseous pollutants; landfill covers particulates and dust storms; NH3 and NOx from fertilizer use positive and negative air quality impacts from plant growth
    14) regulation of organisms detrimental to humans (regulating NCP; 14]) suppression of pathogens by indigenous microbial communities; inactivation of detrimental organisms by abiotic factors reservoir for pathogens; reduced capacity to regulate detrimental organisms when soil health is poor practices that promote soil suppression of pathogens may reduce agricultural productivity
    15) pollination and dispersal of seeds and other propagules (regulating NCP; [7]) healthy, non-polluted soils provide nesting substrate for a vast number of pollinators and seed dispersers, as well as support for alternative (to crops) floral resources; clay from soils is used to counteract toxicity associated with fruit secondary metabolites unhealthy, polluted soils (enriched with nitrogen or other nutrients, pesticides) will change floral resource availability and quality (nutrient and sugar content, odour, size and shape), leading to changes in foraging behaviour and reducing fitness; tilled soils will reduce nesting opportunities while nutrient enrichment can improve crop productivity, when in excess it can lead to loss of pollination services, leading to a null (or negative) net effect
    16) regulation of ocean acidification (regulating NCP; [9]) facilitates weathering which removes CO2 from the atmosphere; reduces the impact of ocean acidification; improves ocean CO2 buffering capacity cation exchange and secondary minerals could reduce weathering contribution element release during weathering could impact wider ecosystems
    17) formation, protection and decontamination of soils and sediments (regulating NCP; [12]) physico-chemical interactions of contaminants with mineral and organic soil components, and biochemical transformations facilitated by soil microorganisms confer contaminants ‘cleaning’ action of soil inorganic contaminants including heavy metal(loid)s are derived from geogenic origin through weathering of parent materials, while both organic/inorganic contaminants are derived from anthropogenic origin in soil soil plays a critical role in the transformation of contaminants and their subsequent transfer to groundwater, surface water, ocean, and atmosphere, and controls the mobility, bioavailability and toxicity of contaminants
    18) maintenance of options (cross-cutting NCP) healthy, well-managed soils allow multiple options to be considered now and in the future unhealthy, poorly managed soils can lead to ecosystem degradation and desertification, with knock on effects for the reduction in other NCP

    In table 6, we map the soil contributions to NCP onto the relevant SDGs using the relationships between NCP and the SDGs outlined in §2.

    Table 6. The contribution of soils to the SDGs, with contributions derived from relationships between NCP and the SDGs outlined in §2. Dependencies enabling positive SDG effects are shown in blue, those leading to negative SDG effects are shown in red.

    NCP potential impacts on SDGs by soil-based NCP dependency on the sign of the likely impact
    1) food and feed Inline Graphic if healthy and well managed, soils provide nutrients and a physical environment to sustain life and support plant growth; poorly managed/polluted soils may lack nutrients, contain toxic compounds or pests and pathogens that inhibit plant growth
    2) materials and assistance Inline Graphic soils provide cheap, low-carbon construction materials with low levels of waste, and can reduce energy use in well-designed earthen architecture; overuse of soils for construction could threaten soils to produce food and mining can have negative impacts
    3) energy Inline Graphic peat soils can be burnt to provide energy and soils contribute nutrients and water to grow energy crops; the burning of peats is bad for climate change and biodiversity; if sited on peats, wind turbines can damage biodiversity and cause loss of carbon
    4) medicinal, biochemical and genetic resources Inline Graphic soils provide ecosystem services that are essential for intact ecosystems, clean water, healthy food, medicinal products and human well-being; soil dust, nutrient depletion and contamination may have adverse effects on human health
    5) learning and inspiration Inline Graphic soils provide an opportunity for study, inspiration leading to art and literature and sources of biomimicry and design. Indigenous knowledge around soils is rich and widespread, contributing to better management around fertility and erosion, in particular
    6) supporting identities Inline Graphic soil has been linked to human identities; concepts of a ‘land ethic’ shape farmer and other identities, as well as gendered experiences and cultural identities through the use of soil; concepts of e.g. ‘blood and soil’ have been used to justify exclusion/violence against others
    7) physical and psychological experiences Inline Graphic green spaces and gardening allow for physical and mental benefits of being in nature; recreation, tourism and sport all depend on, and can bring financial benefits to, good soil management; recreation and tourism can be bad for soils through compaction and damage
    8) regulation of climate Inline Graphic restoration of soil health and increasing soil organic matter contribute to adaptation and mitigation of climate change; poorly managed soils can lose carbon to the atmosphere and be a source of CH4 and N2O emissions
    9) regulation of freshwater quantity, flow and timing Inline Graphic healthy soils have high infiltration capacity that increases green water and regulates blue water, and function as a filter for pollutants; unhealthy soils increase the risk of floods and droughts. Eroded soil can clog up waterways, reservoirs and infrastructure
    10) regulation of freshwater and coastal water quality Inline Graphic natural soils and constructed wetlands provide water purification by absorbing pollutants; water pollution can result from non-point source pollution in farmland with overused chemicals
    11) regulation of hazards and extreme events Inline Graphic by storing water, healthy soils attenuate floods, mitigate droughts, and sustain vegetation root systems that reduce erosion and landslide risk and effects of windstorms; degraded soils exacerbate the above risks
    12) habitat creation and maintenance Inline Graphic soils are a habitat for many species and provide nutrients, water and shelter and enabling the resilience of ecosystems through buffering; soil loss proceeds faster than soil formation and soil restoration is difficult
    13) regulation of air quality Inline Graphic soils are a sink for airborne pollutants, act as a biofilter for gaseous pollutants and are used as landfill covers, all helping to improve air quality; soils contribute particulates and dust storms and NH3 and NOx from fertilizer use
    14) regulation of organisms detrimental to humans Inline Graphic suppression of pathogens by indigenous microbial communities. Inactivation of detrimental organisms by abiotic factors; soils are also a reservoir for pathogens, and poor soil health leads to reduced capacity to regulate detrimental organisms
    15) pollination and dispersal of seeds and other propagules Inline Graphic healthy, non-polluted soils provide nesting substrate for a vast number of pollinators and seed dispersers and support alternative floral resources; unhealthy, polluted soils change floral resource availability and quality leading to changes in foraging behaviour
    16) regulation of ocean acidification Inline Graphic soils facilitate weathering which removes CO2 from the atmosphere, reduces the impact of ocean acidification and improves ocean CO2 buffering capacity; cation exchange and secondary minerals could reduce weathering contribution
    17) formation, protection and decontamination of soils and sediments Inline Graphic physico-chemical interactions of contaminants with soil and biochemical transformations facilitated by soil microorganisms confer the cleaning of contaminants by soils; organic and inorganic contaminants are of anthropogenic and geogenic origin
    18) maintenance of options Inline Graphic healthy, well-managed soils allow multiple options to be considered now and in the future; unhealthy, poorly managed soils can lead to ecosystem degradation and desertification, with knock on effects for other NCP

    As seen from tables 5 and 6, soils have the capacity to contribute positively to all NCP and SDGs, but if poorly managed, degraded or polluted, may contribute negatively. This highlights (i) the great potential of soils to underpin the NCP and SDGs, and (ii) the importance of managing soils well and maintaining them in a healthy, unpolluted condition.

    4. Conclusion

    Figure 1 summarizes the contributions of soils to delivering the SDGs by showing (i) the functions provided by soils, (ii) the NCP provided by soils underpinned by these functions and (iii) impacts on the SDGs through the NCP supported by soils.

    Figure 1.

    Figure 1. Functions provided by soils (inner ring), the NCP provided by soils underpinned by these functions (middle ring) and impacts on the SDGs through the NCP supported by soils (outer ring). Light blue numbered circles in the middle ring show the corresponding soil functions that contribute to the NCP. Grey numbered circles in the outer ring show the corresponding NCP that contribute to the SDGs.

    As shown in the papers in this special issue and summarized here (table 5), soils contribute positively to the delivery of all NCP and have a role in underpinning all SDGs (table 6). While highlighting the great potential of soils to contribute to sustainable development, the recognition that poorly managed, degraded or polluted soils may contribute negatively to both NCP and SDGs shows that this positive contribution cannot be taken for granted. Soils must be managed carefully to keep them healthy and capable of playing this vital role [2327].

    The importance of maintaining healthy soils needs to be viewed against a backdrop of widespread and increasing rates of soil degradation globally [43]. There are around 11 million km2 of degraded land globally [44] and around 120 thousand km2 of land is lost to degradation every year, with over 3.2 billion people adversely impacted by global land degradation [45]. Therefore, soil management is not only required to keep soils healthy; there is also an enormous task to restore millions of km2 of degraded lands to health. In the light of this, a few priorities emerge to allow soils to contribute optimally to the SDGs, as follows:

    For healthy soils in natural ecosystems, protect them from conversion and degradation

    For managed soils, manage in a way to protect and enhance soil biodiversity, health and sustainability and to prevent degradation

    For degraded soils, restore to full soil health

    These priorities map well onto the categories protect, manage and restore, outlined for nature-based solutions [46]. Options to restore degraded soils include revegetation, reduction of grazing pressure where soils are degraded by overgrazing, bioremediation with appropriate vegetation and restoring or maintaining soil organic matter levels by returning organic matter to the soil [43,47]. Options to better manage soils in managed systems include maintaining ground cover, reducing disturbance (e.g. by reducing the intensity of tillage), maintaining soil organic matter levels by returning organic matter to the soil, increasing soil biomass and diversity by providing carbon and reducing disturbance, preventing erosion, minimizing chemical inputs and preventing overgrazing of grasslands [48].

    There is still a wealth of work to be done to better understand the processes linking soil functions to delivery of NCP, and wider work to better understand how NCP contribute to the SDGs. But we have enough knowledge now to move forward with the implementation of best management practices to maintain and improve soil health. This analysis shows that this is not just desirable, but it is essential if we are to meet the SDG targets by 2030, and sustainable development more broadly in the decades to come.

    Data accessibility

    This article has no additional data.

    Authors' contributions

    P.S. wrote the first draft of the article, with input from all authors. All authors supplied information used in this paper, helped to revise drafts and approved the final version to be published.

    Competing interests

    We have no competing interests.

    Funding

    The input of P.S. contributes to Soils-R-GRREAT (NE/P019455/1) and the input of P.S. and S.K. contributes to the European Union's Horizon 2020 Research and Innovation Programme through project CIRCASA (grant agreement no. 774378). P.R. acknowledges funding from UK Greenhouse Gas Removal Programme (NE/P01982X/2). G.B.D.D. acknowledges FoodShot Global for its support. T.K.A. acknowledges the support of ‘Towards Integrated Nitrogen Management System’ (INMS) funded by the Global Environment Facility (GEF), executed through the UK's Natural Environment Research Council (NERC). The input of D.G. was supported by the New Zealand Ministry of Business, Innovation and Employment (MBIE) strategic science investment fund (SSIF). P.M.S. acknowledges support from the Australian Research Council (Project FT140100610). P.M.'s work on ecosystem services is supported by a National Science Foundation grant #1853759, ‘Understanding the Use of Ecosystem Services Concepts in Environmental Policy’. L.G.C. is funded by National Council for Scientific and Technological Development (CNPq, Brazil – grant nos. 421668/2018-0 and 305157/2018-3) and by Lisboa2020 FCT/EU (project 028360). B.S. acknowledges support from the Lancaster Environment Centre Project.

    Footnotes

    One contribution of 17 to a theme issue ‘The role of soils in delivering Nature's Contributions to People

    Published by the Royal Society. All rights reserved.