Preservation of tree species in Douala
Douala is the economic capital of Cameroon and one of its largest cities. The city is located on the banks of the Wouri River (hence a port city) and its climate is tropical. The marine and coastal biodiversity of Cameroon is rich and diverse, and it is highly endangered because of human activities including artisanal and industrial fishing and pollution generated from industries, accidental loss of crude oil in transit or during loading or unloading. In Douala, thousands of inhabitants have settled in and around the mangrove swamps, destroying the mangrove ecosystem and endangering biodiversity including snakes, birds, fish, trees and frogs. Biodiversity studies are rare, and even if they exist, they are done in part and do not give an overview of the real state of biodiversity in the city. The city of Douala is full of many ecosystems of various natures (micro-ecosystems), each of which has species adapted to the environment. Besides this, Douala confronts itself with seasonal flooding and high temperatures due to climate change. In response to some of these challenges, a local entity, the Association of academics and researchers for Biodiversity conservation, initiated in 2020 an action that focused on environmental education and biodiversity conservation. The initiative also provides a framework for reflection and exchange on biodiversity issues. (1,3,4)
Green Belt of Medellin
Medellin is the second-largest city in Colombia. The city used to be one of the most dangerous in the world, as Pablo Escobar founded here the Medellin cartel. After the death of Escobar, the city's homicide rate has decreased by 95% and extreme poverty by 66%, thanks in part to a string of innovative mayors who laid out plans to integrate the poorest and most violent hillside neighbourhoods into the city centre in the valley below. The same innovative mayors realised that Columbia and its cities are very vulnerable to climate change being located in a tropical zone and is influenced by El Niño and the La Niña. In Medellin, the municipality has built upon a tradition of planning to become an urban lab for the construction of public life with the aim of inclusive, peaceful and sustainable development. As such starting in 2008 Medellin began implementing a green strategy whose goal was the creation of a green belt around the city as well as waste control. The intervention discussed in this case is one initiated in 2014 when the municipality carried out planting and reforestation projects for the protection of the eastern slopes of the city. (1,2,3)
Mandaue City Mangrove Eco Park
Touted as a long-term solution to flooding of Mandaue City, establishment of a mangrove eco-park has begun, having received funding from the Department of Budget and Management (DBM) (Ref. 1). Through establishment of mangroves, the eco-park will "perform a significant role in shoreline protection, acting as a buffer against strong winds and waves", which is considered particularly important in light of the anticipated effects of climate change (Ref. 6).
A total 17-hectare plot is to be rehabilitated, as identified in the Mandaue City Government's Comprehensive Land Use Plan (Ref. 3). At present, it is unclear whether nature-based solutions (including mangrove restoration) are to be implemented across the entire 17ha of the site, but initial efforts have been focused on the restoration of a 5-ha section of mangrove forest (Ref. 2). Due to the lack of data on how exactly the remainder of the 17-ha area will be restored, the total NBS area for this project has only been recorded as 5-ha (5000m2) within this case study, rather than the entire 17,000m2 which is encompassed within the site.
The site is situated at the outfall of the Butuanon River which frequently overtops as a result of heavy rain and has been considered "biologically dead" since 1992 (Ref. 7). The site itself comprises a former dumpsite which had been "left derelict and filled with piles of trash", hence in addition to reducing flood risk, its rehabilitation will serve as green space in which "the residents of Mandaue City [can] gather and enjoy a breath of fresh air" (Ref. 2). The eco-park is considered to bring the added benefit of filtering water as it enters the Mactan Channel, in addition to reducing greenhouse gas emissions through carbon dioxide absorption (Refs. 1 & 6).
A total 17-hectare plot is to be rehabilitated, as identified in the Mandaue City Government's Comprehensive Land Use Plan (Ref. 3). At present, it is unclear whether nature-based solutions (including mangrove restoration) are to be implemented across the entire 17ha of the site, but initial efforts have been focused on the restoration of a 5-ha section of mangrove forest (Ref. 2). Due to the lack of data on how exactly the remainder of the 17-ha area will be restored, the total NBS area for this project has only been recorded as 5-ha (5000m2) within this case study, rather than the entire 17,000m2 which is encompassed within the site.
The site is situated at the outfall of the Butuanon River which frequently overtops as a result of heavy rain and has been considered "biologically dead" since 1992 (Ref. 7). The site itself comprises a former dumpsite which had been "left derelict and filled with piles of trash", hence in addition to reducing flood risk, its rehabilitation will serve as green space in which "the residents of Mandaue City [can] gather and enjoy a breath of fresh air" (Ref. 2). The eco-park is considered to bring the added benefit of filtering water as it enters the Mactan Channel, in addition to reducing greenhouse gas emissions through carbon dioxide absorption (Refs. 1 & 6).
Tirana Orbital Forest
The Orbital Forest of Tirana is an innovative urban forest that as a green belt forms a natural growth boundary for the City. Tirana has experienced rapid development in the past decades that led to population growth challenging municipal services and infrastructure, while climate change also posed extensive pressures to the urban area with intense flooding, precipitation, urban heat and degrading environment (1, 4). The Orbital Forest is a ring on the periphery of the City that connects 14,000 ha of Tirana’s parks, agricultural fields, and forests, maintaining the ecosystem and supporting biodiversity. (3, 4) The NBS aims to increase urban greenery through the plantation of 2 million trees that fit well to the existing ecosystem while also creating a natural boundary to halt urban sprawl (1,4,5). The afforestation of the Orbital Forest has been done through the “Donate a Tree For Tirana” campaign started in 2017 where citizens, businesses and international organisations can plant a tree adding to the green belt. As of 2021, more than 440,700 trees in the framework of the "Donate a Tree" campaign are also bringing urban nature closer to residents (3).
Green belt for costal protection
A multi-purpose green belt (12 km in length of Batticaloa Municipal Corporation coast) was established to protect the lagoon and coastal areas, restore mangrove ecosystems and improve coastal biodiversity. The project comes under activity 1.3 of the overarching project Climate Resilient Action Plans for Coastal Urban Areas in Sri Lanka (CCSL). The project focuses on the most urgent and immediate needs of the Sri Lankan coastal cities in adapting to climate change, and mitigating risks and the severity of impacts through Disaster Risk Management (DRM). The green belt plantation was done with Casuarinas plantation in 400 ha (out of which 75% by Mandru and 25% by the Forest Department), mangrove forest redesigning and protection of the existing vegetation. [1, 2, 6]
Aforestation at the Gullele Botanical Garden
In 2019 at the Gullele Botanical Garden in Addis Ababa, the Ethiopian government launched a historic tree planting campaign. Over 350 million trees were planted in an ambitious move to counter the effects of deforestation and climate change. The Gullele Botanical Garden was selected as one of the 1000 sites all over the country involved in the Green Legacy Initiative, a national campaign against the effects of climate change. The United Nations estimates that Ethiopia’s forest coverage has declined drastically to a low of just 4 per cent in the 2000s from 35 per cent a century earlier. (1,2) The Botanical Garden was not selected aleatory as it is Ethiopia's only botanical garden and it is a nursery for various indigenous plant species. Its mission is to conserve and promote the Ethiopian diverse plants and tree population and it is a conservation initiative located at the northwestern tip of the Addis Ababa City Administration. The site covers an area of 1000 ha which is representative of the central plateau of Ethiopia. (3)
"Planting a tree for the climate"
In anticipation of the organisation of the 2016 United Nations Climate Change Conference in Marrakech, the Sidi Mohammed Benabdellah University (USMBA) of Fez has launched an operation to plant 1,000 trees of different species. This intervention was part of a series of scientific, cultural, artistic, sporting and environmental actions undertaken by the University for the Climate, with the cooperation of other partners. Students and faculty as well as NGO representatives were present and implemented the action which ultimately led to the creation of green areas within the campus and around the faculties and universities. Founded in 1975, Sidi Mohamed Ben Abdellah University is named for a 18th century Sultan of Morocco, the nation in which the university is based. The main campus is located in the northern city of Fez, a World Heritage Site and historically the last stop on the famous gold trading route from Timbuktu. (1)
One school, 5 hectares of forest
Ensuring that Ivorians, from an early age, pay attention to the environment, it is one of the Ivorian government’s many environmental objectives. As such, in 2019, the Ministry of Water and Forests initiated a project in the Mamie Fêtai Highschool of the city of Bingerville. The initiative is part of a bigger project that aims at raising awareness and tries to engage the Ivorian school in the recovery of the forest cover of the country. Ivory Coast is a delicate case in West Africa, from a forestry point of view. Since 1960 the country lost more than 80 percent of its forests, mainly to cocoa production and agricultural practices (1,3)
Pocket Parks in Budapest
The creation of pocket parks is an urban initiative that has steadily grown throughout Budapest since 2010 (Reference 1). Most of these projects are citizen-led, but there is often support provided in the form of education and consultancy by initiatives such as the Contemporary Architecture Center (KÉK), or sometimes the local government (Reference 8). These spaces, typically covering an area of 1400 square meters only, are multi-functional and provide a space for small-scale food production, recreation, community sharing, and can be a fundamental element of neighbourhood rehabilitation. Moreover, it provides positive environmental effects such as water retention and the improvement of the area's micro-climate. Pocket-parks are critical in increasing the number of green areas in neighbourhoods that have limited space. (Reference 9)
Green roofs on buses
Green roofs were created on vehicles in the Spanish cities of Barcelona, Girona, Córdoba, Valencia. This initiative is based on the project of Marc Grañén, who developed PhytoKinetic a project for the development of moving gardens. (ref 1) The city of Palma de Mallorca was also considering its introduction as a measure of sustainability. (ref 1) The intervention, however, remained in the pilot stage (ref 1 and 4).

