This paper considers pollination-mutualism systems, including intermediary resources, which are represented by nectar for convenience. In the plant-nectar-pollinator system, we focus on the case in which the plant cannot persist without pollination and the pollinator can live independently. When nectar is assumed to rapidly approach a steady state, the plant-nectar-pollinator system can be described by its approximate plant-pollinator equations. Using dynamical system theory, we exhibit conditions under which the three-dimensional system persists and provide rigorous proof for global dynamics of the approximate equations. The analysis demonstrates mechanisms by which the decay rate of nectar, the nectar-consumption rate by a pollinator, the nectarproduction cost, and the rate of the plant can result in the persistence of pollination-mutualisms. As an example, (a) when the decay rate is low, the plant survives in the system and pollination-mutualisms persist, in which the pollinator approaches an enhanced density.(b) When the decay rate is intermediary, the plant can survive in the system only if the initial density of nectar is not below a threshold. (c) When the decay rate is large, the plant goes to extinction even though the pollinator persists. A novel finding in comparing the plant-nectarpollinator system and its approximate plant-pollinator equations is that varying the initial value of nectar can lead to the persistence/extinction of pollinationmutualisms. Our results are consistent with real observations, and numerical simulations confirm and extend the results.
Considerations for managementTaking into account findings, management considerations may include:1. Mechanisms how pollination-mutualisms persist through intermediary resources are demonstrated.2. The plant's cost for nectar production plays a role in the persistence. 3. The decay rate of nectar, the nectar-consumption rate by a pollinator, and the nectar-production rate of the plant are crucial to the persistence. K E Y W O R D S coexistence, cooperation, mutualism, stability, uniform persistence 2 0 0 0 M S C 34C12; 34C28; 37G20; 37N25
| INTRODUCTIONFlowering plants interact with pollinators through pollination-mutualisms. In the mutualisms, a plant provides food (e.g., nectar and pollen) for its pollinator and the pollinator supplies pollination service for its host plant in return. Pollination-mutualisms indirectly support the survival of most species in natural environments (Holland & DeAngelis, 2010;McCall & Irwin, 2006). For example, herbivores consume plant leaves for survival, while most plant species depend on pollination service for reproduction. Although a series of models has been formed to characterize pollination-mutualisms, many of them have not considered the effect of intermediary resources on plant-pollinator associations (Morales, Morris, & Wilson, 2008). For convenience, the intermediary resources are represented by nectar in this study. Vannette, Gauthier, and Fukami (2013) performed experiments and exhibited that it is neces...