Phenophase and floral abundance affect generalization in plant-pollinator network

Phenophase and floral abundance affect generalization in plant-pollinator network

Background/Question/Methods

Networks are a useful way to analyze the ecology and evolution of species interactions of communities. Temporal dynamics and species abundances are known to be important for interactions but are often overlooked in network studies. Understanding how these variables affect interactions can be helpful to assess drivers of generalization and network structure. The hypotheses tested were that the phenophase and abundance of subalpine plants would be positively correlated with linkage and total number of interactions. Over the course of 16 weeks we constructed plant-pollinator networks to describe interactions of plants and their pollinators. Data on flower abundance and plant-pollinator interactions were collected from six 2 x 30m plots each week. We calculated phenophase for each species as the number of weeks that a given plant was in flower. We calculated floral abundance as the integral of the floral abundance over the season

Results/Conclusions

We found support for our four hypotheses of positive correlations between (1) phenophase and linkage (R² = 0.24, P = 0.05), (2) phenophase and total interactions (R² = 0.45, P = 0.003), (3) floral abundance and linkage(R² = 0.45, P = 0.003), and (4) floral abundance and total interactions (R² = 0.76, P < 0.0001). These findings indicate that phenophase and floral abundances are important determinants of generalization and total interactions. They also suggest that climate change driven changes to phenophase and floral abundances could result in large changes to plant-pollinator networks.