Comparisons of carbon and nitrogen transformation and their coupling relationships among different forest types,including primary and restoration forests after primary forest harvesting in the subalpine region of western Sichuan,are relatively limited.In this study,we measured the seasonal dynamics of soil respiration and gross nitrification rate using the barometric process separation(BaPS)technique and examined their possible effect in Abies faxoniana primary,Picea asperata broadleaved mixed,natural secondary Betula-Abies,and P.asperata plantation forests.The results showed that the average soil respiration and gross nitrification rate during the growing season were the highest in P.asperata broadleaved mixed forest and P.asperata plantation forest,respectively,and were the lowest in A.faxoniana primary forest.The soil respiration and gross nitrification rates varied obviously during the growing season,peaking in July.They were significantly correlated with soil temperature(P<0.05),but were not significantly correlated with soil water content,indicating that soil temperature,rather than soil water content,is a controlling factor in the regulation of the seasonal dynamics of soil respiration and gross nitrification.Soil respiration temperature sensitivity varied from 2.59 to 4.71 with the highest in the A.faxoniana primary forest,suggesting primary forests at high altitudes may be more vulnerable to climate change.Soil respiration and gross nitrification rates among forest types were mainly influenced by litter mass,pH,and soil organic matter.The soil respiration rate was positively correlated with the gross nitrification rate in different forest types,indicating a coupling relationship between soil respiration and gross nitrification rates.