Using Species Distribution Modeling To Improve Conservation Strategies For Angiosperms In The Loess Plateau,China

Loess plateau is transitional zone of China and famous for its' vulnerable ecosystems.For a long time,problems such as: overuse of resources,land use change,global climate change and soil erosion have caused serious destruction to natural vegetation and severely challenged to biodiversity conservation.Since the protection project was implemented in 1999,the vegetation coverage area in the Loess plateau has increased significantly,however,in the process of project implementation,ecological restoration benefits are realized only by increasing the vegetation coverage area without fully considering the quality of vegetation construction.The vegetation productivity of the Loess Plateau is close to the threshold of water resources carrying capacity,and the future vegetation construction will face the shortage of water resources.To further consolidate the results of returning farmland to forests,and to alleviate the conflict among rapid economic development,population growth,biodiversity conservation.In the future,there is a need for a conservation planning network that can quantitatively and objectively and comprehensively analyze biodiversity conservation and human activities.Defining the geographical distribution of species is important for identificating priority areas and vegetation construction.In the reshearch,we modeled the potential distribution areas of 293 woody species and 505 herbaceous plants by incorporating species presence data and environmental layers which including current and future(2050S,2080S)four climate scenarios(RCP2.6,RCP4.5,RCP6.0,RCP8.5),and mapped the species richness pattern when threshold was determined.The results show that the potential distribution patterns of the same species are different under different climate scenarios at different times.The jacknife analysis shows that each species responds differently to the climate and the same species respond consistently to different climate scenarios.Richness patterns under different climate scenarios are dissimilar.The areas with high richness are mainly concentrated on the Qinling mountains which is located on the southern boundary of the Loess Plateau,and the lower areas are mainly concentrated on Inner Mongolia and Ningxia provinces.In the future climate scenarios,the areas with increased richness are mainly concentrated in the Luliang Mountain and Taihang Mountain of Shanxi Province,the Ordos Plateau,the Wushen Banner,Etuokeqian Banner and Etuoke Banner of Inner Mongolia.The areas with reduced richness are mainly the border areas of the Loess Plateau.In order to improve protection efficiency,limited resources put into critical areas.This time,based on the principle of system protection planning,using the Marxan to calculate the irreplaceability value of each spatial unit.Determining irreplaceable value greater than 35 to protect the priority areas,and 11 priority areas are finally determined which were concentrated in the borders and mountainous regions of the Loess Plateau.The existing nature reserves and the priority area are superimposed,we found that the three overlapped levels are low,and the other eight levels are relatively high,indicating that the distribution of existing nature reserves in the Loess Plateau are relatively reasonable.