Projected Shifts in Kppen Climate Zones over China and Their Temporal Evolution in CMIP5 Multi-Model Simulations

Previous studies have examined the projected climate types in China by 2100. This study identified the emergence time of climate shifts at a 1 o scale over China from 1990 to 2100 and investigated the temporal evolution of Koppen-Geiger climate classifications computed from CMIP5 multi-model outputs. Climate shifts were detected in transition regions （7%-8% of China＇s land area） by 2010, including rapid replacement of mixed forest （Dwb） by deciduous forest （Dwa） over Northeast China, strong shrinkage of alpine climate type （ET） on the Tibetan Plateau, weak northward expansion of subtropical winter- dry climate （Cwa） over Southeast China, and contraction of oceanic climate （Cwb） in Southwest China. Under all future RCP （Representative Concentration Pathway） scenarios, the reduction of Dwb in Northeast China and ET on the Tibetan Plateau was projected to accelerate substantially during 2010-30, and half of the total area occupied by ET in 1990 was projected to be redistributed by 2040. Under the most severe scenario （RCP8.5）, sub-polar continental winter dry climate over Northeast China would disappear by 2040-50, ET on the Tibetan Plateau would disappear by 2070, and the climate types in 35.9% and 50.8% of China＇s land area would change by 2050 and 2100, respectively. The results presented in this paper indicate imperative impacts of anthropogenic climate change on China＇s ecoregions in future decades.

Effects of heat on the biological activity of wild Cordyceps sinensis

Background:Current methods of extending the storage time of wild Cordyceps sinensis adversely affect the nutritive and medicinal value of the product.Thus,this study was designed to investigate the effects of heat treatment,a relatively safe storage extension method,on the biological activity of wild C.sinensis.Methods:Samples were heated to 60,80,or 100℃ for 15,30,or 60 minutes.SOD activity in wild C.sinensis before and after heating was assayed using a standard colorimetric assay.Deoxyribonuclease (DNase) activity was measured using the plasmid-nicking assay.Cordycepin content was analyzed using HPLC.Polysaccharide content was measured using the phenol sulfuric method.The Student's t-test was used for comparison.Results:After heating at 60,80,100℃ for 15,30,60 minutes,respectively,no significant reduction in DNase activity or polysaccharide dissolution was noted (P >.05).Interestingly,heating at 80℃ for 30 minutes led to a significant increase in the SOD activity of C.sinensis (P <.05).In addition,heating at 60℃ for 60 minutes or at 80℃ for 15 minutes significantly increased cordycepin dissolution (P <.05).Other heat treatments had no significant effects on SOD activity or cordycepin dissolution (P >.05).Conclusions:These results suggested that heat treatment does not adversely affect SOD or DNase activity,polysaccharide content,or cordycepin dissolution.Thus,heat treatment might be a safe processing method to extend the storage time of wild C.sinensis without compromising biological activity.