A Study On The Vulnerability Of Typical Shrub Species In Northern China Under Climate Change

Climate change has changed the global biodiversity,vegetation distribution pattern and inter-species relationship,what’s more it has accelerated the rate of species extinction to a certain extent.In the future,climate change will continue to affect the survival of species,which will bring severe challenges to global biodiversity conservation.Shrub species in northern China play an important role in greening barren mountains,conserving water and soil,and preventing and controlling desertification,while taking into account high economic and ecological values.However,the survival of shrub species may face the threat of future climate change,and research on the vulnerability of typical shrub species in northern China has become an important issue for climate change adaptive management.Species vulnerability is used to measure the ability of species to resist the adverse effects of climate change.In the context of global warming,how vulnerable are shrub species in northern China? Will shrub species in northern China confront with the threat of climate change? Can the current network of nature reserves in China be able to deal with this threat effectively? In order to solve these problems,this study selected six typical northern shrub species in China as the research objects(Sabina vulgaris,Hedysarum scoparium,Sophora davidii,Rosa xanthine,Caragana korshinskii,Ziziphus jujuba var.spinosa),by calculating the marginality and specificity(Sensitivity)of the climatic niche of each tree species,and combining with the model to predict the potential suitable habitat of typical northern shrub species under future climatic conditions,to quantify the size of the habitat change area and the degree of habitat fragmentation(Exposure),the size of the protected area and the degree of human disturbance(Adaptive capacity),the overall vulnerability index of these species were synthesized,and characterizing the vulnerability of typical shrub species in northern China under climate change.The aim of the study is to improve our understanding of the extinction risk of shrub species under climate change,and to provide a theoretical basis for scientific and reasonable adaptation measures of shrub species in northern China to climate change.The results suggest:(1)The habitat suitability of H.scoparium was mainly affected by climate factors related to heat,while hydrologically-related and heat-related climate factors had equally important effects on the habitat suitability of S.vulgaris,C.korshinskii,S.davidii,R.xanthine and Z.jujuba var.spinosa.Among these six shrub species,the average annual temperature range of S.davidii is the widest,ranging from-1.1°C to 23.0°C,and the range of C.korshinskii is the narrowest,ranging from-0.07°C to 15.4°C.The most suitable annual precipitation of S.davidii is also the most extensive,ranging from 217 mm to 2036 mm,while the most suitable annual precipitation for the R.xanthine is the narrowest,ranging from 123 mm to 742 mm.(2)Through the calculation of the three dimensions of vulnerability(sensitivity,exposure and adaptability),the overall vulnerability index of all species is positive and shows an increasing trend,indicating that all shrub species will not face climate risk for the time being and their ability to resist the adverse effects of climate change will gradually increase.All shrub species will benefit from future climate change,among which S.vulgaris is the least beneficial species,and C.korshinskii is the most beneficial species.(3)The contribution of the protected area change component dimension to the overall vulnerability of each shrub will exceed that of the habitat area change component,indicating that the current Chinese nature reserve network can cope with the climate threat of shrub species in northern China effectively in the future.It also suggests that the protected area of the species by Chinese nature reserve network should be taken seriously in studies assessing the vulnerability of species under climate change.(4)Multi-component and multi-dimensional method system adopted in this study could give a more comprehensively assess species vulnerability than the traditional singledimensional method(only considering changes in habitat area).It can be analyzed from three perspectives of species vulnerability: sensitivity,exposure and adaptive capacity.The method system has high universality,making the result of vulnerability for different species comparable.