Wendy McWilliam

Suburban residential streets have long been criticised for their multiple short-comings, including traffic-related injury, increased stormwater runoff, and lack of aesthetic values. Research suggests that Integrated Green-Grey Infrastructure (IGGI) is likely to play a role in mitigating these problems. IGGI refers to infrastructure that consists of both natural materials (such as plants, soil) and human-made structures (such as concrete, pipes). However, IGGI’s definition remains vague, and little is known about its implementation in suburban street retrofitting, and how effective it is. Using a systematic literature review method, this paper analyses peer-reviewed journal articles published over a period of ten years between 2014 and 2023. The objective was to understand IGGI’s definition, integration, and effectiveness in implemented residential street retrofitting projects. Through a rigorous screening process, 15 papers were selected for qualitative analysis. Clusters developed in analysing the results consist of IGGI’s concepts, components, integration and effectiveness. The most notable subject area is system-scale integration, shared by 14 papers. Findings regarding the effectiveness of IGGI suggest strong empirical evidence related to stormwater management and road user behavioural change; however, there were mixed perceptions toward the aesthetic values of rain gardens.

Wine grape ecosystems with low species richness and reliance on agrichemicals have weak resilience to environmental impacts. Increasing biodiversity through green infrastructure (GI) not only helps mitigate some of these impacts but can provide additional benefits to growers and the public. Despite this, many vineyards have limited GI. While scholars suggest incentive programmes may help to encourage GI implementation, few studies have evaluated their effectiveness. We surveyed winegrowers and their vineyards in the Waipara Valley sub-region, New Zealand, to evaluate an incentive programme aimed at increasing GI on vineyards, particularly indigenous vegetation. The results indicated the programme was effective in encouraging growers to plant indigenous plants in areas incapable or unsuitable for growing grapes, largely in support of nature conservation, aesthetics, branding, and sales. It was less successful in encouraging growers to plant them in productive areas. While substantial GI, primarily in the form of inter-row cover crops, was managed in these areas, most were exotic plants seen by growers to provide superior services (especially erosion control, weed suppression and pest regulation) at lower management complexity and cost. Growers identified six GI enablers: (1) promoting GI types that provide greater grower services than disservices and costs of implementation and management; (2) implementing GI where biophysical conditions support success; (3) providing assistance with plant selection and design; (4) providing GI implementation and/or management funding; (5) developing GI certification policies and regional association programmes; and (6) providing government GI regulations, strategies, and incentives. They also identified five barriers: (1) insufficient grower appreciation for indigenous GI services; (2) grower concerns that some GI disservices were greater than their services; (3) grower belief that costs of GI implementation and/or management were greater than those of alternative practices; (4) harsh and remote GI growing conditions; (5) lack of grower knowledge regarding how to design plantings, especially those that could provide multiple services; and (6) lack of sufficient financial resources for GI implementation and/or management. Twenty recommendations for improving GI implementation are provided.

Marginal hill farmland is a key target for the restoration of temperate indigenous forest, which can help mitigate climate change and biodiversity loss. Reliance on natural regeneration and minimum interference management (MIM) is a low‐cost restoration strategy for farmers, with the transition from pasture to woody scrub vegetation (whether indigenous or exotic) an important early successional phase. However, few studies have determined the key factors that influence the regeneration of woody vegetation on pastoral farmland, nor the rate at which regeneration occurs. Using a geospatial analysis of a New Zealand pastoral hill farm subject to variable grazing and MIM, this study found that only 3.8% of grassland experienced detectable regeneration of woody vegetation over 16 years. The key factor influencing natural regeneration was proximity to existing woody vegetation, with the probability of regeneration decreasing as distance increased. Cattle grazing had a significant negative impact, with regeneration more likely to occur in areas free from cattle. Sheep grazing exhibited no significant positive or negative relationship with regeneration. To support natural regeneration of woody vegetation, landowners should prioritize areas with a higher presence of existing woody vegetation and exclude cattle. To increase the rate of regeneration, landowners should consider active management regimes and supplemental restoration strategies, such as applied nucleation and the introduction of nurse species. Given the increased cost and complexity of such approaches, effective government incentive programmes may be needed to provide landowners with financial support and expertise.

Studies indicate Green Stormwater Infrastructure (GSI) on industrial land can provide substantial adaptive flood mitigation within urban catchments under climate change. To identify a cost-effective adaptive GSI network, planners need to evaluate flood mitigation capabilities of industrial properties through time and understand key characteristics informing when, where, and how GSI should be implemented for maximum effect. We applied the Hydrology-based Land Capability Assessment and Classification (HLCA+C) methodology to a catchment in Christchurch, New Zealand, to evaluate the capabilities of industrial properties clustered into Storm Water Management (SWM) zones under different climate change scenarios. SWM zone potentials and limitations were assessed to develop the most capable adaptive flood mitigation network with climate change. We prioritised six of twenty SWM zones for inclusion in the network based on their substantial flood mitigation capabilities. To maximise their capabilities through time, we orchestrated, and implemented GSI in zones incrementally, using different implementation approaches based on key characteristics determining their capability. The results indicated that the most capable zone could mitigate climate change-induced flooding, by itself, up to the end of this century under the moderate climate change scenario. However, if its capability was combined with that of five others, together they could mitigate flooding just shy of that associated with the major climate change scenario up to the end of this century. The resulting adaptive industrial GSI network not only provides substantial flood protection for communities but allows costly investments in flood mitigation structures, such as barriers and levees, to be safely delayed until their cost-effectiveness has been confirmed under increased climate certainty.

Current flood protection capacities will become inadequate to protect many low-lying coastal cities from climate change-induced flooding in the future. Under climate change uncertainty, an adaptive strategy is required to provide supplemental flood mitigation. Green Stormwater Infrastructure (GSI) in developed areas has the potential to provide substantial catchment runoff reduction. However, individual properties vary in their Flood Mitigation Capability (FMC) depending on their land characteristics. An effective methodology is needed to evaluate the FMC of properties to help urban planners determine which to target for GSI and when to implement GSI in light of increased climate change impacts. We advance the Hydrology-based Land Capability Assessment and Classification (HLCA+C) methodology for evaluating the FMC of large properties over the long term (80 to 100-year). It builds on the strengths of existing methodologies and uses a land unit analysis approach for assessing FMC, considering interdependent hydrological and geographical variables. The FMC classification system groups properties with similar flood mitigation characteristics, helping urban planners to understand their potentials and limitations for flood mitigation toward the development of adaptive strategies through time. Step-by-step instructions demonstrate how to apply the methodology to any low-lying coastal city.

Soil acts as the integrator of processes operating within the biological and hydrological landscapes and responds to external disturbances and processes on varying time scales. The impact of any change results in a corresponding response in the system; which is dependent on the resistance of the soil system to the disturbance. Irreversible permanent change results when the soil system shifts over a threshold tipping point; with the soil system experiencing a regime shift with associated structural and functional collapse. Climate change is the most important external disturbance or stressor on these systems due to changes in precipitation, temperature and moisture regimes. Our research at Mt Grand is focused on approaches to increasing land use resiliency in the face of environmental change. Our purpose is to select and apply soil quality indices which can be used to assess soil resilience to external disturbance events for Mt Grand Station in New Zealand. We will identify biophysical variations and landscape drivers in soil resilience; and use these results to match land management practices with variations in soil resilience. For example, soils with low resilience will only have land management practices that have a low impact on the soil resource. We selected soil attributes that represented indicators of resistance, used to quantify the capacity of a soil to recover its functionality. We mapped this soil resilience framework against a national database of soil and landscape attributes for Mt Grand Station. The output from this research is to posit a conceptual framework of soil quality indices which relates to soil resilience, and thus to create a spatial map of soil resilience for Mt Grand Station.

Substantial environmental impacts and loss of resilience occurs with conventional vineyard designs characterized by monotonous specialized production. Studies support the restoration of green infrastructure (GI) and introduction of other production systems as promising biodiversity design strategies. However, little is known about the degree to which winegrowers are implementing them. We surveyed Willamette valley, Oregon, certified sustainable winegrowers as potential early adopters of innovative biodiversity design strategies. Results revealed growers were implementing up to 11 different types of GI components, providing them with up to 16 different ecosystem services, and six disservices. The GI was implemented at three spatial scales, with growers pursuing a sharing GI design strategy at fine scales, and a sharing and sparing strategy at intermediate and farm-wide scales. Only biodynamic certified farmers had implemented valued additional production systems. Growers can improve the implementation of their biodiversity GI designs by adopting an integrated multi-system whole farm design approach. Key enablers for grower implementation of GI and/or additional production systems included: (1) Grower awareness and value of strategy’s ecosystem services and functions, (2) grower knowledge of their design and management, (3) certifier requirements for GI, (4) availability of land incapable of growing quality grapes, (5) availability of GI backup systems in case of failure, (6) low risk of regional pest outbreaks, (7) premium wine prices, and (8) strong grower environmental and cultural heritage ethics. Further research is required to identify effective ways to advance these enablers among growers, and within certification and government programmes, to improve the implementation of these strategies among growers.

There is a high and growing incidence of skin cancer associated with overexposure to the sun. Most of a person’s exposure occurs during their first eighteen years of life. While many children are taught to wear hats and sunscreen, studies indicate these are inadequate. There is a pressing need to improve the design of our landscapes to reduce exposure. Landscape architects can play a key role in driving this process, but only if they understand the factors determining sun protection behaviours among children in the landscape, and how to design for these. We introduced a systematic evidence-based teaching approach to landscape architecture students in New Zealand where the incidence of skin cancer is one of the highest in the world. In this paper, we describe the methods we used to integrate scientific information into a creative design process that included four design phases: (1) review, summary and translation of evidential theory into design guidelines; (2) inventory and analysis of existing schoolyard; (3) redesign of schoolyard; and (4) final design evaluation. We found this process was effective in developing student appreciation for the need to improve sun protection through design, for increasing their understanding of the evidential science, in addition to developing their ability to translate, often inaccessible, evidential data into its spatial form implications. Furthermore, the process led to a high degree of confidence and pride among many students as their resulting design solutions were not only supported by evidence but were often highly creative. Such evidence-based design courses are essential for preparing future landscape architects to design landscapes that significantly reduce the incidence and health effects of skin cancer.