The advantages of installing ecological roofs on buildings in terms of reducing undesirable thermal gains and losses through these surfaces are known, thus contributing to a reduction in the use of energy in air-conditioning for the same indoor comfort conditions. This practice is, moreover, relatively common in northern European countries. However, the existence of this type of roofing is generally equivalent to an increase in the consumption of potable water for irrigation, which must be minimised particularly in Mediterranean environments where climatic characteristics limit its success.
In this context, Ciências ULisboa, with the support of Galp, Neoturf green spaces and ZinCo, started in 2013 a pilot project, installing an ecological cover using native species adapted to the local climate. The evolution of this cover is being accompanied by teachers and students, contributing to a better knowledge of the functioning and sustainability of these structures in Mediterranean areas. This ecological roof covers an area of 150 m2 and uses 4 species of the genus Sedum, succulent species with fleshy leaves that accumulate water and are particularly resistant to drought and high temperatures, making them potentially suitable for use in extensive ecological roofs. These plants also have a great capacity for regeneration by seeds and vegetative from leaves and stem portions, which allows the natural colonisation of space. Being pollinated by insects it also has the complementary benefit of contributing to the increase of biodiversity on campus. In addition to these plantations, a pilot test for the use of bryophyte (moss) transplants, installed in November 2014, is also underway. Regular monitoring and maintenance of ecological coverage has been ensured by volunteers, mostly Faculty students, translating not only into environmental but also in educational benefits.