Seasonal soil CO2 efflux along a toposequence in the transvolcanic mexican belt

摘要: Soil CO2 emissions have been scarcely studied in Mexico; and these data are very important for constructing greenhouse gas inventory of Mexico. were seasonally determined ten different systems found along an altitudinal gradient a watershed the Mexican transvolcanic belt (Atecuaro, Michoacan, 19°34'N; 101°J O'W). The dominant soils Andosols (top half) Acrisols (lower half), climate is sub-humid template (rain from June to October). most representative climo-toposecuence, Andosol arc: grasslands (P )-2615 m); pine-oak forest with increasing land degradation downslope (P2, P3 P6:2500-2350 fuelwood area (P4-2370 agricultural (P5-2330 Acrisols: patches (P7-2320 m). cultivated fields (P9-2280 (P10-2290 m), eroded areas around gullies (P8-231O Vegetation was characterized at every point soil samples collected. fluxes temperature measured using respiration system (PP Systems, five replicates each point). series measurement conducted during one year. Clear seasonal variations observed. lowest values dry season highest rainy period. I,P2,P3,P5) had higher (higher available water content, SOC contents microbial activity), being on average P5 highest. flux always P8, without A horizon almost null content. In spite that Acris ols presented lower fluxes, bulk density, porosity, clay content than Andosols, differences between two expected. linear positive correlation effluxes established.