Effects of climate warming on species' physiological parameters, including growth rate, mortality rate, and handling time, are well established from empirical data. However, with an alarming rise in global temperature more than ever, predicting the interactive influence of these changes on mutualistic communities remains uncertain. Using 141 real plant-pollinator networks sampled across the globe and a modelling approach, we study the impact of species’ individual thermal responses on mutualistic communities. Further, we study the potential effect of link and node perturbation on the collapse of mutualistic plant-pollinator networks at different temperatures. We also perform stability analyses of the reduced two-dimensional model which employs averaging techniques for sampling the interaction strength of the mutualistic network. Further, the dominant eigenvalue of the Jacobian matrix is evaluated at the steady states, allowing us to draw inferences regarding the stability of the higher dimensional network. We identify network structures (such as connectance, number of nodes and nestedness) that can ascertain the delay of a community collapse. Until the end of this century, many real mutualistic networks can be threatened by sudden collapse, and we frame strategies to mitigate them.
Results/Conclusions
We show the occurrence of tipping points at high temperatures in plant-pollinator networks, whereby a network’s state abruptly shifts to an alternate state as the driver of pollination declines. Striving to recover species by improving environmental conditions, we observe the formation of a hysteresis loop. Evidently, at low mutualistic strength plant-pollinator networks are at potential risk of rapid transitions at higher temperatures. However, we found that mutualistic plant-pollinator networks with an optimal structural property can withstand harsh warming conditions and exhibit increased resilience to perturbations. However, the required optimal structure for sustenance varies with the level of environmental deterioration. Further, we determine the role of the generalist species in triggering a community collapse compared to their specialist and random counterparts. Preventing the loss of such species can be instrumental to prevent or delay a community collapse at high temperatures. Our results indicate that knowing individual species' thermal responses and network structure can improve predictions for communities facing rapid transitions. Overall, our findings underline that efforts to mitigate climate warming and suitable conservation policies can manage the extinction risk of mutualistic communities.
