Green space and habitat

The City of Seville has carried out four tree planting campaigns between 2020 and 2024, aiming to meet the goals of its Urban Tree Management Plan for Seville [Ref. 2-7]. The intervention as described here is based on the planting campaigns to date, but as the Management Plan spans from 2019 to 2039, more campaigns can expected in the future. The tree management plan aims to provide guidelines for the planning of trees in the city to maximise their value and minimize conflicts. As part of the process, the current state of the tree population in Seville has been evaluated. The management plan describes the ecosystem services of trees related to climate adaptation, biodiversity and public health. It also identifies challenges and conflicts that may arise due to urban trees and their management [Ref. 1]. The plan has a goal to increase the tree cover in Seville by 5 % over 20 years, which leads to the ambition of planting 5000 trees yearly and the tree planting campaigns over the last years. Between 2020 and 2024, about 1000-5000 trees have been planted each year [Ref. 1-5].

This initiative is a community-based urban greening effort targeting environmental and social co-benefits in Cartagena’s El Pozón neighbourhood. It involved the planting of 491 fruit and timber trees along a 1,500-meter linear stretch, covering nearly two hectares in the Terraplén sector of the neighbourhood. Led by the "Establecimiento Público Ambiental" (EPA), it was developed in collaboration with various stakeholders, including the Gerencia de Espacio Público, Guardia Ambiental, SENA students, the Police, and community members (ref 1, 2). The project's primary goal was to enhance the environmental quality and aesthetics of the El Pozón neighbourhood by planting trees that provide ecological benefits, such as improving air quality, reducing temperatures, and enhancing biodiversity. Additionally, the initiative aimed to foster community engagement in environmental conservation, particularly in raising awareness about the importance of protecting and maintaining nature. The community is also expected to take on the responsibility of maintaining the planted trees, promoting a sense of ownership and sustainable stewardship (ref 1).

The Molentargius-Salt Works Regional Natural Park, spanning approximately 1,600 hectares, is located in South Sardinia between the towns of Cagliari and Quartu Sant'Elena, adjacent to the Poetto seafront. The park features diverse ecosystems, including wetlands and salt flats, and houses the Orto Botanico di Cagliari, which showcases native Mediterranean plants.
In 2016, a project was initiated by a group of stakeholders to preserve and enhance biodiversity within the park. The project's goals are to protect and promote the unique ecosystems, such as the fossil beach, and manage invasive species like the Louisiana crayfish. Through various activities—educational programs, public engagement, and conservation efforts—the initiative aims to raise awareness and deepen understanding of local biodiversity and its historical evolution.
A primary focus of the project is the conservation of the Orto Botanico area in Is Arenas, which contains a fossil beach that offers valuable geological insights into the region's past. Planned activities include cleaning and securing the area, creating educational pathways, and employing multimedia tools to engage visitors. The emphasis is on teaching the public, especially students, about biodiversity as a result of environmental adaptation through practical learning and cultural exchanges.
Another critical aspect of the project is the study and control of the invasive Louisiana crayfish, which threatens the park’s biodiversity by contributing to riverbank erosion and impacting native fauna. The project will incorporate scientific research on the crayfish and develop strategies to limit its spread, aiming to protect the park’s delicate ecosystems from further disruption by invasive species.
Lastly, the project emphasizes cultural exchange and social inclusion and fosters dialogue on the shared ecological challenges in Parco Molentargius. (Refs. 1, 2 & 5)

The "Active Recreational Green Area Development at Horváth-tető" in Miskolc is a project aimed at revitalizing a central yet underutilized urban space, commissioned by the Municipality of Miskolc in 2017. A distinctive feature of Miskolc is the Avas hill, located in the city center, which beautifully blends nature with urban elements. Despite its potential, the area had been neglected, particularly following the decline of vineyard culture and the reduced use of old wine cellars. To address this, a comprehensive development plan was initiated to rejuvenate the Avas region, with Horváth-tető at its core.
The project aimed to transform the area into an outdoor recreational hub for all age groups. The hill's historic terraces, once popular promenades, were repurposed into distinct, multifunctional spaces. Sports enthusiasts can enjoy facilities such as street workout stations, an outdoor gym, a skate park, a climbing wall, and parkour elements. For those looking to relax, picnic areas, sunbathing spots, and a retro-style terrace are available. The entire development prioritizes accessibility, providing inclusive options for visitors with mobility challenges.
The park also features significant landscaping, including the planting of trees, shrubs, perennials, ornamental grasses, and ferns, enhancing its overall appeal. Infrastructure improvements were made, including the restoration of stairs, paths, retaining walls, and the rainwater drainage system. A special shallow basin was designed to collect rainwater and support plant roots while also serving as a playful area for dogs within the dog park.
Since its opening in 2022, the park has become a popular destination, offering a tranquil escape in a beautiful setting. It provides a wide range of recreational opportunities for people of all ages, making it a valuable addition to Miskolc’s urban landscape and connecting the historical Avas hill with modern city life.(Ref.1,2)

The Adana Central Park stretches along both riverbanks of the Seyhan River. The idea was first introduced by the former mayor of the city, Aytaç Durak, in the late 80s to address the need for accessible green spaces in the developing area (Ref, 2). Previously, citrus gardens and informal settlements were located on these riverbanks, which now host over 400.000 plants and 67 different tree species on an area of 33 ha (Ref. 2,5,6). In 1998 construction of the park began, which lasted until 2004 (Ref. 2,5). The park is appreciated by visitors for its aesthetically landscaped appearance and the many amenities for children, youth, relaxation and socializing (Ref. 7). The two sides of the river are connected via bridges or, alternatively, visitors can board the Venetian style gondolas to access either side (Ref. 5). In 2021, park lighting infrastructure has been extensively replaced to ensure accessibility and safety during day and nighttime (Ref. 3).

The Recovery of Green Area on Avenida del Lago is a group of activities aimed at restoring and preserving the ecological integrity of green space within an urban setting. This project involves multiple stakeholders, including the "Establecimiento Público Ambiental" (EPA) Cartagena, "Fundación Verde Que Te Quiero Verde", Asopopa, and local businesses such as Crepes and Wafles and Centro Comercial Caribe Plaza. The primary focus is environmental restoration, sustainable urban mobility, and public space recovery (ref 1). The project aims to rehabilitate the degraded green spaces along Lago Avenue by enhancing urban greenery, restoring mangrove ecosystems, and improving public access and mobility. It also focuses on reducing pollution, preventing informal waste disposal, and raising environmental awareness among local communities and businesses. These activities align with broader efforts to promote ecological sustainability and enhance urban resilience (ref 1, 3). Since 2020, activities have included the planting of trees, mangroves, and other native vegetation in the green spaces of the avenue. Regular clean-up campaigns have been organized to remove solid waste, and community education programs have been conducted to promote environmental stewardship (ref 2). Previously, Lago Avenue was an area plagued by pollution and homelessness, and with the project, the intention is to gradually transform the area into a wooded area or productive park (ref 2).

The green belt regeneration project along the Byzantine Walls of Thessaloniki aims to revitalize the neglected green spaces surrounding these historic fortifications, which span 4 kilometers and are recognized as a UNESCO World Heritage site for their remarkable Byzantine architecture. The walls are located in Thessaloniki’s densely populated Upper Town, a factor that contributed to their environmental degradation. As such, the project focuses on restoring the degraded space surrounding the walls, improving the urban microclimate, and strengthening urban resilience while maintaining the area’s traditional character. By integrating heritage conservation with sustainable green infrastructure, the initiative seeks to provide both environmental and social benefits to the local community. Proposed by the Municipality of Thessaloniki and approved by the Greek government as part of a program that focuses on Central Macedonia, the project envisions a revitalized green zone along the walls, with vegetation and different types of trees being planted. However, some local families have expressed concerns, as the project involved the demolition of certain homes in the officially designated green belt area. (Refs. 1, 2, 3, 4, 14).

The Jardim do Caracol da Penha project transformed a vacant urban area into a community garden and recreational space in Lisbon. Initially planned as a parking lot, the project was reimagined by local residents, led by Rita Vieira Cruz, and submitted to the Participatory Budget in 2016, garnering over 9,000 votes (Ref 2). The one-hectare garden connects the Arroios and Penha de França parishes and features leisure areas, an amphitheatre, playgrounds, and a community garden (Ref 4). Its design was shaped by citizen input, emphasizing sustainability and accessibility, with plans to support activities such as outdoor cinema and community gatherings (Ref 2).

The City of Marseille is engaged in a city-wide project to develop community gardens across its territory. It supports project leaders by providing municipal land and offering a framework along with technical support (Ref 5). Currently, there are 80 community gardens, including 66 shared gardens and 14 family gardens, covering nearly 32 hectares in total (Ref 1).
Marseille aims to provide all residents with spaces for relaxation and socialization in every neighbourhood, particularly fostering shared gardening spaces in neglected land, forgotten squares, building bases, or areas awaiting development. (Ref 1). Community gardens contribute to the city's beautification and support biodiversity (Ref 1) and are founded on values of solidarity, conviviality, and fostering connections between generations and cultures (Ref 4). This initiative also addresses the issue of agricultural land disappearing due to urbanization, while Marseille's many abandoned wastelands offer genuine opportunities to rethink production models (Ref 3).
The city has created a Charter to be signed between the city and garden managers, which can include groups of residents or associations (Ref 2). The charter includes criteria such as citizen involvement, fostering social connections, promoting biodiversity, restoring soils’ health, planting local species, and eco-responsible gardening practices (Ref 2). In return, the city supports the development of these gardens, providing land and offering technical and methodological assistance, including soil analysis and advice on environmentally friendly gardening practices (Ref 2). Additionally, community gardens can serve an economic purpose by creating jobs and enabling the production of healthy and flavorful fruits and vegetables at a lower cost (Ref 2).

Phoenix is America’s fifth largest and hottest city, a sprawling urban heat island which has expanded without adequate consideration to climate and environmental factors like water scarcity and extreme heat (1). ​Multiple heat records were broken in 2023 including 133 days over 100F (37.7C), and 55 days topping 110F (43C) (1). Only around 9% of Phoenix is protected by tree canopies, yet this citywide figure masks vast inequities between wealthy, majority-white neighborhoods (1). As a response, the City of Phoenix has adopted an equity-driven heat mitigation plan to create a shadier, more livable environment amid rising temperatures and hundreds of heat-related deaths (1). Part of this plan created the Community Canopy Grant program, which offers public schools, churches and homes in qualifying census tracts – low-income neighborhoods with little shade funds for tree planting projects (1). One neighborhood, Grant Park is one of the city’s oldest neighborhoods – and one of the most neglected (1). It is a red lined neighborhood with higher pollution levels, less vegetation, more noise pollution and higher temperatures (1). To change the inequity and create enough shade to provide residents and passersby reprieve from the heat, the city planted around 40 trees in the Grant Park neighborhood within household yards (1-2). Residents can choose from a list of 19 native and desert-adapted trees including the Texas olive, Chinese red pistache and Chilean mesquites (1). The trees, which are a couple of years old and pretty heavy, are planted by contracted arborists (1). Following the planting process, each household was provided with a tree kit – a hose, irrigation timer and instrument to measure the soil pH and moisture, as well as written care instructions (1). This is the fourth tree planting effort by this city and the hope with this initiative is that it lasts (1).