Abstract
Species distribution models deal with the occurrence or abundance of a species along with the environmental factors at a location to predict the present and future distribution of the species. Based on the occurrence records available, different species distribution modelling methods can be carried out. Maximum Entropy (MaxEnt) approach was used to model the current and future distribution (RCP4.5 and RCP8.5 of the year 2050) of Triturus cristatus and Lissotriton vulgaris in Norway and find the most important variables influencing their distribution using presence only records. T. cristatus is listed as Near Threatened and L. vulgaris is listed as Least Concerned in the Norwegian Red List of Species. A total of 260 presence records for T. cristatus and 662 presence records for L. vulgaris was used and climatic and environmental variables were used as predictors. The results from this modelling showed that the distribution of both species is influenced by mean temperature of warmest quarter (bio10) and soil moisture with isothermality (bio3) and precipitation seasonality (bio15) affecting L. vulgaris and T. cristatus respectively. The current predicted distribution highly overlapped the actual distribution of both species. The future spatial distribution of L. vulgaris and T. cristatus was found to be much wider than the actual and current predicted distribution. Expansion of suitable habitats were reported on the northern areas. The robustness of the study is supported by the higher AUC values. Our findings contribute to the understanding of the distribution of L. vulgaris and T. cristatus under present and future condition and this can be considered for the conservation and management purpose of both the newt species.
Keywords: Lissotriton vulgaris, Triturus cristatus, maxent, rcp4.5, rcp8.5, species distribution modelling