<p>The expanding population in Lima continues to reduce green space and degrade natural ecosystems, increasing the need for innovative and sustainable urban greening. Extensive green roofs (GRs) offer a promising alternative by delivering ecosystem services (ES), including removal of airborne particulate matter (PM) and habitat provision for pollinators and threatened plant species. The Lomas ecosystem, a unique natural enclave in the city, faces threats that put native and endemic species at risk. In this study, we applied the habitat template concept to evaluate native Lomas species on extensive GRs, comparing their performance with common GR species under two irrigation levels. Vegetation was monitored for one year (winter season) and ES were assessed after 1.5 years (summer season). Planting treatment was the strongest driver of vegetation responses. Native plots produced more flowers and seeds per plant and achieved the greatest winter vegetation cover, whereas common plots produced more new individuals and some taxa showed reduced survival under low irrigation. Irrigation mainly increased vegetation cover, but it was also associated with higher pollinator visitation . For air-quality regulation, native species retained more PM per unit leaf area at the plant level, but plot-level PM capture was higher in common and mix plots due to greater summer canopy cover. Overall, mix plots that include endangered Lomas species alongside common species can maintain ES on extensive GRs under water scarcity and, importantly, enable the incorporation of native plants, contributing to conservation of a threatened regional flora.</p>