Mountain lakes: Eyes on global environmental change
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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Cites background from "Mountain lakes: Eyes on global envi..."
...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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Cites background or result from "Mountain lakes: Eyes on global envi..."
..., 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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References
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3,179 citations
"Mountain lakes: Eyes on global envi..." refers background in this paper
..., 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)....
[...]
2,939 citations
"Mountain lakes: Eyes on global envi..." refers background in this paper
...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....
[...]
2,140 citations