甘肃兴隆山不同演替阶段群落土壤氮素矿化对温度的响应OA北大核心CSTPCD

Soil nitrogen mineralization is a crucial process of the soil nitrogen cycle,with temperature being one of the most important factors affecting soil nitrogen mineralization.Studying the effect of temperature on soil ni-trogen mineralization characteristics in different successional stages is of great significance for understanding the soil nitrogen cycle in terrestrial ecosystems.In this study,the communities in different successional stages of Xin-glong Mountain in Gansu Province were selected as the research objects.The indoor,constant temperature,aero-bic culture method was used to study the soil nitrogen mineralization characteristics of five successional stages:grasslands,shrub forests,Betula platyphylla forests,Picea wilsonii-Betula platyphylla forests,and Picea wilsonii forests under temperatures of 15℃,25℃,and 35℃.The results showed that(1)except for the soil at a depth of 0-20 cm in grasslands,the increase in the soil nitrogen mineralization rate of the other successional stages was directly proportional to the temperature,and the cumulative mineralization of soil nitrogen in the different succes-sional stages showed a similar trend.(2)with the positive advancement of succession,the soil nitrogen mineral-ization rate and cumulative mineralization amount of different successional stages initially enhanced but then di-minished.The soil nitrogen mineralization rate of B.platyphylla forests was the highest,which was 1.63-,1.61-,1.25-,and 1.47-times more than that of grasslands,shrub forests,P.wilsonii-B.platyphylla forests,and P.wilso-nii forests,respectively.The soil nitrogen mineralization rate and cumulative mineralization amount of P.wilsonii-B.platyphylla forest were the highest,which were 0.68-,0.72-,0.84-,and 0.97-times greater than those of grasslands,shrub forests,B.platyphylla forests,and P.wilsonii forests,respectively.(3)the soil nitrogen mineral-ization rate and cumulative mineralization were inversely proportional to the soil depth,with the maximum detect-ed at a depth of 0-20 cm.(4)the temperature sensitivity coefficient(Q10)at 15℃and 25℃in different succes-sional stages varied markedly(P<0.05).The Q10 at first decreased and then increased in relation to the positive succession.The Q10 between the communities in different succession stages at 25℃and 35℃did not alter re-markably(P>0.05).The results of this study provide a theoretical basis for evaluating the evolution of soil quality and the dynamic changes in the soil nitrogen supply capacities in the community.