COS 272-1 - Andean small-scale peat extraction impacts CO2 fluxes in cushion-plant peatlands.

Abstract: Small-scale peat extraction in the Andes, locally known as champeo, is a common subsistence activity carried out by Andean indigenous communities, who use dried peat for fuel. The climatic impacts and sustainability of this activity in Andean peatlands of the Puna region is poorly understood. We generated a study to evaluate the impact of peat extraction on greenhouse gas CO₂ fluxes in central Andes of Peru in a national reserve inhabited by indigenous communities. We used a closed translucent chamber in combination with the Picarro GasScouter G4301 to measure mid-day Net Ecosystem Exchange (NEE), Ecosystem respiration (ER) and gross primary productivity (GPP) on site. The measurements were performed during the dry season on multiple plots across the cushion-plant peatlands locally known as bofedales. We evaluated intact cushions of Distichia muscoides, areas with bare soil due to the recent extraction of peat and areas with natural new vegetation cover after years of the peat removal. The areas of recovered vegetation did not include D. muscoides and showed an herbaceous plant composition.

Preliminary data shows CO₂ fluxes varies among treatments. D. muscoides cushions and floristic recovered areas had a similar daytime CO₂ uptake by the ecosystem (i.e., negative NEE) of -0.56 ± 0.19 g CO₂ m^-2h^-1 and -0.59 ± 0.16 g CO₂ m^-2h^-1 respectively, and bare ground had an average CO₂ emission of 0.33 ± 0.22 g CO₂ m^-2h^-1. We did not observed differences in the GPP values between D. muscoides cushions and recovered vegetation (-3.27 ± 0.22 g CO₂ m^-2h^-1 and -2.75 ± 0.20 g CO₂ m^-2h^-1 respectively), but both were different from bare ground values of -0.38 ± 0.25 g CO₂ m^-2h^-1. Similarly, ecosystem respiration was similar in areas with vegetation (2.75 ± 0.15 g CO₂ m^-2h^-1 for D. muscoides and 2.24 ± 0.13 g CO₂ m^-2h^-1 for recovered vegetation) and showed small values on bare ground (0.90 ± 0.17 g CO₂ m^-2h^-1). Additionally, ER had a negative response to rising water tables. In conclusion, our study suggests that indigenous Andean peat extraction activity generates an impact in the carbon fluxes of the peatlands, creating CO₂ emissions and decreasing the GPP on such areas. However, the areas with vegetation that colonized the open areas seem to recover the CO2 uptake values, compared to D. muscoides cushions. Nevertheless, peat extraction changes the floristic composition on the bofedales that will likely have repercussions on other ecosystem functions and hydrologic conditions of peatlands.