Browsing by Autor "Bryan G. Mark"

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Drivers of peatland water table dynamics in the central Andes, Bolivia and Peru
(Wiley, 2019) David J. Cooper; Jeremy Sueltenfuss; Eduardo Oyague; Karina Yager; D. A. Slayback; E. Marcelo Cabero Caballero; Jaime Argollo; Bryan G. Mark
Abstract Cushion plant dominated peatlands are key ecosystems in tropical alpine regions of the Andes in South America. The cushion plants have formed peat bodies over thousands of years that fill many valley bottoms, and the forage produced by the plants is critical for native and nonnative domesticated mammals. The sources and flow paths of water supporting these peatlands remain largely unknown. Some studies have suggested that glacier meltwater streams support some peatlands, and that the ongoing loss of glaciers and their meltwaters could lead to the loss or diminishment of peatlands. We analysed the hydrologic regime of 10 peatlands in four mountain regions of Bolivia and Peru using groundwater monitoring. Groundwater levels in peatlands were relatively stable and within 20 cm of the ground surface during the rainy season, and many sites had water tables 40–90 cm below the ground surface in the dry season. Topographic and groundwater elevations in the peatlands demonstrated that the water source of all 10 peatlands was hillslope groundwater flowing from lateral moraines, talus, colluvium, or bedrock aquifers into the peatlands. There was little to no input from streams, whether derived from glacier melt or other sources, and glacier melt could not have recharged the hillslope aquifers supporting peatlands. We measured the stable water isotopes in water samples taken during different seasons, distributed throughout the catchments, and the values are consistent with this interpretation. Our findings indicate that peatlands in the study region are recharged by hillslope groundwater discharge rather than stream water and may not be as vulnerable to glacial decline as other studies have indicated. However, both glaciers and peatlands are susceptible to changing thermal and precipitation regimes that could affect the persistence of peatlands.
Mountain freshwater ecosystems and protected areas in the tropical Andes: insights and gaps for climate change adaptation
(Cambridge University Press, 2021) Estefania Quenta; Verónica Crespo‐Pérez; Bryan G. Mark; Ana Lía Gonzales; Aino Kulonen
Summary Although protected areas (PAs) play an important role in ecosystem conservation and climate change adaptation, no systematic information is available on PA protection of high-elevation freshwater ecosystems (e.g., lakes and watersheds with glaciers), their biodiversity and their ecosystem services in the tropical Andes. We therefore combined a literature review and map analysis of PAs of International Union for Conservation of Nature (IUCN) and national systems of PAs and freshwater ecosystems. We found that seven national parks were created for water resources protection but were not designed for freshwater conservation (i.e., larger watersheds). High-value biodiversity sites have not been protected, and new local PAs were created due to water resource needs. We quantified 31 Ramsar sites and observed that PAs cover 12% of lakes, 31% of glacial lakes and 12% of the total stream length in the tropical Andes. Additionally, 120 watersheds (average area 631 km 2 ) with glaciers and 40% of the total glacier surface area were covered by PAs. Future research into the role of PAs in ecosystem services provision and more detailed freshwater inventories within and around PAs, especially for those dependent on glacier runoff, will fill key knowledge gaps for freshwater conservation and climate change adaptation in the tropical Andes.
Mountain freshwater ecosystems and protected areas in the tropical Andes: insights and gaps for climate change adaptation
(2021) Estefania Quenta; Verónica Crespo‐Pérez; Bryan G. Mark; Ana Lía Gonzales; Aino Kulonen
&lt;p&gt;Protected areas play an important role in ecosystem conservation and climate change adaptation. However, no systematic information is available on the protection of high elevation freshwater ecosystems (e.g.&amp;#160; lakes, glacierized catchments and streams), their biodiversity and ecosystem services. Here we addressed this issue by reviewing literature and analyzing maps of protected areas and freshwater ecosystems in the tropical Andes. Overall, our revision and inventory indicate: &lt;strong&gt;1)&lt;/strong&gt; seven national parks were created with the objective of water resources protection, but they were not designed for freshwater conservation (i.e., larger watersheds), and mainly protect small ecosystems. Furthermore, the creation of new local protected areas was needed for water resources conservation; &lt;strong&gt;2)&lt;/strong&gt; we quantified 12% and 31% of lakes and glacial lakes are protected, respectively. Around 12% of the total stream length is protected. First-order streams predominate in the study area, of which 14% are protected. Furthermore, 29% of glacierized catchments (average surface of 677 km&lt;sup&gt;2&lt;/sup&gt;)&lt;sup&gt;&lt;/sup&gt;are protected, and 46% of the total glacier area is protected. We quantified 31 Ramsar sites; &lt;strong&gt;3) &lt;/strong&gt;high-value biodiversity sites have not been protected, and ecosystems services information is limited. This review highlights the need for future research to fill knowledge gaps for effective freshwater conservation actions.&lt;/p&gt;