The TRANSFORM Institute (HEIA-FR) invites Nathalie Baumann, urban ecologist, leader of the Urban Ecosystem Design Group at the ZHAW School of Life Sciences and Facility Management, and co-author of the book "Végétalisation biodiverse et biosolaire des toitures" (2018) for a talk about "Urban biodiverse habitats for Animals, Plants and Humans – Cities of the Future".

Global warming is an acquired fact. One of the main results of climate change is the fact of increase of temperature – but not only: another important fact is the rapid decline of biodiversity worldwide, increasing temperature of the oceans and more intensive natural hazards.

Up to 75% of urban zones of many cities across the world are covered with permeable and warm absorptive (and highly reflective) surfaces (asphalt, concrete). This means that 75% of normal rains will not be absorbed in the soil, ground waters and runoffs, through drainage systems, into the rivers. The lack of vegetation in urban zones means that the following important functions in the cycle of water, absorption and retention, which are assured by the vegetation and open soils (and rooftop substrates) are missing.

The urban sprawl linked to population growth and other human connected activities such as the production and transport of goods are the main causes of habitats fragmentation and biodiversity loss. The conflict between people and wildness in urban areas (e.g. allergies, anxiety, unawareness) limits the chance of species survival in built environments where land price discourages investments towards nature conservation in favor of more lucrative ones (e.g. housing, construction of shopping centers and other places for entertainment). Moreover, our cities are often characterized by the unequal access of the population to green spaces, the distance of semi-natural areas from city centers, but also the low amount and poor quality of green spaces of the peripheries and suburban areas, often polluted or neglected.

By returning directly to the 75% of permeable surfaces in urban zones, when the same surface is planted, thanks to divers existing measures like: green roofs, green facades, parks, trees etc. up to 90% of the rain is progressively absorbed by the soil and will reduce flash flooding.

All these above mentioned surfaces can provide, if planned as nature-based-solutions (NBS), suitable habitats for animal and plant species – so let’s have a closer look to this and discuss, share and plan our cities now and in the future: biodiverse greener and healthier.