About Ecological Engineering

What is it about?

According to Mitsch und Jorgensen, ecological engineering is defined as

the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both.

 

Bergen et al. (2001) conclude from this four central elements:

1. Ecological engineering is based on ecological science.
    
2. It includes all types of ecosystems and potential human interactions with ecosystems.
    
3. The concept of engineering design is included.
    
4. There is an acknowledgment of an underlying value system.
    

Barrett (2009) concretises the definition of ecological engineering as:

the design, construction, operation, and management (that is, engineering) of landscape/ aquatic structures and associated plant and animal communities (that is, ecosystems) to benefit humanity and, often, nature.

Schönborn und Runge (2021) emphasise the holistic view:

Ecological engineering integrates ecological principles, processes, and organisms with existing engineering practice to a holistic approach for problem-solving

What are central principles?

Schönborn und Runge (2021) propose seven key principles for engineering ecology projects:

1. Avoidance (e.g. hazardous substances, emissions, ...)
    
2. Ecological processes and organisms as tool or model for design (e.g. nature-based solutions)
    
3. Maximum of renewable energy (during operation)
    
4. Maximum of recycling efficiency within its system borders (during operation)
    
5. Low externalized environmental costs during the entire life cycle (e.g. by using materials with low footprints)
    
6. Design aims for multifunctionality (e.g. function of a project for treatment, cooling, recreation, as a biotope ...)
    
7. Enhancement of quality for both humans and nature (e.g. participation of stakeholders as part of the design process, one of them being an "advocate for nature"

What are ecological engineering approaches used for?

Mitsch und Jorgensen (2004) proposed five categories for ecological conceptual planning:

1. Ecosystems are used to reduce pollution.
   (e.g. phytoremediation, wastewater wetlands and bioretention of rainwater to filter excess nutrients and metal pollution)
    

2. Ecosystems are imitated or "copied" to solve a resource problem.
   (e.g. restoration of forests, a wetland alternative and installation of rain gardens in urban areas)
    

3. Ecosystems are supported to regenerate after major interventions.
   (e.g. renaturation of former mining areas and the restoration of lakes and watercourses with ecologically valuable riparian corridors).
    

4. Ecosystems are modified to solve an environmental problem (with an ecological sense of proportion).
   (e.g. selective harvesting or biomanipulation such as the introduction of predatory fish to reduce planktivorous fish -> this increases the abundance of zooplankton -> algae and phytoplankton are consumed -> the water becomes clearer).
    

5. Ecosystems are used effectively without destroying the ecological balance.
   (e.g. sustainable agricultural systems, multispecies aquaculture)

What are current and future fields of activity in ecological engineering?

The Strategy 2030 (from 2021) of the German Ecological Engineering Association (Ingenieurökologische Vereinigung e.V.) describes the following fields:

1. Sustainable settlement ecosystems and urban green infrastructure
(from neighbourhood level to city/landscape level), e.g.

• Ecological design of sustainable and climate-friendly settlement ecosystems, including insect-, plant- and animal-friendly urban development, urban ecology and planning
   
• Climate-sensitive infrastructure planning, temperature regulation in cities
   
• Water-sensitive planning with a focus on ecosystem services, including flood protection and disaster prevention through water retention and retention areas
   
• Sustainable rainwater management
   
• Promotion of local recreation and biodiversity in gardens (urban gardening, urban agriculture), parks and urban forests, etc.

2. Multifunctional structural elements implemented as nature-based solutions
(from building / object level to neighbourhood level), e.g.

• Ecological corridors
   
• Green track networks, roadside greenery, green dams
   
• Roof and vertical greening
  Sustainable rainwater/service water and resource management
   
• Water body restoration
   
• Engineering biological measures for slope stabilisation
   
• Nature-based water and air pollution control, such as constructed wetlands, street trees and permeable pavements

3. Strategies and measures to promote biodiversity in urban areas
(Ecologically valuable urban, private and public green spaces as new habitats for endangered insects, animals and plants), e.g.

• Plant- and animal-friendly (including fungi and lichens) urban development (animal-aided design), urban ecology and planning
   
• Insect-, plant- and animal-friendly design and maintenance of urban green spaces (private + public) with autochthonous plants
   
• Ecological water maintenance

4. Landscape development, landscape ecology and planning, biotope networks, e.g. 

• Nature conservation measures in rural areas, such as field margins and water protection strips
   
• Flood protection and disaster prevention through water retention and retention areas
   
• Restoration, revitalisation and reconstruction measures of ecosystems of different degradation as urban-rural corridors, including areas of former anthropogenic use (succession areas), watercourse oxbows, river floodplain ecosystems, nature-oriented hydraulic engineering, open land, forest, etc.
   
• Soil protection and brownfield renaturation

5. Nature-oriented treatment systems - Circular economy , e.g. 

• Land recycling management
   
• Constructed wetlands, retention soil filters
   
• Wastewater reuse
   
• Technical / artificial wetlands
   
• Sewage sludge humification plants
   
• Biological waste treatment