Tussock Grass

Páramo de sumapaz - vegetation - tussock grass - rainfall & groundwater - soil

Within the Páramo ecosystem, elevation is the main driver for its vegetation, and this results in an internal vertical structure with three main Páramo vegetation belts: the sub-Páramo, the grass Páramo and supra-Páramo (Christmann and Oliveras, 2020). The summit and hillslopes feature well-drained soils covered by tussock grasses or bunch, constituting the grass Páramo. Whereas toeslopes and valley bottoms constitute permanently waterlogged areas covered by hard cushion-forming plants (Molina et al., 2024), such as sphagnum moss.

Tussock grasses’ growth form is the most widespread in the Páramo. In undisturbed areas, grasses may average 1-1.5 m tall with a coverage of up to 100%.  Members of the grass and sedge families frequently form tufts or dense bunches of stems (culms) with rigid, pointed, tubular or inrolled leaves. These dense tufts in which the dead leaves are maintained and decay on the plant, along with the culms, provide good insulation for the buds and young leaves from cold temperatures, high radiation, evaporation, and high heat of fires to 500°C (Ramsay, 1992;  Ramsay & Oxley, 1996).  

Tussock grass vegetation exhibits significant rainfall interception capacity. Due to the low rainfall intensity and lack of climatic stability in Páramo, greater rainfall interception may still occur despite the tussock grasses are stunted (Ochoa-Sánchez, Crespo and Célleri, 2018). Moreover, the distinctive root system of tussock grass enables its vegetation belt to form a homogeneous system that regulates and transmits water evenly through all the soil horizons (Sebastián Páez-Bimos et al., 2023).

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