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

背景英国大部分城镇和城市的家庭花园占总面积的15-25%。英国大部分人口都是城市人口（>80%），并且可以使用家庭花园（>85%），因此我们种植的植物以及我们如何管理花园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，局部冷却或去除空气中的污染物。在花园中增加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，还可以提高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性，但单一物种的“单一栽培”是不可取的。因此，必须在更广泛的群落结构内评价有希望的物种的表现。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，皇家园艺学会最近的一项调查显示，花园植被覆盖率下降。铺路时失去了植被，对控制洪水、城市温度和大气污染产生了不利影响3。新的证据和明确的建议，园丁需要扭转国内gardens.Approach生态系统服务提供的下降，学生将研究对比实验条件下的园林植物群落，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，它们降低空气和土壤温度、减少雨水径流和清除颗粒空气污染物的能力将得到调查，并与无植被地区进行比较。详细的工作将侧重于评估植物性状（冠层大小/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，由于家庭花园中的所有种植决定都是由业主做出或应业主的要求做出的，因此本项目将研究业主/业主对调查种植策略的态度。这项研究的一个关键要素是了解房主如何被“推动”做出支持社区社会和生态效益的决定。作为一个例子，要调查的植物群落可能是“地中海风格”的植物，叶子小或多毛，或者是“大胆风格”的植物，叶子大，无毛。可以研究单一物种的单一栽培、同一类型的多个物种的混合物以及两种类型的物种的混合物，以了解它们的相对性能。我们将评估它们的环境效益，建立和管理的便利性，并将其与代表非植被花园的铺砌区域进行比较。该项目的特点是学术界和英国最大的园艺慈善机构皇家园艺协会密切合作。因此，除了科学发现外，该项目的主要成果之一将是向RHS成员提供关于简单实用的解决方案的建议，这些解决方案将鼓励业主开发他们的花园空间，以最大限度地提高环境效益。1 Blanusa et al. 2019（j.ufug.2019.126391）; 2 Vaz Monteiro et al. 2017（doi.org/10.1016/j.enbuild.2017.02.011）; 3卡梅隆和Blanusa 2016（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)