PS 16-226 - Consequences of methodology and sampling effort on seasonal interaction dissimilarity in plant-pollinator networks

Understanding the dynamics of plant-pollinator networks is imperative for further investigation of how communities may be impacted by global changes, including climate change. These dynamics can be investigated through interaction dissimilarity and its two additive components of species turnover and interaction rewiring. However, studies quantifying plant-pollinator interaction dissimilarity over time are few, and methods for doing so face a lack of consensus in the literature. Additionally, the sensitivity of plant-pollinator interactions to sampling effort is not well understood and requires further investigation. The objectives of this study are to examine interaction dissimilarity, including components of species turnover and rewiring over seasons, using eight years of plant-pollinator interaction data from a subalpine meadow in the Rocky Mountains. We asked (1) how do temporal interaction dissimilarity and its components change over the season, and how do these patterns compare to previous studies of plant-pollinator networks, (2) how using different calculation methods affects the interpretation of patterns of interaction dissimilarity and its components, and 3) how species turnover and rewiring change as a function of sampling effort. We found a high degree of variation in week-to-week and season-long plant-pollinator interaction dissimilarity, as well as over multiple years when compared to previous short-term studies. Generally, species turnover was higher at the beginning and end of a season, and rewiring increased in contribution in the middle of a season. The contribution of interaction rewiring to seasonal interaction dissimilarity depended on the method of calculating turnover used to analyze the data. We hypothesize that sampling effort will shift the contributions of species turnover and rewiring to interaction dissimilarity. Species turnover may decrease in contribution and rewiring may increase in contribution as sampling effort increases. These results suggest that networks are even more temporally variable than previously documented, and long-term data may be necessary to capture seasonal dynamics. Interpretation of the role of rewiring in interaction dissimilarity is sensitive to the method of calculation. Future investigation is necessary to understand better how rewiring changes as a function of sampling effort and the degree to which interaction dissimilarity responds to climate variability.