Towards an integrated evidence base to support sustainable management of the páramos

Despite the spatial-temporal variability and complexity of the hydrological processes of páramos, as well as the logistical challenges imposed by the remote and barren environment, the above review shows great advances in hydrological knowledge of the páramos. This is exceptional for a remote mountain environment, and arguably unique in the Andes. We consider that this knowledge was gained as a result of the interdisciplinary participation of actors, combined with the use of well-established methods and technologies. This has led to the creation of an unwritten “common agenda”, leading to a focusing of research activities and fostered convergence between seemingly independent research efforts. The acceleration of hydrological research in the late 1990s coincided with an increasing awareness of the ecological and societal value of the páramo highlands, notwithstanding páramos provided crucial ecosystem services long before this (Johansen et al., 2018). Indeed, especially in Ecuador and northern Peru, páramos have been inhabited for centuries and major centers of the Inca empire were located in or near the páramo border (Bendix et al., 2013). Ingenious hydraulic infrastructure drew water from the páramo headwaters and used the region for agricultural activities and livestock grazing in particular. Since the 1970, forestation with pine species became a widespread activity as an attempt to support the economic activity of paper production (Bonnesoeur et al., 2019). However, the most direct ecosystem service of the páramos has been water supply, especially for major Andean cities. Population growth and related increase in water demand put rising pressure on these resources as well as an augmenting awareness of their vulnerability among decision-makers. In 2000, the city of Quito in Ecuador, established one of South America’s first and most successful water funds (FONAG), with the aim to protect and manage the city’s water supply regions. As more than 90% of these regions are covered by páramos, initiatives like these drew political and scientific attention to the lack of scientific understanding of their hydrological functioning and the potential impact of changes in land use, as well as global climate change. Throughout its first decade, this focus was strengthened further by growing evidence of mountain environments as hotspots of biogeographical and human vulnerability to climate change (e.g., Myers et al., 2000; Viviroli et al., 2011). The issue of climate change not only stressed the need to better understand the páramo water cycle, but also its links to other processes such as the carbon cycle and biodiversity (Buytaert et al., 2011). These processes shaped a local and international research agenda which led to a step-change in scientific activity in the páramos. In addition, large scale initiatives on the science-policy interface connected and integrated these efforts. Among those efforts, the Global Environmental Facility funded Proyecto Páramo Andino, which ran from 2006 to 2012, which stood out because of its role in building a research community. In 2010, the project initiated the iMHEA regional network (Célleri et al., 2009; Ochoa-Tocachi et al., 2016b). Such initiatives created a strong connection between the scientific and operational communities. For example, many recent studies on the spatial-temporal variability of precipitation processes in the Andes are joint efforts between national meteorological offices and scientists (e.g., Manz et al., 2017; Nerini et al., 2015). This has led to an accelerated uptake of the use of satellite-based precipitation products in operational practice, and an optimization of the monitoring efforts between different research groups. Political decisions to make hydrometeorological datasets available for scientific use have further accelerated this evolution. The iMHEA started originally as a community of practice of scientists, government institutes, decision-makers and civil society representatives. All these actors aimed at understanding the high Andean water resources and address the critical data scarcity in the region (Célleri et al., 2009). The network grew until today and manages 27 flow gauging stations and 67 rain gauges in headwater catchments of the Andes of Ecuador, Peru, and Bolivia. The network is designed to complement institutional hydrometeorological monitoring, and to generate evidence on land management practices through a pairwise catchment design (Ochoa-Tocachi et al., 2018). In addition, to the scientific productivity the network is creating an institutional legacy as well. In Peru, the iMHEA methodology has been adopted by the National Drinking Water and Sanitation Regulation Agency (SUNASS) to evaluate the implementation of recent laws on ecosystem services. The mentioned methodology promotes the use of natural infrastructure for water security. The exceptional experience of linking evidence generation with in-situ water management have raised similar convergence between scientific and policy priorities in other disciplines. The growing awareness of the potentially dramatic impact of climate change on high mountain regions (e.g., Vuille et al., 2018) has triggered several concerted efforts to improve the predictive capacity of global climate models. This has promoted the development of more appropriate downscaling methods, the evaluation of the multiple impacts of climate change, and the development of better and more flexible adaptation strategies in the tropical Andes. A notable initiative in this regard was the Andean Climate Change Interamerican Observatory Network (ACCION), which ran from 2012-2014 (Vuille, 2015). Similarly, research on ecological processes and carbon recycling in páramos emerged in parallel to hydrological research (e.g., R. G. M. Hofstede, 1995; Podwojewski et al., 2002; Tonneijck et al., 2010). Interdisciplinary endeavors to link these processes are becoming increasingly common (e.g., Minaya, Corzo, Romero-Saltos, et al., 2016). The use of tracer hydrology has been especially instrumental in analyzing the biogeochemical cycles that underpin and connect these processes (e.g., Correa et al., 2017, 2018; Esquivel-Hernández et al., 2018; Mosquera, Célleri, et al., 2016).