Microbial population dynamics in an extreme environment: controlling factors in talus soils at 3750 m in the Colorado Rocky Mountains

Ley, Ruth E.; Williams, Mark W.; Schmidt, Steven K.

doi:10.1023/b:biog.0000031032.58611.d0

Cited by 78 publications

(83 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many of the substrates used for growth by this organism are plant-derived compounds (e.g. cellobiose, arbutin, salicin) indicating that it can take advantage of Aeolian transported plant material that is likely the main source of organic matter to extreme high-elevation ecosystems (Ley et al 2004; Mladenov et al 2012; Vimercati et al 2016). Our working hypothesis is that N. friedmannii on Llullaillaco and other volcanoes are dormant during long periods of dryness and only come out of dormancy and opportunistically metabolise Aeolian organic debris following the melting of rare snow events.…”

Section: Ecological Tolerances Of Naganishiamentioning

confidence: 99%

ANaganishiain high places: functioning populations or dormant cells from the atmosphere?

et al. 2017

View full text Add to dashboard Cite

Here, we review the current state of knowledge concerning high-elevation members of the extremophilic Cryptococcus albidus clade (now classified as the genus Naganishia). These fungi dominate eukaryotic microbial communities across the highest elevation, soil-like material (tephra) on volcanoes such as Llullaillaco, Socompa, and Saírecabur in the Atacama region of Chile, Argentina, and Bolivia. Recent studies indicate that Naganishia species are among the most resistant organisms to UV radiation, and a strain of N. friedmannii from Volcán Llullaillaco is the first organism that is known to grow during the extreme, diurnal freeze-thaw cycles that occur on a continuous basis at elevations above 6000 m.a.s.l. in the Atacama region. These and other extremophilic traits discussed in this review may serve a dual purpose of allowing Naganishia species to survive long-distance transport through the atmosphere and to survive the extreme conditions found at high elevations. Current evidence indicates that there are frequent dispersal events between high-elevation volcanoes of Atacama region and the Dry Valleys of Antarctica via “Rossby Wave” merging of the polar and sub-tropical jet streams. This dispersal hypothesis needs further verification, as does the hypothesis that Naganishia species are flexible “opportunitrophs” that can grow during rare periods of water (from melting snow) and nutrient availability (from Aeolian inputs) in one of the most extreme terrestrial habitats on Earth.

show abstract

Section: Ecological Tolerances Of Naganishiamentioning

confidence: 99%

ANaganishiain high places: functioning populations or dormant cells from the atmosphere?

et al. 2017

View full text Add to dashboard Cite

show abstract

“…It is currently unclear how microbial communities in oligotrophic soils obtain the carbon (C) and energy necessary to sustain life. In many regions, these soils are snow covered for more than 9 months of the year, and the short snow-free period provides limited time for the acquisition of C and nutrients (Ley et al, 2004). The C budget for alpine catchments is not well constrained, and mounting evidence for active C cycling in alpine lakes and soils suggests that allochthonous delivery of C and other nutrients may be extremely important.…”

Section: N Mladenov Et Al: Atmospheric Deposition As a Source Of Camentioning

confidence: 99%

“…Precipitation has been shown to be an important C input for carbon-poor environments, such as coastal areas (Kieber et al, 2006(Kieber et al, , 2007 and the open ocean (Willey et al, 2000, Economu and Mihalopoulos, 2002, Jurado et al, 2008. For alpine environments, Litaor (1987) and Ley et al (2004) in the Colorado Rocky Mountains and more recently Mladenov et al (2009Mladenov et al ( , 2010 in the Sierra Nevada of Spain reported that aeolian deposition comprised about 10 % to 20 % organic C. Lawrence et al (2010) also found surprisingly high organic C content in dust deposition. Mladenov et al (2009) used spectroscopic techniques (UV-vis absorbance and fluorescence) in combination with air mass backward trajectories to demonstrate that water soluble organic carbon (WSOC) from dust emitted in Africa and deposited at an alpine site in Spain contained substantial amounts of humic-like fluorescent compounds.…”

Section: N Mladenov Et Al: Atmospheric Deposition As a Source Of Camentioning

confidence: 99%

“…Dry deposition at Niwot Ridge also contains substantial amounts of organic matter. Dust collector studies set up at Niwot Ridge (Litaor et al, 1987;Ley et al, 2004) found that dust comprised roughly 10 % to 17 % organic matter. Estimates of 0.42 g OC m −2 yr −1 in dust from the Ley et al (2004) study are higher but comparable to the POC loading in the snowpack at maximum accumulation we measured at Niwot Ridge (0.28 g POC m −2 yr −1 ).…”

Section: Seasonality and Sources Of Atmospheric Depositionmentioning

confidence: 99%

“…Dust collector studies set up at Niwot Ridge (Litaor et al, 1987;Ley et al, 2004) found that dust comprised roughly 10 % to 17 % organic matter. Estimates of 0.42 g OC m −2 yr −1 in dust from the Ley et al (2004) study are higher but comparable to the POC loading in the snowpack at maximum accumulation we measured at Niwot Ridge (0.28 g POC m −2 yr −1 ). The association of organic matter with dust at Niwot Ridge is consistent with recent hypotheses that dust transport is a vector for organic matter deposition globally (Mladenov et al, 2011).…”

Section: Seasonality and Sources Of Atmospheric Depositionmentioning

confidence: 99%

See 2 more Smart Citations

Atmospheric deposition as a source of carbon and nutrients to an alpine catchment of the Colorado Rocky Mountains

et al. 2012

View full text Add to dashboard Cite

Abstract. Many alpine areas are experiencing deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, atmospheric deposition sources may be an important source of C and nutrients for these environments. We evaluated the magnitude of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long-term dataset (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were 1.12 ± 0.19 mg l −1 , and weekly concentrations reached peaks as high at 6-10 mg l −1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. To investigate potential sources of C in atmospheric deposition, we evaluated the chemical quality of dissolved organic matter (DOM) and relationships between DOM and other solutes in wet deposition. Relationships between DOC concentration, fluorescence, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from sub-alpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring, which may reflect an association of DOM with dust. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples. Our C budget estimates for the Green Lake 4 catchment illustrated that wet deposition (9.9 kg C ha −1 yr −1 ) and dry deposition (6.9 kg C ha −1 yr −1 ) were a combined input of approximately 17 kg C ha −1 yr −1 , which could be as high as 24 kg C ha −1 yr −1 in high dust years. This atmospheric C input approached the C input from microbial autotrophic production in barren soils. Atmospheric wet and dry deposition also contributed 4.3 kg N ha −1 yr −1 , 0.15 kg P ha −1 yr −1 , and 2.7 kg Ca 2+ ha −1 yr −1 to this alpine catchment.

show abstract

Nitrate content and potential microbial signature of rock glacier outflow, Colorado Front Range

Williams

Knauf

Cory

et al. 2006

Earth Surf Processes Landf

View full text Add to dashboard Cite

Here we characterize the nutrient content in the outflow of the Green Lake 5 rock glacier, located in the Green Lakes Valley of the Colorado Front Range. Dissolved organic carbon (DOC) was present in all samples with a mean concentration of 0·85 mg L − − − − −1 . A one-way analysis of variance test shows no statistical difference in DOC amounts among surface waters ( p = = = = = 0·42). Average nitrate concentrations were 69 µ µ µ µ µmoles L − − − − −1 in the outflow of the rock glacier, compared to 7 µ µ µ µ µmoles L − − − − −1 in snow and 25 µ µ µ µ µmoles L − − − − −1 in rain. Nitrate concentrations from the rock glacier generally increased with time, with maximum concentrations of 135 µ µ µ µ µmoles L − − − − −1 in October, among the highest nitrate concentrations reported for highelevation surface waters. These high nitrate concentrations appear to be characteristic of rock glacier outflow in the Rocky Mountains, as a paired-difference t-test shows that nitrate concentrations from the outflow of 7 additional rock glaciers were significantly greater compared to their reference streams ( p = = = = = 0·003). End-member mixing analysis suggest that snow was the dominant source of nitrate in June, 'soil' solution was the dominant nitrate source in July, and base flow was the dominant source in September. Fluoresence index values and PARAFAC analyses of dissolved organic matter (DOM) are also consistent with a switch from terrestrial DOM in the summer time period to an increasing aquatic-like microbial source during the autumn months.for chemical content in rugged and isolated environments. Collecting and analyzing samples for nutrient content is even more difficult because organic nutrients are delicate and concentrations can change rapidly without strigent collection and handling techniques.There is some urgency to understanding the sources, fate, and transport of nutrients to high-elevation areas of the Rocky Mountains. Numerous authors in the last decade have reported on the increasing amounts of inorganic nitrogen in wet deposition to the Rocky Mountains and resulting changes in ecosystem function in these areas (e.g. ). Several studies have shown that discharge from talus and blockfields in the Rocky Mountains contain elevated amounts of nitrate (e.g. Williams et al., 1997;Bieber et al., 1998;Campbell et al., 2000;Clow et al., 2003). The nitrate in the outflow of talus and blockfields appears to result primarily from microbial activity where the microbes are carbon limited and hence move the nitrogen cycle towards net nitrification (e.g. Ley and Schmidt, 2002;Ley et al., 2004). An outstanding question is whether rock glaciers act like blockfields and also have high nitrate in their outflow, or are rock glaciers biologically inert?Here we characterize the nutrient content in the outflow of the Green Lake 5 rock glacier (RG5) in 2003, located in the Green Lakes Valley of the Colorado Front Range. The primary focus is on nitrate, but we also evaluate ammonium and DOC content. The nutrient content in the outflow ...

show abstract

Microbial population dynamics in an extreme environment: controlling factors in talus soils at 3750 m in the Colorado Rocky Mountains

Cited by 78 publications

References 42 publications

ANaganishiain high places: functioning populations or dormant cells from the atmosphere?

ANaganishiain high places: functioning populations or dormant cells from the atmosphere?

Atmospheric deposition as a source of carbon and nutrients to an alpine catchment of the Colorado Rocky Mountains

Nitrate content and potential microbial signature of rock glacier outflow, Colorado Front Range

Contact Info

Product

Resources

About