NbS Triple Win Toolkit: Implementation Guidance – Executive Summary 6 Biodiversity can be complex to measure, so indicators can be misapplied, or objectives assumed to be achieved with no adequate indicators or monitoring. For example, invasive non-native trees might be planted into naturally treeless ecosystems and be claimed as a benefit for carbon sequestration and even for biodiversity when, in fact, biodiversity has been damaged. Though measuring and appropriately addressing biodiversity can be difficult, the important role biodiversity plays for human well-being – providing ecosystem services, resiliency, and resources – is increasingly well understood. Ecosystems with greater biodiversity often are resilient to changes from climate or stochastic events. Diverse ecosystems also support food security or access to water – fish diversity is linked to higher productivity and fish biomass harvested. Healthy wetlands can provide water purification. Delivering for biodiversity, therefore, can support delivery on climate and poverty objectives for the triple win. Summary of findings The following are key findings from a review of the relevant literature and case studies (n=2,934) which utilise NbS (n=378), with particular consideration given to those in ODA-eligible countries (n=283).The biodiversity indicators used in these case studies and anadditional 66 indicator frameworks were reviewed (n=460)to make specific recommendations for measuring biodiversitybenefits. Detailed Methods can be found in the supporting material. Some findings may be attributable to the databases and programmes selected for review and their reporting requirements. However, our general findings were confirmed from literature review and other synthesis and review work of longstanding NbS programmes. Biodiversity benefits from NbS are often inadequately monitored. Especially for ODA work, tracking climate and poverty reduction outcomes are fairly well understood with established metrics. Biodiversity indicators, however, are often misunderstood or mismatched to outcome objectives. Several case studies thatfit selection criteria did provide quantified biodiversity objectives, however these objectives often relied upon activity-based indicators which are insufficient to assess long-term outcomes for biodiversity. This is certainly due to the databases selected for review, which were conservation programmes. Measuring biodiversity is a complex and wide-ranging concept that cannot be effectively captured in single metrics. There are numerous metrics or measurements of biodiversity currently in use, but a gap is monitoring of biodiversity outcomes for ODA projects. A number of wider considerations should be made when developing biodiversity measurements. Recommendations are made to address the lack of biodiversity monitoring in Biodiversity Indicators in Context, including two potential headline indicators and considerations for further indicators relevant from project to portfolio level. Most NbS projects focus on terrestrial ecosystems – especially reforestation or agroforestry. Marine and urban examples are fewer but could represent less opportunity for scalable solutions or value for money. NbS provide an opportunity to incorporate a greater diversity of ecosystem types through landscape- or multi-ecosystem scale planning. This way the diversity, dynamics, and connectivity of ecosystems can be addressed, and any negative impacts avoided.