Tag: green spaces

Flooded cities: A flood-regulating ecosystem services assessment for heavy rainfalls in urban areas

Scientists from Germany developed a framework with indicator suggestions to quantify and compare flood-regulating ecosystem services supply and demand.

Extreme weather events – like heavy rainfall – are a major environmental risk. Only recently after the Ecosystem Services Partnership (ESP) 2022 Europe Conference on Crete (Greece) some conference attendees were able to directly experience the effects of heavy rainfall, when air traffic was stopped in Heraklion for many hours, streets were flooded, properties damaged, and even people died.

Heavy rainfall can occur anywhere and are usually highly localized. Cities are particularly vulnerable to pluvial flooding because of the high degree of surface sealing, the high population density and the high potential of socio-economic damage in urban areas. In this light, ecosystems are important natural flood-regulating elements that can relieve grey infrastructure such as sewer systems. They can buffer rain events and prevent flooding as their functions turn into a flood-regulating ecosystem service (ES) to protect society.

So far, flood-regulating ES supply and demand for heavy rainfall in urban areas have rarely been studied. Therefore, scientists from the Climate Service Center Germany and the Leibniz University Hannover (Germany) developed a framework with indicator suggestions to quantify and compare flood-regulating ES supply and demand. Interception by canopies and infiltration in the soil serve as essential indicators for urban flood-regulating ES supply. The indicators can be quantified based on the outputs of a hydrological model that has explicitly been developed for this study. The model is based on single, individual landscape elements. It considers vegetation-hydrological interaction, and 2D surface water routing. Social-economic indicators and the surface flooding indicate the related ES demand.

A flooded neighbourhood. Photo by U.S. Geological Survey

In their study, published in the journal One Ecosystem, they assessed the flood-regulating ES of an urban district in the City of Rostock (Germany) for a one-hour heavy rainfall event. They found the highest mean ES supply on greened areas of forests, woodlands and green areas, resulting in a supply surplus. Whereas, sealed areas (paved surface where water cannot infiltrate into the soil), such as settlements, urban dense areas, traffic areas and industry, showed an unmet demand resulting from both low supply and relatively high actual demand. The results indicated that vegetation plays an important part in flood regulation, if the soils are saturated or sealed and, thus, should be considered in urban flood-regulating ES assessments.

Budget of the flood-regulating ecosystem services supply and demand resulting in unmet demand and supply surplus.

Analysing the supply and demand for flood-regulating ES is particularly important for urban planning in order to identify ES supply-demand mismatches. Based on this information, adaptation measures such as Nature-based Solutions can be planned and their possible ES contributions can be quantified. Since heavy precipitation events are projected to become more frequent and intense in the future, the future functionality of current flood-regulating ES and the benefits of adaptation measures under changing climate conditions need to be assessed. This provides information about changing ES supply and the development of ES demand.

Research article:

Wübbelmann T, Bouwer LM, Förster K, Bender S, Burkhard B (2022) Urban ecosystems and heavy rainfall – A Flood Regulating Ecosystem Service modelling approach for extreme events on the local scale. One Ecosystem 7. https://doi.org/10.3897/oneeco.7.e87458

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Threatened South American coati found roaming in a large city

Researchers recorded an individual at the Canoas Airbase, one of the last remaining green spaces in a densely urbanized area of a large city in southern Brazil.

You may assume that metropolitan areas are devoid of wildlife, but that is very far from the truth. The remaining green spaces within the urban matrices of large cities can serve as corridors or stepping stones for wild animals. Sometimes, even threatened mammal species end up using them.

On August 12, 2020, a research team from Brazil recorded a South American coati in Canoas, the fourth most populous and densely urbanized city in the southernmost state of Brazil, Rio Grande do Sul. The animal was detected with a camera trap during a Masters research project conducted at the Canoas Airbase, one of the last green spaces remaining in the municipality.

South American Coati at the Canoas airbase in Rio Grande do Sul, Brazil. Video by Diego Floriano da Rocha, Thaís Brauner do Rosario and Cristina Vargas Cademartori

Widely distributed throughout the continent, the South American coati is a medium-sized carnivore living on trees and feeding mainly on small invertebrates and fruits. The species is classified as Vulnerable in Rio Grande do Sul, and it’s considered threatened mainly because of the loss of its forest habitats.

The study that recorded an individual in the urban area was conducted as part of a partnership between the Canoas Airbase and La Salle University. Led by Dr Cristina Vargas Cademartori from La Salle University, the research team was made up of Diego Floriano da Rocha (Doctoral student), Thaís Brauner do Rosario (Masters student), Ana Carolina Pontes Maciel (biologist at the Canoas Airbase), and Duana Suelem Alves (undergraduate student). They described in detail the record and the study area in a paper in the open-access journal Neotropical Biology and Conservation.

The researchers were surprised to find the coati in the midst of a dense urban area. Although the species is not considered threatened in the majority of its area of distribution, its populations have been in decline because of habitat loss and hunting.

“This record confirms the capacity of this species to use environments that have been changed by anthropic activity,” the researchers write in their paper, adding that, because of all the food that humans leave behind, urban environments can in fact favor the establishment of more adaptable species like the coati.

The discovery highlights the importance of urban green spaces for wildlife conservation. “This is very important for defining appropriate conservation measurements for endangered species, especially beyond protected areas,” the authors conclude.

Research article:
da Rocha DF, do Rosario TB, Maciel ACP, Alves DS, Cademartori CV (2022) Record of occurrence of Nasua nasua (Linnaeus, 1766) (Carnivora, Procyonidae) in a densely urbanized area of the city of Canoas, southern Brazil. Neotropical Biology and Conservation 17(2): 111-116. https://doi.org/10.3897/neotropical.17.e81824

Green backyards help increase urban climate resilience: Here is how

New study evaluates the effects of greenery on thermal comfort, biodiversity, carbon storage and social interactions.

Green spaces in cities have a number of positive effects: they’re good for our physical and mental health, they’re good for the environment, and they can even help fight off the effects of climate change.

To explore the impact of additional green structures in cities, Katja Schmidt and Ariane Walz, affiliated with the University of Potsdam, Germany, quantified their effects on different aspects such as thermal comfort, biodiversity, carbon storage and social interaction. Their study, published in the open-access, peer-reviewed journal One Ecosystem, combines knowledge from health research, ecology and socio-ecological research, and shows how the better we know a particular type of ecosystem, the better we can adapt to climate change.

Green residential courtyards in Potsdam. Photo by Jan Michalko, University of Potsdam

Pursuing a multi-method approach that ranged from local climate measurements to habitat and tree mapping, the authors compared four green residential courtyards in Potsdam. The spaces were similarly built, but had different ratios and sizes of features (lawns, flowerbeds, paths, playgrounds and allotments), as well as different tree and shrub population. 

While doing their research, Schmidt and Walz saw how even small differences in the green structure affect the provision of benefits, but one thing was clear: the greener courtyards yielded more benefits. Trees have the vital ability to cool down the environment and increase thermal comfort. Remarkably, the researchers report additional cooling effects of up to 11°C in the greener court yards. This means that residential green structures can prove of great value for human health during summertime heat, when asphalt and buildings make hot days even hotter. Considering the ageing demographic and the likely increase of heatwaves in the area, this is likely to have even greater health implications in the coming years. 

Microclimatic measurements in residential courtyards. Photo by Tobias Hopfgarten, University of Potsdam

Urban green spaces can also be an important factor in carbon storage, as urban soils and trees have the capacity to act as a sink for atmospheric carbon dioxide. The residential yards with more and larger trees, logically, have the power to store more carbon. This is where proper maintenance comes in: when yards are managed sustainably, trees live longer and can store more carbon.

“Considering the trend of increasing quantity and magnitude of extreme weather events and the vulnerability of urban areas, green spaces are known to provide great potential to increase urban climate resilience. Our work highlights the widespread positive effects of additional green structures in residential open spaces, a type of urban green space that is frequently understudied,” points out Dr. Schmidt.

As a conclusion, the researchers point out that if land owners and leaseholders receive incentives to commit to climate adaptation, and neighbourhoods come up with deliberate management strategies, these benefits could be further enhanced, contributing to a more sustainable urban development.

Research article:

Schmidt K, Walz A (2021) Ecosystem-based adaptation to climate change through residential urban green structures: co-benefits to thermal comfort, biodiversity, carbon storage and social interaction. One Ecosystem 6: e65706. https://doi.org/10.3897/oneeco.6.e65706