Implementation of city-wide or neighborhood initiatives focused on biodiverity protection (e.g. bee-friendly initiatives, butterfly protection, "Spring cleaning")

The project ‘Planting the Future and Cultivating Life’ aims to create an ecological corridor in the city by reforesting an area of 28 hectares, under the direction of the Porto Velho City Council. It encourages citizen participation in tree planting activities or the management of green areas. To this end, the municipality is carrying out tree planting programmes in parks, squares and along public roads, encouraging citizens to get involved in this endeavour by actively participating in tree planting actions, caring for trees already on their property or raising awareness of the importance of these actions. (1) They seek to involve organisations such as schools, colleges, companies, associations and public organisations to increase the community's and young people's interest in responsible practices and positive attitudes to value and preserve the environment (1).
To achieve this goal, the Porto Velho city council organised a tree-planting day on October 23rd 2023, where 31,000 tree seedlings of native and fruit trees were planted in the Park Passarela Espaço Alternativo (1, 7). This was done with the support of the Municipal Secretariat of Environment and Development (1). This activity is part of the project Virada Ambiental, which seeks to promote the planting of native trees in municipalities across the country, raising awareness of the importance of planting native species and training municipal civil servants and the general public (3, 5). The National Confederation of Municipalities also supports this project and aims to mobilise society to encourage the planting of native trees to rescue biodiversity and recover environmental services, favouring social welfare by promoting tourism, and outdoor sports activities (6), providing shade, protecting the soil and combating high temperatures (2).

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).

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].

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).

This project, implemented in several schools across Fort-de-France in 2018, focuses on creating arboretums in schools to educate children about Martinique's native natural heritage and raise awareness of biodiversity loss. An arboretum is a curated collection of trees selected for scientific, conservation or public enjoyment.
The initiative, led by the Martinican National Botanical Conservation, is supported technically by the municipal landscaping department and administratively by the city of Fort-de-France and the Martinican School Rectorate. It includes three main activities: a seminar on Martinique's rich yet fragile botanical heritage, an excursion into a forest, and a tree planting event at schools featuring native or endangered plant species. The program has reached at least six schools in and around Fort-de-France.
(Ref. 1,2,5)

FoodLink, a network for food transition in the Lisbon Metropolitan Area (LMA), aims to create sustainable, competitive, and resilient agri-food systems closely integrated with regional and local spatial planning. The network's goals are to promote food security, economic and energy efficiency, environmental sustainability, and socio-territorial cohesion by 2030. The network seeks to ensure that by 2030, 15% of the metropolitan area's food supply is secured locally through sustainable production methods, innovative solutions in water management, soil conservation, climate adaptation, and low-carbon distribution networks involving community gardens, urban allotments, and agricultural spaces within the Lisbon Metropolitan Area. (Ref 2)

The NatureRx Rain Garden Pilot is a community-driven initiative aimed at addressing urban runoff and its associated challenges, implemented by Bí URBAN, a community hub and social enterprise in Dublin focused on urban regeneration. The pilot project developed in Stoneybatter, Dublin involves diverting rainwater from residential rooftops into specially designed rain gardens (1). The area is used as the first trial area by installing around 100 rain gardens (3, 11). Built to fit neatly into available spaces, these self-sustaining planters will filter rainwater through the garden, with overflow pipes in place to prevent flooding during heavy downpours (1).
It is expected that these gardens will transform sterile urban spaces into green areas, enhancing biodiversity, providing habitats for pollinators, and acting as carbon sinks (1,3).

Mehr Bienen für Berln - Berlin blüht auf is a project that aims to provide an example of how public green spaces can be upgraded to be pollinator-friendly, thus creating urban habitats for wild bees and other insect species (Ref. 4). The project was implemented by the German Wildlife Foundation in cooperation with the Berlin Senate Department for Mobility, Transport, Climate Protection and Environment and other stakeholders, in all 12 Berlin districts, whereby the districts support the allocation of the exact location for the NBS (Ref. 3; Ref. 4). Measures for each location are compiled based on the specific surroundings, use and existing vegetation with a low mowing frequency in all areas (Ref. 2; Ref. 4). Most of the areas are road median strips, roundabouts, designated areas in parks or residual commercial areas (Ref. 4). After the first phase (2018-2022), the project has now entered its second phase (2023-2025) and was renamed to “Mehr Bienen in Berlin - Aus Grün wird Bunt” (engl.: More bees in Berlin - from green to colourful) (Ref. 3). The main goals are to reach a minimum of 100 flowering areas in 2025, to halt the sharp decline in bees and other insects, and to inspire citizens to protect wild bees (Ref. 1,2, 3). The project has so far limited acceptance among the population, as the areas are regarded as unkempt due to the low mowing frequency. Public relations work, like the installation of information signs next to the areas, is intended to increase understanding among the public (Ref. 4).

Lomas are endemic seasonal ecosystems found in Peru and Chile. They provide a variety of benefits such as soil stabilisation, air purification, recreational spaces, water retention, and are habitats for endemic and threatened species (Ref 7). They are of great ecosystem value to the city of Lima, as green areas have been reduced in the urban area, occupying up to 24% of urban green ecosystems. These ecosystems are threatened by unplanned urban growth, traffic, pollution and lack of government regulation. Given this context, Eab Lomas is a project that focuses on the conservation, management and rehabilitation of the ecosystems found in the Lomas of Lima (Ref 1, 2, 3, 4, 5). It focused on 4 lines of action: conservation of Lomas' ecosystems; implementation of territorial planning; economic diversification focused on the conservation and recovery of vegetation through low-impact recreational activities; and management of water resources (Ref 1, 2, 3, 4).