| The giant panda(Ailuropoda melanolecua) is a unique and endangered species in China, which is also flagship species in biodiversity protection. Landslides triggered by earthquake caused deaths, damaged infrastructure and threatened endanger species. Compared with human disturbance, landslides caused increasingly greater, intensive and far-reaching impacts on giant pandas habitats. The Wolong Natural Reserve is the third national nature reserve, locating only 30 km from the epicenter of the Wenchuan earthquake. A large scales of landslides distributed in the study area.Therefore, analyzing and evaluating landslide impacts on giant pandas and their habitats is useful for panda habitat research, management and protection during post-quake reconstruction and recovery periods in China.This paper is supported by program of international S&T Cooperation(Grant No.S2013GR0477) and Open Fund of the center for Earth observation and Digital Earth, the Chinese Academy of Sciences(grant No. 2013LDE006). Based on previous studies and multidisciplinary theory, such as earth system science, geology,environment science and ecology, we select Wolong Natural Reserve as the study area using remote sensing and GIS to produce landside susceptibility maps by logistic regression(LR), Analytical Hierarchy Process(AHP), combined fuzzy and support vector machine(F-SVM) hybrid method and to analyze landslides impacts on giant pandas and their habitats by following aspects:(1) threatening panda lives;(2) damaging panda habitat;(3) increasing habitat fragmentation;(4) influencing giant panda behavior; and(5) blocking gene flow by cutting off corridors. Finally,constructing the habitat assessment system after earthquake in Wolong, and the results are necessary for government agencies and decision makers to select suitable locations for giant pandas, providing scientific and reasonable advices during post-quake reconstruction and conservation and wildlife projects. Made following main conclusions:(1) The relationship between landslides distribution and giant pandas habitats were explored quantitatively.The main type of geohazard in the study area is landslides and the second isdebris flows, rock avalanches and mud flows. In the scale, large areas and large rock mass volumes of landslides controlled in the study area. In the regional distribution,the landslides presents primarily in Gengda country, Zhuanjinlou, Hetaoping, Wolong giant panda research center and two sides of province road S303. Landslides regional distribution has close relationship with giant panda habiat in following characteristics:landslides in elevation between 1200-3800 m, slope degree 30°-45° hava overlapped with giant panda signs. Landslides destroyed mainly coniferous forest and fargesia robusta with the total areas in about 9460hm2, consisting of 4% areas in the study area.(2) Evaulating the regional landslides susceptiable in Wolong natural reserve systematically.(1) The scales, units and sampling strategies were discussed. In this paper, the main scarp(the higher portion of depletion zone, especially its upper edge) is the most evident morphological feature of a landslide and used as training data to represent the failure condition of landslide by researchers.(2) Discussing the relationship between landslide controls factors and landlides qualitatively and quantitatively.Then, this paper proposed a hybrid model(Combined Fuzzy similarity and SVM, F-SVM) to assess landslide susceptibility zonation(LSZ). LSZ with five different categories(very high, high, moderate, low,and very low) were generated and compared with three different approaches(LR,AHP, F-SVM). The results demonstrate that F-SVM has higer prediction accuracy.(3) Various impacts caused by landslides on giant panda habitas were discussed.(1) Not all landslides are bad for ecosystems, and their effects are permanent.Forest covers are the most serious destroyed by rock avalanches and falling rocks, and the second is debris flows and mud flows.However, rotational landslides can promot plant root development to some extent.(2) Analyzing the vegetation cover and habitat fragmentation using 3S technique and SVM supervised classification method.The results show that landslides turned a large area of forest land into grassland and bare land, increasing heterogeneity and in habitat patches. After manual intervention restoration, such as afforestation, spreading and closing forest, habitat restoration level approach to pre-earthquake. Among these landscapes, forest land restoration is much better, and second is grass land, bareland needs a lot of time to recover.(3) The least cost paths(the probable migration paths) are identified based on the selected source points and accumulative resistance surface in order to analyze the correlation between landslides and giant panda behavior. The results show that landslides within an area of 1km2 have the most significant influence on giant pandas compared to other areas.(4) Majority of species have good connectivity except several isolated pandasigns near Qicenglou. The gene flows of these pandas are blocked because the surrounding geological disasters increase the communication cost based on the least cost path theory. The long term viability of the species will be significantly threatened by inbreeding if habitat fragmentation and population isolation continue.(4) Constructing Wolong habitat suitability of giant pandas after earthquake. Considering restricting factors influence on giant panda distribution and robust, we construct habitat suitability of giant pandas from physical environmental factors, biotic factors and environmental disturbance factors based on ecological theories of habitat choice. Previous analyses have not focused landslide impacts.Thus, this article evaluates giant panda habitat suitability by integrating the effects of landslides and other variables. The results illustrate that about 49% of the study area can be classified as unsuitable(very low and low)for giant pandas, and 30%(very high and high) of the study area is suitable, consisting of majority of endanger species(73%). In a word, landslides haven’t played worse impact on giant panda except the species near northeast of Gengda might face inbreeding difficulty. |
