Dissertation Research: Fitness Consequences of Floral Nectar Production Rate for the Hummingbird-Pollinated Plant Ipomopsis aggregata

花蜜是被子植物最常见的赏花物质，但人们对花蜜产量对传粉成功率的影响知之甚少。本文将重点研究蜂鸟传粉的单果植物聚波多冈（Ipomopsis aggregata）的这种关系。本研究的主要问题涉及到花蜜产量对适合度的整体影响：1)花蜜产量高的植物是否有更高的授粉成功率？初步的现场证据表明，这种情况确实发生（至少对于雄性功能授粉成功），因此研究这种影响的因果机制将是有益的。这个问题的答案是：2)NPR是如何影响直立作物的？3)直立农作物如何影响访客行为？4)访花行为如何影响传粉成功？该研究将通过多种相互加强的方法来调查这些问题，包括计算机模拟，观察自然变化对NPR的影响，以及在野外和鸟舍进行的操纵性实验。对每一种机制单独影响的估计可以结合起来，得出传粉成功的估计，并与问题1中的基准值进行比较，从而检验所提出机制的充分性。这项研究不仅会增加对NPR变异的适应性后果的理解，而且会增加对这种影响可能表达的机制的理解。

Nectar is the most common floral reward produced by angiosperms, but little is known about the effect of nectar production rate on pollination success. This investigation will focus on this relationship for the hummingbird-pollinated monacarpic plant Ipomopsis aggregata. The primary question of the study involves the overall effect of nectar production rate on fitness: 1) Do plants with higher nectar production rates have greater pollination success? Preliminary field evidence indicates that this does occur (at least for male function pollination success), so study of the causal mechanisms of this effect will be profitable. This question will answered by: 2) How does NPR affect standing crop? 3) How does standing crop affect visitation behavior? 4) How does visitation behavior affect pollination success? The study will investigate these questions with a variety of mutually reinforcing approaches, including computer simulation, observation of the effects of natural variation in NPR, and manipulative experiments in the field and aviary. Estimates of the effect of each mechanism in isolation can be combined to produce an estimate of pollination success that can be compared with benchmark values from Question 1, testing the adequacy of the mechanisms proposed. The research will increase understanding, not only of the fitness consequences of variation in NPR, but the mechanisms through which such effects may be expressed.