Biodiversity

Cities are extremely important habitats for animals and plants. Indeed, there are often more diverse habitats here than in the countryside, since monocultures are becoming every more widespread in agriculture. A cornfield exhibits far less biodiversity than a city, where there are literally many niches. And so cities are an important piece in the puzzle when it comes to maintaining biodiversity. Through the transformation of formerly sealed surfaces into new parks and the restoration of stone and steel-clad quaysides to create promenades, flora and fauna have been granted more space in HafenCity, too. By the end of 2021, about 1,800 new trees had been planted in all the public areas of HafenCity alone – and about 11 hectares of public open green spaces, parks and promenades are being created, equal to nearly 16 soccer pitches.

However, because it is an extension of Hamburg’s city center, HafenCity is being developed to have a high urban density. The cityscape here is also characterized by main traffic axes such as Shanghaiallee and Versmannstrasse. In western HafenCity, in particular, the areas of water are the primary determining natural component. And yet nature has regained its place in HafenCity, which for more than one hundred years was used exclusively for port and industrial purposes, and more and more new, surprising green biotopes are emerging where they are least expected. One of these surprises is tucked away in Oberhafen: On the northern side of the buildings there, a passageway leads to a public urban garden. Following intensive planning and active participation by users, lawns, raised beds with flowers and vegetables, wildflower meadows lovingly fenced with ships’ hawsers, fruit trees and water pumps have been laid out. A rich green diversity has grown up in the narrow strip between the quayside and the buildings, making its own contribution to the biodiversity of the district.

But to take things in order, the green spaces in HafenCity today already look different than they did in the early phase. After all, the development of green spaces and their subsequent colonization by different species takes time. Many of the measures one can see in HafenCity today were initiated years ago. As early as 2009, HafenCity Hamburg GmbH prompted discussion – entitled “living better in green and blue” – of the importance of public spaces, especially in waterfront locations, and the ecological and social sustainability of waterfront projects in urban development in the face of climate change. Much has happened since then. Elaborate measures were adopted for plants worth of protection, e.g. in Versmannstrasse, where, during construction works, alkanet (Anchusa officinalis) was transplanted, propagated and subsequently replanted. In Baakenpark, a multitude of wild flowers and plants can be discovered in zones especially designed for them. These areas are mown only occasionally and thus provide food and habitat for insects and small mammals. In Lohsepark, a “fenced wilderness” has even been created: In a protected section, plants are left to develop naturally, thus creating a colorful diversity for butterflies and other insects. Here, for example, stinging nettles can grow freely without being cut back. They are a favorite with butterflies but are seldom welcomed elsewhere in public spaces.

Meanwhile, the topic of diversity has been more and more in the public eye in recent years. Thus when it comes to green issues, the focus is now more on civic engagement than before, and practical projects to increase biodiversity and quality of life are being realized with the local population. In HafenCity these include projects such as tree sponsorship or urban gardening taken on by residents. There are also individual initiatives, such as the “Friends of Lohsepark” association setting up nesting boxes or insect hotels, or beekeepers looking after bees on rooftops in the district. Knowledge often plays a role here: small, biodiverse areas in the city, which a few years ago would have been perceived as “untidy” and “overgrown”, are now largely accepted by the public. They are already taken for granted as part of the cityscape – precisely because people have recognized their value for species diversity. The design of public spaces as communally used areas therefore relies on close cooperation with the public and with residents.

After its successful beginnings in HafenCity – where in the Baakenhafen and Elbbrücken neighborhoods the parks and many building initiatives have been designed from the outset with the goal of increasing biodiversity – the “green city by the water” is now being developed a lot more intensively in Grasbrook. The holistic development of HafenCity, Grasbrook and Billebogen makes it much easier to link biotopes across the various districts: The large parks, such as Lohsepark, will be augmented by new green spaces such as Baakenpark and the planned new park in Grasbrook, forming a web of biotopes and creating an ecological network reaching from the city center to the south of Hamburg.

Today’s urban and landscape planners aspire even more than in the past to view the city holistically as an interconnected system. The interconnection of different process, material and recycling streams includes urban green spaces here. For example, grass clippings, which today are often disposed of, could in future be used for energy generation. Water will be purified and reused locally instead of being channeled away. Intelligent rainwater management can make irrigation with drinking water largely unnecessary. In future, food production could also become part of the urban environment. Forest gardening, already being used in organic farming, offer ideal conditions and resilient ecosystems. So-called Miyawaki forests are already part of planning by HafenCity Hamburg GmbH. And the trend towards roof gardens and green building facades will continue anyway. Overall, by adding more green space to the city, we will all be making an important contribution to restoring a natural water balance and improving the microclimate as part of climate change adaptation.