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An endemic rat species complex is evidence of moderate environmental changes in the terrestrial biodiversity centre of China through the late Quaternary

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ABSTRACT

The underlying mechanisms that allow the Hengduan Mountains (HDM), the terrestrial biodiversity centre of China, to harbour high levels of species diversity remain poorly understood. Here, we sought to explore the biogeographic history of the endemic rat, Niviventer andersoni species complex (NASC), and to understand the long-term persistence of high species diversity in this region. In contrast to previous studies that have proposed regional refuges in eastern or southern of the HDM and emphasized the influence of climatic oscillations on local vertebrates, we found that HDM as a whole acted as refuge for the NASC and that the historical range shifts of NASC mainly occurred in the marginal regions. Demographic analyses revealed slight recent population decline in Yunnan and south-eastern Tibet, whereas of the populations in Sichuan and of the entire NASC were stable. This pattern differs greatly from classic paradigms of temperate or alpine and holarctic species. Interestingly, the mean elevation, area and climate of potential habitats of clade a (N. excelsior), an alpine inhabitant, showed larger variations than did those of clade b (N. andersoni), a middle-high altitude inhabitant. These species represent the evolutionary history of montane small mammals in regions that were less affected by the Quaternary climatic changes.

No MeSH data available.


Ecological niche modelling of the NASC using 19 bioclimatic variables.The predicted potential distribution reclassified by MTPLT are given in different colors. The predicted potential distribution in different historical periods are mapped on the world topographic layer in ArcGis [9.0] (http://www.esri.com/software/arcgis/arcgis-for-desktop).
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f5: Ecological niche modelling of the NASC using 19 bioclimatic variables.The predicted potential distribution reclassified by MTPLT are given in different colors. The predicted potential distribution in different historical periods are mapped on the world topographic layer in ArcGis [9.0] (http://www.esri.com/software/arcgis/arcgis-for-desktop).

Mentions: Under the modelled climatic conditions of the Last Interglacial (LIG), the suitable habitat of N. excelsior prominently contracted (Fig. 5A). A dominant trend of westward and northward expansion since the Last Glacial Maximum (LGM) (Fig. 5A). The pattern of the mid-Holocene was extremely similar to the present condition and hence is not shown in Fig. 5. The range of N. excelsior is predicted to contract substantially in the future (Fig. 5B). In contrast to N. excelsior, N. andersoni showed less range shifts in different historical periods (Fig. 5C,D). The ENM results revealed that the historical range shift of the whole NASC primarily occurred in the north-eastern, north-western and south-eastern HDM (Fig. 5E,F). The average test of AUC for the replicate runs was greater than 0.97 for all five periods, confirming the excellent predictive power of the models. The binomial probabilities (<0.001) for eleven common thresholds indicated that our predictions were significantly better than those of a random model.


An endemic rat species complex is evidence of moderate environmental changes in the terrestrial biodiversity centre of China through the late Quaternary
Ecological niche modelling of the NASC using 19 bioclimatic variables.The predicted potential distribution reclassified by MTPLT are given in different colors. The predicted potential distribution in different historical periods are mapped on the world topographic layer in ArcGis [9.0] (http://www.esri.com/software/arcgis/arcgis-for-desktop).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5385558&req=5

f5: Ecological niche modelling of the NASC using 19 bioclimatic variables.The predicted potential distribution reclassified by MTPLT are given in different colors. The predicted potential distribution in different historical periods are mapped on the world topographic layer in ArcGis [9.0] (http://www.esri.com/software/arcgis/arcgis-for-desktop).
Mentions: Under the modelled climatic conditions of the Last Interglacial (LIG), the suitable habitat of N. excelsior prominently contracted (Fig. 5A). A dominant trend of westward and northward expansion since the Last Glacial Maximum (LGM) (Fig. 5A). The pattern of the mid-Holocene was extremely similar to the present condition and hence is not shown in Fig. 5. The range of N. excelsior is predicted to contract substantially in the future (Fig. 5B). In contrast to N. excelsior, N. andersoni showed less range shifts in different historical periods (Fig. 5C,D). The ENM results revealed that the historical range shift of the whole NASC primarily occurred in the north-eastern, north-western and south-eastern HDM (Fig. 5E,F). The average test of AUC for the replicate runs was greater than 0.97 for all five periods, confirming the excellent predictive power of the models. The binomial probabilities (<0.001) for eleven common thresholds indicated that our predictions were significantly better than those of a random model.

View Article: PubMed Central - PubMed

ABSTRACT

The underlying mechanisms that allow the Hengduan Mountains (HDM), the terrestrial biodiversity centre of China, to harbour high levels of species diversity remain poorly understood. Here, we sought to explore the biogeographic history of the endemic rat, Niviventer andersoni species complex (NASC), and to understand the long-term persistence of high species diversity in this region. In contrast to previous studies that have proposed regional refuges in eastern or southern of the HDM and emphasized the influence of climatic oscillations on local vertebrates, we found that HDM as a whole acted as refuge for the NASC and that the historical range shifts of NASC mainly occurred in the marginal regions. Demographic analyses revealed slight recent population decline in Yunnan and south-eastern Tibet, whereas of the populations in Sichuan and of the entire NASC were stable. This pattern differs greatly from classic paradigms of temperate or alpine and holarctic species. Interestingly, the mean elevation, area and climate of potential habitats of clade a (N. excelsior), an alpine inhabitant, showed larger variations than did those of clade b (N. andersoni), a middle-high altitude inhabitant. These species represent the evolutionary history of montane small mammals in regions that were less affected by the Quaternary climatic changes.

No MeSH data available.