Research On The Influence Of Road On Breeding Habitat Of Crested Ibisbased With Maxent Model

The Crested Ibis(Nipponia nippon) is a protected animal in China, used to be widely distributed in the East Asian region, and now distributed mainly in the territory of the Qin Ba area in Shaanxi Province The influence of road for breeding crested ibis habitat has been paid more attention due to the increase of traffic.In this paper, we first analysis meteorological data, DEM, the land use data, two phase of the TM remote sensing image data in the study area, then extract nine environmental variables which play important role in nest site selection of Crested ibis, including the climate data:the annual average temperature, annual rainfall, topography data: elevation, gradient, slope direction, human disturbance data:the distance from the road, a distance from population centers, and NDVI data and distance from water using GIS tools(Arcgis10.2).We analyzethe distributionof the 9 environment variablesand in the study area,statisticthe distribution area and the crested ibis frequencyof each variables between different levels. Predict and evaluate crested ibis breeding habitat using Crested ibis nest site and the 9 environment variables based on the Maxent model, and analyze the effects of each environmental variables in the evaluation.It is made contrast between effects of road in consideration and non-consideration based on the Maxent model in order to obtain the effects of road on the Crested Ibis suitable nesting area. Our results can provide scientific support for the protection of the breeding habitat of Crested Ibis, also can provide scientific basis in selection of road, and the studyhas important significance to the environmental impact quantitative assessmentof road and other construction project in the future. The main results of the study are as follows:1. Average annual temperature, NDVI, the average annual precipitation, the distance from the road and the distance from the body of water is the main factor affecting the crested ibis to nest, and the corresponding contribution rate to model are respectively 25.6%,24.8%,15.2%,10.5%,10.5%. The best breeding habitat of Crested Ibis is the area with average annual temperature of 12.6-14.2℃ the average annual rainfall of 790-845mm, NDVI is 0.34-0.80, the distance from the water less than 700m, the distance from the road 1000-4900m, slope 2-23°, distance from settlements 1200-3800m, altitude 500-1200m.2. By the rate of crested ibis breeding habitat suitability considered two kinds of situational variables that containedroad and non-containedroad,indicating that high, medium and low suitable nest area were 48.65 km2,148.79 km2,5225.57 km2in scenarios involved road factor, and high, medium and low suitable nest area were 55.90km2、166.89km2、5200.22 km2 in scenarios non-involved road factor. The high and middle sustainable nesting area of Crested Ibisdecreased, the low sustainable areas increased with the occurrence of road. All the study show that road a negative impact on crested ibis breeding habitat3. Comparing thedistribution of the crested ibis nesting suitabilityin the two situations, Crested Ibis nesting area suitabilityin situation two was significantly higher than that of situationonewhen the distance to road within 1500 meters, while theCrested Ibis nesting area suitabilitywas obvious lower than that ofsituation one with the distance to road beyond 1500meters, indicating that theCrested Ibis would choose to stay away from the road, the average avoidance distance was 1500meters.4. Calculating the patch number, average patch area and isolation degreeof the high and medium nesting area of Crested Ibis in the two situations with the help of the Fragstats3.4, the area of the high and medium able nesting area of Crested Ibis decreased while the patch number and the isolation degree respectively increased by 72 and 183, and the separation index increased by 3041.15 and 65113.7 respectively, and the average patch area decreased by 1.78×10-2km2 and 0.09×10-2km2. With the occurrence of road, indicating that the road has a fragmentation effect on high and medium suitable nesting areas.