A SWOT analysis of a citizen science BioBlitz event for recording biodiversity on green roofs in Portugal

Urban areas can contain significant levels of biodiversity, contributing to more resilient ecosystems and healthier environments. Urban habitats like green roofs, that convert building surfaces into vegetated areas, can offer environments for organisms, though more information is needed about the biodiversity patterns within and across them. Human residents can help generate valuable urban biodiversity data through monitoring programs while strengthening their own awareness and connection to urban nature. This study explores the role of BioBlitzes in documenting biodiversity on urban green roofs by engaging citizen scientists, biodiversity experts and engineers. Four events were conducted in Lisbon, Portugal on 13 publicly accessible green roofs, yielding 1,123 observations of 345 taxa of plants, fungi, insects, arachnids, and birds. Based on the organisers’ experience and dialogue between citizens and researchers, a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis reflected how BioBlitzes can promote public engagement, highlight the ecological potential of green roofs, and foster interdisciplinary collaborations. Strengths included cost-effective biodiversity assessment, public education, and increased visibility of green roofs as urban habitats. Weaknesses encompassed limited seasonal coverage, and uneven expertise among participants. Opportunities included long-term biodiversity monitoring, early detection of invasive species, and promotion of native flora. Threats involved misinterpretations of the importance of green roofs to biodiversity due to short time sampling, logistical constraints, and vegetation maintenance. These findings demonstrate how BioBlitzes on green roofs contribute to urban biodiversity knowledge, foster engagement of local residents in research, support policies about green infrastructure and nature-based solutions in city planning.