Deforestation and forest degradation

The Metropolitan Linear Park is a project initiated by the national government of Bolivia, funded by the Inter-American Development Bank (IDB) (1-8). The proposed park will be located along a disused railway corridor between the cities of La Paz and El Alto, spanning 18.2 km (8, p. 8). The project involves the construction of a linear park, divided into five sections, each with distinct objectives, uses, and designs (8, p. 9). This large-scale initiative aims to improve access to public spaces in La Paz and El Alto, enhance connectivity between the two cities, protect surrounding biodiversity and natural spaces, and strengthen resilience to and mitigate the effects of climate change (3 & 8, pp. 11-12).
To achieve these goals, the project design includes outdoor sports and recreational facilities, pedestrian and cycling circuits, as well as the restoration of parks, squares, and public spaces adjacent to the park corridor (8, p. 9). Some features include balcony corridors, flower and food-producing urban gardens, and viewpoints (5). The project also plans for the re-vegetation of the area with native species and aims to stop the environmental degradation of surrounding natural environments, such as the Pura Pura forest, which has been suffering from ongoing deforestation and waste dumping (8, p. 9). These efforts are expected to increase and support biodiversity in the area (7 & 8, p. 12).
Additionally, the project emphasizes social inclusion, with policies designed to incorporate women, indigenous populations, and persons with disabilities (8, pp. 7-8). The park is intended to raise awareness about climate change and biodiversity, ultimately improving the quality of life and health of nearby residents and the citizens of La Paz and El Alto (8, p. 13).

The Recovery of Cienaga Juan Polo project is primarily aimed at reopening the natural mouth of the Manzanillos to restore water flow between the sea and the Juan Polo coastal wetland, which has been affected by human activities leading to high salinity and water stagnation issues (ref 2). The project is led by Fundacion Serena del Mar. Environmental and social sustainability are core components of the project design, which has included extensive community consultations since 2013. These consultations have resulted in agreements covering employment opportunities, education, and infrastructure development (ref 2). Key implementation activities include the reforestation of mangroves and targeted interventions to address ecological degradation, such as increased salinity, water stagnation, and biodiversity loss (ref 2). The project also seeks to enhance the quality of life for surrounding communities by restoring traditional economic activities, particularly fishing, and integrating sustainable urban planning elements such as canals, sluices, and navigable waterways. These features are designed to support the development of a "blue corridor" for aquatic mobility within Serena del Mar (ref 2, 3). In addition, it also contributes to local capacity building through environmental education programs that engage community members, researchers, and NGOs in biodiversity monitoring and sustainable practices​ (ref 1).

The project La Ruée Verte aims to create a green corridor connecting two emblematic locations for social and environmental justice: La Base Marseille and L’Après M. The route spans over 7 km and passes through La Friche de La Belle de Mai and aims to bring more nature into the city on a larger scale in a fair and equitable way (Ref 2).
Given the challenges of climate change—rising temperatures, urban heat islands, fewer trees in Marseille, and increasing urbanization—the green corridor will offer a solution to combat the suffocating effects of the city’s concrete sprawl (Ref 2). Additionally, it aims to reduce pollution peaks and improve air quality (Ref 2), increase biodiversity (Ref 2), and provide access to green spaces and places for social interaction (Ref 2).
The project also addresses the broader social crisis, with rising costs of food, housing, and transportation (Ref 2). Local solidarity is key, ensuring that all green initiatives foster community interaction and consider the urgent needs of residents, such as precarious living conditions and isolation (Ref 2). Collective participation is central to the project, ensuring that it is designed by and for residents of different neighborhoods, reflecting their realities. The project, called “La Ruée Verte,” aims to unite various citizen groups, social centers, and associations to amplify their voices (Ref 2).
The project's first phase, “La Petite Ruée,” will launch in October 2024, following a year of preparation. It will start with neighbourhood micro-projects and shared advocacy, including events and gatherings (Ref 2). The goal is to collectively think about social and climate justice and begin taking concrete actions towards popular ecology in each neighbourhood (Ref 2).

The Vale da Ameixoeira Urban Park is a key part of Lisbon's Peripheral Green Corridor, covering 20 hectares and aiming to enhance the city's ecological and social resilience. It includes pedestrian and cycling paths, rest areas, picnic spots, skate parks, and playgrounds, enabling recreational activities while providing scenic views (Ref 1). The park has undergone several requalification initiatives, including the tree planting project in 2018, which saw the community and municipal bodies plant over 130 native trees and shrubs, promoting biodiversity and environmental sustainability (Ref 3). Additionally, the park supports community-based vegetable gardens, integrating horticultural practices to promote local engagement and foster social inclusion (Ref 3). More recently, as part of the Life Lungs project, another 600 drought-resistant trees were planted to mitigate climate change impacts, such as urban heating and water scarcity (Ref 5). The Lisbon Participatory Budget funds the project and reflects the community’s demand for sustainable urban development (Ref 2).

The "Tree Plantation Month" is an annual national initiative in Romania, organized by the Ministry of Environment, Water, and Forests through the National Directorate of Forests. This initiative focuses on afforestation, forest regeneration, and raising awareness about the ecological benefits of forests, while promoting sustainable behaviors (4, 9, 10). Having been in place for 60 years, the program has recently aligned with the principles outlined in the 1991 Paris Declaration on the Sustainable Development of Forests (10). At the national level, the initiative is regulated with overarching goals aimed at protecting and sustainably managing Romania's forests (9). The program allows for the involvement of various actors, including public institutions, municipalities, NGOs, and schools, who collaborate with regional forestry directorates to implement local activities (4).
In 2019, as part of this initiative in Iași, the Asociația Tineretul Ortodox Român Iași (ATOR), a youth-led religious association, actively participated in one of the campaigns . They planted 1,000 tree saplings in the Moara de Vânt district, an area that had suffered from deforestation and was prone to landslides (1, 2). The afforestation efforts were designed to address these environmental challenges by stabilizing the soil, reducing the risk of overflow and flooding, maintaining soil moisture, and regulating extreme temperatures (1). To ensure long-term success, the saplings were regularly monitored, and restoration efforts were carried out in cases where the trees were affected by fires or drought (3).

The Olaya Herrera neighbourhood in Cartagena has been the focus of a series of projects that involve ecological restoration, environmental education, and community resilience building. These initiatives have centred around the restoration of the Ciénaga de la Virgen, an ecologically significant but heavily degraded coastal wetland bordering the neighbourhood. The primary goals of the projects in Olaya Herrera include the restoration of degraded mangrove ecosystems, mitigation of flooding and water pollution, strengthening community participation in environmental management, and promoting sustainable urban environments (ref 1, 2). The project is led by the EPA Cartagena, which coordinates actions such as collecting solid waste, planting timber trees and ornamental plants, and restoring green spaces that had become informal dumping grounds (ref 1). It also includes a community-led initiative called Los Guardabosques de Olaya that focuses on reforestation and environmental stewardship, it involves children, youth, and local mothers in reforesting mangrove areas around the Ciénaga de la Virgen. The community has established a mangrove nursery and employs innovative waste management practices, such as installing traps in canals to prevent solid waste from entering the Ciénaga (ref 2). The project also involves the private sector in 2022, the EPA led a campaign with local companies like Konfirma, Acuacar, and Pacaribe that focused on improving environmental health through the removal of 10 cubic meters of waste, promoting healthy living environments and fostering community participation in environmental monitoring and waste management practices​ (ref 4). Also, in collaboration with community leaders and local companies, the ANDI-TRASO Alliance supports large-scale reforestation and restoration activities in the southern parts of the Ciénaga de la Virgen adjacent to Olaya Herrera. The alliance plans to plant 40,000 mangrove seedlings (ref 6).

Planting Oxygen in the Community is an initiative initiated by the medical company Antibiotice S.A., one of the largest drug producing company in Romania, with headquarters in Iasi. The initiative involves an annual tree plantation campaign that has been carried out over the past four years. Originally implemented in cooperation with the municipality of Iași, the campaign is now independently managed by the medical company Antibiotice S.A. The selected planting area is located adjacent to the company headquarters in Iași and consists of undeveloped grassland.
Throughout the campaign, a total of 1,175 trees and 6,000 shrubs have been planted, including species such as oaks, lindens, and maples. The initiative has engaged 310 volunteers from the company to assist with the planting efforts.
The campaign aims to achieve several goals: rehabilitating green spaces, protecting the environment, reducing carbon emissions, mitigating the effects of climate change, and providing cleaner air for future generations. Additionally, it seeks to enhance the company’s environmental impact and foster social interaction among employees by reconnecting them with nature.
(1-8)

Eliseo Collazos is located in the coastal desert ecosystem of the Lomas or ‘fog oasis’, an area that receives less than 10 mm of rainfall per year. Vegetation cover is of particular importance in the hills surrounding Lima, as it provides critical solutions to erosion, landslides and soil degradation in the ecologically degraded ecosystem of the Lomas. However, this ecosystem is facing risks from urbanisation, illegal mining and agricultural practices, resulting in the lack of the delicate mist-fed greenery for which the Lomas are known (2). This has led to increased particulate matter in the air due to exposure to sand and wind, aggravating respiratory diseases such as tuberculosis, which is prevalent in Lima's informal communities (2).
Low-income communities have inhabited this area, forced to migrate from the rainforest, highlands and city to the desert slums (4), who have only been able to settle in these landscapes with little access to resources, prone to disaster risk, little public investment in infrastructure and little access to green spaces (2). As a result, these communities live in poor conditions (1). For this reason, in 2013, the University of Washington, under its Urban Informal Communities Initiative programme (1), initiated a participatory project that sought to address the challenges faced by the inhabitants of this area (1, 2). In a series of participatory workshops, residents identified greenspace and food security as top priorities in their community; the Gardens, Greenspace and Health project responds to these priorities as an initial step towards the expansion of greenspace, agriculture and ecological restoration in and around the Eliseo Collazos community (2, 4).
Although individual families constructed them, the front yard gardens contribute to a shared public realm and community greening (4). The general project also involved the installation of fog catchers and the creation of common recreational spaces (4).

The "Plan Arbre" is a tool for ecological planning and renaturation aiming to plant 308,000 trees between 2023 and 2029, sourced from the municipal nursery with seeds purchased from local suppliers (Ref 1, Ref 2). In 2023, 14,922 trees were planted, with plans to double this number in 2024 (Ref 1). The project addresses the loss of 50% of Marseille's natural spaces over the past 75 years, aiming to reverse this trend and reintroduce nature into the urban environment (Ref 2). It also tackles issues like drought and heatwaves, particularly in summer, by using trees and shrubs to cool the air, restore biodiversity, reduce air pollution, and enhance public spaces while absorbing CO2 (Ref 2).

The plan is divided into two phases. Phase I focuses on planting in Marseille's 58 parks and 273 squares and gardens, as well as around childcare centres, schools, socio-cultural centres, and sports facilities (Ref 2, Ref 3). From 2020 to 2023, various improvements were made, including playground renovations, installation of misting systems, automatic watering, and the creation of a CrossFit area (Ref 3). Phase II will involve identifying major boulevards, avenues, and streets lacking trees to enhance the urban canopy (Ref 2).
A diverse range of tree species were selected for their drought resistance, water efficiency, and ability to attract biodiversity (Ref 2, Ref 3). The project also focuses on increasing biodiversity and managing invasive species through natural methods to protect trees from pests without chemicals (Ref 3). Furthermore, the initiative includes de-impermeabilizing soils and implementing a smart irrigation system with tensiometric sensors, developed with the start-up GreenCityZen, which has saved 66% of water in two years (Ref 3). The Plan Arbre also promotes citizen participation, with 23 parks selected for community gardening projects, where ten winning associations will receive plants from the municipal nursery (Ref 1).

Välen is a natural area 8 km south of central Gothenburg, established as a protected nature reserve in 2013. Prior to the establishment of the nature reserve, Välen was an agricultural area that experienced environmental degradation due to pollution from a nearby sewage treatment plant. Västra Frölunda Nature Conservation Association leased the land in 1985 in order to allow cattle to graze through the overgrown meadows as a form of landscaping approach [Ref. 5].
The City of Gothenburg took the initiative to protect and manage the area as a protected reserve [Ref. 1, 2]. It is formed of wet meadows and deciduous forests and has a total area of about 68 hectares, of which 52 ha are land and 16 ha are water. Välen is situated by the sea and the mouth of a small river, and protects some of the coastal waters. Residential areas surround the nature reserve and are a popular destination for recreation [Ref. 1-3]. In creating the nature reserve, efforts were made to make the area more accessible to visit and to provide learning opportunities. New paths, entrances and signs were established [Ref. 3-4]. The nature reserve is described as contributing to several national environmental goals, particularly goals related to biodiversity [Ref. 2].