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Soils for Sustainable Development October 2014 Academic Literature Links Healthy urban soils are becoming increasingly important as our cities rapidly grow. We face greater demand for land, food, and nutrients and less polluted environments. These challenges can all be addressed through a Soils for Sustainable Development program. Planning for density and urban ecology Reduce resource constraints (land, nitrogen, food, phosphurus) Soils for Cities Transdisciplinary Support emerging economy of green chemistry and electric vehicles Reduce soil, air and water body pollution Evidence-based strategy and regulation Capacity building, training, research, networks Soils for Cities Holistic Approach Community links including open mapping Market and green industry response This paper collates relevant academic literature to guide an evidence-based approach. Some key points from the paper are provided. LOCII MELBOURNE Artmann, M 2014 ‘Institutional efficiency of urban soil sealing management – from raising awareness to better implementation of sustainable development in Germany’ Landscape and Urban Planning 131 83-95 Managing urban environments and steering soil sealing is a challenge for policymakers and planners dealing with land use conflicts due to their complex and driving forces. It is concluded that local authorities need to be more aware of their authority and responsibility to limit soil sealing and guarantee a high urban living quality. Hence more stringent rules should be justified with proof of their effectiveness before implementation. P83 Soil sealing has become the most intense form of land take (see citations) p84 Decision makers and planners are confronted by a range of barriers to implement sustainable development such as fiscal constraints or lack of information (see citations) p84 In Germany, aiming to reduce daily land take to 30 ha/day by 2020 p84. 30ha is considered best practice in EU’s soil sealing guidelines. Guidelines on best practice to limit, mitigate or compensate soil sealing . Institutional inefficiencies is hampering soil sealing management. Was 130 ha/day (97-03) then 93 ha/day (06-09) p90 A lack of restrictive quantitative land take and sealing targets is also due to a lack of acceptance by local decision makers and federal states (see citations). P86 Flexibility is needed with soil sealing target, even though flexibility can hamper ecological sustainability goals at the expense of economic goals. P90 According to Grint (2010), solving wicked problems requires a leader who asks questions and collaborates with others to find solutions to the problem. As urban authorities hold the main responsibility in steering urban soil sealing they should act as leader. P91 Cameron, R., Blanusa, T., Taylor, J., Salisbury, A., Halstead, A., Henricot, B. and Thompson, K. (2012) The domestic garden: its contribution to urban green infrastructure. Urban Forestry and Urban Greening. ISSN 1618-8667 Domestic gardens contribute between 22 and 36% of total urban area. In USA lawns cover between 8 and 16 million ha, far surpassing land coverage of major crops. There may be as much carbon stored within the top 100mm of soil profile alone, as in the entire vegetation biomass above ground. Soil carbon storage is reduced by disturbance, so gardens that mimic forest or are low maintenance, follow permaculture principles have the least impact in terms of CO2 release. Fertilised lawns are thought to emit up to 10 times more N2O than neighbouring grasslands, mostly because of higher irrigation rates and soil temperatures. This doesn’t include the energy intensive production of nitrogen based fertilisers. Phosphate and potassium fertilisers is 20-fold less energy intensive. Although vegetation and trees hold water temporarily in canopies during flood events, and soil reduces surface flow, front gardens are increasingly being paved over (75% of the 13% increase of hard surfaces in Leeds UK in 2008 was due to people paving over front gardens). Leeds subsequently endured more severe flooding. Lower-density housing has 3-fold less storm water run-off than high-density… (the density conundrum). Since 2008 you need permission to lay impermeable paving in the UK. Small city centre gardens support much the same invertebrate wildlife as large suburban ones. In Manhattan gardens with sunny, flower-rich patches supported diverse pollinator communities, and in Toronto, small microcosms (sun filled pots with or without vegetation) introduced into gardens recruited plants, seeds and invertebrates in much the same way as those placed in grassland or forest. Chen, Y., Day, SD., Shresta, RK., Strahm, BD., Wiseman, PE 2014 ‘Influence of Urban Land Development and Soil Rehabilitation of Soil-Atmosphere Greenhouse Gas Fluxes Geoderma 226-227, 348-353 A significant element of land use change is the soil disruption that typically accompanies urban land development, including topsoil removal and replacement, grading, compaction and construction. Soil movement and post-development soil treatment can have profound effects upon soil carbon stores. P348 Although soil co2 emissions will vary significantly by region, it is still unclear whether urban soils are a net co2 source or sink and whether this is primarily influenced by management inputs or the initial process of urbanisation. P349. Soils are a ch4 methane sink. LOCII MELBOURNE Claessens J, Schram-Bijkerk D, Dirven-van Breeman L, Otte P, van Wijnen H ‘The soil-water system as basis for a climate proof and healthy urban environment: Opportunities identified in a Dutch case study’ Science of the Total Environment 485-486 (2014) 776-784 Unsealed soil and green spaces increase water storage capacity and can consequently prevent flooding. The planning of public or private green spaces can have a cooling effect and, in general, have appositive effect on how people perceive their health. In practice, technical interventions are often chosen to combat flooding rather than the existing soil-water system p779 Municipal soil management plans often put the chemical quality of the soil at the centre and devote less attention to sustainable land use. In order to put the natural soil-water system to optimum use, ambitions in te field of water storage should be linked to ambitions in the field of soil and green spaces. P.783 An important part of sustainable land use is, for example, the water storage ability of the soil, which combats flooding but also drought. P783 Cordell, Dana; White, Stuart. 2011. “Peak Phosphorus: Clarifying the Key Issues of a Vigorous Debate about Long-Term Phosphorus Security.”Sustainability 3, no. 10: 2027-2049. Estimates of depletion timeline for phosphate rock reserves rang from 30-300 years. Timeline is shrouded by lack of publically available data and substantial uncertainty. There is general consensus that the quality and accessibility of remaining reserves are decreasing and costs will increase. p2027 Phosphorus is essential for all life. There is no substitute for phosphorus in crop growth and therefore in food production. Phosphorus cannot be manufactured (or destroyed). p2028 80% of the phosphorus in rock never reaches the food consumed by humans p2041 To meet future demand: rely less on phosphate rock, reuse manure/human excreta/crop residues/food waste, change diet, efficiency of food chain, efficiency of agriculture. p2044 Edmondson, JL, Davies ZG, Gaston KJ, Leake JR 2014 ‘Urban Cultivation in Allotments Maintains Soil Qualities Adversely Affected By Conventional Agriculture’ Journal of Applied Ecology 2014 51, 880-889 Modern agriculture, in seeking to maximise yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own-growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown. Maintenance and protection of the quality of our resource is essential for sustainable food production and for regulating and supporting ecosystems services upon which we depend. Our study establishes, for the first time, that small scale urban food production can occur without the penalty of soil degradation seen in conventional agriculture, and maintains the high soil quality seen in urban green spaces. Given the involvement of over 800 million people in urban agriculture globally, and its important contribution to food security, our findings suggest that to better protect soil functions, local, national and international urban planning and policy making should promote more urban own-growing in preference to further intensification of conventional agriculture to meet increasing food demand. McBride et al 2014 ‘Concentration of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables’ Environmental Pollution 194 (2014) 254-261 The poor relationship between vegetable and soil metal concentrations is attributable to particulate contamination of vegetables and soil characteristics that influence phytoavailability. LOCII MELBOURNE Urban garden soils can be moderately to severely contaminated nu one or more metals, with lead, cadmium, and mercury reported to be most likely to pose some hazard for human health (see citations) p254 However despite some success in linking concentrations of metals in vegetable crops to soil contamination levels, the results overall have been inconsistent, particularly for lead (see citations) p254 For most garden soils, crop type as proven to be a stronger determinant of the edible crop metal concentration than soil contamination level (see citations) p255 Hazelton P and Murphy B 2011 Understanding soils in urban environments. CSIRO Publishing, Australia Failure of soils can impact cities by damaging buildings, roads, landslip, poor water quality, soil contamination, dryland salinity, degraded ecosystems p1 Soils affect urban ecosystem functions by (p5): a. -absorbing rain to prevent floods b. -absorbing effluents and pollutants c. -nourishing parks and gardens d. -natural habitat protection of conservation areas Contaminants in soils influenced by clay content, organic material, iron, manganese oxides, ionic strength, redox potential and pH p84 Organic contaminants eg dioxins, result from industry eg. Petrol, fuels, oils, solvents. These are toxic, hydrophobic, 0-20 years, bioaccumulative p85-86 The nature of an ecosystem determined by many parameters including soil type, sunlight, temperature, elevation, rainfall and seasonal variation in climate. These parameters determine the various nutrients, their quantities and movement within a natural ecosystem p97 Heat islands within cities can have an impact on soil temp, changing soil quality and soil health p102 Montgomery, D 2008 Dirt – The Erosion of Civilization University of California Press A civilisation can persist only as long as it retains enough productive soil to feed its people. P23 The estimated rate of world soil erosion now exceeds new soil production by as much as 23 billion tons per year, an annual loss of not quite one percent of the world’s agricultural soil inventory (xii). P4 At this rate will run out in a century. Given that the state of soil determines what can be grown for how long, preserving the basis for the wealth of future generations requires intergenerational land stewardship. p4 Soil loss is not inevitable. Society still prioritises production over long-term stewardship of the land. P176 Every dollar invested in soil and water conservation can save 5 to 10 times that amount in costs associated with dredging rivers, building levees and flood control in downstream areas p211 The only ways around the boom and bust cycle that has characterised agricultural societies are to continuously reduce the amount of land needed to support a person, or limit population and structure agriculture so as to maintain a balance between soil production and erosion. P237 Today, roughly 6 billion people and 1.5 billion hectares of cultivated land (0.25ha to feed each person). The worlds most intensively farmed areas ca get to 0.2ha per person which would feed 7.5b people if it becomes the norm. BUT at our projected loss of cropland by 2050 we will only have 0.1ha available. P239 This is where cities can help. Poggio, L, VrA Aaj, B, Hepperle, E, Schulin, R, Marsan, FA, ‘Introducing a method of human health risk evaluation for planning and soil quality management of heavy metal-polluted soils- An example from Grusgliasco (Italy)’ Landscape and Urban Planning. Dec 1, 2008, Vol. 88 Issue 2-4, p64 Land use always had a strong influence on soils. In most areas, it is the main factor in today’s soil quality p64 The most important factors influencing health risks that arise from soil contamination are: land use, potential occupancy by children, bioavailability of contaminants, potential exposure pathways and state of the site surface (eg paved, with grass or exposed). P65 LOCII MELBOURNE Soil is only one of the sources of exposure to contaminants. The risks due to soil contamination and the costs of dealing with soil contamination need to be kept in proportion with the total exposure to contaminants from all sources. P65 The implementation of human health risk information into urban planning would facilitate the development of healthy and sustainable urban environments (Wong et al 2006) A decline in environmental quality within the city will eventually worsen the living conditions of the population (see citations) p65 Less expensive remediation option is change of land use to disrupt source-receptor pathway. P70 Potentially Contaminated Lands Advisory Committee Potentially Contaminated Lands Advisory Committee Report 9 March 2012 http://www.dtpli.vic.gov.au/planning/panels-and-committees/recent-panels-andcommittees/potentially-contaminated-land-advisory-committee Recommends changes in identifying sites, applying a precinct-based approach, applying risk-based approach, dealing with groundwater, dealing with service stations, enforcement, amending Ministerial Direction No 1 and Environmental Audit Overlay. Rawlins BG, Harris J, Price S, Bartlett M ‘A review of climate change impacts on urban soil functions with examples and policy insights from England UK Soil Use and Management 2013 doi:10.1111/sum.12079 Urban soils are very likely to be subject to more extreme variations in climate over the coming decades p1 Climate change direct impacts include variations in soil moisture because of variations in precipitation, evapotranspiration and erosion. p2 The rising cost of food and the movement towards consumption of locally produced food from domestic gardens (Hopkins 2008), which typically account for 22-27% of land in urban areas on the UK could substantially enhance primary production and associated nutrient cycling in urban soils. p3 Carbon storage in urban soil could be enhanced by the application of fine demolition wastes to soil leading to the formation of inorganic carbonate (Manning 2008) p3 Construction processes increase the susceptibility of soil to sealing through compaction p4 Sealing causes loss of soil function as it introduces a physical barrier between soils and the atmosphere, reducing their capacity to exchange air and water (Wood et al 2005). P3 Little is clearly understood concerning the role of soils in disease regulation because of the exposure of human populations to microbial ecology and genotoxic hazards p4 p11 Shrink swell factors are (1) subsoil properties (amount and type of clay particles) (2) climate variables (temp, rainfall and solar radiation) leading to change in soil moisture (3) uptake of water by roots leading to changes in soil moisture p5 Prolonged periods of dry weather during summer months are known to increase soil hydrophobicity which may enhance rapid runoff in urbanised catchments p7 Soil organic matter has a key functional role for urban soils as both a nutrient reserve and as buffering capacity to contaminants (Craul 1985). Soil microbial communities are clearly different in the urban setting compared with those found in rural ones, but it is not clear how these differences are functionally manifested p7 Rates of ingestion of soil by children is relatively high, 95% of the population consume 208 mg/day or less, with a mean estimated intake of 45 mg/day or less (Stanek and Calabrese 1995) Currently there is a lack of understanding and experience of ecosystem structure and function in planning departments in part because of the lack of tools suitable to support ‘ecosystem goods and services’ based approaches to planning. P11 LOCII MELBOURNE For many urban soil function, our knowledge of the soil processes (eg organic matter turnover, biodiversity) governing them is still insufficient for us to be confident in making predictions relating to the direction of any change (Kaye et al 2006) p12 As urbanisation continues through the 21st century, governments urgently need to consider how best to monitor urban soils and their functions. P12 Setala, S, Bardgett, RD, Birkhofer K, Brady, M, Byrne, L, de Ruiter, PC, de Vries, FT, Gardi, C, Hedlund, K, Hemerik, L, Hotes, S, Liiri, M, Mortimer, SR, Pavao-Zuckerman, M, Pouyat, R, Tsiafouli, M, van der Putten, WH ‘Urban and Agricultural Soils: Conflicts and Trade-Offs in the Optimization of Ecosystem Services’ Urban Ecosystem (2014) 17:239-253 Despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services. P240 Economic incentives that encourage land managers to recognise and respond to cross scale connections can be applied to balance demands for different types of ecosystem services. To be effective, incentives need to: o Account for relationship between biophysical and economic process p248 o Set up feedback processes o Design to allow costs and benefits for different stakeholder groups to vary through space and time. Landscape design and planning tools can help. Eg, if the spatial arrangement of unsealed soil surfaces in a city is designed in relation to the runoff of water instead of being randomly dispersed or arising from unplanned sprawl development, the infiltration of water into soils during storm events can be maximised (Hatt 2004) Victorian Auditor Generals Office Managing Contaminated Sites December 2011 Victorian Government Printers http://www.audit.vic.gov.au/publications/2011-12/20111207-Contaminated-Sites/20111207Contaminated-Sites.html Around 80% of situations involving contaminated sites are dealt with through the planning element of the framework, and the remaining 20% are dealt with through the environment protection element. p.vii an undue emphasis on avoiding legal and financial liability, rather than protecting human health and the environment. p.vii DPCD the EPA and Councils are not effectively managing contaminated sites, and consequently cannot demonstrate that they are reducing potentially significant risks to human health and the environment to acceptable levels. ...this inaction being driven in part by an undue emphasis on avoiding legal and financial liability rather than protecting human health and the environment. p.vii Around 80% of contaminated site issues are being dealt with by councils, as planning and responsible authorities, however, the councils audited did not have the technical capability required to manage the complex issues associated with contaminated sites. Councils therefore rely heavily on legal advice. P.xi Victorian Government Cleaner Environments – Smarter Urban Renewal September 2014 http://www.depi.vic.gov.au/environment-and-wildlife/sustainability/Cleaner-Environments-Smarter-UrbanRenewal Vision: Victoria has an efficient and effective framework for managing contaminated environments that facilitates safe and sustainable urban renewal by: o Making it easier to unlock the value of brownfield sites and return them to productive uses o Harnessing redevelopment activity to create cleaner environments o Directing regulation and resources towards a safer environment. LOCII MELBOURNE References Artmann, M 2014 ‘Institutional efficiency of urban soil sealing management – from raising awareness to better implementation of sustainable development in Germany’ Landscape and Urban Planning 131 83-95 Cameron, R., Blanusa, T., Taylor, J., Salisbury, A., Halstead, A., Henricot, B. and Thompson, K. (2012) The domestic garden: its contribution to urban green infrastructure. Urban Forestry and Urban Greening. ISSN 1618-8667 Chen, Y., Day, SD., Shresta, RK., Strahm, BD., Wiseman, PE 2014 ‘Influence of Urban Land Development and Soil Rehabilitation of Soil-Atmosphere Greenhouse Gas Fluxes Geoderma 226-227, 348-353 Claessens J, Schram-Bijkerk D, Dirven-van Breeman L, Otte P, van Wijnen H ‘The soil-water system as basis for a climate proof and healthy urban environment: Opportunities identified in a Dutch case study’ Science of the Total Environment 485-486 (2014) 776-784 Cordell, Dana; White, Stuart. 2011. "Peak Phosphorus: Clarifying the Key Issues of a Vigorous Debate about Long-Term Phosphorus Security. "Sustainability 3, no. 10: 2027-2049. Edmondson, JL, Davies ZG, Gaston KJ, Leake JR 2014 ‘Urban Cultivation in Allotments Maintains Soil Qualities Adversely Affected By Conventional Agriculture’ Journal of Applied Ecology 2014 51, 880-889 McBride et al 2014 ‘Concentration of lead, cadmium and barium in urban garden-grown vegetables: the impact of soil variables’ Environmental Pollution 194 254-261 Hazelton P and Murphy B 2011 Understanding soils in urban environments. CSIRO Publishing, Australia Montgomery, D 2008 Dirt – The Erosion of Civilization University of California Press Moonee Valley City Council Land Contamination Strategy 2012 Poggio, L, VrA Aaj, B, Hepperle, E, Schulin, R, Marsan, FA, ‘Introducing a method of human health risk evaluation for planning and soil quality management of heavy metal-polluted soils- An example from Grusgliasco (Italy)’ Landscape and Urban Planning. Dec 1, 2008, Vol. 88 Issue 2-4, p64 Potentially Contaminated Lands Advisory Committee Potentially Contaminated Lands Advisory Committee Report 9 March 2012 http://www.dtpli.vic.gov.au/planning/panels-and-committees/recent-panels-andcommittees/potentially-contaminated-land-advisory-committee Rawlins BG, Harris J, Price S, Bartlett M ‘A review of climate change impacts on urban soil functions with examples and policy insights from England UK Soil Use and Management 2013 doi:10.1111/sum.12079 Setala, S, Bardgett, RD, Birkhofer K, Brady, M, Byrne, L, de Ruiter, PC, de Vries, FT, Gardi, C, Hedlund, K, Hemerik, L, Hotes, S, Liiri, M, Mortimer, SR, Pavao-Zuckerman, M, Pouyat, R, Tsiafouli, M, van der Putten, WH ‘Urban and Agricultural Soils: Conflicts and Trade-Offs in the Optimization of Ecosystem Services’ Urban Ecosystem (2014) 17:239-253 Victorian Auditor Generals Office Managing Contaminated Sites December 2011 Victorian Government Printers http://www.audit.vic.gov.au/publications/2011-12/20111207-Contaminated-Sites/20111207-Contaminated-Sites.html Victorian Government Cleaner Environments – Smarter Urban Renewal September 2014 http://www.depi.vic.gov.au/environment-and-wildlife/sustainability/Cleaner-Environments-Smarter-Urban-Renewal Prepared by Sheridan Blunt, Locii Melbourne [email protected] LOCII MELBOURNE