Strategies for environmental governance and conservation in Africa have relied on regulatory mechanisms (policies) that further restrict already limited livelihood options by prohibiting certain land uses and isolating people from forest resources. Environmental service rewards (ESR) present an opportunity for incentives-based conservation, enabling livelihood and conservation goals to be more easily reconciled. Yet context has an important effect on the viability of ESR and on the trade-offs or synergies that emerge between conservation and livelihood, local and off-site benefits. This article analyzes ethnobotanical data from three sites in the eastern African highlands to analyze the likely consequences of applying diverse regulatory and incentive (ESR) schemes. Data illustrate that when applied in isolation, carbon rewards can undermine water conservation and local livelihood objectives alike through expansion of fast-growing tree species at the expense of water supply and other land uses. The article presents an approach for building upon local knowledge and scenario analysis during the planning phase of environmental service reward schemes to identify a suite of incentive and regulatory mechanisms most likely to reconcile local livelihood with local, national, and international conservation objectives.