Maximising the environmental benefits of gardens through optimal planting choices and understanding of occupants' engagement

背景家庭花园占英国大多数城镇总面积的15%-25%。大多数英国人都是城市人(80%)，而且有权使用家庭花园(85%)，所以我们种植的植物和如何管理我们的花园可能会对环境产生重大影响。最近的研究1，2将某些园林植物特征(例如，叶片多毛或高蒸散速率)与提供生态系统服务的能力联系起来，包括降雨捕获、局部降温或去除空气中的污染物。在花园中更多地使用具有特定环境效益的植物，不仅可以减少极端天气和污染带来的环境风险，还可以增加城市空间的可持续性。我们知道，一些园林植物物种具有非常有益的特征，但单一物种的“单一栽培”也是不可取的。因此，对有前途的物种在更广泛的群落结构中的表现进行评估是至关重要的。此外，越来越极端和不可预测的天气条件要求同一花园空间提供一系列功能。不幸的是，英国皇家园艺学会最近的一项调查显示，花园中的植被覆盖率有所下降。植被消失在铺路上，对控制洪水、城市温度和大气污染造成不利影响3。需要给园丁提供新的证据和明确的建议，以扭转国内园艺提供的生态系统服务的下降。学生将在受控实验条件下研究对比园艺植物群落，以描述它们提供的环境效益的范围。植物将作为单一物种单一栽培和混合种植，其降低空气和土壤温度、减少雨水径流和消除颗粒状空气污染物的能力将被调查，并与非植被地区进行比较。详细的工作将集中在评估植物特性(树冠大小/密度、叶片形状和表面特性、根系类型)如何决定性能以及它们如何与种植组合相互作用。显然，由于家庭花园的所有种植决定都是由业主或在业主的要求下做出的，这个项目将研究业主/房东对调查的种植策略的态度。这项研究的一个关键要素将是了解房主可能会如何“推动”做出支持他们所在社区的社会和生态利益的决定。例如，要调查的植物群落可以是具有小的或多毛的叶子的地中海风格的植物，或者具有大而无毛的叶子的‘大胆风格’植物。可以研究单一物种单一培养、同一类型的多物种混合以及两种类型的混合物种，以了解它们的相对性能。我们将描述它们的环境效益、易于建立和管理的特点，并将其与非植物花园的铺面区域进行比较。该项目的特点是学术界与英国最大的园艺慈善机构皇家园艺协会密切合作。因此，除了科学发现，该项目的主要成果之一将是向RHS成员提供关于简单而实用的解决方案的建议，这些解决方案将鼓励房主开发他们的花园空间，以最大化环境收益。2019年(doi.org/10.1016/j.ufug.2019.126391)；2017年(doi.org/10.1016/j.enBuild.2017.02.011)；3卡梅伦和布兰努萨2016年(doi.org/10.1093/aob/mcw129)

BackgroundDomestic gardens form 15-25% of total area of most UK towns and cities. Most of the UK population is urban (>80%) and has access to domestic gardens (>85%), so what we plant and how we manage our gardens can have a significant environmental impact. Recent research1,2 links certain garden plant characteristics (e.g. leaf hairiness or high evapotranspiration rate) with the capacity to provide ecosystem services including rainfall capture, localised cooling, or removal of airborne pollutants. Increased use of plants with specific environmental benefits in gardens would not only reduce environmental risks posed by extreme weather and pollution, but also increase sustainability of urban spaces.We know that some garden plant species possess highly beneficial traits, but also that 'monocultures' of single species are undesirable. An evaluation of promising species' performance within a wider community structure is thus essential. Moreover, increasingly extreme and unpredictable weather conditions require a range of functions to be delivered by the same garden space. Unfortunately, a recent Royal Horticultural Society survey shows a decline in garden vegetative cover. Vegetation is lost to paving, with detrimental effects on the control of flooding, urban temperature and atmospheric pollution3. New evidence and clear advice to gardeners is needed to reverse the decline in ecosystem service provision by domestic gardens.Approach The student will study contrasting garden plant communities in controlled experimental conditions to describe the range of environmental benefits they provide. Plants will be grown as single species monocultures and as mixtures, and their ability to reduce air and soil temperatures, reduce rainwater run-off and remove particulate air pollutants will be investigated and compared to non-vegetated areas. Detailed work will focus on assessing how plant traits (canopy size/density, leaf shape and surface properties, root system type) determine performance and how they interact with planting combinations. Clearly, as all planting decisions in a domestic garden are taken by or at the behest of the owner, this project will research the attitude of homeowners/landlords towards investigated planting strategies. A key element of the study will be understanding how homeowners may be 'nudged' towards making decisions that support social and ecological benefits in their neighbourhood.As an illustration, plant communities to be investigated could be 'Mediterranean style' plants with small or hirsute leaves or 'Bold style' plants with large, glabrous leaves. Single species monocultures, multiple species mixtures of the same type and a mixture of species of both types can be studied to understand their relative performance. We will characterise their environmental benefits, ease of establishment and management, and compare these to paved areas representative of non-vegetated gardens. The project features close collaboration between academia and the Royal Horticultural society - UK's largest gardening charity. Thus, alongside scientific discovery, one of the main outcomes of the project will be advice to RHS membership on simple and practical solutions which would encourage homeowners to develop their garden space to maximise environmental gains.1 Blanusa et al. 2019 (doi.org/10.1016/j.ufug.2019.126391); 2 Vaz Monteiro et al. 2017 (doi.org/10.1016/j.enbuild.2017.02.011); 3 Cameron and Blanusa 2016 (doi.org/10.1093/aob/mcw129)