The role of large environmental noise in masting: General model and example from pistachio trees

Background/Question/Methods

Masting is synchronous, highly variable reproduction in a plant population, or synchronized boom–bust cycles of reproduction.  These pulses of resources have cascading effects through ecosystems, and thus it is important to understand where they come from. How does masting happen and synchronize?  Here we suggest a novel mechanism for masting, which is inspired by data from a pistachio orchard.  We test its plausibility through development and analysis of a mathematical model of plant reproduction, which is based on the simple resource budget model for plant reproduction.

Results/Conclusions

Our results suggest that large environmental noise may be a crucial part of the mechanism of masting in many types of plant populations, including pistachio.  These include plants that are not pollen-limited (including self-pollinating species), dioecious species (pollen decoupled from female flowers, as in pistachio), and/or plants that reproduce every year.  Moreover, our model can account for synchrony of masting among different species of plants, which are decoupled (not pollen-coupled) by definition.  This is also a specific example of an important functional consequence of the interactions between stochasticity and nonlinearity.