Nicholas S G Williams

University of Melbourne | MSD · School of Ecosystem and Forest Sciences

Background and aims Wildflower meadows are a low-maintenance landscape treatment that can improve urban biodiversity and achieve conservation outcomes, especially when designed to use plants from threatened grassy ecosystems. Cost-effective approaches to create meadows include direct seeding onto mined sand substrates that are placed onto site soil...

Wildflower meadows support biodiversity in urban environments, whilst providing low‐maintenance, amenity landscapes. By moving from international plant palettes to those that include species from threatened plant communities in meadows, we can reintroduce native species to urban landscapes and help achieve conservation objectives. Adapting horticul...

Green roofs, integrated into conventional buildings, offer valuable thermal benefits, with extensive research and validated models focused on specific climates and summer conditions. However, their applicability requires further refinement, as conflicting year-round performance results have been observed. This study investigates the thermal perform...

Cities provide opportunities for biodiversity conservation through the design of urban greenspaces as wildlife habitat. A significant proportion of urban public land is narrow linear road verges, though their small size and harsh environmental conditions (e.g. high soil temperatures) may limit their ability to support plants and animals. We worked...

Cities can host significant biological diversity. Yet, urbanisation leads to the loss of habitats, species, and functional groups. Understanding how multiple taxa respond to urbanisation globally is essential to promote and conserve biodiversity in cities. Using a dataset encompassing six terrestrial faunal taxa (amphibians, bats, bees, birds, cara...

Green roofs can reduce stormwater runoff in urban areas by capturing rainfall. The extent of this capture is partially influenced by vegetation type and cover, which can be manipulated to optimise run-off reduction. However, in the absence of routine maintenance, planted green roof vegetation is often replaced by 'weedy' spontaneous species with un...

Lack of maintenance can lead to ‘weedy’ spontaneous vegetation on green roofs. Aspects of green roof design, including substrate depth and roof height, have been shown to influence the composition of spontaneous vegetation. In drier climates, Sedum species are often planted on shallow substrate ‘extensive’ green roofs and irrigated during summer to...

Urban biodiversity conservation is critical if cities are to tackle the biodiversity‐extinction crisis and connect people with nature. However, little attention has been paid to how urban environmental managers navigate complex socio‐ecological contexts to conserve biodiversity in cities. We interviewed environmental managers from Australian cities...

The combined challenges of climate change, urban densification, and pandemic-related isolation and stress have strengthened the case for increased greening in cities where their social and environmental benefits have captured the interest of policy-makers. Green roofs, walls, and facades (GRWF) are an established solution in many space-constrained...

Modern cities are dominated by impervious surfaces that absorb, store and release heat in summer, create large volumes of runoff and provide limited biodiversity habitat and poor air quality can also be a health issue. Future climate change, including more frequent and extreme weather events will likely exacerbate these issues. Green infrastructure...

Since the 1990s, recognition of urban biodiversity research has increased steadily. Knowledge of how ecological communities respond to urban pressures can assist in addressing global questions related to biodiversity. To assess the state of this research field in meeting this aim, we conducted a systematic review of the urban biodiversity literatur...

Underutilised public spaces such as streetscapes offer substantial opportunities to integrate habitats that increase biodiversity into existing urban landscapes and create more ecologically connected cities. Cooperation and collaboration from diverse stakeholders are paramount to achieving this because growing conditions for plants in streetscapes...

***************For full article see Share link: https://authors.elsevier.com/a/1f3G%7E5m5d7vr7W*************** Annual plant species have great potential on green roofs as many are highly attractive, fast and cheap to establish via sowing, and can provide rapid cover and growth, which is important for ecosystem service provision. While irrigation i...

Surveys aimed at finding threatened and invasive species can be challenging due to individual rarity and low and variable individual detection rates. Detection rate in plant surveys typically varies due to differences among observers, among the individual plants being surveyed (targets), and across background environments. Interactions among these...

Green roofs have the potential to provide socio-ecological services in urban settings that lack vegetation and open space. However, implementation of green roofs is limited by high construction and maintenance costs. Consequently, green roof projects often disproportionately benefit wealthy communities and can further marginalise disadvantaged comm...

Green roofs are an effective green infrastructure tool to reduce stormwater runoff in cities, but their considerable weight is a constraint on widespread uptake. Consequently, lightweight green roof substrates with high water retention are desirable. Biochar addition to green roof substrates may reduce green roof weight and improve stormwater reten...

Australian cities have been slow to implement green roofs. This is because there are many potential barriers to their widely acceptance as a nature based solution that can make cities more liveable and help them adapt to, and mitigate, climate change. Due to significant differences in rainfall, temperature, available substrates and suitable vegetat...

Underutilised public spaces such as streetscapes offer substantial opportunities to integrate habitats that increase biodiversity into existing urban landscapes and create more ecologically connected cities. Cooperation and collaboration from diverse stakeholders are paramount to achieving this because growing conditions for plants in streetscapes...

Technology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report th...

Technology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report th...

We introduce the AusTraits database - a compilation of measurements of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 375 traits across 29230 taxa from field campaigns, published literature, taxonomic monographs, and individual taxa descriptions. Traits vary in scope from physiological measures of...

Rapid urbanization and the global loss of biodiversity necessitate the development of a research agenda that addresses knowledge gaps in urban ecology that will inform policy, management, and conservation. To advance this goal, we present six topics to pursue in urban biodiversity research: the socioeconomic and social-ecological drivers of biodive...

This report investigates the opportunities for threatened species conservation within Australian cities and towns

Three experimental green roofs in Melbourne with depth of 100, 150 and 300 mm have been assessed to quantify their thermal performance. To evaluate the benefit of substrate depth, temperature was recorded every 50 mm along a vertical profile. Green roofs consisted of scoria substrate and a mix of three species of plants: Lomandra longifolia, Dianel...

Heterogeneity in quantity and quality of resources provided in the urban matrix may mitigate adverse effects of urbanization intensity on the structure of biotic communities. To assess this we quantified the spatial variation in butterfly richness and abundance along an impervious surface gradient using three measures of urban matrix quality: flora...

Road verge gardening is a civic greening practice undertaken by residents, which can contribute to the quantity, diversity and structural complexity of the greenery within the road easement. By understanding the social drivers of verge gardening, we can potentially increase biodiversity, ecosystem function and human amenity. We surveyed residents o...

Green roofs are increasingly promoted for urban biodiversity conservation, but the value of these novel habitats is uncertain. We aimed to test two hypotheses: (i) green roofs can support comparable invertebrate family and order richness, composition and abundances to ground-level habitats and (ii) green roofs planted with native species from local...

Soil water limitations often restrict plant growth in unirrigated agricultural, forestry and urban systems. Biochar amendment to soils can increase water retention, but not all of this additional water is necessarily available to plants. Differences in the effectiveness of biochar in ameliorating soil water limitations may be a result of difference...

Verge gardening is a citizen-led form of public urban greening where residents plant and maintain understorey and trees in the road easement, and it has the potential to significantly increase the diversity and complexity of street greenery which is, most commonly, mown grass and monocultures of street trees. In Melbourne, Australia, two forms of v...

Verge gardening is a citizen-led form of public urban greening where residents plant and maintain understorey and trees in the road easement, and it has the potential to significantly increase the diversity and complexity of street greenery which is, most commonly, mown grass and monocultures of street trees. In Melbourne, Australia, two forms of v...

While a relatively small body of research links green roofs to psychological benefits such as aesthetic enjoyment and improved concentration, these outcomes are becoming important objectives in green roof design. Claims regarding benefits of green roofs are therefore often derived from research on psychological benefits of ground-level urban greens...

Green roofs can significantly reduce stormwater runoff volumes. Plant selection is crucial to retention performance, as it is influenced by how well plants dry out substrates between rainfall events. While the role of plants in evapotranspiration (ET) on green roofs is well-studied, their potential influence on retention via their impacts on water...

To protect remnant ecosystems within urban areas, guidelines are needed for the biophilic design, construction, and ongoing occupation of the suburban subdivisions, industrial land, or business parks surrounding them. Planners, urban designers, architects, landscape architects, road engineers, and the community need tools to help design and manage...

Despite repeated calls to action, proposals for urban conservation are often met with surprise or scepticism. There remains a pervasive narrative in policy, practice, and the public psyche that urban environments, although useful for engaging people with nature or providing ecosystem services, are of little conservation value. We argue that the ten...

Accumulating evidence indicates that time spent in natural environments promotes creativity, but few researchers have considered how this occurs. We evaluate two candidate mechanisms, attention restoration and mind wandering. We compare the accounts in terms of attentional focus, brain network activation, cognitive effects, and the temporal progres...

Aim Urbanization broadly affects the phylogenetic and functional diversity of natural communities through a variety of processes including habitat loss and the introduction of non‐native species. Due to the challenge of acquiring direct measurements, these effects have been studied primarily using “space‐for‐time” substitution where spatial urbaniz...

Cities tend to be built in areas of high biodiversity, and the accelerating pace of urbanization threatens the persistence of many species and ecological communities globally. However, urban environments also offer unique prospects for biological conservation, with multiple benefits for humans and other species. We present seven ecological principl...

Climate Change Mitigation and Adaptation—ZEMCH 2016; Direct link: http://www.mdpi.com/books/pdfview/book/636

Management of an invasive plant species can be viewed as two separate and successive processes. The first, survey, aims to find infested areas and remove individuals. The second, monitoring, consists of repeated visits to these areas in order to prevent possible re-emergence. As detection probability may vary over time, the timing and number of mon...

Aim Urban macroecology studies can provide important insights into the impacts of climate change and human intervention in ecosystems. Current theory predicts that urban trees are constrained by temperature in very cold climates but not in other climates. Here we predict the climatic niche variables of planted urban tree populations from the realiz...

Cities are rapidly expanding world‐wide and there is an increasing urgency to protect urban biodiversity, principally through the provision of suitable habitat, most of which is in urban green spaces. Despite this, clear guidelines of how to reverse biodiversity loss or increase it within a given urban green space is lacking. We examined the taxa‐...

Green roofs can be used to reduce the volume of polluted stormwater that is generated by cities. Modelling rainfall retention is critical, but green roof water balance models often rely on the physical properties of substrates. In these models, substrate water holding capacity (WHC) determines the depth of water which can be stored before runoff is...

Cities are increasingly considered important places for biodiversity conservation because they can harbor threatened species and because conservation in cities represents an opportunity to reconnect people with nature and the range of health and well-being benefits it provides. However, urbanization can be catastrophic for native species, and is a...

Green roofs are consistently being used to reduce some of the negative environmental impacts of cities. The increasing interest in extensive green roofs requires refined studies on their design and operation, and on the effects of their relevant parameters on green roof thermal performance. The effects of two design parameters, substrate thickness...

Green roofs are increasingly being used among the suite of tools designed to reduce the volume of surface water runoff generated by cities. Plants provide the primary mechanism for restoring the rainfall retention capacity of green roofs, but selecting plants with high water use is likely to increase drought stress. Using empirically-derived plant...

Urbanization causes major environmental changes globally, which can potentially homogenize biota across cities through the loss and gain of particular types of species. We examine whether urban environments consistently select for plants with particular traits and the implications of such changes on the functional composition of urban floras. We cl...

Raingardens capture and filter urban stormwater using sandy soils and drought-tolerant plants. An emerging question is whether raingardens can also be used as vegetable gardens, potentially increasing their popularity and implementation. A successful vegetable raingarden will need to both retain stormwater and produce vegetables, despite potential...

Insects are key components of urban ecological networks and are greatly impacted by anthropogenic activities. Yet, few studies have examined how insect functional groups respond to changes to urban vegetation associated with different management actions. We investigated the response of herbivorous and predatory heteropteran bugs to differences in v...

The growing interest in extensive green roofs prompts more refined studies on green roof design and operation. To assist in the design, installation and operation of green roofs, the effects of design and operating parameters on green roof thermal performance need to be fully understood. The effects of two design parameters: substrate thickness (ST...

In Australia, there is an increasing interest in using extensive green roofs to make buildings more sustainable and provide a number of social, ecological, aesthetic and thermal benefits to cities. The potential of green roofs to reduce building energy consumption has been extensively studied overseas in a variety of different climates. However, in...

There has been growing interest in using extensive green roofs for commercial and residential buildings in urban areas. Green roofs provide many benefits, including adding an additional insulation layer. The potential of this benefit depends on many factors, including the thermal properties of the green roof substrate. Thermal conductivity values o...

To balance the needs of people and biodiversity in cities, local governments are increasingly incorporating green spaces and urban greening initiatives into urban planning frameworks. Despite this, there is little information on which vegetation features or management actions are most useful in supporting biodiversity within these green spaces. We...

The majority of humanity now lives in cities or towns, with this proportion expected to continue increasing for the foreseeable future. As novel ecosystems, urban areas offer an ideal opportunity to examine multi-scalar processes involved in community assembly as well as the role of human activities in modulating environmental drivers of biodiversi...

HIGHLIGHTS Vegetation structure and composition were measured in four major green space types Remnants and golf courses supported highest native plant richness Residential neighborhoods and urban parks supported highest exotic plant richness Residential neighborhoods lacked key habitat structures including old trees Green spaces can achieve complex...

Green or vegetated roofs are increasingly built in cities to provide multiple environmental and social benefits and are an emerging horticultural industry in Australia. Since 2008, researchers at the University of Melbourne s Burnley Campus have undertaken transdiciplinary research developing and evaluating green roofs for southern Australian condi...