<p> Although knowledge of peatland CH<sub>4</sub> and CO<sub>2</sub> exchange in temperate mountain ecosystems is available, information about carbon (C) exchange in peatlands of the Andean mountains is limited and these ecosystems may behave differently given the particular characteristics of the Andean tropics. These ecosystems are highly productive and under pressure by grazing. Our first objective was to measure baseline carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) flux in an undisturbed peatland in Cayambe-Coca National Park. Our second objective was to quantify CO<sub>2</sub> and CH<sub> 4</sub> fluxes in an intensively cattle grazed peatland near Antisana Ecological Reserve. CO<sub>2</sub> and CH<sub>4</sub> effluxes were measured using a static chamber method. The mean NEE values for the undisturbed and disturbed site were -0.69 ± 0.08 and -1.25 ± 0.13 g CO<sub>2</sub> m<sup> -2</sup> hr<sup>-1</sup> respectively. A significant correlation between microtopography and CO<sub>2</sub> and CH<sub>4</sub> flux was found in the undisturbed site, with higher NEE, GPP, ER and CH<sub>4</sub> values in hummocks than in lawns. Microtopography doesn’t seem to be a controller of CO<sub> 2</sub> efflux in the grazed site, although the NEE and GPP rates are higher than those found in the undisturbed site, and show a linear relationship with vegetation cover. CH<sub>4</sub> emissions in the undisturbed site were low (8.1 ± 1.17 mg CH<sub>4</sub> m<sup>-2</sup> d<sup> -1</sup>). However, CH<sub>4</sub> emissions at the grazed site were very high (132.25 ± 34.22 mg CH<sub>4</sub> m<sup>-2</sup> d<sup> -1</sup>), which might be attributed to the high physical impact and inputs from cattle. In summary, it appears that cattle grazing may be capable of large changes to C exchange and greenhouse gas fluxes in Andean peatlands. </p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10241527 |
| Date | 12 March 2017 |
| Creators | Sanchez, Maria Elisa |
| Publisher | Michigan Technological University |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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