Abstract:

Herein, we have proposed and implemented a predictive species distribution system (PSDS) based on GIS (Geographic Information Systems) and using multiple models, according to the situation in the field of species habitat modeling. The new system (PSDS 2.0) was developed from PSDS1.0, originally initiated by our research group. We introduced three models into PSDS 2.0, including a mahalanobis distance model (MD), an environmental envelope plus limiting factor model (EELF), and a support vector machine (SVM) model. In this paper, we describe the implementation of the system and introduce the main functions in detail. In order to compare and evaluate results from different algorithms, an iterative cross-validation technique has been implemented in PSDS 2.0, which also facilitates the selection of suitable algorithms for different sample data. A function for flexibly dealing with pseudo-absences has been incorporated into presence-absence models. A GIS interfaces with the software for data preparation and further analysis of the model results. We also present a case study using the Reeve’s pheasant, Syrmaticus reevesii, as a practical application to introduce the entire modeling process. The performance of all model types is compared within this unified system.

Key words: ecological niche model, limiting factors, species’ potential distribution, pseudo-absence, cross validation