Biodiversity loss

Martinique is a biodiversity hotspot, home to over 1,500 endemic plants, 70% of which are under threat from human activities. In response to these pressures, the Péyi Vert [Green Country] initiative was launched to plant endemic trees and strengthen the island's biodiversity. Beyond simply preserving species, these trees are crucial in maintaining healthy ecosystems, as they provide essential services such as carbon sequestration, shade, food for human consumption, soil decontamination, pollination, and protection against coastline erosion.
Launched in June 2020 by Entreprises et Environnement (EE), a not-for-profit business association representing 80 Martinican companies, the Péyi Vert initiative aims to plant 1 million native trees (either Martinican or Caribbean) over five years. It can be seen as a Martinique-wide strategy to adapt to and mitigate climate change. Péyi Vert facilitates connections between people who want to plant trees and Martinican companies that serve as financial sponsors. The initiative emphasizes conserving natural heritage by planting endangered species, as well as promoting native species that, while not necessarily threatened, provide valuable ecosystem services or contribute to biodiversity restoration.
Between 2020 and 2023, EE reported planting 50,000 trees (Refs 1, 4, 6, 7). Although individuals can make donations, Péyi Vert primarily seeks funding from companies looking to offset their carbon emissions or enhance their Corporate Social Responsibility (CSR). To achieve its goals, the initiative mainly collaborates with municipalities, companies, and farmers (Ref 3).

Rainwater management in Gdańsk presents significant challenges due to the city's hydromorphological conditions, including high groundwater levels and steep terrain. These factors, coupled with the periodic inefficiency of the storm sewer system and the intensification of extreme weather events such as heavy rainfall, have necessitated innovative solutions. Gdańsk has responded by implementing a climate change adaptation policy that promotes the use of open drainage systems, including small retention facilities like rain gardens. These gardens help mitigate the risks associated with excessive rainfall while enhancing urban sustainability.
The first rain garden in Gdańsk was established in the Stogi district at the Flood Control Warehouse on Kaczeńce Street. This facility collects and utilizes rainwater from nearby paved surfaces, aiming to manage rainfall of at least 30 mm during intense, short-term downpours. Utilizing a variety of perennials such as marsh marigold, common loosestrife, comfrey, hemp agrimony, common calamus, and arrowhead, the garden retains and filters rainwater naturally, increasing efficiency and ecological benefits. Rain gardens absorb water up to 40% better than traditional lawns. They reduce rainwater runoff, mitigate flood risks, filter pollutants, improve biodiversity, and enhance urban air quality while lowering temperatures.
The garden was created as part of a broader investment in the Flood Control Warehouse in Stogi, a facility opened in 2017 at a cost of over PLN 5 million. Strategically located near the Sucharski Route and the Martwa Wisła tunnel, the warehouse supports rapid response to flood emergencies, storing over 100 types of equipment, from shovels to large generators. This combination of infrastructure and green solutions demonstrates Gdańsk's commitment to urban resilience and environmental sustainability. (1-4)

In the bay of Fort-de-France, mangroves cover nearly 1,300 hectares, representing about 70% of the total mangrove area in Martinique. This plant formation, characteristic of tropical marine environments, is essential for the ecological balance of the bay. Mangroves act as filters, purifying marine and river waters, protecting the coastline against erosion, and providing habitat for various marine flora and fauna.
However, this fragile ecosystem is threatened by wave-induced erosion, urbanization, the spread of invasive species, and pollution. In response to these challenges, the French Coastal Protection Agency (Conservatoire de l'espace littoral et des rivages lacustres, CELRL) and its partners have launched an initiative to restore several mangrove areas as part of the “Contrat de la Grande Baie de Martinique" which is a collaborative initiative aimed at the sustainable management and restoration of the coastal and marine environment of the Greater Bay of Martinique. This contract typically involves partnerships between various stakeholders, including government agencies, local municipalities, environmental organizations, and community groups. The project identified several sites totaling 3.81 hectares in the Greater Bay area that require reclamation.
The project aims to restore mangrove populations by creating favorable conditions through actions such as clearing invasive species and trash, followed by replanting with white, black, or red mangrove seedlings, depending on the environmental characteristics of each site. Additionally, the initiative seeks to engage the public and youth through volunteering days and awareness campaigns (Refs 1-9).

The rate of deforestation in the Brazilian Legal Amazon in 2023 was consolidated at 9,064 km2. Initiatives that promote forest restoration in this biome are emerging to overcome this scenario. One such initiative is Floresta Productiva which aims to reforest more than 200 hectares of degraded land in the southwest of the Brazilian Amazon, known as the ‘arc of deforestation’ (1). Led by the Instituto Socioambiental in partnership with the NGO Rioterra, it focuses on creating and disseminating native forest restoration models that combine ecosystem recovery with income generation for rural producers in Porto Velho (2). By fully integrating local communities, the project promotes traditional agroforestry practices (muvuca) and trains communities to maintain the planted land. This not only restores the forest but also provides economic benefits through the cultivation of timber, fruit trees and other species (2), strengthening sustainable agriculture, breaking the cycle of deforestation and restoring deforested areas through various native species grown in nurseries (1). The project is being developed in the cultivation area of the Amazon Bioeconomy Centre (CBCA), from 2023 to 2025, where it will directly benefit the rural community of Vila Nova de Teotônio (3).
The project started in 2019 and has impacted other communities in the area, such as the communities in Nova Mutum Paraná and Ji-Paraná (1). During these years, more than 123,000 trees have been planted in agroforestry on about 110 hectares of land, and edible forests have been created. Since 2022, a new planting phase has been underway, to plant more than 100,000 trees of 87 native species on 40 hectares of degraded forest (4). In conclusion, this project focuses on the development of agroforestry in the face of widespread monospecific soybean fields and intensive cattle ranching (3); the creation of edible forests (3); and the restoration of forest cover to ensure the long-term resilience of the forest (3).

The "Mangle Verde" project is a community-led intervention aimed at reforesting mangrove areas in Cartagena, particularly around the Ciénaga de la Virgen and Ciénaga de Juan Polo. Initiated by Gloria Sánchez and other members of the Villa Gloria community, this project is a response to the environmental degradation caused by urban development, including the construction of a viaduct, and the damages inflicted by invasive settlements and pollution​(ref 1,4). The primary goal of the project is to restore the mangrove ecosystems, which are essential for maintaining water quality, preventing coastal erosion and supporting marine biodiversity conservation (ref 4). In addition, this initiative provides socio-economic benefits by fostering ecotourism and increasing fish populations, which directly benefit the local fishing economy​(ref 1). The "Mangle Verde" project emerged as a grassroots response to compensations granted by the Concesión Costera for the damage caused by infrastructure projects in the region. Local residents of Villa Gloria, recognizing the importance of the mangrove ecosystem, established nurseries in their homes where they cultivate three types of mangroves (ref 2,4). So far, the initiative has planted over 26,860 mangrove saplings and is committed to continuing the reforestation efforts, which also include cleaning and maintaining the canals around the mangroves​ (ref 1). Beyond ecological restoration, the project also addresses key environmental risks in Cartagena, including coastal flooding and habitat degradation, driven by both natural phenomena (e.g., tides) and human activities such as urban sprawl and illegal dumping (ref 6, 7).

The Alexandria Governorate is especially susceptible to the impacts of climate change, a vulnerability exacerbated by its dense coastal communities and rapidly growing population (2). Both demographic shifts and urban development intensify how climate phenomena affect the people and infrastructure of Alexandria (1). Buildings, roads, and other concrete structures absorb and release solar heat, significantly contributing to the urban heat island effect, which is causing temperatures in the city to rise faster than in less developed areas (1). Despite Alexandria’s growing need for cooling green spaces, they currently make up only 0.25 percent of the total area within the Governorate, highlighting an urgent need for environmental interventions (3-6).
In response, Ahmed Gaber, chairman of the Alexandria Water Company, initiated a public awareness campaign in 2023 focused on the numerous benefits of planting green roofs (3-6). Green roofs serve multiple purposes: they extend the longevity of buildings, lower energy consumption, improve air quality, increase biodiversity, manage rainwater runoff, and mitigate the urban heat island effect (3). Furthermore, Gaber has emphasized the visual appeal of eco-friendly roofs, noting that green roofs offer an aesthetically pleasing option that enhances the urban landscape while serving critical environmental functions (4).
This initiative by the Alexandria Water Company marks a pioneering step among governmental organizations in the region, as they lead efforts to address climate and environmental challenges actively. The company has begun planting green roofs across its facilities, including the new Al-Mashishya water station, where green spaces atop buildings are set to bring lasting environmental benefits to Alexandria. Through these efforts, the Alexandria Water Company is working to set an example for public and private sectors alike (3-6).

Rapid urbanization and a population density of 6,247 people per km² have placed significant stress on Nairobi's natural resources (Ref 1). The 40-km long Nairobi River Basin, originating from the Ondiri Swamp, serves as a vital water source for the city (Ref 1, 2). However, it has suffered severe pollution from untreated sewage, solid waste, industrial contaminants, plastics, and agricultural runoff (Ref 1, 3). This degradation has had a serious impact on the ecosystem, local residents, and biodiversity (Ref 3).

To address these issues, the Nairobi River Basin Programme (NRBP), sponsored by UNEP, was launched in 1999 (Ref 4). Since then, government and non-state actors have worked together on solid waste management, riparian restoration, and wastewater control (Ref 1). The program was implemented in two phases: Phase I (2003–2006) and Phase II (2006–2009), involving stakeholders from the government, private sector, and civil society (Ref 1, 4, 5). Despite these efforts, a study from 2017 found significant tree removal along the river, and between 1988 and 2014, encroachment into the 30-meter riparian buffer zone dramatically increased, particularly between 2010 and 2014, further degrading the river’s health (Ref 1).

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).

In Sjöhåla, west of Kungälv, an abandoned pasture on a wet meadow by the coast was restored by reintroducing grazing, clearing bushes and reeds, digging ponds and renovating stone walls. The aim was to increase biodiversity in the area and to promote the production of local organic meat. Additionally, the project made it easier for visitors to pass through the area for recreational purposes. The project was carried out by the municipality of Kungälv and the non-profit organisation Omställning Kungälv, and involved other local associations, farmers and citizens. It was funded through the "Local nature conservation investment" by the Swedish Environmental Protection Agency. As a result of the project, the area is more accessible, and many species of plants, insects, and birds have been found. [Ref. 1-3]

The John Michuki Memorial Park was transformed from a vast dumpsite in 2008 and established in honor of John Michuki, the Environment Minister during the Kibaki administration, in 2012. Michuki garnered admiration and accolades for his enthusiasm and determination to clean and preserve the environment (Ref 1, 2). Situated along the Nairobi River, the park serves as a historically rich recreational facility (Ref 3).
However, several issues arose after the park was transferred to the county administration in 2013 (Ref 2). A section of the Nairobi River flowing through the park experienced severe environmental degradation due to illegal discharges and poor waste management, negatively impacting the riparian ecosystem and biodiversity (Ref 4). Additionally, the park became a refuge for drug users, street children, and thieves, with stray dogs posing safety threats in the area (Ref 1, 2).
As the first project within the Cleaning Up Kenya Campaign, the restoration of Michuki Memorial Park was launched in 2020 by the government (Ref 5). The park is now managed by the Kenya Forest Service (KFS) following a directive from the national government (ibid.). With funds from the treasury, a perimeter fence was erected, a 2.4 km walkway was constructed, and 4,200 seedlings and 6,357 indigenous trees were planted, along with the establishment of a nursery (Ref 1, 6). A total of 20,000 tons of solid waste were removed (Ref 6). Additionally, a community forest association was formed to ensure community engagement (Ref 2).