Distribution of macroalgae epiphytes and host species from the Cuban marine shelf inferred from ecological modelling

Abstract

Ecological Niche Modelling (ENM) is a tool widely used in ecology to determine environmental conditions and the potential distribution of species. In this article we assess the potential distribution, tolerance limits and similarity niche of macroalgae epiphytes and hosts from the Cuba marine shelf. Using different methods (BIOCLIM, Gower, Maxent and SVM) we have modelled the niche for each species. The final prediction map of distribution was made using the ensemble prediction technique. The similarity of ENMs was quantified by Schoener D and Hellinger I distance. The predictive power of all models was reasonable, since the values of the area under the curve (AUC) were greater than 0.9. The host macroalgae most closely related to the spatial distribution pattern of potential abundance of epiphytic macroalgae are Stypopodium zonale (Kendall correlation, r2 = 0.886) and Digenea simplex (Kendall correlation, r2 = 0.777). Environmental variables that contributed mostly (30 %) to the ecological niche models were: the average maximum salinity per year (35.5−36 PSU); the average minimum flow velocity per year (0.2 m·s−1) and the average minimum light at ground level per year (10−60 E·m−2·yr−1). The results show that epiphytic macroalgae and their most common hosts are generalist species (niche width 0.8) with high overlap in their niche (Schoener D > 0.7; Hellinger I distance = I > 0.6).