Study on the ecology of urban habitats – paper

author: AnneMarie Maes, title: Study on the ecology of urban habitats, guided by the observation of city honeybees, published at the occasion of the TIK (Time Inventors Kabinet) conference in Graz (2010)

The range of habitats in urban areas is surprising. Most of the major terrestrial habitat types are represented in towns and cities, either as remnants of previously rural environments, or as artificial analogues of semi-natural habitats.
The OpenGreens project focuses on two rooftopgardens located in Brussels’ city center on 400 m from one another: an edible forest rooftop garden on top of a parking lot and a wild flower rooftop garden on top of an old warehouse.
The OpenGreens project blends organic and technological matter into one and the same nature. Through analogue and digital means we do long term observations on the growth, blossoming and decay of plants and insects submitted to natural elements such as wind, sun, rain and pollution in an urban context.
We monitor and extract data from natural processes both on micro garden level as on macro city level and make these data in realtime available online via open wireless citynetworks.

We research the connections between people, technology and the possible uses of the rooftop gardens. Can the gardens’ evolution be controlled, generated, enhanced or imagined in artworks? Does the fusion of natural and artificial matter produce new organisms, new environments, new natures? Can technology animate nature and vice versa?
The OpenGreens is an artificial environment, a hybrid of nature and culture. The harvest is about scraping data of any kind from the garden and using it for organic ánd for media applications.

Till recently the design of green roofs was based almost entirely on engineering considerations: how they affect building performance as energy consumption and storm-water retention. We would like to focus on the role that green roofs can play in the conservation of biodiversity in the cities, their functionality in terms of habitats for wild plants, for insects (bees, solitary bees, wasps and ants) and for birds. Green roofs not only provide food habitats but also breeding habitats for those animals.
With the OpenGreens project, we want to research if a diverse flora develops on green roofs in inner cities as well as in rural areas. By monthly observations of some permanent quadrats we will research the long-term vegetation dynamics on two rooftops (150 and 300 m2) in the inner city of Brussels. We created a variety of sunny and shady areas and monitor the plant diversity in these different microclimates of the rooftop gardens. In our finding we take into account the different soil compositions: lava, crushed bricks and concrete, organic matter, homemade compost, volcanic tuff, native soil.
We make statistics of climatological factors as temperature and rainfall to study how they affect the floral diversity. We also take the surrounding city vegetation into account.
We research if we can mimic natural habitats with varied microtopographies, scattered rocks, rubble, dead wood and a more diverse vegetation.
We look into natural analogs of these manmade environments. We study species of plants that are adapted to shallow substrates and extreme temperature and moisture conditions. Barren ecosystems often bear the same characteristics and therefore can be useful natural models for green roofs.

We model one rooftop garden as an edible forest garden. The other rooftop is set free to the natural elements. Both garden-models are an important part of our ‘urban permaculture system’. Permaculture is about designing human environments that have the stability, diversity and resilience of natural ecosystems. The system integrates energy efficiency, food and gardening systems, natural building, rainwater harvesting and urban planning along with the economic, political and social policies that make sustainable living possible and practical.
The forest garden is modelled on a natural woodland – the original state of most non-cultivated land in north-western Europe. It has at least 3 (or more) layers of vegetation: trees, shrubs and herbaceous plants. The annual vegetables reproduce by self-seeding.
The wild flower garden is a patch where we observe month by month the evolution of pioneer-plants brought by the wind and the birds
Both gardens form a basis for experiments between nature and culture, plants and electronics, organic and digital examination methods.

We store the data of our long-term observations in the OpenGreens Database.
This relational database covers and reveals information on all elements of the OpenGreens rooftop gardens in numbers, text and images. Historical and current state of the gardens, goals of the project, people involved, sustainability factor. Permanent quadrat monitoring and poetic observations. It offers links to existing databases for further detailed information on plant- and animallife. It informs on data gathering and data treatment.

We organise our research on urban habitats via the observation of city honeybees. Hives are installed in both of the city gardens. The bees will manage to bridge the spatial distance and will associate the locations. The activities of the bee colonies make the gardens interconnect and interfere. The respective trajectories and areas of floral visits will overlap and an interference of the hives and gardens takes place. The emerging inter-space can be perceived as place of encounters and neighborhood. Observing and monitoring the activities of the hives makes bee information directly available online.
An important source of nectar and pollen, essential for the honeybees in the late summer months when the melliferous trees stop blossoming, are the wild flowers.
One can find a selection of those plants on city wastelands, on building sites and non-use parcels, on track-sides and in parks.
To give the bees a helping hand we can make seed balls and by sowing them we can reclaim a little bit of the urban public space. The seed balls contain the necessary seeds for a wild or domestic ecosystem.
A lot of different seeds can be used to make seedballs, and mixed together with local soil, homemade compost, some sand, clay and water they become little potential gardens. They are cost effective and can be made by anyone, anywhere where there is soil and seed. We use 1 part of seeds, in this case a mix of native wild flowers and herbs called Tübinger. This mix is benefiicial for pollinating insects, in special for the honey bee. It consists of 10 annual flowering plant species in different proportions : borage, buckwheat, marigold, white mustard, coriander, caraway, centaurea jacea, cheeseplant, dill and phacelia.