Patterns of richness of freshwater mollusks from Chile: predictions of its distribution based on null models

PeerJ

article

Carmen Gloria Fuentealba Jara¹  Reinaldo Rivera²  Cristian Franco³  Ricardo Figueroa⁴  Victor Faúndez⁵ 

[1] Instituto de Ciencias Naturales, Universidad de las Américas;Laboratorio de Ecología Evolutiva y Filoinformática, Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas. Universidad de Concepción;Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción;Facultad de Ciencias Ambientales y Centro EULA-Chile, Universidad de Concepción;Departamento de Medio Ambiente y Energía. Laboratorio de Genómica y Biotecnología Aplicada, Universidad Católica de la Santísima Concepción

关键词: Freshwater mollusks;    Macroecology;    Mid-domain null;    Rapoport;    Source-sink dynamic;    Freshwater molluscs;   

DOI  :  10.7717/peerj.7097

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The freshwater mussels from Chile are characterized by a high percentage of endemism and a fragmented latitudinal diversity, which has been attributed to the features and geomorphological history sculpted by the hydrographic basins. In this work, a set of hypothesis under a macroecological approach is addressed, with the aim to explore environmental, topographic and hydrological factors that define the latitudinal distribution of this mussel group. In order to achieve this goal, Rapoport’s rule, geometrics limits and co-ocurrence were evaluated. In addition, we analyze the source and sink hypotheses through the nested analysis. We observed a noticeable mid-domain effect (MDE), where a major richness than expected was randomly observed between 40 and 41°S. The results revealed that the distribution pattern was not concordant with Rapoport’s rule (r = 0.123; p = 0.128). Regarding to historical dynamic of the distribution, the results show a significant nestedness pattern, suggesting a source-sink dynamic, that is, poorer communities are a subset of richer communities in species. According to the co-occurrence analysis, an aggregate pattern existed, suggesting potential regulatory mechanisms. The specific richness pattern is explained by the variable seasonality of the temperature with a variance percentage explained of 35%. The full model indicated that variables which characterize the heterogeneity of habitat (i.e. range, Shannon), water availability (i.e., precipitation, density of water bodies) and topography (i.e., altitude area available) jointly explain 40% of the variability of the observed richness. This study shows that the geographical distribution of mollusc richness is mainly explained by mainly climatic and topographical environmental components, as well as by the source-sink dynamics.

【 授权许可】

CC BY