Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Urban growth causes more biodiversity loss outside of cities

10.12.2019

In a rapidly urbanizing world, the conversion of natural habitats into urban areas leads to a significant loss of biodiversity in cities. However, these direct effects of urban growth seem to be much smaller than the indirect effects outside of cities. An international team of researchers including researchers from The Nature Conservancy (TNC), the German Centre for Integrative Biodiversity Research (iDiv), Martin Luther University Halle-Wittenberg (MLU) and other institutions assessed the direct and indirect effects on a global scale. The results have been published in the journal Nature Sustainability.

We are living in the period of fastest urban growth in human history, with more than 2 billion additional people expected in cities by 2030 – a pace that is the equivalent to building a city the size of New York City every 6 weeks. But what do scientists know and not know about how urban growth is affecting biodiversity?


To answer this question, an international team of researchers reviewed more than 900 studies. The work of the highly international synthesis working group was funded and supported by sDiv, the synthesis centre of German Centre for Integrative Biodiversity Research (iDiv).

The researchers found that the direct effects of cities on natural habitat and biodiversity are large and straightforward to map using satellite data. Direct effects occur when urban areas expand, converting natural habitat into cities.

Direct effects are cumulatively significant, with 290,000 km2 of nature habitat forecast to be converted to urban land uses between 2000 and 2030. This is equal to an area larger than the entire United Kingdom. Urban areas are causing the most destruction of high-biodiversity habitat in places like coastal China, Brazil, and Nigeria.

This adds up to a big loss of biodiversity, because species richness (number of species) at a site is globally on average 50% lower at urban sites than in intact natural habitat.

However, the indirect effect of urban growth on biodiversity is likely far greater than the direct effect. Indirect effects include the biodiversity impacts of resources consumed within the city as well as the impacts of pollution released from cities. The researchers estimate that just the area required to feed the world’s cities is 36 times greater than the urban area of cities.

“In other words, the food urban dwellers eat turns out to be more important for global biodiversity than the direct environmental impact of the urban areas”, said co-author Dr Andressa Vianna Mansur, postdoctoral researcher at iDiv. Similar conclusions can be made for other indirect effects, including the role of greenhouse gas emissions from cities in making climate change worse.

To date, much research has been done on the direct effects of urban expansion in particular cities or places – out of 900 studies, more than 600 dealt with the direct effects of urban growth. However, the effects of urban growth are not studied in the regions where the satellite data suggests the most intense effects.

“Most studies are in developed countries like the United States and the European Union. Relatively few papers are from developing countries, where cities are expanding the most rapidly into high-biodiversity habitat”, commented first author Robert McDonald from The Nature Conservancy. “As a result, we don’t know much about the way ecosystems change in these habitats in response to urbanization.”

In contrast to the direct effects, little research has been done on the indirect effects of urban growth – only 34% of all studies of urban impacts on biodiversity consider indirect effects. “In other words, we are spending about twice as much effort to study direct effects than indirect effects, even though indirect effects seem to be far more important in magnitude”, said Robert McDonald.

This gap in the literature may have an effect on policymaking: “The lack of data on the significance of urban biodiversity loss in middle- and low-income countries could lead policymakers to underestimate the importance of the issue”, said Prof Henrique Pereira, research group head at iDiv and MLU.

Moreover, there is a lack of information on how unique socioeconomic processes in developing countries, such as informal settlements (slums), affect biodiversity. “Only by closing these research gaps will society be able to make smart and informed decisions about how to protect biodiversity in an increasingly urban world."

Wissenschaftliche Ansprechpartner:

Dr Robert McDonald

Originalpublikation:

Robert I McDonald, Andressa V Mansur, Fernando Ascensão, M’Lisa Colbert, Katie Crossman, Thomas Elmqvist, Andrew Gonzalez, Burak Güneralp, Dagmar Haase, Maike Hamann, Oliver Hillel, Kangning Huang, Belinda Kahnt, David Maddox, Andrea Pacheco, Henrique Pereira, Karen C Seto, Rohan Simkin, Brenna Walsh, Alexandra S Werner, Carly Ziter, 2019. Research gaps in knowledge of the impact of urban growth in biodiversity. Nature Sustainability, DOI: 10.1038/s41893-019-0436-6

Kati Kietzmann |
Further information:
http://www.idiv.de/

More articles from Ecology, The Environment and Conservation:

nachricht New exhaust gas measurement registers ultrafine pollutant particles for the first time
21.01.2020 | Technische Universität Graz

nachricht ZMT-Expert supports the implementation of the ambitious marine reserve in Palau
17.01.2020 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Integrate Micro Chips for electronic Skin

Researchers from Dresden and Osaka present the first fully integrated flexible electronics made of magnetic sensors and organic circuits which opens the path towards the development of electronic skin.

Human skin is a fascinating and multifunctional organ with unique properties originating from its flexible and compliant nature. It allows for interfacing with...

Im Focus: Dresden researchers discover resistance mechanism in aggressive cancer

Protease blocks guardian function against uncontrolled cell division

Researchers of the Carl Gustav Carus University Hospital Dresden at the National Center for Tumor Diseases Dresden (NCT/UCC), together with an international...

Im Focus: New roles found for Huntington's disease protein

Crucial role in synapse formation could be new avenue toward treatment

A Duke University research team has identified a new function of a gene called huntingtin, a mutation of which underlies the progressive neurodegenerative...

Im Focus: A new look at 'strange metals'

For years, a new synthesis method has been developed at TU Wien (Vienna) to unlock the secrets of "strange metals". Now a breakthrough has been achieved. The results have been published in "Science".

Superconductors allow electrical current to flow without any resistance - but only below a certain critical temperature. Many materials have to be cooled down...

Im Focus: Programmable nests for cells

KIT researchers develop novel composites of DNA, silica particles, and carbon nanotubes -- Properties can be tailored to various applications

Using DNA, smallest silica particles, and carbon nanotubes, researchers of Karlsruhe Institute of Technology (KIT) developed novel programmable materials....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

11th Advanced Battery Power Conference, March 24-25, 2020 in Münster/Germany

16.01.2020 | Event News

Laser Colloquium Hydrogen LKH2: fast and reliable fuel cell manufacturing

15.01.2020 | Event News

„Advanced Battery Power“- Conference, Contributions are welcome!

07.01.2020 | Event News

 
Latest News

Researchers discover vaccine to strengthen the immune system of plants

24.01.2020 | Life Sciences

Brain-cell helpers powered by norepinephrine during fear-memory formation

24.01.2020 | Life Sciences

Engineered capillaries model traffic in tiny blood vessels

24.01.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>