Pollinator Floral Resources in Response to Extreme Drought in Mesic Successional Old-Field Grasslands
Secondary succession is known to have influential effects on the levels of flowering due to the altered conditions of the land. In turn, secondary succession is expected to have a direct influence on pollinator species. The effect of climate change, while commonly distinguished from the effects of secondary succession, has been heavily studied and is thought to display interconnected relatedness with secondary succession. However, the link relating drought to pollinator-flower interactions has yet to be studied as a sub disciplinary field of research. The effect of drought on pollinator species is crucial to understand as these organisms pose important ecological roles on the environment by facilitating flower reproduction, and the effects of drought are increasing in severity on a long-term scale. Pollinators highly depend on the resources available to them during flowering season, so it was hypothesized that drought will decrease the number of flowers present in mesic grasslands, as well as that the onset of peak flowering will be delayed. In this experiment, we examined the effects of shading and drought on plant communities to evaluate the effects these have on flowering potential of different communities across fields of varying ages. Three treatments were tested to determine the differences between these factors: an open treatment (i.e. a control), inverted shelter (100% precipitation & shading effects), and a drought treatment (only ~43% precipitation allowed). Results of this study show that our predictions were correct, with the drought treatment having a significantly lower abundance of flowers present in those plots, as well as a delayed time of peaking flowering during the season prior to senescence. These results signify that the availability of flower resources for pollinators may be decreased which can ultimately decrease biodiversity and community interactions, as well as enforce a potential shift in migration patterns. The implications of these results put a greater emphasis on the importance of investigating restorative strategies to counteract the effects of droughts, as well as suggest further studying the specific differences in the aged fields to identify what habitat characteristics may be more beneficial for these changing conditions.