Occurrence of an invasive coral in the southwest Atlantic and comparison with a congener suggest potential niche expansion

Abstract

Tubastraea tagusensis, a coral native to the Galapagos Archipelago, has successfully established and invaded the Brazilian coast where it modifies native tropical rocky shore and coral reef communities. In order to understand the processes underlying the establishment of T. tagusensis, we tested whether Maxent, a tool for species distribution modeling, based on the native range of T. tagusensis correctly forecasted the invasion range of this species in Brazil. The Maxent algorithm was unable to predict the Brazilian coast as a suitable environment for the establishment of T. tagusensis. A comparison between these models and a principal component analysis (PCA) allowed us to examine the environmental dissimilarity between the two occupied regions (native and invaded) and to assess the species' occupied niche breadth. According to the PCA results, lower levels of chlorophyll-a and nitrate on the Atlantic coast segregate the Brazilian and Galapagos environments, implying that T. tagusensis may have expanded its realized niche during the invasion process. We tested the possible realized niche expansion in T. tagusensis by assuming that Tubastraea spp. have similar fundamental niches, which was supported by exploring the environmental space of T. coccinea, a tropical-cosmopolitan congener of T. tagusensis. We believe that the usage of Maxent should be treated with caution, especially when applied to biological invasion (or climate change) scenarios where the target species has a highly localized native (original) distribution, which may represent only a small portion of its fundamental niche, and therefore a violation of a SDM assumption.

Determinants of Tubastraea coccinea invasion and likelihood of further expansion in the northern Gulf of Mexico

“…Carlos-Júnior et al (2015b) analyzed 57 T. coccinea occurrence data also collected from the invaded area in the southwest Atlantic and used Maxent to develop an ecological niche model. Even though the two studies analyzed occurrence data from the same area, Riul et al (2013) found that mean sea surface temperature, along with minimum diffuse attenuation and minimum chlorophyll-a, were the most important factors affecting model performance, whereas Carlos-Júnior et al (2015b) found that mean nitrate concentration and maximum chlorophyll-a concentration were the most important factors affecting model performance. In our study, we analyzed 86 T. coccinea occurrence records collected from the northern GoM and used boosted regression trees to develop a species distribution model.…”

Rarity and beta diversity assessment as tools for guiding conservation strategies in marine tropical subtidal communities

“…As discussed above, it could also suggest that the central channel is under the most intensive anthropogenic pressure, which is consistent with previous studies (Creed et al, ). Since the extension of a taxon's adaptation to a broader range of environmental conditions influences its geographical distribution (Holt, ; but see Carlos‐Junior, Neves, Barbosa, Moulton, & Creed, ), the species capable of surviving in this region would also presumably be capable of inhabiting a larger range of environmental conditions across the whole bay.…”

Identifying priority reserves favors the sustainable development of wild ungulates and the construction of Sanjiangyuan National Park

“…A total of 77 environment variables closely related to six large wild herbivores were collected for species distribution models, which were divided into four categories (Table S1 ). The autocorrelations and multiple linear duplications among environment variables might affect the prediction results of the model (Carlos‐Júnior et al, 2015 ). To reduce the overlap of information between variables, SPSS v22 software was used to calculate the environmental attribute values of six herbivores and calculate the correlation coefficient to screen the environmental variables.…”