Review PaperUsing the Soil and Water Assessment Tool (SWAT) to model ecosystem services: A systematic review

- Greater attention should be paid to SWAT as an ecosystem service modeling tool.
- Key ecosystem services modeled by SWAT: water quantity and sediment regulation.
- SWAT analysis potential not limited to provisioning and regulating services.
- SWAT output variables can serve as proxy for modeling supporting services.
- Model software updates are required to incorporate cultural services.

SummarySWAT, a watershed modeling tool has been proposed to help quantify ecosystem services. The concept of ecosystem services incorporates the collective benefits natural systems provide primarily to human beings. It is becoming increasingly important to track the impact that human activities have on the environment in order to determine its resilience and sustainability. The objectives of this paper are to provide an overview of efforts using SWAT to quantify ecosystem services, to determine the model's capability examining various types of services, and to describe the approach used by various researchers. A literature review was conducted to identify studies in which SWAT was explicitly used for quantifying ecosystem services in terms of provisioning, regulating, supporting, and cultural aspects. A total of 44 peer reviewed publications were identified. Most of these used SWAT to quantify provisioning services (34%), regulating services (27%), or a combination of both (25%). While studies using SWAT for evaluating ecosystem services are limited (approximately 1% of SWAT's peered review publications), and usage (vs. potential) of services by beneficiaries is a current model limitation, the available literature sets the stage for the continuous development and potential of SWAT as a methodological framework for quantifying ecosystem services to assist in decision-making.