Elsevier

Anthropocene

Volume 32, December 2020, 100272
Anthropocene

Sediment carbon storage increases in tropical, oligotrophic, high mountain lakes

https://doi.org/10.1016/j.ancene.2020.100272Get rights and content

Highlights

  • El Sol and La Luna are valuable sentinels of global change by displaying detectable signs of anthropic disturbances from 1950 onwards.

  • The higher mass accumulation rates and organic carbon burial rates from 1950 onwards are result of human activities and atmospheric dust deposition.

  • Sharing the same climatic conditions, climate change unlikely caused the recent higher organic carbon burial observed in both lakes.

Abstract

High mountain lakes are valuable sentinels of global change because they are sensitive to environmental stress and integrate changes in the atmosphere and their catchment areas. This study tested the hypothesis that local and regional anthropogenic stressors have affected productivity, sedimentation, and organic carbon burial in two tropical high mountain lakes in central Mexico. We studied changes in the water column (Secchi disc depth, total suspended solids (TSS), and chlorophyll-a concentrations) and surface sediments (chlorophyll-a and organic carbon concentrations) in El Sol Lake and La Luna Lake during the period 2000–2018, and organic carbon burial rates in sediment cores (∼1884–2014) dated with lead-210 (210Pb). We observed increasing water turbidity, TSS, and organic carbon in surface sediments in El Sol Lake. Different responses of the two lakes were caused by lower pH in La Luna Lake and a threefold residence time of TSS in El Sol Lake compared to La Luna Lake, mostly attributable to their different surface/volume ratios. Organic carbon burial rates were slightly higher at La Luna Lake until 2000, when they became higher at El Sol Lake due to increasing sediment accumulation and organic carbon concentrations. In both lakes, results show significantly higher organic carbon burial rates since the 1950s, likely resulting from the deposition of human-induced wind-blown particles derived from activities at the volcano slopes and long-distance transport from highly urbanized areas. Anthropogenic impacts rather than climate change, therefore, caused the recent higher organic carbon burial rates observed in both lakes. Methods and findings from this study provide a valuable basis for comparing changes in other high mountain lakes worldwide.

Introduction

Earth is subject to ever-increasing transformations by humans (global change), which have accelerated during the second half of the twentieth century (Steffen et al., 2005). Lakes are amongst the most valuable sensors of global change impacts on the environment, particularly high mountain lakes. These lakes are located on the largest and highest mountains and volcanoes on the planet, and their basins, derived from orogenic processes (Catalan et al., 1993; Catalan and Camarero, 1991), are remote and usually embedded in areas of high natural value, where global change impacts are usually low (MOLAR Water Chemistry Group, 1999; Catalan and Donato Rondón, 2016). High mountain lakes have cold climates, poorly developed soils, and limited vegetation coverage (Sommaruga, 2001; Granados et al., 2006). Their main water supply is derived from atmospheric sources, either directly as precipitation (rain, snow, and hail) or indirectly through runoff and thaw. High mountain lakes usually hold cold waters (3−10 °C) with high oxygen saturation, poor mineralization, low nutrient concentrations (oligotrophic), and medium to low alkalinity (e.g., Battarbee et al., 2002a,b).

High mountain lakes are particularly sensitive to environmental changes and can be used as early alert systems (sentinels) of anthropogenic changes at local and regional scales, including global warming trends and long-distance transport of airborne particles (e.g., Adrian et al., 2009; Schindler, 2009). Because high mountain lakes worldwide share many characteristics, they are considered among the most comparable ecosystems across the world, allowing for comparisons between temperate and tropical regions (Catalan and Donato Rondón, 2016). Most high mountain lakes studies have been performed in temperate zones, while less information has come from tropical areas (Payne, 1986). Data for available tropical high mountain lakes have come mainly from the Andes (Aguilera et al., 2013), the Himalayas (Löffler, 1964), Africa (Eggermont et al., 2007; Fetahi et al., 2011; Rietti-Shati et al., 2000), and Central and South America (Löffler, 1972; Rivera et al., 2005; Widmer et al., 1975).

Although temperate and tropical high mountain lakes share many characteristics, they also present important contrasts, mainly due to differences in solar radiation (Lewis, 1996). For example, tropical high mountain lakes show higher minimum water temperatures, and their winter ice covers (common in temperate high mountain lakes) are thin or absent in the tropics (Löffler, 1964). Moreover, allochthonous organic carbon loads in temperate zones are usually low, whereas in tropical areas, they tend to be higher (Buytaert et al., 2006; Catalan and Donato Rondón, 2016) due to the high mountain vegetation above the timberline (i.e., “paramo”). Nevertheless, very few studies exist on the dynamics of organic carbon in the water column and sediments of tropical high mountain lakes (e.g., Gunkel, 2003).

The dynamics of organic carbon in lakes has received increasing attention recently (e.g., Heathcote et al., 2015; Mendonça et al., 2017) because burial in sediments removes organic carbon from the short-term biosphere-atmosphere carbon cycle. This burial contributes to reducing greenhouse gas emissions from natural systems and thus lessens climate change, one of the main ecosystem services provided by inland water bodies (Cole et al., 2007). However, the magnitude of organic carbon burial in inland waters is not well constrained, and information on tropical high mountain lakes is practically noneexistent. Moreover, human activities may affect the role of inland waters in global carbon cycling and climate forcing in ways that go unnoticed due to the remoteness of high mountain lakes and the lack of the long-term information needed to evaluate organic carbon burial trends.

Mexico has only two perennial high mountain lakes, El Sol and La Luna, both located inside the crater of the Nevado de Toluca volcano in Central Mexico, which is one of the most intensely industrialized and urbanized areas in the country (including the industrial city of Toluca and the megalopolis Mexico City). Despite the protected status of the Nevado de Toluca volcano, urbanization, illegal logging, and open-pit mining are amongst the several anthropogenic threats affecting the ecosystem services provided by the lakes. The deposition of soils eroded from the surroundings and dust transported over long distances (originated from Toluca and Mexico City; Ibarra-Morales et al., 2020) are important sources of contamination for these lakes.

Direct human impacts on the lakes have also threatened these ecosystems, such as the introduction of exotic fish (rainbow trout) during the 1950s, sport diving activities, an increasing flow of tourists visiting the lakes, and even intense subaquatic activities related to archaeological research since the 1960s (e.g., Guzmán Peredo, 1991; Luna et al., 2009; Vigliani and Junco, 2013). Changes in the diatom and planktonic cladocerans assemblages in the paleolimnological records of both lakes occurred within the timeframe of the introduction of rainbow trout (Cuna et al., 2014; Zawisza et al., 2017).

In this work, our main goal was to understand how organic carbon burial and the trophic status of both high mountain lakes have been affected by local and regional anthropogenic activities. For this purpose, we addressed the following research questions: (1) How have the water’s primary productivity and turbidity changed during the past 18 years? (2) How have organic carbon and chlorophyll-a concentrations in the surface sediments evolved in this period? (3) What are the residence times of total suspended solids and organic carbon in both lakes? (4) Have organic carbon burial rate trends changed during the past 100 years?

Our central hypothesis was that land-use changes in the surroundings of the lakes and other anthropogenic regional activities (e.g., urban and industrial development), mostly occurring since the 1950s, have affected sedimentation, productivity, and organic carbon burial in the lakes. Specifically, we expected these anthropogenic activities to cause (1) reduced water quality (higher turbidity and total suspended solids) and higher productivity (higher chlorophyll-a concentrations); (2) higher organic carbon and chlorophyll-a concentrations in surface sediments, reflecting changes in productivity and suspended matter in the water column; (3) higher residence times of total suspended solids and organic carbon in El Sol Lake, given its surface/volume ratio; and (4) larger organic carbon burial rates in both lakes caused by these trends.

To answer the research questions and test the proposed hypothesis, our approach was to evaluate the temporal changes in the (a) water quality and trophic status of the lakes using data derived from monthly monitoring of the water column and surface sediments during three periods within the past 18 years (2000−2001, 2006−2007, and 2017−2018), as well as (b) organic carbon burial rates within the past ∼100 years, from 210Pb-dated sediment cores.

Section snippets

Study area

El Sol and La Luna crater lakes (19°06′N, 99°45′W) at 4200 m a.s.l. are part of the Nevado de Toluca volcano (Fig. 1), a Pleistocene age andesitic–dacitic stratovolcano (García-Palomo et al., 2002; Bloomfield and Valastro, 1974). The Nevado de Toluca volcano has a cold alpine climate (“páramo” type), with average monthly mean air temperatures ranging from 2.8 °C in February to 5.8 °C in April (SMN-CONAGUA, 2017). The mean annual rainfall is 1244 mm, mainly between June and September, and ranges

Water transparency

The Secchi disk depth (ZSD) in La Luna was total, and the lake’s bottom could be clearly seen during the three sampling periods. Conversely, the Secchi disk depth in El Sol ranged from 22 to 69 % of the maximum depth (SI-Table 1). The Secchi disk depth in El Sol was 4.6 ± 1.0 m in 2000−2001, 5.3 ± 1.0 m in 2006−2007, and 4.1 ± 0.3 m in 2017−2018. The Secchi disk depths in 2000−2001 and 2006−2007 were statistically similar (p > 0.05), whereas the Secchi disk depths in 2017−2018 were lower (p <

Water column

The relatively high organic carbon content of surface soils around the lakes (2.6 ± 0.8 % and 13.6 ± 1.5 % in El Sol and La Luna, respectively; Ruiz-Fernández, unpublished data) suggests that the sources of allochthonous organic materials in high mountain lakes are mostly the surrounding soils and vegetation. However, the TSS composition showed that allochthonous materials make a relatively minor contribution (<10 %) compared to autochthonous sources, although this contribution is slightly

Conclusions

In conclusion, studying the temporal variations of environmental data from El Sol and La Luna lakes allowed us to answer the proposed research questions:

  • (1)

    Within the past 18 years, turbidity in El Sol Lake increased (lower Secchi disk depth, higher total suspended solids), but we observed no changes in productivity (comparable chlorophyll–a concentrations). No significant temporal changes were observed in La Luna Lake, and the water column Secchi disk depth, total suspended solids, and

Declaration of Competing Interest

The authors report no declarations of interest.

Acknowledgements

This work had financial support from the Fondo Sectorial de Investigación Ambiental SEMARNAT-CONACYT 2015 through project 262970, the Universidad Nacional Autónoma de México DGAPA/PAPIIT through projects IN105009 and ES209301, and Programa de Investigación en Cambio Climático (PINCC 2012-2014). The Comisión Estatal de Parques Naturales y de la Fauna (CEPANAF, Secretaría de Ecología, Gobierno del Estado de México) provided the permit for scientific research at the Área de Protección de Flora y

References (102)

  • M. Rietti-Shati et al.

    Stable isotope composition of tropical high-altitude fresh-waters on Mt. Kenya, Equatorial East Africa

    Chem. Geol.

    (2000)
  • A.C. Ruiz-Fernández et al.

    210Pb-derived ages for the reconstruction of terrestrial contaminant history into the Mexican Pacific coast: potential and limitations

    Mar. Pollut. Bull.

    (2009)
  • J.A. Sanchez-Cabeza et al.

    210Pb sediment radiochronology: an integrated formulation and classification of dating models

    Geochim. Cosmochim. Acta

    (2012)
  • J.A. Sanchez-Cabeza et al.

    Monte Carlo uncertainty calculation of 210Pb chronologies and accumulation rates of sediments and peat bogs

    Quat. Geochronol.

    (2014)
  • R. Sommaruga

    The role of solar UV radiation in the ecology of alpine lakes

    J. Photochem. Photobiol.

    (2001)
  • R. Adrian et al.

    Lakes as sentinels of climate change

    Limnol. Oceanogr.

    (2009)
  • X. Aguilera et al.

    Tropical high-altitude Andean lakes located above the tree line attenuate UV-a radiation more strongly than typical temperate alpine lakes

    Photochem. Photobiol. Sci.

    (2013)
  • J. Alcocer

    Aportaciones limnológicas al estudio del ‘Lago del Sol’ y ‘Lago de la Luna’

    Nevado de Toluca, Edo. de México

    (1980)
  • J. Alcocer

    Limnología

  • J. Alcocer et al.

    Phytoplankton biomass and water chemistry in two high-mountain tropical lakes in Central Mexico

    Arct. Antarct. Alp. Res.

    (2004)
  • J. Alcocer et al.

    Deposition, burial and sequestration of carbon in an oligotrophic, tropical lake

    J. Limnol.

    (2014)
  • N.J. Anderson et al.

    Land-use change, not climate, controls organic carbon burial in lakes

    Proc. R. Soc. B: Biol. Sci.

    (2013)
  • N.J. Anderson et al.

    Lake eutrophication and its implications for organic carbon sequestration in Europe

    Glob. Change Biol.

    (2014)
  • E.J. Arar et al.

    Method 445.0. In vitro determination of chlorophyll a and pheophytin a in marine and freshwater algae by fluorescence

    (1997)
  • A.G. Banderas Tarabay

    Phycoflora of the tropical high-mountain lake El Sol, Central Mexico, and some biogeographical relationships

    Hydrobiologia

    (1997)
  • R.W. Battarbee et al.

    Climate variability and ecosystem dynamics of remote alpine and arctic lakes: the MOLAR project

    J. Paleolimnol.

    (2002)
  • R.W. Battarbee et al.

    Comparing paleolimnological and instrumental evidence of climate change for remote mountain lakes over the last 200 years

    J. Paleolimnol.

    (2002)
  • J.M. Blais et al.

    The influence of lake morphometry on sediment focusing

    Limnol. Oceanogr.

    (1995)
  • K. Bloomfield et al.

    Late Pleistocene eruptive history of Nevado de Toluca volcano, Central Mexico

    Geolog. Soc. Am. Bull.

    (1974)
  • A. Brancelj et al.

    Lake Jezero v Ledvici (NW Slovenia) – changes in sediment records over the last two centuries

    J. Paleolimnol.

    (2002)
  • I. Buffam et al.

    Integrating aquatic and terrestrial components to construct a complete carbon budget for a north temperate lake district

    Glob. Change Biol.

    (2011)
  • D.J. Burdige

    Burial of terrestrial organic matter in marine sediments: a re-assessment

    Global Biogeochem. Cycles

    (2005)
  • M. Caballero-Miranda

    The diatom flora of two acid lakes in central Mexico

    Diatom Res.

    (1996)
  • V. Carnero-Bravo et al.

    Sedimentary record of water column trophic conditions and sediment carbon fluxes in a tropical water reservoir (Valle de Bravo, Mexico)

    Environ. Sci. Pollut. Res. - Int.

    (2015)
  • J. Catalan et al.

    Ergoclines and biological processes in high mountain lakes: Similarities between summer stratification and the ice-forming periods in Lake Redó (Pyrenees)

    Verhandlungen Internationale Vereinigung für Theoretische und Angewandte Limnologie

    (1991)
  • J. Catalan et al.

    Perspectives for an integrated understanding of tropical and temperate high-mountain lakes

    J. Limnol.

    (2016)
  • H.E. Chmiel et al.

    The role of sediments in the carbon budget of a small boreal lake

    Limnol. Oceanogr.

    (2016)
  • D.W. Clow et al.

    Organic carbon burial in lakes and reservoirs of the Conterminous United States

    Environ. Sci. Technol.

    (2015)
  • A.S. Cohen

    Paleolimnology: the history and evolution of lake systems

    Palaios

    (2003)
  • J.J. Cole et al.

    Plumbing the global carbon cycle: integrating inland waters into the terrestrial carbon budget

    Ecosystems

    (2007)
  • E. Cuna et al.

    Environmental impact of the Little Ice Age cooling in Central Mexico: the record from a tropical alpine lake

    J. Paleolimnol.

    (2014)
  • W.E. Dean

    The carbon cycle and biogeochemical dynamics in lake sediments

    J. Paleolimnol.

    (1999)
  • X. Dong et al.

    Carbon burial by shallow lakes on the Yangtze floodplain and its relevance to regional carbon sequestration

    Glob. Change Biol.

    (2012)
  • J.A. Downing et al.

    Sediment organic carbon burial in agriculturally eutrophic impoundments over the last century

    Global Biogeochem. Cycles

    (2008)
  • H. Eggermont et al.

    Physical and chemical limnology of alpine lakes and pools in the Rwenzori Mountains (Uganda-DR Congo)

    Hydrobiologia

    (2007)
  • M. Elías-Gutiérrez et al.

    A checklist of the littoral cladocerans from Mexico, with descriptions of five taxa recently recorded from the Neovolcanic Province

    Hydrobiologia

    (1997)
  • FAO

    Potato and Soil Conservation

    (2008)
  • E. García

    Modificaciones al Sistema de Clasificación Climática de Köeppen

    (2004)
  • A. García-Palomo et al.

    Geology of Nevado de Toluca Volcano and surrounding areas, central Mexico

    (2002)
  • I. Granados et al.

    Laguna grande de Peñalara, 10 años de seguimiento limnológico

    (2006)
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