Effects of temperature on the recruitment phenology and niche overlap of shallow epifaunal assemblages in southern New England

Abstract

Recruitment phenology, or the timing of recruitment, can have a large influence on individuals and populations by affecting their exposure to adverse environmental conditions and interspecific competition. In this study, we examined whether temperature parameters could predict the timing of recruitment, the duration of recruitment and total recruitment in 18 benthic epifaunal species using partial least squares regression (PLSR) and ordinary least squares regression. Additionally, we used a null model to test whether temperature parameters and inter-annual variation in those parameters affect the temporal niche overlap of these benthic species. We specifically examined the recruitment patterns of non-native species to help illustrate how shifts in phenology may help drive changes in the community composition. Results from the PLSR helped determine the most instructive regressors for univariate least-squares models. For many (14 of 18) of the species examined, recruitment patterns could be predicted by seasonal growing degree days. Additionally, communities at cooler sites exhibited greater temporal niche overlap than assemblages found at warmer sites. Finally, we observed a unique pattern among invasive species, with more recent invaders recruiting later in the season, which may be a result of shifts in niche overlap. The findings of this study illustrate potential mechanisms for species coexistence and increased rates of invasion resulting from climate change. © Inter-Research 2013 · www.int-res.com.