Predicting the Potential Geographical Distribution of Hainan Odorous Frog(Odorrana hainanensis) in Hainan Province by MaxEnt
HUANG Yong-Jie;LU Jia-Bing;WANG Feng-Tang;LIN Ying-Hua;LIU Lei;MI Hong-Xu;MO Fang-Qun;FANG Jing;LI Jia-Ling;Institute of Wetland Research, Chinese Academy of Forestry;College of Tropical Biology and Agronomy, Hainan Tropical Ocean University;Hainan Yinggeling National Nature Reserve;Hainan Jianfengling Forestry Bureau;Hainan Limushan Provincial Nature Reserve;Hainan Wuzhishan National Nature Reserve;
Habitat analysis and prediction are the foundation on threatened species protection. In this study, we used the ecological niche model, Max Ent, based on Arc GIS, combined with 66 occurrence records and 17 30 m × 30 m resolution environmental variables, to predict the potential distribution of Hainan Odorous Frog(Odorrana hainanensis) and analyzed the relationship of this species with the environmental factors in Hainan Island, China. The prediction and analysis were conducted in Max Ent 3.3.3. Then we employed the receiver operating characteristic(ROC) curve to evaluate the accuracy resulting from the model analysis and performed the Jackknife test to evaluate the importance and contribution of environmental variables. Finally, we analyzed the potential distribution of Hainan Odorous Frog produced by Max Ent model by habitat suitability index(HSI), in which areas with value HSI 0.44 was considered to be high suitability, 0.20 HSI ≤ 0.44 was moderate suitability, 0.06 HSI ≤ 0.20 was low suitability and HSI ≤ 0.06 was unsuitability. The potential distribution of Hainan Odorous Frog is approximately 2 179 km2 at an altitude range of 200﹣1 200 m with the optimum distribution range between 600 m and 1 000 m(Fig. 4). The overall pattern of potential distribution of this species is uncontinuity and occurs in three patches(Fig. 2). The Patch Ⅰ named Jianfengling is a minimum potential distribution with an area of 218.4 km2(Table 1), which mainly occurs in the Sanfenqu and Wufenqu in the center and Nanya in the south of Jianfengling. The Patch Ⅱ is as large as 963.5 km2 which locates in the region of Bawangling, Yinggeling and Limushan within the regions Yaqiong, Nanmeiling of northern Bawangling, and Yinggezui, Shenhan, Xiuzhailing of easthern Yinggeling and Sifenchang of central Limushan. The Patch Ⅲ is found in the region of Wuzhishan and Diaoluoshan and its size is 997.1 km2 that is similar to Patch Ⅱ. The majority of Patch Ⅲ is in the Naluoling in the west, Haodingling in the south of Wuzhishan, and Dujiacun, Baishuiling in central Diaoluoshan, as well as the Niushangling in eastern study area. A further analysis for the potential distribution area which occurs within six nature reserves gave the following results:(1) The total potential distribution(HSI 0.06) of this frog species was 565.1 km2, of which 10.8% was highly suitable(HSI 0.44). These habitats located in six protected areas and approximately accounted for 26.0% of the overall potential distribution region. The largest potential distribution(HSI 0.06) with an area of 156.4 km2 was located in the Bawangling National Nature Reserve, the next one was detected in Yinggeling National Nature Reserve with 137.9 km2(HSI 0.06) in size. While the minimum value of potential distribution region 44.3 km2 was found in Wuzhishan National Nature Reserve(Table 2). The result of Jackknife test showed the land altitude was the main environmental factor affecting the distribution of Hainan Odorous Frog for 45.2%, the slope for 23.9%, then distance to water for 8.3%, normalized difference vegetation index for 5.2% and annual precipitation, with a value of contribution 5.2% respectively(Table 3). Temperature, humidity and sunshine had little impact. Our study indicated that the area of suitable habitat of Hainan Odorous Frog in protected areas was relatively large, while the quality of habitat outside the nature reserves may be influenced by the climate and human factors.
【Key Words】： Hainan Odorous Frog(Odorrana hainanensis) MaxEnt model Potential distribution
【CateGory Index】： Q958
【CateGory Index】： Q958