Arid (Desert, Steppe)

Phoenix is grappling with severe urban heat problems. As the city continues to grow, it is expected to experience a rise in temperatures of three to five degrees on average in the coming years. This makes urban heat a significant concern, especially for vulnerable populations. Phoenix’s extensive urban sprawl, combined with a lack of green space, has exacerbated the urban heat island effect, where cities become significantly hotter than surrounding rural areas due to the high concentration of concrete, asphalt, and infrastructure. In 2022, Nick Lodato, the principal of Emerson Elementary School, wanted to mark the school's 100th anniversary in a meaningful way. He decided that planting trees would be the perfect way to celebrate this milestone while also benefiting the community. The tree planting event not only symbolized the school's strong sense of community but also represented an investment in its sustainable future. Prior to the project, Emerson had only 9% tree canopy cover, which was far below what is necessary to address some of the pressing environmental challenges Phoenix faces.
Tree cover has become critical infrastructure for heat mitigation. Trees provide natural shade and help cool the environment by reducing surface temperatures, which in turn lowers energy consumption and promotes better public health. In addition to offering shade, the native, drought-tolerant trees and plants planted at Emerson will also contribute to carbon sequestration, purify the air, and improve mental health by creating more green spaces for relaxation and outdoor activities.
To complete this project, Emerson Elementary partnered with the Arizona Sustainability Alliance (ASA), a local nonprofit. Together, they planted over 100 trees and plants across the school’s campus, with approximately 125 people attending the event. Volunteers included students and their parents, Tau Psi Omega fraternity members, APS employees, neighbors, former Emerson students and teachers. (1-3)

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)

Urban areas are particularly vulnerable to climate change due to the extensive use of concrete and asphalt, higher levels of pollution, increased population densities, and the concentration of infrastructure, all of which amplify the effects of extreme heat, drought, and severe weather. Urban tree cover play a vital role in helping cities mitigate the impacts of climate change by reducing greenhouse gases and alleviating the effects of extreme heat and other climate alterations that negatively impact human health. In 2023, dozens of volunteers from Bethune Elementary School planted 33 trees on the school grounds to provide future shade and help cool the environment. The project was funded by Arizona’s Public Service (APS) Community Tree Program, which aims to reduce the urban heat island effect by increasing tree canopy coverage in vulnerable communities.
The initiative was driven by Trees Matter, a local nonprofit organization focused on enhancing tree infrastructure in schools while educating students and staff on the importance of trees and tree care. Involving children in the tree planting process allows them to take what they’ve learned in textbooks and apply it in real-life situations, while also fostering a sense of community and belonging. This hands-on involvement not only educates but also creates lasting memories. The project’s goal is to combat the urban heat island effect by expanding tree canopy coverage, thus creating cooler, healthier shaded spaces for students in areas of Phoenix most affected by high temperatures.
With support from APS and Trees Matter, the volunteers worked together to plant trees that will provide much-needed shade on the school campus. APS’s Community Tree Program aims to provide shade and cooler spaces in neighborhoods that need it most, helping to reduce temperatures by 20 to 45 degrees. This effort is part of a broader initiative to improve the quality of life and mitigate the impacts of extreme heat in Phoenix (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).

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)

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).

Project Roots is a community-based nonprofit organization dedicated to fostering sustainable living and enhancing food security in South Phoenix, Arizona. Founded in 2020 in response to rising food insecurity—an issue impacting one in seven Arizonans—Project Roots aims to provide lasting solutions through community education, accessible fresh produce, and supportive services for vulnerable populations.
Central to Project Roots’ mission is its work in community gardening. The organization manages and maintains several community gardens, including 20 reserved rows at the Spaces of Opportunity Garden, where individuals and families can cultivate their own produce. Through these gardening spaces, Project Roots empowers community members to grow their own food, promoting self-sufficiency and healthier food choices.
Education is a cornerstone of Project Roots' outreach. The organization offers hands-on gardening classes, workshops, and educational resources that teach sustainable food production practices. A significant part of this educational effort focuses on South Phoenix's youth, helping them understand where their food comes from and how to grow it, fostering both awareness and skills that encourage lifelong healthy habits.
Project Roots also works to ensure that fresh, locally grown produce reaches the wider community. By distributing produce through farmers' markets, produce bags, and partnerships with local food banks and soup kitchens, Project Roots provides a consistent source of nutritious food to those who need it most. The produce bags, often delivered to community centers and low-income housing areas in Phoenix, help bridge the gap for those with limited access to fresh food.
In addition to its food-centered programs, Project Roots extends its support to include essential services such as food assistance, hygiene items, and temporary shelter, making it a vital resource for individuals and families experiencing hardship. (1-5, 8-14)

The Miraflores Bicentennial Park has been built on the Malecón de la Reserva and the Quebrada de Armendáriz. It was inaugurated in June 2022 as one of the created projects within the framework of the commemorations of the 200 years of Independence celebrations (1). It is considered a new green lung of Lima (2), as it has a green area of 30,400 square metres and stands on one of the cliffs of the Costa Verde (1). It has a system of terraces that replicates the construction model of the Incas, which has made it possible to additionally reinforce the soil and the slopes with the use of retaining walls up to 10 metres high, with horizontal geogrids and vertical geocells (1, 2). It was structured on a stabilised slope in order to mitigate the risk of landslides (4), and an irrigation system was implemented to stabilise the soil (4).
This space was built as a biodiversity garden with more than 160,000 xerophilic coastal species with low water consumption, 300 trees and 80 palm trees. It also offers places for tourism, such as viewpoints and squares, where cultural events, open-air activities and rest areas are held (1). It also aims to connect aspects of landscape conservation, preservation of biodiversity in the city, and the construction of a cultural landscape in which human action is complementary and friendly to the natural environment (9). Finally, it seeks to contribute to the reduction of the municipality's carbon footprint by reducing the harmful effects of urban expansion on the Lima cliff ecosystem, such as deforestation, water pollution and loss of biodiversity (9).

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).

The World Health Organization estimates that 80% of the population in developing countries use medicinal plants for health prevention and care, primarily in rural areas (3). These plant species have therapeutic potential in treating various diseases, and they are considered safe and effective medications with fewer side effects and affordable prices (3). In Peru, medicinal plants have historically been used to treat respiratory, gastrointestinal, and digestive ailments. To this day, they continue to be used by both native and urban communities (3).
To promote, develop, and encourage research, innovation, and technologies related to the use, preservation, conservation, and employment of medicinal and food plants, the National Center for Social and Intercultural Research in Health (CENSI) of the National Institute of Health (INS) has inaugurated its medicinal and food plant nursery located in one of its facilities (Chorrillos) in Lima (1, 3). The primary objective of this project is to adapt various species from the coast, mountains, and jungle of the country and initiate a plant production program that contributes to improving public health, environmental quality and the revitalization of the ancestral knowledge of indigenous, Amazonian, Andean, and Afro-Peruvian communities (1). Additionally, it aims to contribute to mitigating the effects of climate change by creating green areas, reducing atmospheric carbon dioxide levels through plant photosynthesis, improving soil quality, and promoting the responsible use of water resources, among others (3).
For the development of this project, the INS is working in collaboration with the International Organization for Migration to benefit not only the health and well-being of the Peruvian community but also promote the integration and care of the migrant population in the country (2).