Orchards and allotments show similar benefits to parks and other open areas regarding their environmental and partly social benefit, as they are comprised of similar structural elements (trees, shrubs, meadow like areas) and therefore exhibit similar properties in terms of infiltration and water quality. However, what makes these types of urban green spaces unique is the social and cultural aspect of food production and land ownership in an otherwise urban environment. The ecosystem services provided depend on how the allotments/orchards are used and guidance for allotment owners and users should be considered within the management of surface water and multiple ecosystem services.
While allotments are not freely accessible, they provide significant health benefits to a wide number of people, especially in an older age group. They provide an important space to form community ties and social cohesion. (3,5,6,7)
Air quality is not a significant benefit provided by allotments, hover they can have an impact on a regional scale, with trees being able to filter pollutants. Orchards are likely to have a more significant impact. (3,13)
Open surfaces allow infiltration and can increase groundwater recharge, therefore improving low flow conditions. Infiltration on vegetated areas is 20%+ higher than on impermeable ground, and grassed areas have been shown to have the potential to nearly completely eliminate runoff. (3,4,15,16,17,18)
Allotments can only contribute to reducing fluvial flood risk by infiltrating water before it reaches streams. (17)
Allotments and orchards provide mitigation of the UHI effect by lowering air temperatures and allowing influx of fresh air, and store carbon in vegetation and soils. This benefit is likely to be greater from orchards. (3,14)
Allotments and orchards can provide great habitats for pollinators and other insects as well as mammals, birds and amphibians etc. More plant species have been found in allotments than in parks in a study in Manchester, although no rare species were found.(2,3)
Infiltration can enable groundwater recharge and so have a positive impact on low flows.
Bioretention can improve water quality in many aspects, and it is likely that similar processes occur in allotment soils. Water and with it pollutants are captured by existing vegetation this can be increased by installing filter and buffer strips in runoff pathways. (3,4,16)
The aesthetic quality of a site is the second most important aspect in choosing an allotment site, it can therefore be inferred that they generate significant aesthetic benefits.(6,7)
Growing food is an – in urban environments rare – cultural and educational activity and allotments are often used to experiment with exotic as well as native species. (5,6,7,8,9,10)
Attractive views of green spaces have been shown to increase property values by 10+%, however there is no specific literature on the effect of allotments. (19)
By reducing the impermeability of an urban area, allotments can help to reduce severity of floods.(17)
Considering the Bigger Picture
The high land take of allotments makes them unlikely to be used on a large scale. As they cover a significant amount of land, they have the potential to contribute locally not only by infiltrating runoff and providing amenity benefits but also provide the opportunity to incorporate other interventions – e.g ponds, swales – within them, maximising multiple benefits.
As they are not accessible to the public, certain benefits – access, social cohesion, education, … – can only be provided on a fairly limited scale. However, this is likely to benefit particularly older demographics, which can be an important aspect
Allotments, like parks, provide prime opportunities to incorporate multiple interventions in one area and overall reach a provision of benefits that is greater than the sum of its parts. Filter strips and swales can be incorporated to provide initial treatment and lead surface water off to further storage or treatment areas like ponds, that can also enhance the quality of allotments as a habitat for wildlife. Allowing some areas to be set aside for this, along with natural vegetation, can also help the allotment owners: natural pest control reduces the need for pesticides, and the natural environment around them allows a connection to nature and relaxation. Of course, this has to be done while ensuring that plots are not at risk and pests are not encouraged.
Below, you see some of the multitude of additional benefits that trees provide in the context of the urban landscape.
The cost of allotments or orchards are hard to estimate and are more dependent on the opportunity costs from lost opportunities for housing/commercial develop-ment. Users of allotments pay for accessing the space, with fees varying in different areas but on average between £30-£40 for a 250m2 plot (2).
The main factor determining the feasibility of allotments is the availability of suitable land. Demand is usually given, with many allotments having waiting lists for plots. Opportunities for new creation are undeveloped land or reclaiming of previous allotment sites, as well as protection of existing sites.
As allotments are managed privately, maintenance costs depend on the individual owner.
Avoiding soil compaction, planting and maintaining buffer strips and allowing wild habitat can maximise provision of ecosystem services.
Trade-offs and Potential Dis-services
Allotments have been shown to generate a sense of pride, engagement with nature and an increased well-being is reported by 80% of allotment gardeners. They are especially important as community resources and generate multi-cultural meeting spaces.
People who own an allotment eat more fresh fruit and vegetables than those who 0don’t. A study in Manchester has quantified the economic benefit of food production on allotments to be on average 698£ per plot and year (3). Another report has found the total food production in London in urban gardens to be £1.4 million per year.
The use of pesticides and fertilizer can have a negative impact on the water quality of receiving systems. Organic fertilizer and pest control through natural mechanisms (e.g. providing habitat for natural predators) should be encouraged.
Allowing runoff to collect in allotments is only viable as long as the area does not suffer from permanent waterlogging. Hydraulic connectivity should be as high as possible, and structures increasing infiltration – e.g. trees or infiltration trenches – as well as storage structures like ponds should be incorporated.
- Environment Strategy Unit Chichester District Council (no date) A Guide to Setting up and Managing a Community Orchard.
- Natural England (2007). Wildlife on Allotments. This document gives guidance on obtaining an allotment and making it a valuable resource for wildlife, advising that prizes for a plot of 250m2 are on average between £30 and 40, but can be much higher in dense areas. The habitat can be enhanced by installing nesting boxes, hedgerows, ponds or similar, and the report gives further guidance on what plants to use and how to manage a plot in order to encourage biodiversity.
- Speak, A. F., Mizgajski, A. and Borysiak, J. (2015) ‘Allotment gardens and parks: Provision of ecosystem services with an emphasis on biodiversity’, Urban Forestry & Urban Greening, 14(4), pp. 772–781.This study is an attempt to assess and compare the ecosystem services provided by AGs in Manchester, UK, and Poznań, Poland as well as a comparison to city parks. The results of this study show that AGs can be highly species-rich environments and may offer a method of food production that does not incur as many trade-offs with biodiversity as other land uses. The study also shows that the highest potential for benefits arises from provisioning and cultural services, e.g. generating knowledge, recreation, food production and genetic resources. It is worth noting that many of the additional ecosystem services beyond food production, provided by AGs, have spatial impacts beyond the confines of the gardens. Local climate regulation, flood protection and air quality regulation will especially benefit a large number of local residents in cities at the neighbourhood scale.
- Ashley, R. M., Nowell, R., Gersonius, B. and Walker, L. (2011) ‘Surface Water Management and Urban Green Infrastructure’, 44(0), pp. 1–76.This report investigates the benefits of urban green infrastructure, specifically with regards to the management of surface water quantity and quality.
- Social Benefits:
- van den Berg, A. E., van Winsum-Westra, M., de Vries, S. and van Dillen, S. M. E. (2010) ‘Allotment gardening and health: a comparative survey among allotment gardeners and their neighbors without an allotment.’, Environmental health : a global access science source, 9, p. 74.After adjusting for income, education level, gender, stressful life events, physical activity in winter, and access to a garden at home as covariates, both younger and older allotment gardeners reported higher levels of physical activity during the summer than neighbors in corresponding age categories. The impacts of allotment gardening on health and well-being were moderated by age. Allotment gardeners of 62 years and older scored significantly or marginally better on all measures of health and well-being than neighbors in the same age category. Health and well-being of younger allotment gardeners did not differ from younger neighbors. The greater health and well-being benefits of allotment gardening for older gardeners may be related to the finding that older allotment gardeners were more oriented towards gardening and being active, and less towards passive relaxation.
- Ferres, M. and Townshend, T. G. (2012) ‘The social, health and wellbeing benefits of allotments: five societies in Newcastle’, School of Architecture, Planning and Landscape, 47, pp. 1–47.This report investigates the benefits of having an allotment for residents of Newcastle. It seeks to fill a gap in the knowledge around why people choose to maintain an allotment. Three main reasons were identified: growing one’s own food, enjoyment of the activity itself, and dedicating time to relaxation and exercise. In the study, 79% of participants state they obtain psychological or spiritual benefits from having an allotment and 72% state they gain physical benefits. However, allotment holders also have concerns regarding the future of the allotments in Newcastle, with many people saying that the biggest threat comes from development pressure by local councils.
- Ferris, J., Norman, C. and Sempik, J. (2001) ‘People, Land and Sustainability: Community Gardens and the Social Dimension of Sustainable Development’, Social Policy & Administration, 35(5), pp. 559–568.Community gardens vary enormously in what they offer, according to local needs and circumstance. This article reports on research and experience from the USA. The context in which these findings are discussed is the implementation of Local Agenda 21 and sustainable development policies. In particular, emphasis is given to exploring the social dimension of sustainable development policies by linking issues of health, education, community development and food security with the use of green space in towns and cities. The article concludes that the use of urban open spaces for parks and gardens is closely associated with environmental justice and equity.
- Glover, T. D., Parry, D. C., & Shinew, K. J. (2005). Building relationships, accessing resources: Mobilizing social capital in community garden contexts. Journal of Leisure Research, 37(4), 450-474.This paper explores the role of social capital and formation of relationships in the context of community gardening. CG are presented as settings for building social networks and a knowledge base and can therefore provide important social and cultural benefits.
- Flachs, A. (2010) ‘Food For Thought: The Social Impact of Community Gardens in the Greater Cleveland Area’, Electronic Green Journal, 1(30).This paper explores the social and cultural effects of urban gardening in the greater Cleveland area. Gardening is shown to have a multitude of motivating factors, including economic, environmental, political, social, and nutritional.
- Joe Howe (2002) Planning for Urban Food: The Experience of Two UK Cities, Planning Practice & Research, 17:2, 125-144This article puts urban food growing in the context of the Agenda21 and discusses the role of allotments in urban policy and sustainability. It finds multiple important drivers in using an allotment, and pressures on their development and use.
- Woolley, H., Rose, S., Carmona, M. and Freedman, J. (2004) The Value of Public Space, Exchange Organizational Behavior Teaching Journal. London.This report mentions especially the social benefits of allotment and community gardens as benefits gained from this type of public space. Allotments have for example been shown to encourage cross-cultural community ties.
- Sustain (2014). Reaping Rewards. Can Communities Grow a Million Meals for London? Based on this analysis, and knowledge of the types and sizes of food growing spaces throughout the 2,200+ membership of the Capital Growth network, this report estimates that London’s community food growers could be growing as much as £1.4 million worth of food over the course of a year.
- Forest Research (no date) Improving Air Quality.
- Forestry Commission (20130. Air Temperature Regulation by Urban Trees and Green Infrastructure. Farnham.
- Surface Water Management
- Armson, D., Stringer, P. and Ennos, A. R. (2013) ‘The effect of street trees and amenity grass on urban surface water runoff in Manchester, UK’, Urban Forestry & Urban Greening, 12(3), pp. 282–286. doi: 10.1016/j.ufug.2013.04.001. This study assessed the impact of trees upon urban surface water runoff by measuring the runoff from 9m2 plots covered by grass, asphalt, and asphalt with a tree planted in the centre. It was found that, while grass almost totally eliminated surface runoff, trees and their associated tree pits, reduced runoff from asphalt by as much as 62%.
- Davis, A. P., Shokouhian, M., Sharma, H. and Minami, C. (2001) ‘Laboratory study of biological retention for urban stormwater management.’, Water environment research : a research publication of the Water Environment Federation, 73(1), pp. 5–14. Urban stormwater runoff contains a broad range of pollutants that are transported to natural water systems. A practice known as biological retention (bioretention) has been suggested to manage stormwater runoff from small, developed areas. Bioretention facilities consist of porous soil, a topping layer of hardwood mulch, and a variety of different plant species. Reductions in concentrations of all metals were excellent (> 90%) with specific metal removals of 15 to 145 mg/m2 per event. Moderate reductions of TKN, ammonium, and phosphorus levels were found (60 to 80%).
- Perry, T. and Nawaz, R. (2008) ‘An investigation into the extent and impacts of hard surfacing of domestic gardens in an area of Leeds, United Kingdom’, Landscape and Urban Planning, 86(1), pp. 1–13. doi: 10.1016/j.landurbplan.2007.12.004. A study in Leeds has linked the increase in paved front gardens (and therefore increase in impermeable area) to an increased severity in surface water flooding in that area. A 13% increase in paved area was observed over 33 years, of which 75% is due to paving of front gardens, that lead to a predicted 12% increase of average surface water runoff. This prediction was reflected by actual events in Leeds, where heavy rainfall led to more frequent and severe flooding.
- Yao, L., Chen, L., Wei, W. and Sun, R. (2015) ‘Potential reduction in urban runoff by green spaces in Beijing: A scenario analysis’, Urban Forestry & Urban Greening, 14(2), pp. 300–308. The results show that urban green space offers significant potential for runoff mitigation. In 2012, a total of 97.9 million m3 of excess surface runoff was retained by urban green space; adding nearly 11% more tree canopy was projected to increase runoff retention by >30%, contributing to considerable benefits of urban rainwater regulation. At a more detailed scale, there were apparent internal variations. Urban function zones with >70% developed land showed less mitigation of runoff, while green zones (vegetation >60%), which occupied only 15.54% of the total area, contributed 31.07% of runoff reduction.
- Luttik, Joke. 2000. “The Value of Trees, Water and Open Space as Reflected by House Prices in the Netherlands.” Landscape and Urban Planning 48 (3-4): 161–67.