New tools to assess biodiversity, resilience, and ecological functionality in cities.

The quality of urban soils is often an invisible yet fundamental component of city sustainability. Soils underpin essential ecosystem services such as climate regulation, water management, support for biodiversity, and, more broadly, the resilience of urban ecosystems. Within this context, a recently published scientific study presents an innovative, rapid, and cost-effective method for assessing the ecological status of urban soils, fully aligned with the objectives of MUSA – Multilayered Urban Sustainability Action.

A New Approach to Monitoring Urban Biodiversity

The study addresses a well-known challenge: traditional methods for analyzing soil biodiversity are accurate but require long timeframes, specialized expertise, and high costs. Moreover, many standard ecotoxicological tests struggle to effectively capture real changes in the ecological functionality of soils, especially in complex urban environments.

To overcome this challenge, the researchers propose the use of behavioral bioassays as first-tier screening tools – that is, as an initial level of assessment to quickly identify early signs of environmental degradation. The idea is simple yet powerful: observing how key soil organisms respond to environmental conditions can provide early and sensitive indicators of ecosystem health.

The Case Study: Urban Green Areas as Open-Air Laboratories

The research was conducted as a pilot study in three urban green areas on the campus of the University of Milan-Bicocca, characterized by different levels of anthropogenic disturbance. This real urban context is perfectly aligned with the MUSA approach, which promotes the city as a space for experimenting with environmental sustainability solutions.

The study integrated three levels of analysis:

  • Behavioral bioassays on soil organisms with different ecological roles;
  • Analysis of soil invertebrate biodiversity (structural and functional) and microbial communities, through bacterial DNA sequencing;
  • Chemical and physical characterization of the soil, including parameters such as pH, organic matter content, and water retention capacity.

What Organism Behavior Reveals

The results clearly show that soil organism behaviors – particularly avoidance and disaggregation – effectively reflect differences in ecological quality among the studied areas.

These behavioral signals often prove to be more sensitive and immediate than some traditional biodiversity indices, enabling the detection of ecological degradation at an early stage. The relationship with microbial biodiversity appears more complex and less direct, highlighting the need for further investigation.

Why This Study Matters for MUSA

The findings reinforce a core principle of MUSA: the transition toward more sustainable cities requires integrated, scalable, and field-applicable monitoring tools.

Within an increasingly soil-focused European regulatory framework – from the Green Deal to forthcoming directives on Soil Monitoring and Resilience – such tools can support public administrations and decision-makers in:

  • identifying degraded urban areas,
  • defining intervention priorities,
  • evaluating the effectiveness of renaturalization and green space management strategies.

Toward More Efficient Monitoring Systems

The study’s conclusion is clear: combining multiple behavioral bioassays represents a promising approach for assessing the ecological functionality of urban soils. The goal is not to replace traditional analyses, but to complement them with more agile tools capable of quickly and effectively guiding environmental management decisions.

For MUSA, this work stands as a concrete example of how scientific research can be translated into operational solutions for urban sustainability, helping to build cities that are more resilient, informed, and grounded in robust data.