Ecological restoration of ecosystems

Two River Urban Park is a public space located towards the confluence of the Liesbeek and Black Rivers and is one of the largest urban green lungs in the City of Cape Town. It is approximately 240 hectares in extent. The Park comprises sensitive ecological systems and habitats, extensive open space areas, institutions, historical buildings and cultural landscapes (2). The City of Cape Town and the Western Cape Province own significant proportions of the park and in 2011, the Western Cape Government started considering the sustainable redevelopment of the TRU Park into a mixed-used urban green area including housing development, heritage protection, the rehabilitation of the degraded environment and recreation opportunity creation (1). Since 2016, the project has been on hold due to the modification of the planning law Local Spatial Development Framework that affects the redevelopment plans of the Two Rivers Urban Park (1).

The Nature Conservancy established the Cape Town Water Fund in 2016 using the worldwide applied water fund to enable downstream water users to invest in land conservation and restoration upstream. (4,5) In 2018, the Water Fund started its pilot project on the catchment area of the Atlantis Aquifer, outside of Cape Town's boundaries on state land. The pilot project "seeks to increase water supply to Cape Town by removing invasive plant species in water catchment areas. Invasive species have been found to use significantly more water than indigenous species and uptake millions of litres of water from the catchment area annually that would otherwise be added to the city’s water supply" ( 1 p7). The intervention also supports the empowerment of marginalized communities by providing training and employment for them. As one of the main characteristics of the water fund model, various local stakeholders from all sectors are invited to develop and implement water connected challenges (1).

The Gorla Maggiore water park, inaugurated in March 2013, is situated within the municipality of Gorla Maggiore, in the Italian region Lombardy, located about 30 kilometers northwest of Milan. The water park is a constructed wetlands (CW) built on the banks of the Olona river that includes (a) a pollutant removal area composed of a grid, a sedimentation tank and four vertical sub-surface flow constructed wetlands; (b) a multipurpose area with a surface flow constructed wetland or pond with multiple roles; and (c) a recreational park with restored riparian trees, green open space, walking and cycling paths. [1]

The Tree Strategy is a municipal action plan in progress, aiming to address some of the main sustainability challenges described in the Environmental Program of Malmö City. Its main relations to sustainability challenges include improved health and well-being, decrease differences in those among different social groups and increase biodiversity. The Strategy includes a range of possibilities for evaluating its ecological and social success (ref. 1).

Initially the park was created in 1903 as a summer residence for the royal family and had a no-visitor’s policy. For over 40 years the park collected 821 trees, shrub and, grass species from all over the world on less than 100 ha. After the estate was given back to the successors of Tsar Boris III, they partially donated the park to Sofia municipality and in 2013 the park-museum ‘Vrana’ was opened for visitors. Due to its rare species, well-preserved wilderness and historical significance, the park enjoys great interest from tourists as well as scientists as a biodiversity hotspot. (Ref 1)

Mercedes-Benz helps in the Reforestation of the Park of the Pena, in Sintra: "As part of its social responsibility actions, and as a socially responsible company and involved in its community, the Daimler Group in Portugal decided to intervene and help in the reforestation of the Pena Park in Sintra after it was flogged in 2013 and 2015 By violent storms that caused the fall of more than 2000 trees." (ref 1)

The renaturalization of the water canal Hirtenbach project was part of the larger city-wide initiative that aimed at the naturalization of different parts of the city's drainage system including small trenches and streams. The initiative aimed to decrease the risk of floods, improve the water quality, protect the local flora and fauna from the pollution, as well as provide for an additional recreational area for the citizens. (Reference 1)
In 2000, natural remodelling or the creation of near-natural structures began in sections. A 20, 000 m3 retention basin was also built. These actions improved flood protection and ecology of the area, and it provided local recreation opportunities. However, a study conducted in 2014 revealed that the restoration measures brought positive changes, but it was not enough to achieve a “good water status” defined by the European Water Framework Directive. Intensive care from silting and lush plant growth, wide margins, and the reduction of nutrients coming from the drainage and agriculture, need to be addressed. (Reference 2)
A new landscape is expected to be created when the alder trees grow. Waterbirds and waders, as well as insects like dragonflies, bees, butterflies and crickets, have been observed in the area (Reference 3).
The large drainage system of the city of Hannover includes many small trenches and streams with a total length of 152 kilometres. The intervention in Hirtenbach involved renaturalization worked on the total length of approximately 10,5 km (of which 3,3 km in the urban area). (Reference 2)

An intervention in the parks of Sintra relying on volunteer participation to eradicate invasive species from the green areas. The intervention was carried out on International Volunteer Day and volunteers removed the exotic weed species manually.
The manual work with volunteering was carried out in more sensitive places where herbicide can not be applied (water lines, protected habitats, etc ...) (ref.5)

A group of companies, coordinated by Citigroup and framed by the Sintra-Monte da Lua and Naturlink Parks, met to promote the environmental recovery of the Tapada do Mouco by rehabilitating the plant diversity in the area and removing invasive species in 2001.
The action took place when more than a hundred volunteers from the sponsoring companies triggered Tapada's recovery work” “selective cleaning of invasive alien species and afforestation with native trees and shrubs, such as oaks, ash, willows, arbutus, hazelnuts and holm oaks.” (1,2)

The project revitalized two old ponds – previous industrial and derelict area – and created two new ponds on the Marczukowska street in the city of Bialystok. The investment in its current shape is a tourist attraction and a valuable ecosystem for birds and amphibians. The project resulted in the increase of biodiversity in the area (additional ponds for the breeding of amphibians, two nesting islands not accessible to the public), and more effective management of the local water resources (cleaning and deepening of ponds, restoring an outflow for the excess water directly to the Biała river). Finally, it is a popular place with publicly open educational trails and bicycle paths [2,3,4].