Jasper Oshun, Wyeth Wunderlich, Kristina Keating, Margaret Lang, Wilner Bandera

Humid puna
Bofedales, or low gradient peat-forming wetlands, are a characteristic feature of the
humid puna - a high elevation, seasonally dry grass- and shrub-land found throughout
the Central Andes. Despite the importance of the humid puna in supplying water to
downstream communities, and the inference that bofedales may play an important role,
few studies have explored the hydrology of the humid puna, and none have quantified
the amount of water bofedales contribute to streamflow. We designed a 3-year study in
the Upper Ramuschaka Watershed (URW), a 2.12 km 2 humid puna catchment
sustaining a perennial stream used for irrigation. We monitored precipitation,
subsurface moisture, bofedal groundwater, and streamflow, measured discharge in 19
nested subbasins through the wet and dry seasons, and investigated the structure and
hydraulic properties of bofedales.
We discovered a positive relationship between unit runoff and the percent of bofedal cover across subbasins. Bofedales collect groundwater from areas 4-12 times their size, store large volumes in high porosity peat, and release water to streams through lower conductivity layers. Bofedales cover 11.6% of the URW, dynamically store
105,000 m^3 of water and yield 49 mm at the catchment scale, accounting for 20 –
98% of dry season runoff. Bofedales regulate drainage from the humid puna to
downstream communities and are therefore vital to local and regional water security.