Impact Study

Aggregate Effects on Ecosystem Services from Certification of Tea Farming in the Upper Tana River Basin, Kenya

The role of certification in achieving sustainability outcomes is not limited to the farm-level. However, it can be difficult to measure and map the aggregate impacts of certification since adoption often varies and landscapes are complex. This impacts study provides an interesting example of how the cumulative impacts of certification can be quantified at the landscape scale.

Using ecosystem service modeling, the authors show how Rainforest Alliance certification of tea farms influences water quality in Kenya’s Tana River watershed, with implications for downstream hydropower and drinking water infrastructure. In its response to the study, the Rainforest Alliance discusses these findings in light of the development of its new standard and its landscape-level work.