Native plant vegetation

The Mobile Tree Trail is a nature-based solutions (NBS) initiative aimed at preserving Mobile, Alabama’s urban forest while celebrating its cultural and ecological heritage (Ref 1, Ref 2). First established in the early 1990s by volunteers, the original trail featured 24 iconic trees, selected for their historical significance, environmental value, and beauty (Ref 1, Ref 2). Over the years, some trees were lost to development and storms, and the trail faded into obscurity (Ref 1, Ref 4).
From 2021, the Mobile Tree Commission, with support from The Nature Conservancy, is leading efforts to revive the trail (Ref 3, Ref 6). Activities include reviewing past entries, opening public nominations, and selecting new trees that best represent Mobile’s identity (Ref 3, Ref 4). The project emphasises inclusivity and public participation, welcoming volunteers and local input to shape a trail that evolves with the city (Ref 4, Ref 6).
Mobile faces environmental threats such as hurricanes, urban expansion, and loss of native tree cover (Ref 1, Ref 6). The revitalised trail helps address these challenges by promoting awareness, conserving old-growth specimens like the 300-year-old Duffie Oak, and maintaining vital green spaces (Ref 4, Ref 6).
The Mobile Tree Trail blends education, tourism, and conservation, enhancing urban resilience while telling the city’s story through its trees (Ref 3, Ref 6).

The Lower Perdido Islands – Bird, Robinson and Walker Islands – are located in the Perdido Pass, in Orange Beach. The area is a popular destination, attracting many visitors due to its blue-green water and diverse wildlife, which, however, leads to erosion from boat wakes and marine debris. Its popularity impacts these wildlife habitats, including the seagrasses, marsh and forests which provide habitat for nesting birds and nurseries for local fish. Therefore, the Nature Conservancy, the City of Orange Beach, Moffatt & Nichol, and Olsen Associates Inc. started working together in 2017 to create a conservation management plan for the Perdido Islands, as well as develop some restoration initiatives to support this critical habitat for the future [1,3]. This Lower Perdido Islands' restoration project is part of a larger Perdido Bay Watershed restoration plan [2]

Located southeast of Bayou La Batre, Coffee Island is a barrier island that provides a buffering capacity for shorelines in Mobile County [5]. Since 1950, the shoreline on the island has been eroding. In response, the Nature Conservancy has put in a ‘’living shoreline’’ construction in 2010 to reduce wave energy and decrease erosion the island has been facing [1]. A ‘’living shoreline’’, ‘’refers to the use of nature-based techniques and materials such as oyster shells, reef blocks, bagged shells, live shellfish, and plants to help protect eroding shorelines’’ [2]. While the living shorelines constructed in 2010 still provide habitat benefits, these efforts no longer protect the shoreline from erosion. This in turn threatens not only the island's buffering capacity, but also the integrity of the marsh on the island [5]. Therefore, the Nature Conservancy has secured funding for a second project on the island, the Coffee Island Restoration project (in 2023) that aims to implement a (longer) 5,000-foot living shoreline breakwater, including the use of ‘’super sacks’’ – a specific kind of sediment barriers functioning as dikes – to protect the coastline while enhancing habitat [4, 6]

The Liberties is one of the most recognizable urban areas in Dublin and Ireland, strongly associated with old Dublin, working-class communities, and the brewing and distilling industries. While rich in history, cultural significance, and local stories, The Liberties faces numerous placemaking and quality-of-life challenges. The area continues to experience significant dereliction, a fragmented urban fabric, and a shortage of high-quality green spaces. For instance, tree coverage in The Liberties is sparse, with good-quality street trees only found in a few small areas, such as Gray St. and Reginald St., along the South Quays, Cornmarket, and near the fountain on James St. The area has approximately 1,200 trees, amounting to less than 5% canopy coverage.
In response to these challenges, Dublin City Council enacted The Liberties Greening Strategy in 2015. Building on the Liberties' Local Area Plan, this strategy aims to develop a network of new urban parks, improve access to heritage green spaces, and refurbish existing parks and play areas. It addresses multiple goals, including ecological connectivity, water management, flood risk reduction, air quality improvement, social cohesion, environmental education, and public health. This strategy is an initiative of the Parks and Landscape Services Division of Dublin City Council, in collaboration with the South Central Area Office and with input from Áit Urbanism + Landscape and Mary Tubridy & Associates.
Since its implementation in 2015, the strategy has resulted in the development of two new community parks, enhancements to several green spaces, and the greening of public spaces. It has also introduced measures to support food production in community gardens and allotments, revitalize ecosystems, strengthen water management, improve air quality, boost carbon sequestration through tree planting, divert water from the local sewer network, prevent flooding, and regulate heat. (1, 2, 3)

The likely impacts of climate change in South Dublin County include an increased risk of flooding, more frequent summer droughts, deteriorating air and water quality, and biodiversity loss (1). To address these climate challenges, the county developed the County Development Plan 2016-2022 as part of the South Dublin Climate Action Plan, aiming to establish a comprehensive legislative and policy framework for green infrastructure (GI) planning (1).
The plan outlines various objectives, including creating a coherent, integrated, and adaptable GI network across South Dublin County. One key initiative is the establishment of native mini woodlands throughout the city, designed to form strategic links and integrate the GI Strategy’s objectives into all relevant land-use plans and development across the county (1).
The purpose of these mini woodlands is to connect green spaces across the city (minimum size of 100 sq m), sequester carbon, and promote biodiversity in suitable locations, such as built-up areas, low-grade parkland, and other zoned areas deemed appropriate (1). Given the long time required for tree growth, the project employs the Miyawaki method, planting a high density of diverse native species to create mature forests up to ten times faster than traditional plantations (2). These forests are estimated to host 20 to 100 times more biodiversity and absorb carbon up to 40 times more effectively, without the use of chemicals or fertilizers; key factors include ground preparation, planting density, and species diversity (2).
In 2022, the project held a planting day for the mini woodlands initiative on Mill Lane, where 1,200 native trees and shrubs were planted with the help of volunteers from local schools, the community, a corporate group, and the Mayor of South Dublin, Councillor Emma Murphy (2).

Over the past century, vast portions of the world’s oldest forests have been lost to clear-cutting and managed forestry (1). Arboretum Detroit is working to counter this trend by reforesting Detroit’s urban landscape, transforming abandoned city blocks into thriving groves of trees (1). Each parcel of land features trees that showcase the unique contours and characteristics of specific species, creating a diverse urban forest mosaic across the city (1). These "forest patches" are protected, designed to mature safely for generations, offering a space of tranquility and natural beauty for all Detroiters (1).
Arboretum Detroit’s main goal is to cultivate environmental consciousness, inspiring the community to consider our interconnectedness with nature and our impact on it (1). Through their reforestation mission, they demonstrate the ecological, cultural, aesthetic, and economic value of trees, both locally and globally (1). Trees alter our environment by using their leaves to filter the air we breathe by removing dust and other particles. Deciduous shade trees cool homes in the summer and allow the winter sun to heat homes when they lose their leaves. Trees can serve as a windbreak. The more compact the foliage on the group of trees the more effective the windbreak. Their pilot project, launched on Earth Day 2019, brought these values to life. Volunteers and members planted 21 trees across the site, including species like Princeton Sentry Ginkgo, Redpoint Red Maple, Paper Birch, Cedar, Yew, and understory trees like Kousa Dogwood and Forest Pansy Redbud, enhancing the habitat for local pollinators and birds (2). The trees were arranged in trios, interspersed with native seeds, soil, compost, and glacial boulders to create a healthy and engaging environment for all (2).

HortaFCUL is a project created and managed by the Faculty of Sciences at the University of Lisbon to raise awareness and promote the practice of permaculture as a solution to the ecological, social, and economic problems the world is facing (1). This initiative began in 2009 on the University campus through a garden, which allowed HortaFCUL to start conducting some activities that could answer some socio-environmental challenges, such as food security and sovereignty, ecosystem degradation and climate change (13), by raising awareness, teaching, and practising many aspects involved in permaculture and urban agriculture (2). Its focus has been on regenerating soil in an urban environment and creating productive landscapes for people and other beings (12). They grow different types of plants (vegetables, shrubs, trees) in different ways (swales, raised beds, greenhouses) to increase plant diversity and foster ecosystems (13).
The project is managed by students and researchers, who hold educational activities, such as courses, workshops, and dissemination activities (events, discussions, fairs, and conferences) (2). The project is organised according to a non-hierarchical sociocratic model, in which all decisions are made as a group, and where all ideas, critiques, and suggestions are seen as added value and an opportunity to improve techniques and knowledge (3). Additionally, it is open to the community, allowing anyone interested to participate and volunteer (1).
HortaFCUL is also one of the pioneering permaculture projects in operation in the Lisbon region and is now recognized as a national reference centre for permaculture (2). Since its inception, HortaFCUL has sought to be a hub that attracts people, organizations, and other initiatives, and it is currently a point of contact between different projects and associations, such as local businesses, educational institutions, and networks (5).

The financial capital of Sri Lanka, Colombo, is the fastest-growing city in Sri Lanka, and as such, it is constantly changing. Most expansions in urban areas are taking place without proper planning, which can cause damage to existing pockets of forests, landscapes and green areas in and around the city (1). The environmental impacts of this rapid urbanisation include increased pollution, increased heat due to the expansion of roads/pavements, tall structures that block out light and wind and reduced biodiversity in fauna and flora (1).
To face these challenges, the Federation of Environmental Organisations (FEO) proposed a city-wide Tree Planting Campaign to create an Urban Forest Strategy in public and private lands in the greater Colombo area (1). The plan is to kick-start the program at the Borella Cemetery as it has a large land area available for planting, specifically 178062 sq meters (3). The project started to be implemented in July 2020 with the seasonal rains (1). This project aims to grow urban trees to help mitigate some of the negative impacts of unplanned and rapid urbanisation, thus making the city more resilient to these changes (1).
The trees that will be planted will be mostly native species and also exotic plants will be selected based on specific requirements (1, 3). It is also planned to have flowering plants and shrubs to encourage butterflies, bees and birds to interspace the trees (1). The new parking space near the Borella Cemetery will also be planted with deep root shading trees interspaced with flowering plants (1).
The project aimed to include a large number of stakeholders including the government, the private sector and the residents of Colombo (1). And they have also reached schools in Colombo and hope to involve environmental associations to further the cause (3).

The Mediterranean climate in Lisbon, already characterised by low precipitation, has been further exacerbated by climate change. The city faces challenges related to biodiversity loss, urban loneliness, and climate anxiety (1). To address these issues, Lisbon's urban development plans have prioritised the re-naturalisation of urban spaces and the integration of ecological networks. Urban nature is now a central component of the city's Master Plan (2012) and other strategic agendas (1).
It is being developed by the LISGREEN project, which aims to enhance ecological connectivity and mitigate the effects of urban heat islands in Lisbon. By establishing nature-based solutions, it aims to restore forests within the city (1, 2, 3). This project encompasses different strategies, such as the RENATURA pilot project. It is a collaboration with the NGO URBEM and involves active public participation in tree planting and forest maintenance. This initiative aims to educate the community about nature, promote well-being, and mitigate extreme climate events (1), through the creation of urban forests.
The main strategy is to create fast forests using the Miyawaki method, which involves dense planting of native trees, removal of invasive plants, and intensive initial care. This approach accelerates the growth of natural forests within a short period, using native species and reducing the need for watering (1)
The first fast forest was developed in Parque Casal Vistoso within Bela Vista Park, within the Eastern Green Corridor of Lisbon. The park is being underutilised because of the lack of shade (1). Thus, this initiative encouraged volunteers to participate in tree planting and forest maintenance activities (3). The NbS intervention began with a 300m² experimental plot near the Vale da Montanha pedestrian bridge and has since expanded to a new 1,500m² plot on the opposite side of the bridge (2). Over 500 volunteers joined the effort, planting more than 3,800 trees (1)

Public spaces in Colombo are disappearing due to rising land prices, causing infrastructure issues that harm citizens' health, especially in low-income areas (3). One proposed solution to address the problems caused by rapid urbanization is the creation of community gardens, which can at least improve low-income residents' diets and immune systems and address malnutrition (3).
Considering the limited urban space for both citizens and other living beings, the organization Eco-friendly Volunteers decided to create a community garden. The Metta Garden in Colombo (1, 2) aims to bring back urban biodiversity through organic home gardening, generating healthy food for people and creating living space for many other animals and plants (2). Following the Buddhist concept of Metta (loving-kindness to all beings), it promotes walking meditation paths and facilities to experience nature using all five sensory organs (1), in addition to being a place for experiencing loving-kindness for both human and non-human living beings, seen and unseen (4, 5).
It has become a training institute for many stakeholders seeking to grow organic food and earn a better income through the high demand for organic products (2). At the same time, it serves as a biodiversity spot, attracting butterflies, bees, and other forms of wildlife to an urban environment (2).
The area is located in the middle of a semi-urbanized area, on the outskirts of Boralesgamuwa (2, 3). Maintained by a group of volunteers, it features a greenhouse and a plot of land of around 5,000 sq feet, populated with vegetable patches, a butterfly garden, flowers and rare medicinal plants (3, 4). The garden was divided into four sections representing the Buddhist elements: water, heat, air, and solid. Each section features specific plants and designs, like a pond for water, a compost pit for heat, tall plants for air, and a rock garden for solid. The layout follows a mandala design based on permaculture principles (4).