PARENT SESSION
Poster Session 35: Evolutionary Ecology
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Does adaptive reproduction strategy stabilize population dynamics?

Nakazawa, Takefumi^*,1, Yamamura, Norio¹, ¹ Kyoto University, Otsu, Shiga, Japan

ABSTRACT- One of the most controversial problems in ecology is that population dynamics in nature seems to be stable compared with the theoretical prediction from simple models. Therefore, many researchers have proposed various mechanisms to resolve this paradox. Recently, stability theories incorporated with adaptive foraging strategy was proposed, and it has come to be recognized that adaptation of organisms has an important role in stabilizing population dynamics. However, there are few studies that examined the relationship between population stability and adaptivitiy of life-histories other than foraging. In this study, we focused on reproduction which influences population dynamics as well as foraging, and examined the effects of adaptive reproduction strategy on population stability by developing simple one consumer-one resource models. We considered the following reproductive traits; (1) timing of reproduction, (2) reproductive investment, (3) allocation of reproductive investment to offspring. Consequently, we found that adaptive timing of reproduction stabilizes population dynamics, and that adaptation in the other two traits destabilizes population dynamics. Moreover, by incorporating resource-dependent reproductive trade-offs, we suggested that whether adaptive life-history strategy stabilize or destabilize population dynamics depends on the combination of optimized traits under some trade-off. Finally, with empirical literatures we discussed that we should develop comprehensive framework integrating two theories that have progressed in parallel, that is, population stability and life-history evolution, in order to evaluate ecosystem stability.

Key words: population stability, resource-dependent trade-off, life-history evolution, adaptivity