Soil heterotrophic CO2 emissions from tropical high-elevation ecosystems (Páramos) and their sensitivity to temperature and moisture fluctuations

Increasing temperatures and changes in the intensity and frequency of precipitations may impact the ability of tropical high-elevation Andean ecosystems (Páramos) to store and retain carbon (C). We, therefore, examined how warming and fluctuations in soil moisture could influence soil CO emissions from heterotrophic respiration (R, the result of microbial respiration), of two Páramos of contrasting climatic regimes within their area of distribution. We here show high sensitivity of both R and Q under warmer and fluctuating moisture conditions. Together with the high rates of C-normalized R compared to other soil C-rich ecosystems from higher latitudes (2 μmol gC h versus 0,4 μmol gC h, respectively) our results evidenced how soil heterotrophic-derived CO emissions could potentially increase under expected climate scenarios, eventually altering the capacity of soil Páramos to sequester C.This work was supported by >becas Santander para jovenes investigadores> and the project VERONICA (CGL 2013-42271-P) Spanish Ministry for Economy and Competitiveness (MINECO).Peer Reviewe