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Journal ArticleDOI

Mountain lakes: Eyes on global environmental change

TL;DR: A review and update of the growing body of research that shows that sediments in remote mountain lakes archive regional and global environmental changes, including those linked to climate change, altered biogeochemical cycles, and changes in dust composition and deposition, atmospheric fertilization, and biological manipulations can be found in this paper.
Abstract: Mountain lakes are often situated in protected natural areas, a feature that leads to their role as sentinels of global environmental change. Despite variations in latitude, mountain lakes share many features, including their location in catchments with steep topographic gradients, cold temperatures, high incident solar and ultraviolet radiation (UVR), and prolonged ice and snow cover. These characteristics, in turn, affect mountain lake ecosystem structure, diversity, and productivity. The lakes themselves are mostly small, and up until recently, have been characterized as oligotrophic. This paper provides a review and update of the growing body of research that shows that sediments in remote mountain lakes archive regional and global environmental changes, including those linked to climate change, altered biogeochemical cycles, and changes in dust composition and deposition, atmospheric fertilization, and biological manipulations. These archives provide an important record of global environmental change that pre-dates typical monitoring windows. Paleolimnological research at strategically selected lakes has increased our knowledge of interactions among multiple stressors and their synergistic effects on lake systems. Lakes from transects across steep climate (i.e., temperature and effective moisture) gradients in mountain regions show how environmental change alters lakes in close proximity, but at differing climate starting points. Such research in particular highlights the impacts of melting glaciers on mountain lakes. The addition of new proxies, including DNA-based techniques and advanced stable isotopic analyses, provides a gateway to addressing novel research questions about global environmental change. Recent advances in remote sensing and continuous, high-frequency, limnological measurements will improve spatial and temporal resolution and help to add records to spatial gaps including tropical and southern latitudes. Mountain lake records provide a unique opportunity for global scale assessments that provide knowledge necessary to protect the Earth system.

Summary (2 min read)

A C C E P T E D M

  • Of particular significance is the effect that humans are having on the Earth's climate system.
  • Using climate change as the overarching theme of this review, the authors highlight some of the exciting opportunities available through technological and methodological advances to show how paleolimnology assessments of mountain lakes are providing insights into global environmental change, including climate change, the carbon cycle, atmospheric deposition, dust, and biological manipulations .
  • Wider application of dual isotope (carbon and Advances in methodologies for characterizing shifts in algal functional groups in lake sediment cores complement more established methods, such as diatom assemblages and pigment analyses.
  • The cascading effects of climate change on physical variables in mountain lakes may have significant consequences on biological communities.

A C C E P T E D M A N U S C R I P T

  • The authors frame their review in the context that climate connects lakes to atmospheric, landscape, and in-lake processes (Leavitt et al.
  • Below, the authors present examples of environmental changes that affect mountain lakes, starting first with contemporary descriptions Climate warming is rapidly occurring as a result of human activities, and there is an urgency to determine how atmospheric circulation, precipitation patterns and extreme events will affect water resources, which are often concentrated in mountain regions.
  • On average, dusts are enriched by a factor of 1.6 over soils (Lawrence and Neff, 2009) and therefore have the capacity to fertilize mountain aquatic environments.
  • The rapidity of these climatic changes has led to ecological restructuring of phytoplankton assemblages and the crossing of ecological thresholds (Michelutti et al., 2015b; 2016; Labaj et al., 2018) here and around the world (Rühland et al., 2015) .

2. Paleolimnological advances provide opportunities for studying global change in mountain lakes

  • Paleolimnologists have used a number of well-established proxies to contribute to their understanding of environmental change from local to global scales.
  • These proxies include geological and geochemical (e.g., grain size and composition, organic matter, stable isotopes, heavy metals), biological (e.g., diatoms, cladocerans, chironomids, pollen, pigments), biogeochemical (e.g., biogenic silica, stable isotopes), and environmental (.

3.2.1 Carbon cycling and mountain lakes

  • Variations in DOC source and supply may have a direct bearing on microbial C utilization and respiration dynamics (Sadro et al., 2011) .
  • It is, however, plausible that C respiration will increase with higher water temperatures and shorter periods of full ice-cover (Gudasz et al., 2010; Hampton et al., 2017; Kainz et al., 2017) .
  • Warmer temperatures and longer growing season will increase the flux of particulate carbon to the sediments (Hanson et al., 2004; Downing et al., 2008) .
  • Phenological changes in snowmelt timing, flushing, nutrient delivery, and warming associated with dry years in a high elevation lake in the Sierra Nevada of California resulted in increased phytoplankton biomass (Sadro et al., 2018) .

3.2.2 Historical perspectives elucidate the role of lakes for carbon storage

  • Even though most lakes are supersaturated with respect to CO 2 and thus outgas CO 2 (Cole et al., 1994) , the rate of carbon burial in lake sediments is similar to that in marine sediments and important to the global carbon cycle (Dean and Gorham, 1998; Cole et al., 2007; Mendonça et al., 2017) .
  • Several studies have determined records of organic C burial rates using loss-on-ignition (Dean, 1974) of sediments in dated cores to examine spatial and temporal variations of C burial in lakes at regional to global scales (Kastowski et al., 2011; Heathcote et al., 2015; Mendonça et al., 2017) .
  • As the climate continues to change mountain lakes may have an increasingly important role for carbon storage.
  • Important to understanding the role of lakes and refining carbon budgets is knowledge of the relative New research using the δ 13 C of specific biomarkers (e.g., n-alkanes, fatty acids) and mixing models may help to improve their ability to fingerprint OC sources and in-lake carbon processes.

3.3.1 Sensitivity and susceptibility of mountain lakes to atmospheric deposition

  • Atmospheric deposition of pollutants is indicative of regional to global changes, as is climate change, and there are interactions among these potential stressors.
  • Atmospherically deposited materials can be stored in either short-or long-term reservoirs within the catchment before entering surface waters .
  • Reservoirs with short residence times include the lake surface itself and seasonal snow.
  • Time scales of nutrient or contaminant delivery depend on the hydrology of the system and can range from instantaneous to annual.

3.3.2 Insights from paleolimnology on the effects of atmospheric deposition

  • Increased N inputs have altered diatom species assemblages and reduced diversity.
  • Including flushing and increased mineralization, may contribute to N-.

3.4.2 Paleolimnological analyses show the importance of dust deposition in lakes

  • The capacity for dust to affect phosphorus subsidies in mountain lakes systems was first identified in the Austrian Alps (Psenner, 1999) .
  • Since then, other studies elsewhere in mountain regions of Europe, Asia, and the USA have shown the effects of dust associated P deposition on.

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Accepted Manuscript
Mountain lakes: Eyes on global environmental change
K.A. Moser, J.S. Baron, J. Brahney, I.A. Oleksy, J.E. Saros, E.J.
Hundey, S.A. Sadro, J. Kopáček, R. Sommaruga, M.J. Kainz, A.L.
Strecker, S. Chandra, D.M. Walters, D.L. Preston, N. Michelutti,
F. Lepori, S.A. Spaulding, K.R. Christianson, J.M. Melack, J.P.
Smol
PII: S0921-8181(18)30670-2
DOI: https://doi.org/10.1016/j.gloplacha.2019.04.001
Reference: GLOBAL 2943
To appear in: Global and Planetary Change
Received date: 30 November 2018
Revised date: 18 February 2019
Accepted date: 3 April 2019
Please cite this article as: K.A. Moser, J.S. Baron, J. Brahney, et al., Mountain lakes: Eyes
on global environmental change, Global and Planetary Change, https://doi.org/10.1016/
j.gloplacha.2019.04.001
This is a PDF file of an unedited manuscript that has been accepted for publication. As
a service to our customers we are providing this early version of the manuscript. The
manuscript will undergo copyediting, typesetting, and review of the resulting proof before
it is published in its final form. Please note that during the production process errors may
be discovered which could affect the content, and all legal disclaimers that apply to the
journal pertain.

ACCEPTED MANUSCRIPT
Mountain Lakes: Eyes on Global Environmental Change
Invited Manuscript for Global and Planetary Change
Moser, K.A.
1
, Baron, J. S.
2
, Brahney, J.
3
, Oleksy, I. A.
4
, Saros, J.E.
5
, Hundey, E.J.
6
, Sadro, S.A.
7
,
Kopáček, J.
8
, Sommaruga, R.
9
, Kainz, M.J.
10
, Strecker, A.L.
11
, Chandra, S.
12
, Walters, D.M.
13
,
Preston, D.L.
14
, Michelutti, N.
15
, Lepori, F.
16
, Spaulding, S.A.
17
, Christianson, K.R.
18
, Melack,
J.M.
19
, Smol, J.P.
15
1
Corresponding Author, The University of Western Ontario, Dept. of Geography, 1151
Richmond St., North, London, Ontario N5Y 2S9 CANADA kmoser@uwo.ca
2
U.S. Geological Survey, Natural Resource Ecology Laboratory, Colorado State University, Fort
Collins CO 80523-1499 USA jill_baron@usgs.gov
3
Department of Watershed Sciences, Utah State University, 5210 Old Main Hill, Logan Utah
84322 USA Janice.Brahney@usu.edu
4
Natural Resource Ecology Laboratory, Colorado State University, Fort Collins CO 80523-1499
USA bellaoleksy@gmail.com
5
Climate Change Institute, University of Maine, USA jasmine.saros@maine.edu
6
Centre for Teaching and Learning, The University of Western Ontario, 1151 Richmond St
North, London Ontario, N6A 3K7 CANADA beth.hundey@uwo.ca
7
Department of Environmental Science and Policy, University of California, Davis, One Shields
Ave, Davis, CA 95616-5270, USA ssadro@UCDAVIS.EDU
8
Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, 370 05 České
Budějovice, Czech Republic jkopacek@hbu.cas.cz
9
Department of Ecology, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
Ruben.Sommaruga@uibk.ac.at
10
WasserCluster Lunz - Inter-university Center for Aquatic Ecosystem Research, Dr. Carl
Kupelwieser Promenade 5, A-3293 Lunz am See, Austria Martin.Kainz@donau-uni.ac.at
11
Center for Lakes and Reservoirs & Dept of Environmental Science and Management, Portland
State University, Portland, OR, 97203 USA strecker@pdx.edu
12
Global Water Center and Biology Department University of Nevada, 1664 N. Virginia St,
Reno, NV, 89557 USA sudeep@unr.edu
13
U.S. Geological Survey, Columbia Environmental Research Center, 4200 East New Haven
Road, Columbia, MO, 65201 USA waltersd@usgs.gov
14
Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA
daniel.preston@wisc.edu
15
Paleoecological Environmental Assessment and Research Lab (PEARL), Queen's University,
Dept. Biology, 116 Barrie St., Kingston, Ontario K7L 3N6, Canada nm37@queensu.ca;
smolj@queensu.ca
16
University of Applied Sciences and Arts of Southern Switzerland, Institute of Earth Sciences,
CH-6952 Canobbio, Switzerland fabio.lepori@supsi.ch
17
US Geological Survey / INSTAAR, 4001 Discovery Drive, Boulder CO 80303 USA
sspaulding@usgs.gov
18
Dept. of Fish, Wildlife, and Conservation Biology, 1474 Campus Delivery, Colorado State
University, Fort Collins, CO, USA kchrist@rams.colostate.edu
19
Bren School of Environmental Science and Management, University of California, Santa
Barbara, CA, USA melack@bren.ucsb.edu
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
Abstract
Mountain lakes are often situated in protected natural areas, a feature that leads to their role as
sentinels of global environmental change. Despite variations in latitude, mountain lakes share
many features, including their location in catchments with steep topographic gradients, cold
temperatures, high incident solar and ultraviolet radiation (UVR), and prolonged ice and snow
cover. These characteristics, in turn, affect mountain lake ecosystem structure, diversity, and
productivity. The lakes themselves are mostly small and shallow, and up until recently, have
been characterized as oligotrophic. This paper provides a review and update of the growing body
of research that shows that sediments in remote mountain lakes archive regional and global
environmental changes, including those linked to climate change, altered biogeochemical cycles,
and changes in dust composition and deposition, atmospheric fertilization, and biological
manipulations. These archives provide an important record of global environmental change that
pre-dates typical monitoring windows. Paleolimnological research at strategically selected lakes
has increased our knowledge of interactions among multiple stressors and their synergistic
effects on lake systems. Lakes from transects across steep climate (i.e., temperature and effective
moisture) gradients in mountain regions show how environmental change alters lakes in close
proximity, but at differing climate starting points. Such research in particular highlights the
impacts of melting glaciers on mountain lakes. The addition of new proxies, including DNA-
based techniques and novel stable isotopic analyses, provides a gateway to addressing novel
research questions about global environmental change. Recent advances in remote sensing and
continuous, high-frequency, limnological measurements will improve spatial and temporal
resolution and help to add records to spatial gaps including tropical and southern latitudes.
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
Mountain lake records provide a unique opportunity for global scale assessments that provide
knowledge necessary to protect the Earth system.
Key Words: Mountain lakes, paleolimnology, climate change, atmospheric deposition, dust,
carbon cycle, species invasions
ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
1. Introduction
“A lake is the landscape’s most beautiful and expressive feature. It is the earth’s eye, looking
into which the beholder measures the depth of his own nature. Henry David Thoreau, Walden,
Chapter 9, pg. 121.
“We touch the ancient mysteries of life in the wild. We may even learn to see in new ways
more closely, perhaps, and deeper into geologic time. If we’re lucky we get close to learning how
to ‘think like a mountain,’ in Aldo Leopold’s great phrase.” Philip Connors, author of Fire
Season, 1992, in interview with Marianne Moore March 2011 for Zyzzyva
https://www.zyzzyva.org/2011/03/
Mountain ranges are found across the world and, owing to the glacial history of many
mountain regions, alpine lakes are important features of these landscapes (Figure 1). Regardless
of location, mountain lakes are often remote, located in environments characterized by cold
temperatures, high incident solar and ultraviolet radiation (UVR), experience prolonged ice and
snow cover, and are frequently dilute and oligotrophic. These characteristics, in turn, affect
mountain lake ecosystem structure, diversity, and productivity (Wolfe et al., 2003; Catalan et al.,
2006; Hobbs et al., 2010).
Important information on long-term environmental change is archived in lake sediments
(Catalan et al., 2013a). Using a comparative approach across different mountain regions, lake
sediments can provide insights about global change (e.g., climate change, acidification, reactive
nitrogen loading, dust and species introductions) (Catalan et al., 2006; Williamson et al., 2009;
Catalan and Donato Rondón, 2016). At present, this knowledge is especially important given that
ACCEPTED MANUSCRIPT

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  • ...Terrestrially derived dissolved organic matter (DOM) strongly and selectively absorbs the most damaging UV-B radiation and decreases at higher elevations due to low inputs arising from sparse streamside terrestrial vegetation (Clements et al., 2008; Jacobsen & Dangles, 2017; Moser et al., 2019)....

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  • ..., 2017b), lakes (Moser et al., 2019), and terrestrial plants (Vitasse et al....

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  • ...We identify mountains (and by proxy, mountain ecosystems) in the same way as a related review (Moser et al., 2019), which used the definition provided by Körner et al....

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TL;DR: The Global Energy Assessment (GEA) as mentioned in this paper identifies strategies that could help resolve the multiple challenges simultaneously and bring multiple benefits, including sustainable economic and social development, poverty eradication, adequate food production and food security, health for all, climate protection, conservation of ecosystems, and security.
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TL;DR: In this paper, the role of inland water ecosystems in the global carbon cycle has been investigated and it is shown that roughly twice as much C enters inland aquatic systems from land as is exported from land to the sea, roughly equally as inorganic and organic carbon.
Abstract: Because freshwater covers such a small fraction of the Earth’s surface area, inland freshwater ecosystems (particularly lakes, rivers, and reservoirs) have rarely been considered as potentially important quantitative components of the carbon cycle at either global or regional scales. By taking published estimates of gas exchange, sediment accumulation, and carbon transport for a variety of aquatic systems, we have constructed a budget for the role of inland water ecosystems in the global carbon cycle. Our analysis conservatively estimates that inland waters annually receive, from a combination of background and anthropogenically altered sources, on the order of 1.9 Pg C y−1 from the terrestrial landscape, of which about 0.2 is buried in aquatic sediments, at least 0.8 (possibly much more) is returned to the atmosphere as gas exchange while the remaining 0.9 Pg y−1 is delivered to the oceans, roughly equally as inorganic and organic carbon. Thus, roughly twice as much C enters inland aquatic systems from land as is exported from land to the sea. Over prolonged time net carbon fluxes in aquatic systems tend to be greater per unit area than in much of the surrounding land. Although their area is small, these freshwater aquatic systems can affect regional C balances. Further, the inclusion of inland, freshwater ecosystems provides useful insight about the storage, oxidation and transport of terrestrial C, and may warrant a revision of how the modern net C sink on land is described.

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  • ..., 1994), the rate of carbon burial in lake sediments is similar to that in marine sediments and important to the global carbon cycle (Dean and Gorham, 1998; Cole et al., 2007; Mendonça et al., 2017)....

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TL;DR: In this article, a modified ignition loss method is described for determining organic and carbonate carbon in calcareous sedimentary materials using equipment found in most laboratories and has been found to equal or excel the accuracy and precision of other methods tested and has the advantage of being considerably faster if large numbers of samples are to be analyzed.
Abstract: A modified ignition loss method is described for determining organic and carbonate carbon in calcareous sedimentary materials using equipment found in most laboratories. The method has been found to equal or excel the accuracy and precision of other methods tested and has the advantage of being considerably faster if large numbers of samples are to be analyzed.

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