Topic 1 Green roofs as ecosystem. Understanding biodiversity parameters to take into account

Green roofs can provide environmental benefits in urban cities and create ecosystems for living organisms thus help to enhance biodiversity.

Building development in urban areas destroys habitats and it results in biodiversity loss; the built environment created by green roofs is one of the mitigation methods for biodiversity conservation.

Green roofs can be part of the environmental green lung that provides important ecosystem services. Moreover, green roofs may be part of a larger system of wildlife corridors in urban and suburban areas, including park areas and gardens, offering an environment for plants, birds and invertebrates. As a result, green roofs can be used to promote urban biodiversity by connecting isolated habitat and ecosystem pockets.

What are ecosystem services?

Ecosystem services are grouped into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and oxygen production; and cultural, such as spiritual and recreational benefits.

Agriculture, livestock, forestry benefit from and influence ecosystem services, impact can be positive or negative, as follows:

Positive impact on ecosystem services:

  • Agriculture provides habitats to wild species and creates aesthetic landscapes
  • Forests help maintain healthy aquatic ecosystems and provide reliable sources of clean water
  • Animal excreta can be an important source of nutrients, seed dispersal and can maintain soil fertility in grazed grasslands 

Negative impact on ecosystem services:

  • Pesticides, as well as landscape homogenisation, can decrease natural pollination
  • Deforestation or poor management can increase flooding and landslides during cyclones
  • Excess of animal excreta and poor management can lead to water pollution and threaten aquatic biodiversity

Biodiversity is the degree of variation of life forms within a given ecosystem with different cycles (v.g. water). It is a measure of the health of ecosystems. It is believed that biodiversity contributes to a relentless and often invisible ecosystem service that is provided within atmospheric, hydrologic and biogeochemical life cycles where air and water and living and dead elements are cycled and recycled in a continuous circle of life.

Biodiversity includes diversity within species, as well as between species of ecosystems. Biodiversity is not just about counting the number of species on a roof or in any other landscape; it is composed of both structure and function. The complex, food chains and interconnected community of living organisms in an ecosystem affects the level of biodiversity.