Land use and Socio-economic change

The Horta Nova Urban Park, located in the Carnide parish (Lisbon), is a recently inaugurated green space that combines horticulture with community recreation. The Carnides neighbourhood is characterised by an inspiring history of overcoming hardship, with residents turning food shortages into opportunities by cultivating community gardens since the 70s. Currently, "the neighbourhood continues to be an example of solidarity, innovation and community spirit" (Ref. 2). In 2013, as a response to food scarcity caused during the post-Troika economic crisis, a group of local residents created an unauthorised vegetable garden overnight, on previously derelict space in the neighbourhood. Only in 2021 did the local authorities officially recognise the vegetable gardens, which since 2013 had operated under an informal agreement (Ref. 3). With the official establishment of the horticultural park, in addition, the park has a newly planted broad lawn, an open-air gym, and a dedicated dog park, creating a versatile space for residents (Ref 3).
Currently, this park features 80 vegetable plots, each with a dimension of 100 m2 per plot, attributed by the municipality through an official application process (Ref. 1). The park is a great reflection of the neighbourhood’s resilience and its history of small-scale citizen-oriented agricultural production that began as a response to social difficulties (Ref 1, 2).

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)

A biodiversity park was built on an abandoned plot of land that felt unsafe to local residents. In the future, the plot may eventually be used for the construction of something more permanent. In the meantime, this project seeks to increase safety and access to greenspace while benefiting biodiversity, specifically flowers and insects.
Recycled materials were used to create the structure of the park, places to sit and insect hotels, while trees and a flowering meadow were planted. A mix of annual and perennial flowers was used to promote biodiversity over time. The locals are reported to be happy with the project. Familjebostäder i Göteborg AB, a publicly owned real estate company, conducted the project. [Ref. 1-5]

In 2018, a group of residents from Sector II in the Villa El Salvador district initiated a communal effort to transform an abandoned space into an urban garden (3). This is how Ayllu 21, the first community-based agroecological garden in Villa El Salvador, was born. The project was spearheaded by a group of mostly migrant senior women who decided to dedicate their time and labour to reclaiming a landfill space, to turn it into a productive green area (1). Their philosophy is rooted in the concept of "ayllu," a Quechua word signifying family, collective identity, solidarity, and respect for the environment to foster harmonious coexistence (3).
Today, Ayllu 21 spans 1400 square meters and features 40 plots where agroecological practices are employed (1, 3). The garden aims to become a space for comprehensive development, through promoting environmental awareness, political advocacy, and the fight against gender-based violence in a district that ranks third in the number of violence cases (1).
The vegetables produced are primarily for self-consumption, with any surplus distributed among neighbouring families. If there are any sales, the profits are shared among the members, who work an average of two days per week in the garden (3).
This space seeks to strengthen socialization among women and seniors and foster learning and community-building among neighbours through agriculture. It was initiated with the support of IPES Promotion of Sustainable Development as part of the Sowing in the Desert program (3, 6), and it has received support from a diversity of programmes, such as the framework of the Women United for Food and Environmental Security (MUSA) (1).

Berlin has faced severe water shortages in recent years, with ponds, small lakes, and pools suffering significantly. Many have dried out or disappeared, causing habitats for countless animals and plants to vanish. Urbanization exacerbates the issue, as more areas become sealed, preventing rainwater from replenishing soil and water bodies. Recognizing the urgency, Berlin introduced the Eco-Account, a strategic reserve of areas and initiatives to mitigate the effects of urban development on nature and landscapes. Central to this is the Blue Pearls for Berlin program, focusing on revitalizing small water bodies to restore biodiversity and ecological balance.
The project identified approximately 30 ponds, pools, lakes, and ditches from over 100 candidates to be transformed into "blue pearls." These revitalized areas will support local ecosystems and improve Berlin’s water cycle. The Berlin Rainwater Agency, alongside departments responsible for nature, climate protection, and water management, is spearheading the initiative in collaboration with the Berlin Nature Conservation Foundation.
Two pilot sites—the Schleipfuhl/Feldweiher water complex in Marzahn-Hellersdorf and the Lankegrabenteich in Steglitz-Zehlendorf—were prioritized for restoration in 2024. These efforts include improving water quality and creating diverse habitats for wildlife. Enhancing small water bodies not only provides a refuge for animals and plants but also contributes to climate adaptation. Restored ponds and lakes can cool surrounding areas and improve the urban microclimate by utilizing locally accumulated rainwater. Blue Pearls for Berlin, approved by the Senate in 2022, aligns with the city’s Eco-Account framework, ensuring that these restored blue spaces offset ecological damage caused by infrastructure and urban projects. The initiative offers Berliners new ways to experience nature, fostering a balance between development and environmental preservation. (Ref. 1, 2, 4, 6, 7)

Maya’s Farm is a small, CSA (Community Supported Agriculture) sustainable urban farm located in Phoenix, Arizona, where urban development has limited farmland availability. In 2020 alone, Phoenix lost nearly 200 acres of farmland to urban sprawl, putting farms like Maya’s at risk. The farm faced potential closure until the City of Phoenix intervened, providing funding through the Farm Preservation Program, which established the city's first urban agricultural conservation easement. Maya's Farm strives to inspire a local appreciation for sustainable food and to bring renewed value to local food systems.
The farm’s mission is to provide accessible, fresh, locally grown produce to the community while promoting awareness of healthy, sustainable food practices. Through its CSA program, members receive a weekly produce box and have opportunities to come together, honor food traditions, and share stories over locally harvested food. As a CCOF (California Certified Organic Farmers) certified organic farm, Maya’s Farm is committed to organic practices that exclude GMOs, nurture the soil, foster biodiversity, and innovate growing systems. These methods result in healthy soil and cleaner air, contribute to carbon sequestration, and support critical wildlife habitats.
To broaden educational outreach, Maya’s Farm offers several programs that promote sustainable food practices, including its CSA program, an edible classroom series, and a partnership with Arizona State University (ASU). Through this ASU partnership, students gain hands-on experience by participating in daily farm operations.
Building stronger community connections is another cornerstone of Maya's Farm’s work. The farm collaborates with local restaurants, farmers' markets, and community groups to expand its impact. Maya’s Farm, ASU, and Arizona Sustainability Alliance launched an agrivoltaics project with solar-shaded crops. (2, 9, 11, 13, 15)

The D'Olive Creek Restoration project is designed to address the significant environmental challenges facing the D’Olive Creek Watershed and its tributaries (Tiawasee and Joe’s Branch), primarily caused by increased urbanization. Over the last several decades, the area has experienced severe erosion, sedimentation, and habitat degradation due to stormwater runoff from new residential and commercial developments. This runoff has led to stream channel instability, loss of wetlands, and impaired water quality in both D'Olive Creek and Mobile Bay, threatening aquatic and wildlife habitats (Ref 2).
The project involves restoring degraded streams and implementing management measures to reduce the downstream impacts within the watershed. Key activities include stormwater retrofits, stream restorations, and continuous monitoring. These efforts aim to stabilize stream segments and significantly reduce sediment loading into the northeast quadrant of Mobile Bay. This is crucial for improving water quality and clarity, which is necessary for re-establishing submerged aquatic vegetation (SAV) beds that serve as critical nursery areas for shellfish and finfish (Ref 1). By using natural materials like rock and living plants, the project also seeks to create a sustainable and ecologically balanced watershed system (Ref 3).
The anticipated outcomes include enhanced water quality in D'Olive Creek and Mobile Bay, reduced erosion and sedimentation, and the restoration of vital habitats, which will contribute to the region's overall ecological health (Ref 1, 3). This restoration project is part of a broader strategy outlined in the 2002 Comprehensive Conservation Management Plan for the Mobile Bay Estuary (Ref 1).

The Bela Flor Respira (BFR) project, also known as "ComBOA", is an urban agroecology initiative located in the Campolide neighbourhood of Lisbon, Portugal. This project exemplifies a transformative approach to community development and environmental sustainability by repurposing a neglected urban space into an agroforest. Launched in 2018 by the NGO Circular Economy Portugal, BFR engages local residents of the neighbourhood, from children to the elderly, volunteers, and academic partners, in creating a regenerative space that combines food production with social interaction (Ref 1). The project emphasises the co-production of public policies, fostering social cohesion through collective intelligence and civil society entrepreneurship (Ref 1). BFR’s innovative approach integrates syntropic agriculture, blending fruit trees, vegetables, and native species to create a resilient ecosystem that supports both the environment and the community. Through this initiative, BFR not only enhances urban green spaces but also strengthens community bonds, making it a model of sustainable urban development (Ref 3).

At the beginning of the twenty-first century, Kunming’s urban planning faced major challenges, including fragmented development, environmental degradation, and limited green spaces (Ref 1). In response, the municipal government launched a series of strategic plans aimed at promoting high-quality urban development and environmental restoration.
Baisha Lake was identified as a key area in these strategies, with plans for Baisha Lake Park first highlighted in 2017 (Ref 2) and reaffirmed in the "Opinions on Supporting High-Quality Development in Kunming" in 2021 (Ref 2). To implement parts of this broader strategy, the government entered into public-private partnerships. In 2018, land development rights for parts of East Baisha Lake were granted to Dahua Group, on the condition that 40% of the area be reserved as green space and that ecological restoration efforts be undertaken (Ref 3, 4).
The Eastside Baisha Lake Park project, launched by Dahua Group in February 2023 (Ref 3, 5), is thus one component of this larger government-led urban renewal effort. The project follows the city's planning framework of “one lake, six zones, 46 scenic nodes” and includes 55 hectares of green space, with 40% designated as parkland. By the end of 2023, 6.5 hectares had been completed, and the south bank of the park opened to the public in September 2023 (Ref 3, 6).
The broader East Baisha Lake area's development was originally planned by the state-owned Kunming Urban Construction Company, but land rights were later transferred to Dahua Group. Thus, while a private developer is leading the construction, the project remains a part of Kunming’s publicly driven strategy to restore the lake and enhance urban livability.

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).