22 March 2020
Andean ‘water sponges’: The role of plants in water supply
Is vegetation important for water storage and capture in the context of a changing landscape in Páramos?
Páramos are the most biodiverse high-altitude ecosystems distributed along the misty Neotropical Andean mountain range in Venezuela, Colombia, Ecuador and Northern Peru.
They are also critical for the survival of millions of people, providing the main source of clean water for inhabitants of capital cities such as Bogota and Quito.
Páramos are recognisable by the presence of “Frailejones” (Espeletiinae subtribe of Asteraceae family), that stand out in these mountain prairies. Other plant groups include shrubs from Ateraceae and Ericaceae families, and peat mosses.
Used for centuries, the Páramos have provided a source of medicinal plants, grazing and agricultural land for indigenous peoples. However, over recent decades these landscapes have been changing and their functionality may have reduced.
Myself and Mauricio Diazgranados are working with other UK institutions together with Colombian counterparts on the interdisciplinary PARAGUAS project (meaning umbrella in Spanish, and standing for PARAmo + AGUA (=water) + Society).
Focusing on the province of Boyacá in Colombia, we are analyzing how the Páramo functions, both above and below ground, and how we can protect it.
Our work will establish how plant and habitat diversity contributes to water regulation; identify and quantify how crop and livestock farmers engage with and affect the Páramo; and provide a better understanding of Páramo functioning, enabling sustainable and conflict-free solutions.
To do this we will be using hydrological models, aerial photographing, radar imaging and talking to local stakeholders.
Vegetation and Water
As all living organisms, plants require water both for their physiological processes (i.e photosynthesis), and to keep the necessary turgor to maintain their structure.
During photosynthesis plants suck water from the soil which is carried through the stem into the leaves where it is processed and released into the atmosphere.
Therefore, plants may actually remove water from the ground (the source we can actually use), to release it to a source which is not directly available for us: the atmosphere.
We think that plants also have an important effect in delivering water into the ground and into streams.
Plants intercept water from the abundant Andean mountain fog. Páramos plant species may contain structures which store and release this water into the ground (such as hanging necromass – dead plant material), and are hence indirectly important for water storage.
Finally, the vegetation in this ecosystem may also reduce evaporation rates from the ground, by providing cover and more favorable micro environmental conditions.
Our fieldwork began last year and we established 145 survey plots.
We are currently surveying the structure and composition of these. We will also be estimating the biomass which will be incorporated into our hydrological models to try to identify and understand water stream differences between conserved and managed catchments.
The Páramos for me are astonishing landscapes.
It has so far been a fulfilling experience to work with top researchers and early career students, of different disciplines, who are full of enthusiasm and open to sharing and learning in order to provide useful information for decision makers and for local inhabitants
The PARAGUAS project is supported by the Newton Caldas Fund and funded by the NERC and AHRC [grant number NE/R017654/1]. The project is a collaboratino between researchers from Centre for Ecology and Hydrology, Royal Botanic Gardens, Kew, University of Nottingham, Imperial College London, Bristol University, University of Edinburgh and Loughborough University.
In Colombia it is supported by the Universidad Pedagógica Tecnológica de Colombia (UPTC), the Instituto de Investigación de Recursos Biológicos – Alexander von Humboldt (IAvH, The Universidad Nacional de Colombia (UN) and the Institute of Hydrology, Meteorology and Environmental Studies (IDEAM).