EFFECTS OF NITROGEN ON THE DRY MATTER ACCUMULATION,CARBON ANDNITROGEN METABOLISM OF WHEAT LEAVES UNDER ELEVATED ATMOSPHERIC CO2 CONCENTRATION Effects of simulated elevated atmospheric CO2 concentration and temperature on soil enzyme activity in the subalpine fir forest The effects of elevated atmospheric CO on AMF community colonized in roots of various plant species Effects of elevated atmospheric CO2 on soil enzyme activities at different nitrogen level Effects of atmospheric CO2 enrichment on the population sizes of aquatic microbial and coliform group in paddy field ecosystem