Evidence-base for urban green-blue infrastructure to support insect diversity.

Area of Science:

• Urban ecology
• Conservation biology
• Landscape architecture

Background:

• Insects are crucial for ecosystem function, yet face widespread declines.
• Green-blue urban infrastructure offers potential benefits for both people and nature.
• Understanding insect conservation within urban environments is increasingly important.

Purpose of the Study:

• To review existing research on green-blue infrastructure's effectiveness for insect diversity.
• To identify key characteristics of infrastructure that support insect populations.
• To explore how green-blue infrastructure can be designed for multifunctionality, including insect conservation.

Main Methods:

• Systematic review of 201 studies on green-blue infrastructure and insect diversity.
• Analysis focused on local and landscape-level characteristics.
• Comparison of different infrastructure types and their impact on insect communities.

Main Results:

• Plant diversity and reduced management intensity (e.g., mowing) are crucial for most insect groups.
• Local infrastructure characteristics are generally more influential than landscape factors.
• Ground-level habitats support more insects than green roofs; connectivity also plays a role.

Conclusions:

• Green-blue infrastructure can support urban insect diversity, with specific design elements being more effective.
• Local factors like plant diversity and management practices are paramount for insect conservation.
• Designing for multifunctionality, considering both insect needs and other ecosystem services, is achievable.