5.1 MOSAIC MOWING ROTTERDAM

An experiment was set up in Rotterdam to find the optimal mowing method for the municipality to enhance biodiversity. Urban ecologists have called this ‘mosaic mowing’. This type of mowing is used for broader roadside verges with nutrient-rich soil. With mosaic mowing, there are three rounds of mowing, whereby one part is done in the first round and another part in the next. The vegetation is never completely mowed in one go and one part is always left untouched during the winter. This is especially beneficial for insects, which use the vegetation throughout the year in all their life stages (egg, larva, pupa and imago). By removing the cuttings, the soil is prevented from becoming too rich in nutrients. The first round is scheduled early in the year (in May), so the herbs in one third of the area have the chance to bloom at the end of the summer. Verges at crossings and the first 50 centimetres along the roads are always kept short for safety reasons. Already within a year, measurements indicated that biodiversity was significantly higher than in similar parts with traditional management. Many grasses and herbs completed their entire flowering cycle, thus increasing the wealth of insects, especially butterflies. Not only the species that live in these grass strips benefit from this mosaic mowing, but perhaps these strips also serve as a refugium for the more picky species from the surrounding areas. In 2017, the survey will be extended with an inventory of bees.

-ROTTERDAM (NL) 2016

-REMKO ANDEWEG, BUREAU STADSNATUUR

5.1 BO01 VÄSTRA HAMNEN

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Bo01 is part of the residential district Västra Hamnen in Malmö. It started as a housing exposition project ‘city of tomorrow’. A team led by urban designer Klas Tham planned a high density residential area with state of the art environmental measurements regarding energy, water and ecology. Despite the densely built-up urban character, much attention was paid to the diversity of green spaces and to biodiversity. During the development, two methods were used to turn Bo01 into a green neighbourhood: the ‘green points system’ and the ‘greenspace factor’. The basis for the green points system was a long-list of measures from which developers had to choose ten to use in the future inner courts. The greenspace factor was developed on the basis of experiences in Berlin in the 1990s. This factor describes the ecological value of a lot as an average of the qualities of its parts. Depending on whether the part-lot provides room for green, ecological measures and rainwater management, it is given a value between 0.0 and 1.0. The rule was that each plot as a whole had to score an average of at least 0.5. Most developers and architects were enthusiastic about these clear guidelines. It enabled them to discuss sustainability with the future residents. Some ecologists and landscape architects were less enthusiastic because the greenspace factor left out certain aspects, did not count spontaneous interventions and was in danger of losing sight of the big picture. They thought this approach would not result in a coherent system. Experiences so far have shown these fears to be largely unfounded. The Anchor Park is situated in the lee of Bo01. The park is not only designed as a rainwater buffer but also a place to learn about nature. Thus, it is furnished with three typical Swedish biotopes; an alder swamp, oak forest and saltwater habitat.

-MALMÖ (SE) FROM 2001

-KLAS THAM, MUNICIPALITY OF MALMÖ

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more info: Green factor

5.1 VACANT LOT

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Vacant Lot is an example of social sustainability where the residents are activated to bring more social cohesion to their neighbourhoods, and to strengthen the (experience of) urban nature and urban farming. The project takes vacant plots in deprived urban areas in London into use. The neighbourhoods are given new green outdoor spaces, urban farming plots and meeting places. The project provides for collective use of locations that are made accessible and laid out with bespoke design elements. From 2007 to 2015, 21 of such allotment gardens were created in London for 880 residents, with a total surface area of 1.9 acres. Vacant Lot is an example of what is happening in many cities. In Berlin, the activists of Nomadisch Grün are active; in Rotterdam, Creatief Beheer is; and the NoHo district in New York runs the Community Garden District programme. In addition to support for urban nature, such projects provide important small steppingstones that can strengthen the ecological system as a whole.

-LONDON (GB), FROM 2007

-DESIGNERS’ COLLECTIVE WHAT IF: PROJECTS

more info: website Vacant lot