Phenological shifts drive biodiversity loss in plant–pollinator networks

Abstract

Plant-pollinator interactions are key for ecosystem maintenance and world crop production, and their occurrence depends on the synchronization of life-cycle events among interacting species. Phenological shifts observed for plant and pollinator species increase the risk of phenological mismatches, threatening community stability. However, the magnitudes and directions of phenological shifts present a high variability, both among communities and among species of the same community. Community-wide consequences of these different responses have not been explored. Additionally, variability in phenological and topological traits of species can affect their persistence probability under phenological changes. We explored the consequences of several scenarios of plant-pollinator phenological mismatches for community stability. We also assessed whether species attributes can predict species persistence under phenological mismatch. To this end, we used a dynamic model for plant-pollinator networks. The model incorporates active and latent life-cycle states of species and phenological dynamics regulating life-cycle transitions. Interaction structure and species phenologies were extracted from eight empirical plant-pollinator networks sampled at three locations during different periods. We found that for all networks and all scenarios, species persistence decreased with increasing magnitude of the phenological shift, for both advancements and delays in flowering phenologies. Changes in persistence depended on the scenario and the network being tested. However, all networks exhibited the lowest species persistence when the mean of the expected shift was equivalent to its standard deviation and this shift was greater than two weeks. Conversely, the highest species persistences occurred when earlier-flowering plants exhibited stronger shifts. Phenophase duration was the most important attribute as a driver of plant persistence. For pollinator persistence, species degree was the most important attribute, followed by phenophase duration. Our findings highlight the importance of phenologies on the stability and robustness of mutualistic networks. Author summaryPlant-pollinator interactions involve a great number of species and are essential for the functioning of natural and agricultural systems. These interactions are facing a great March 31, 2020 1/15 number of threats. In both plants and pollinators, life-cycle events including flowering and adult emergence are triggered by environmental cues such as temperature and snowmelt. Climate change has the potential to alter the timing of these events. These phenological shifts generate mismatches in the timing of interacting species. Thus, plants and their pollinators may not match in time and/or space, leaving flowers unpollinated and disrupting pollinator feeding. Given that natural communities are composed of multiple species interacting in complex ways, experimentally assessing the effects of this kind of perturbation is difficult. To tackle this challenge, we simulated different ...

Phenological Patterns and Seasonal Segregation of Coprophilous Beetles (Coleoptera: Scarabaeoidea and Hydrophilidae) on a Cattle Farm in SE-Michigan, United States Throughout the Year

“…Phenologies are dynamic and can be altered by changes in abiotic factors most significantly by the global climate crisis (Brown et al, 2016;Forrest, 2016;Scranton and Amarasekare, 2017) and/or biotic factors such as invasive species (Alexander and Levine, 2019) and biodiversity loss (Wolf et al, 2017), which are often entangled with the effects of the climate crisis (Colautti et al, 2017). Shifting phenologies may affect species' range limits (Chen et al, 2011), increase competition (Carter and Rudolf, 2019) and may disrupt other direct and indirect interactions (Morente-López et al, 2018), leading to species extinctions (Rudolf, 2019) and may thus reduce biodiversity (Franco-Cisterna et al, 2020) causing substantial shifts in SCs. Due to the profound effects of phenological shifts and mismatches between species (Kharouba et al, 2018;Renner and Zohner, 2018;Damien and Tougeron, 2019), it is important to predict how the phenology of the species within a SC might shift under the influence of changing weather patterns or introduced invasive species (van den Heuvel et al, 2013;Wolkovich and Cleland, 2014;Colautti et al, 2017;Chmura et al, 2019).…”

Topographic heterogeneity lengthens the duration of pollinator resources

“…A longer flowering phenology across a landscape may aid both pollinator and plant species to cope with these changes by buffering the magnitude of asynchrony at the landscape level (Olliff‐Yang et al., 2020). Recent modeling predicts duration as one of the most important factors in species persistence for plants and pollinators with shifts in phenology (Franco‐Cisterna, Ramos‐Jiliberto, de Espanés, & Vázquez, 2020), and topographic diversity has been predicted to reduce the chance of mismatch for some species (Hindle et al., 2015). Conserving, restoring, and maintaining high species diversity across topography may therefore support species interactions by buffering the impacts of mutualism asynchronies with climate change.…”

Climate Change and Its Impact on Mountainous Plant Species: A Review

“…Further, the survival of plant species depends on the reproductive success of pollinators [40]. Therefore, the risk of plant-pollinator mismatches increases with changing flowering phenology, which threatens the stability of the plant community and impacts ecosystem structure and functions [57]. For example, the changes in the timing of flowering of Corydalis yanhusuo W. T. Wang gave rise to a phenological mismatch with bumblebees (pollinators), which resulted in a low seed setting rate [58].…”

“…At the community level, the "web of interactions" among different populations is likely to be modified due to the various effects of climate change [133,134]. As described in the sections above, climate change alters phenological events, thereby disrupting plant-pollinator interactions [57]. This can cause the extinction of both pollinators and plants, with expected impacts on the structure of plant-pollinator networks [135,136].…”