Informal settlements or slums

The "Ventanilla Wetlands" Regional Conservation Area (ACR) is an area of 275.45 hectares protected and administered by the Regional Management of Natural Resources and Environmental Management of the Regional Government of Callao (1, 2). It was established on December 20, 2006, by Supreme Decree No. 074-2006-AG, to conserve a representative sample of the coastal wetlands of the Subtropical Pacific Desert (2). With an ecosystem shaped by various hydrological and ecological processes, the "Ventanilla Wetlands" ACR is home to 126 bird species and 27 native plant species, making it an ideal area for ecotourism, recreational, educational, scientific, and cultural activities, thanks to its landscapes and biodiversity (2). However, the Ventanilla Wetlands face several challenges due to urban growth, water pollution, waste, traffic and plane overflights from the National Police and Navy, leading to a decline in bird populations due to noise exposure (5).
This area is fed by the hydrological system of the Chillón River, by surface waters from the Sedapal oxidation ponds, and by water seepage from nearby human settlements and populations adjacent to the wetland. The Ventanilla Wetlands are also influenced by the marine system, especially in the northwest zone. This gives the ACR area lagoon-like characteristics, meaning that its waters are slightly brackish despite being separated from the sea. The internal hydrological system supports the growth of species such as cattails, bulrushes, and reeds. In total, there are 27 native plant species, which serve the function of filtering and purifying the wetland's water. Additionally, the flora provides protection and food for various fauna species, particularly birds, with 126 species recorded, including resident and migratory birds from the Andes, local areas, and the Northern and Southern Hemispheres. Moreover, this protected natural area is home to five reptile species, including endemic species from Lima that are endangered (3).

The initiative consists of an afforestation campaign promoted by the local government of La Paz, with the objective of planting 10,000 trees and shrubs (1 & 2). Carried out between 2023 and 2024, the campaign included plantations across all the macrodistricts of La Paz (1). To ensure the campaign's success, the municipality encouraged the participation of volunteers from various institutions, such as public services, environmental groups, schools and universities, neighborhood associations, church groups, and even Army and Navy units (1 & 2). The trees play specific roles in mitigating climate change, improving air quality, reducing odors from nearby landfills, and decreasing the risk of landslides and soil erosion (3 & 4). Furthermore, the campaign aims to foster environmental awareness among citizens and replace trees lost due to illegal deforestation (1).

The species selected for planting were provided by EMAVERDE, the public company responsible for managing green spaces in the city. The selection included primarily native species, along with a few introduced ones, all chosen for their resilience to La Paz's varying climate conditions (1, 2 & 4). Given the challenging climate and difficult soil conditions, the municipality informed volunteers about the importance of maintaining the saplings, particularly during drought periods, to ensure their proper growth (1 & 2). The campaign also supported the municipality’s urban development plan (Plan Territorial de Desarrollo Integral "Para Vivir Bien") and the "Plan Integral de Recuperación de la Tormenta a la Esperanza," the latter developed in response to extreme rain events and floods that occurred during the campaign months (5).

The "EnRútate por el Ambiente" initiative is a collaborative strategy implemented in Cartagena through a partnership between Ecopetrol, EPA Cartagena, and the Cartagena Refinery. The initiative aims to promote sustainable community development in neighborhoods adjacent to the refinery by addressing key environmental challenges such as pollution and the degradation of water bodies and green spaces. Its overarching objective is to improve quality of life through the promotion of sustainable practices and environmental stewardship (ref 5).
The strategy is structured around three programs. The first component focuses on the management of public spaces for recreation and environmental care. The second, Guardians of the Channels, seeks to empower local residents as promoters of water body conservation within their communities. The third program promotes the engagement of all community members, including schools and educational institutions, through participatory environmental initiatives (ref 1).

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).

As part of France's New National Urban Renewal Program (NPNRU) and its strategy to enhance urban quality of life, the Urban Integrated Farm in Desclieux was established in 2021, with a particular emphasis on urban agriculture.
This project is implemented by the Centre de Culture Populaire Ypiranga de Pastinha Martinique (CCPYPM or Ypiranga Martinique) in collaboration with the city of Fort-de-France and is located in the socioeconomically disadvantaged Ravine-Bouillé neighborhood. It aims to create a farm on a 2-hectare former military site that previously housed fuel cisterns connected to the French Navy at Fort Saint-Louis. Since falling into disuse in the 1990s, only the reinforced concrete structures remain.
The farm will feature various activities, including a composting zone, a café, a beehive, a botanical trail, a play garden, and areas for crop and animal production. Additionally, it will house a decontamination and materials library and a public living space for community use. Overall, this site aims to serve educational, recreational, and socioeconomic purposes, enriching the local urban ecosystem.
Even though the intervention commenced in 2021 it has encountered several challenges since 2022 due to administrative hurdles. The implementers are currently awaiting temporary authorization to proceed. The primary obstacle remains the development and execution of a comprehensive soil decontamination plan. (Ref 2; 3; 4)

The municipality of Ciudad Juarez, in collaboration with UN-Habitat, has drafted a redevelopment strategy for an area known as "Paso de Oñate." This intervention falls within the broader framework of "Vision Ciudad Juarez 2040." The plan involves constructing a forested green belt along the southern edge of the Rio Grande (/Bravo) in the northwest part of Juarez, bordering the USA.
Currently in the planning stage, the project aims to restore the ecological function of various degraded areas along the Rio Grande, transforming them into a continuous, green, walkable, and recreational space. The strategy includes allowing vegetation to recover, introducing native plant species, and increasing tree cover to rehabilitate unmaintained parks, derelict areas, and degraded riverbanks. These areas will be equipped with new features and integrated with existing parks, schools, and playgrounds. The envisioned green corridor will enhance walking conditions, improve the perception of safety, offer recreational opportunities for all age groups, and deliver valuable ecosystem services such as temperature regulation, improved air quality, and water retention.
In addition to its ecological goals, the project has a historical and geographical dimension. It aims to incorporate cultural heritage elements, such as the monument of the New Citizen, Paso de Oñate, Turtles Park, and the beginning of the Acequia Madre. It will also connect with other green space initiatives, including the Mega Park "El Chamizal" and the "Corredor Cultural," which runs through the city center.
This intervention is being prioritized due to the area's ongoing social and ecological decline. Paso de Oñate is a critical border crossing point, which negatively affects mobility and air quality. The area also suffers from a high concentration of vacant housing, which contributes to the residents' perception of insecurity. (Ref. 1, 2, 3, 4)

Fondo Unido Chihuahua, in collaboration with its corporate partners, is committed to raising awareness about environmental care and reforestation. One of its flagship initiatives is the annual tree-planting campaign, "Planting Today to Have Oxygen Tomorrow," organized by United Way Chihuahua in Ciudad Juárez. This environmental initiative focuses on improving the quality of different urban green spaces (parks, school grounds, streets) while fostering ecological awareness in vulnerable communities across the city. The primary objective is to plant a significant number of trees throughout Ciudad Juárez, using native species that are water-efficient and well-adapted to the local climate and soil. In 2022 the initiative aimed to reforest 18 parks located mainly in the south-eastern part of this border city with 1,000 trees. In 2023 and 2024 the intervention focused on planting 850 trees scatted all over the city.

The campaign brings together donations and volunteers through partnerships with various stakeholders, including local and regional governments, private companies, community organizations, and the general public.
United Way Chihuahua oversees the planning, coordination, and logistical efforts for the campaign. On planting days, volunteers gather at designated sites, guided by the organization to ensure successful planting efforts and community engagement (Ref 1-4).

In the city of Ciudad Juárez, the municipality, in collaboration with UN-Habitat, aims to design and create a park that encompasses the yards and unmaintained areas surrounding the railway station, transforming these spaces into an accessible and safe public area. This project covers over 500,000 square meters and addresses not only degraded areas but also several public squares. Described as "a coordinated urban recycling strategy," this initiative seeks to repurpose existing public squares and rehabilitate neglected spaces into vibrant green areas that feature universal accessibility, native vegetation, and urban furniture designed to enhance safety. The project also aims to provide increased recreational opportunities, improve permeability, and introduce additional shaded areas. A key component of improving permeability involves the restoration and incorporation of acequias—traditional historical irrigation systems that absorb and manage excess rainwater, thereby reducing the likelihood of flash floods.
Additionally, the project focuses on the restoration and promotion of significant historical buildings, such as the old railway station and the whiskey factory, integrating them into a larger cultural and sports facility area at the municipal scale. The overarching goal is to revitalize the site through effective coordination with the relevant authorities responsible for the spaces adjacent to the railway station, stretching from Plaza Misión de Guadalupe to Blvd. Municipio Libre. This collaborative effort aims to accommodate both sports and cultural facilities while also creating a green corridor.
Furthermore, the project intends to reforest, redesign, and enhance Plaza Misión de Guadalupe, Plaza Monumento a Benito Juárez, and other residual public spaces and gardens. This initiative aligns with its Public Space Strategy, which emphasizes the development of gender-inclusive and resilient public spaces.(Ref 1, 3, 4).

According to the FAO, in 2022, 16.6 million Peruvians faced moderate or severe food insecurity, representing an increase of 1.5 million compared to the previous year (3). This situation was exacerbated by the health crisis, inflation, and job losses, leaving three out of ten Peruvians in poverty in 2021. The situation was particularly critical in Metropolitan Lima and Callao, with 14% of families reporting difficulties in acquiring protein-rich foods due to their precarious economic situation (2).
In response to this food crisis, the Municipality of Lima implemented the "Lima te Cuida" (Lima Takes Care of You) initiative, in which residents from vulnerable areas got training to create urban gardens and produce organic compost to help the community kitchens in these areas become self-sustainable (1, 2). An example of this initiative is the community garden in A.H. Villa Mosha in San Juan de Lurigancho, where a community garden has been built, and community members have been trained in small-scale planting, cultivation, care, and harvesting of various foods (2).
This initiative has been supported by the MUSA project "Mujeres Unidas por la Seguridad Alimentaria y Ambiental" (Women United for Food and Environmental Security) as part of the project "Alimentando a Lima desde Adentro" (ALDA) (Feeding Lima from within), which has had an impact in eight districts of Lima to strengthen food security (3). In addition to promoting urban agriculture, the project seeks to influence public policy through training and development of proposals to promote urban agriculture at the local level (4).

The Juan Angola River is an urban channel included in the system of rivers and channels of Cartagena, and it connects the Ciénaga de la Virgen wetland and the Bay of Cartagena, facing similar issues as the Cienaga de la Virgen such as illegal occupation of its shores, illegal waste dumping, deforestation of mangroves, and pollution. The recovery plan for the Juan Angola River is led by the EPA Cartagena (Environmental Protection Agency), with the support of other institutions, aiming to restore the Juan Angola’s ecosystem. This includes targeting the mangrove forest, dredging the natural channel, and delineating buffer zones with urban infrastructure to create public recreational spaces. The activities involve relocating people illegalling cupping informal settlements from the river shore, moving an existing bridge (the Benjamín Herrera bridge) which obstructs the current, recovering the low tide and riverbed areas, building pedestrian paths, clean the riverbank, recover mangrove areas and establish programs of education and environmental awareness (ref 1 and 2).