Kasetsart Journal of Social Sciences 41 (2020) 83–90 Kasetsart Journal of Social Sciences Implementation effects of incentive policies on Tanzanian wetland ecosystems Norbert John Ngowi a, b, * , Agnes Godfrey Mwakaje a, 1 a Institute of Resource Assessment, University of Dar es Salaam, Dar es Salaam, Tanzania b Institute of Development Studies, Mzumbe University, Mzumbe, Tanzania article info Article history: Received 2 September 2017 Revised 27 February 2018 Accepted 19 May 2018 Available online 19 June 2018 Keywords: TEMPLATE, TREND, vinyungu, wetlands friendly investments, wildfires ABSTRACT Incentive conservation policies are acknowledged to reduce the degradation of natural re- sources for improved ecosystem services worldwide. However, there have been few studies conducted on the contribution of development programs using such policies in wetlands of local importance. This paper examined the implementation effects of an incentive-based Wetlands Friendly Investments (WFI) strategy in the Ndembera Valley, Tanzania. Data were collected using a survey of 208 households and in-depth interviews, supplemented by Landsat 8 imagery and topographical maps. ERDAS Imagine 15 was used to process land cover changes and water flow using the TREND software. The results indicated: (i) all major wetlands areas had declined; (ii) the differences in land cover (t ¼.418, df ¼ 8, p ¼ .687) and water flow (t ¼.418, df ¼ 8, p ¼ .9) before and after introduction of the strategy were not significant; (iii) weak correlation was observed between rainfall and water flow (r ¼ .37); and (iv) land con- version was the main driver for the decline in cover. These findings represent a failure of the WFI incentives to improve the ecological effects of wetland cover and water flow. This suggests that application of the strategy alone was not sufficient for substantial improvement of the desired short-term cover and flow effect. Integrating land use and livelihood into incentive policies can improve WFI incentive implementation practices for sustainable land conserva- tion in the study area. The multi-method approach used minimized human behavior-response limitations, therefore it can be replicated elsewhere. © 2018 Kasetsart University. Publishing services by Elsevier B.V. Introduction Wetland ecosystems support food production, water supply, climate regulation, and culture (Gray, Hagy, Nyman, & Stafford, 2013). In Tanzania, wetland ecosystems exist in various forms including lakes, swamps, rivers, mangroves, and grassland plains (Mwakaje, 2009). These ecosystems are estimated to cover 10 percent of Tanzania's total land area although no full inventory has been conducted to establish the actual coverage (Mombo, Speelman, Huylenbroeck, Hella, & Moe, 2011). Wetlands have long supported a range of services including provision of water, control floods, fishing, dry season grazing areas, agriculture, and wildlife habitats (Kangalawe & Liwenga, 2005). In Iringa district and the Ndembera Valley in particular, wetland ecosystems have potential for bottom valley cultivation, locally known as vinyungu (Magembe, 2007). Given this socio-ecological importance of wetlands, Magembe (2007) found that any sign of degradation can be a sufficient reason to seek different ways to address the problem. Expansion of agriculture, overfishing, overgrazing, over- use of water in irrigation, sedimentation, and climate * Corresponding author. E-mail addresses: norbert.ngowi@gmail.com (N.J. Ngowi), agneselishadai@gmail.com (A.G. Mwakaje). Peer review under responsibility of Kasetsart University. 1 Co-author https://doi.org/10.1016/j.kjss.2018.05.016 2452-3151/© 2018 Kasetsart University. Publishing services by Elsevier B.V. Abstract Article Info Keywords: