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Carbon dioxide and methane fluxes in grazed and undisturbed mountain peatlands in the ecuadorian Andes

Abstract:

Peatlands are widespread throughout the tropical Andean páramo. Despite the large carbon stocks in these ecosystems, carbon dioxide (CO2and methane (CH4flux data are lacking. In addition, cattle grazing is widespread in the páramo and could alter gas fluxes. Therefore, our objectives were to measure CO2and CH4fluxes with the static chamber technique in an undisturbed and in an intensively cattle grazed peatland in the mountains of Ecuador. We found that hummocks in the undisturbed site had higher net ecosystem exchange (NEE), gross primary production (GPP), ecosystem respiration (ER), and CH4fluxes, compared to lawns. In contrast, microtopography at the grazed site did not pbkp_redict CO2fluxes, whereas vegetation cover was correlated for all three metrics (NEE, ER, and GPP). At low vegetation cover, NEE was positive (losing carbon). CH4emissions in the undisturbed site were low (8.1 mg CH4m-2d-1In contrast, CH4emissions at the grazed site were much greater (132.3 mg CH4m-2d-1This is probably attributable to trampling and nutrient inputs from cattle. In summary, the two peatlands differed greatly in CO2and CH4exchange rates, which could be due to the variation in climate and hydrology, or alternatively to intensive grazing by cattle.