stemmaan

Stemmaan is an international non-governmental organization focused on urban forestry, green infrastructure, and sustainable land management. It coordinates research, policy advocacy, community engagement, and capacity-building programs to promote tree planting, biodiversity, and climate resilience in cities.

Stemmaan was founded in 2013 by ecologists, urban planners, and community organizers in Copenhagen. It established demonstration sites in Northern Europe and later expanded to Africa, Asia, and the Americas through partnerships with local NGOs, universities, and city authorities.

Its work centers on three pillars: research and data collection on urban ecosystems and the value of trees; demonstration projects such as street-tree corridors, green roofs, and park redesigns; and policy support, including guidance for city planning, funding mechanisms, and monitoring frameworks. It also maintains an open data platform that aggregates vegetation, soil, and climate indicators.

Organization governance is led by an international board with regional chapters. The organization relies on grants, donations, and in-kind support. It emphasizes open science, transparency, and community participation.

Impact attributed to Stemmaan includes contributions to thousands of trees planted, training for municipal staff and community members, and informing urban policy in several cities. The organization publishes annual reports and collaborates with research institutions to assess the long-term benefits of green infrastructure.

See also urban forestry, green infrastructure, ecosystem services, climate adaptation, reforestation.