Journal articles on the topic 'Alpine soils'
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Doolette, Ashlea L., Ronald J. Smernik, and Timothy I. McLaren. "The composition of organic phosphorus in soils of the Snowy Mountains region of south-eastern Australia." Soil Research 55, no. 1 (2017): 10. http://dx.doi.org/10.1071/sr16058.
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Few studies have considered the influence of climate on organic phosphorus (P) speciation in soils. We used sodium hydroxide–ethylenediaminetetra-acetic acid (NaOH–EDTA) soil extractions and solution 31P nuclear magnetic resonance spectroscopy to investigate the soil P composition of five alpine and sub-alpine soils. The aim was to compare the P speciation of this set of soils with those of soils typically reported in the literature from other cold and wet locations, as well as those of other Australian soils from warmer and drier environments. For all alpine and sub-alpine soils, the majority of P detected was in an organic form (54–66% of total NaOH–EDTA extractable P). Phosphomonoesters comprised the largest pool of extractable organic P (83–100%) with prominent peaks assigned to myo- and scyllo-inositol hexakisphosphate (IP6), although trace amounts of the neo- and d-chiro-IP6 stereoisomers were also present. Phosphonates were identified in the soils from the coldest and wettest locations; α- and β-glycerophosphate and mononucleotides were minor components of organic P in all soils. The composition of organic P in these soils contrasts with that reported previously for Australian soils from warm, dry environments where inositol phosphate (IP6) peaks were less dominant or absent and humic-P and α- and β-glycerophosphate were proportionally larger components of organic P. Instead, the soil organic P composition exhibited similarities to soils from other cold, wet environments. This provides preliminary evidence that climate is a key driver in the variation of organic P speciation in soils.
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Lu, Xuyang, Shuqin Ma, Youchao Chen, Degyi Yangzom, and Hongmao Jiang. "Squalene Found in Alpine Grassland Soils under a Harsh Environment in the Tibetan Plateau, China." Biomolecules 8, no. 4 (November 20, 2018): 154. http://dx.doi.org/10.3390/biom8040154.
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Squalene is found in a large number of plants, animals, and microorganisms, as well as other sources, playing an important role as an intermediate in sterol biosynthesis. It is used widely in the food, cosmetics, and medicine industries because of its antioxidant, antistatic, and anti-carcinogenic properties. A higher natural squalene component of lipids is usually reported as being isolated to organisms living in harsh environments. In the Tibetan Plateau, which is characterized by high altitude, strong solar radiation, drought, low temperatures, and thin air, the squalene component was identified in five alpine grasslands soils using the pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) technique. The relative abundance of squalene ranged from 0.93% to 10.66% in soils from the five alpine grasslands, with the highest value found in alpine desert and the lowest in alpine meadow. Furthermore, the relative abundance of squalene in alpine grassland soils was significantly negatively associated with soil chemical/microbial characteristics. These results indicate that the extreme environmental conditions of the Tibetan Plateau may stimulate the microbial biosynthesis of squalene, and the harsher the environment, the higher the relative abundance of soil squalene.
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Wagner, Andreas O., Katrin Hofmann, Eva Prem, and Paul Illmer. "Methanogenic activities in alpine soils." Folia Microbiologica 57, no. 4 (April 17, 2012): 371–73. http://dx.doi.org/10.1007/s12223-012-0145-2.
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Kashulina, Galina M. "Overview of recent soil investigations in the Polar-Alpine Botanical Garden-Institute." Transaction Kola Science Centre 12, no. 6-2021 (December 31, 2021): 252–58. http://dx.doi.org/10.37614/2307-5252.2021.6.12.9.037.
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In the last two decades, Polar-Alpine Botanical Garden carried out soil studies on the Kola Peninsula and Svalbard in several directions: soil genetics and morphology of natural and damaged soils, complex landscape monitoring of the environment, complex biogeochemical environmental studies, soil ecology, and fertility of manmade soils in botanical garden.
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Streit, Kathrin, Frank Hagedorn, David Hiltbrunner, Magdalena Portmann, Matthias Saurer, Nina Buchmann, Birgit Wild, Andreas Richter, Sonja Wipf, and Rolf T. W. Siegwolf. "Soil warming alters microbial substrate use in alpine soils." Global Change Biology 20, no. 4 (February 5, 2014): 1327–38. http://dx.doi.org/10.1111/gcb.12396.
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Broll, Gabrielle. "Diversity of soil organisms in alpine and arctic soils in Europe. Review an research needs." Pirineos 151-152 (December 30, 1998): 43–72. http://dx.doi.org/10.3989/pirineos.1998.v151-152.118.
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McDaniel, Marshall D., Marcela Hernández, Marc G. Dumont, Lachlan J. Ingram, and Mark A. Adams. "Disproportionate CH4 Sink Strength from an Endemic, Sub-Alpine Australian Soil Microbial Community." Microorganisms 9, no. 3 (March 15, 2021): 606. http://dx.doi.org/10.3390/microorganisms9030606.
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Soil-to-atmosphere methane (CH4) fluxes are dependent on opposing microbial processes of production and consumption. Here we use a soil–vegetation gradient in an Australian sub-alpine ecosystem to examine links between composition of soil microbial communities, and the fluxes of greenhouse gases they regulate. For each soil/vegetation type (forest, grassland, and bog), we measured carbon dioxide (CO2) and CH4 fluxes and their production/consumption at 5 cm intervals to a depth of 30 cm. All soils were sources of CO2, ranging from 49 to 93 mg CO2 m−2 h−1. Forest soils were strong net sinks for CH4, at rates of up to −413 µg CH4 m−2 h−1. Grassland soils varied, with some soils acting as sources and some as sinks, but overall averaged −97 µg CH4 m−2 h−1. Bog soils were net sources of CH4 (+340 µg CH4 m−2 h−1). Methanotrophs were dominated by USCα in forest and grassland soils, and Candidatus Methylomirabilis in the bog soils. Methylocystis were also detected at relatively low abundance in all soils. Our study suggests that there is a disproportionately large contribution of these ecosystems to the global soil CH4 sink, which highlights our dependence on soil ecosystem services in remote locations driven by unique populations of soil microbes. It is paramount to explore and understand these remote, hard-to-reach ecosystems to better understand biogeochemical cycles that underpin global sustainability.
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Meyer, A. F., D. A. Lipson, A. P. Martin, C. W. Schadt, and S. K. Schmidt. "Molecular and Metabolic Characterization of Cold-Tolerant Alpine Soil Pseudomonas Sensu Stricto." Applied and Environmental Microbiology 70, no. 1 (January 2004): 483–89. http://dx.doi.org/10.1128/aem.70.1.483-489.2004.
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ABSTRACT Alpine soils undergo dramatic temporal changes in their microclimatic properties, suggesting that the bacteria there encounter uncommon shifting selection gradients. Pseudomonads constitute important members of the alpine soil community. In order to characterize the alpine Pseudomonas community and to assess the impact of shifting selection on this community, we examined the ability of cold-tolerant Pseudomonas isolates to grow on a variety of carbon sources, and we determined their phylogenetic relationships based on 16S ribosomal DNA sequencing. We found a high prevalence of Pseudomonas in our soil samples, and isolates from these soils exhibited extensive metabolic diversity. In addition, our data revealed that many of our isolates form a unique cold-adapted clade, representatives of which are also found in the Swedish tundra and Antarctica. Our data also show a lack of concordance between the metabolic properties and 16S phylogeny, indicating that the metabolic diversity of these organisms cannot be predicted by phylogeny.
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Acharya, S. N., B. A. Darroch, R. Hermesh, and J. Woosaree. "Salt stress tolerance in native Alberta populations of slender wheatgrass and alpine bluegrass." Canadian Journal of Plant Science 72, no. 3 (July 1, 1992): 785–92. http://dx.doi.org/10.4141/cjps92-094.
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Alpine bluegrass [Poa alpina L.] and slender wheatgrass [Elymus trachycaulus (Link.) Gould ex Shinners] accessions from alpine and subalpine regions of the Canadian Rocky Mountains and eastern foothills were tested for tolerance to salinity stress. Accessions with higher emergence (%) than salt-tolerant Orbit tall wheatgrass [Thinopyrum elongatum (Host) D. R. Dewey, comb, nov.], after 21 d in vermiculite saturated with a NaCl-salinized half-Hoagland solution (electrical conductivity 15 dS m−1) and nurtured in growth cabinets set to repeat 20/15 °C day (16-h)/night temperatures, were considered tolerant of salt-stress. This test identified 72 alpine bluegrass and 11 slender wheatgrass salt-tolerant accessions. Most of these accessions originated from two specific sites near the Alberta-British Columbia border. Slender wheatgrass accessions tolerant to NaCl were also tolerant to the other salts commonly found in Alberta soils. In slender wheatgrass, the ability to emerge in a salinized nutrient solution had moderate heritability (61–68%), suggesting the possibility of genetic improvement through selection.Key words: Salt tolerance, selection, heritability, alpine bluegrass, slender wheatgrass
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Xiao-gang, Li, Feng-min Li, Bhupinderpal-Singh, Rengel Zed, and Zhan Zheng-yan. "Soil management changes organic carbon pools in alpine pastureland soils." Soil and Tillage Research 93, no. 1 (March 2007): 186–96. http://dx.doi.org/10.1016/j.still.2006.04.003.
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Dethier, David P., Noah Williams, and Jordan F. Fields. "Snowmelt-Driven Seasonal Infiltration and Flow in the Upper Critical Zone, Niwot Ridge (Colorado), USA." Water 14, no. 15 (July 26, 2022): 2317. http://dx.doi.org/10.3390/w14152317.
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The hydrology of alpine and subalpine areas in the Colorado Front Range (USA) is evolving, driven by warming and by the alteration of precipitation patterns, the timing of snowmelt, and other components of the hydrologic budget. Field measurements of soil hydraulic conductivity and moisture along 30-m transects (n = 13) of representative soils developed in surficial deposits and falling head slug tests of shallow groundwater in till demonstrate that hydraulic conductivity in the soil is comparable to hydraulic conductivity values in the shallow aquifer. Soil hydraulic conductivity values were variable (medians ranged from 5.6 × 10−7 to 4.96 × 10−5 m s−1) and increased in alpine areas underlain by periglacial deposits. Hydraulic conductivities measured by a modified Hvorslev technique in test wells ranged from 4.86 × 10−7 to 1.77 × 10−4 m s−1 in subalpine till. The results suggest a gradient from higher hydraulic conductivity in alpine zones, where short travel paths through periglacial deposits support ephemeral streams and wetlands, to lower hydraulic conductivity in the till-mantled subalpine zone. In drier downstream areas, streambed infiltration contributes substantially to near-channel groundwater. As summer temperatures and evapotranspiration (ET) increase and snowmelt occur earlier, alpine soils are likely to become more vulnerable to drought, and groundwater levels in the critical zone may lower, affecting the connectivity between late-melting snow, meltwater streams, and the areas they affect downstream.
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Kaštovská, Eva, Michal Choma, Petr Čapek, Jiří Kaňa, Karolina Tahovská, and Jiří Kopáček. "Soil warming during winter period enhanced soil N and P availability and leaching in alpine grasslands: A transplant study." PLOS ONE 17, no. 8 (August 2, 2022): e0272143. http://dx.doi.org/10.1371/journal.pone.0272143.
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Alpine meadows are strongly affected by climate change. Increasing air temperature prolongs the growing season and together with changing precipitation patterns alters soil temperature during winter. To estimate the effect of climate change on soil nutrient cycling, we conducted a field experiment. We transferred undisturbed plant-soil mesocosms from two wind-exposed alpine meadows at ~2100 m a.s.l. to more sheltered plots, situated ~300–400 m lower in the same valleys. The annual mean air temperature was 2°C higher at the lower plots and soils that were normally frozen at the original plots throughout winters were warmed to ~0°C due to the insulation provided by continuous snow cover. After two years of exposure, we analyzed the nutrient content in plants, and changes in soil bacterial community, decomposition, mineralization, and nutrient availability. Leaching of N and P from the soils was continuously measured using ion-exchange resin traps. Warming of soils to ~0°C during the winter allowed the microorganisms to remain active, their metabolic processes were not restricted by soil freezing. This change accelerated nutrient cycling, as evidenced by increased soil N and P availability, their higher levels in plants, and elevated leaching. In addition, root exudation and preferential enzymatic mining of P over C increased. However, any significant changes in microbial biomass, bacterial community composition, decomposition rates, and mineralization during the growing season were not observed, suggesting considerable structural and functional resilience of the microbial community. In summary, our data suggest that changes in soil temperature and snow cover duration during winter periods are critical for altering microbially-mediated processes (even at unchanged soil microbial community and biomass) and may enhance nutrient availability in alpine meadows. Consequently, ongoing climate change, which leads to soil warming and decreasing snow insulation, has a potential to significantly alter nutrient cycling in alpine and subalpine meadows compared to the current situation and increase the year-on-year variability in nutrient availability and leaching.
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Kaňa, Jiří, Jiří Kopáček, Lluís Camarero, and Jordi Garcia-Pausas. "Phosphate Sorption Characteristics of European Alpine Soils." Soil Science Society of America Journal 75, no. 3 (May 2011): 862–70. http://dx.doi.org/10.2136/sssaj2010.0259.
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Scalenghe, Riccardo, Eleonora Bonifacio, Luisella Celi, Fiorenzo C. Ugolini, and Ermanno Zanini. "Pedogenesis in disturbed alpine soils (NW Italy)." Geoderma 109, no. 3-4 (October 2002): 207–24. http://dx.doi.org/10.1016/s0016-7061(02)00176-3.
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Tai, X. S., W. L. Mao, G. X. Liu, T. Chen, W. Zhang, X. K. Wu, H. Z. Long, B. G. Zhang, and T. P. Gao. "Distribution of ammonia oxidizers in relation to vegetation characteristics in the Qilian Mountains, northwestern China." Biogeosciences Discussions 11, no. 4 (April 1, 2014): 5123–46. http://dx.doi.org/10.5194/bgd-11-5123-2014.
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Abstract. Nitrogen is the major limiting nutrient in cold environments, and its availability is strongly dependent on nitrification. However, microbial communities driving this process remain largely uncharacterized in alpine meadow soils in northwestern China, namely those catalyzing the rate-limiting step of ammonia oxidation. In this study, ammonia-oxidizing communities in alpine meadow soils were characterized by real-time PCR and clone sequencing by targeting on amoA genes, which putatively encode ammonia monooxygenase subunit A. The results demonstrated that ammonia-oxidizing archaea (AOA) outnumbered ammonia-oxidizing bacteria (AOB) in the alpine meadow soils. Most of the AOA phylotypes detected in the study region fell within typical Group I.1b of Thaumarchaeota. Interestingly, a new ammonia-oxidizing archaeal group named "Kobresia meadow soil group" was found. Phylogenetic analysis of AOB communities exhibited a dominance of Nitrosospira-like sequences affiliated to beta-Proteobacteria. Compared with other alpine environments, Qilian Mountains had a great phylogenetic diversity of ammonia oxidizers. Principal Component Analysis (PCA) analysis showed that distinct AOA/AOB phylotype groups were attributed to different meadow types, reflecting an overall distribution of ammonia-oxidizing communities associated with meadow types. Redundancy Analysis (RDA) analysis showed that Axis 1 (90.9%) together with Axis 2 (9.1%) explained all the variables while Axis 1 exhibited a significant explanatory power. So that vegetation coverage mostly correlated to Axis 1 was the most powerful environmental factor in the study region. Characteristics of ammonia-oxidizing communities showed a close association with vegetation coverage.
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Margesin, R., D. Labb�, F. Schinner, C. W. Greer, and L. G. Whyte. "Characterization of Hydrocarbon-Degrading Microbial Populations in Contaminated and Pristine Alpine Soils." Applied and Environmental Microbiology 69, no. 6 (June 2003): 3085–92. http://dx.doi.org/10.1128/aem.69.6.3085-3092.2003.
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ABSTRACT Biodegradation of petroleum hydrocarbons in cold environments, including Alpine soils, is a result of indigenous cold-adapted microorganisms able to degrade these contaminants. In the present study, the prevalence of seven genotypes involved in the degradation of n-alkanes (Pseudomonas putida GPo1 alkB; Acinetobacter spp. alkM; Rhodococcus spp. alkB1, and Rhodococcus spp. alkB2), aromatic hydrocarbons (P. putida xylE), and polycyclic aromatic hydrocarbons (P. putida ndoB and Mycobacterium sp. strain PYR-1 nidA) was determined in 12 oil-contaminated (428 to 30,644 mg of total petroleum hydrocarbons [TPH]/kg of soil) and 8 pristine Alpine soils from Tyrol (Austria) by PCR hybridization analyses of total soil community DNA, using oligonucleotide primers and DNA probes specific for each genotype. The soils investigated were also analyzed for various physical, chemical, and microbiological parameters, and statistical correlations between all parameters were determined. Genotypes containing genes from gram-negative bacteria (P. putida alkB, xylE, and ndoB and Acinetobacter alkM) were detected to a significantly higher percentage in the contaminated (50 to 75%) than in the pristine (0 to 12.5%) soils, indicating that these organisms had been enriched in soils following contamination. There was a highly significant positive correlation (P < 0.001) between the level of contamination and the number of genotypes containing genes from P. putida and Acinetobacter sp. but no significant correlation between the TPH content and the number of genotypes containing genes from gram-positive bacteria (Rhodococcus alkB1 and alkB2 and Mycobacterium nidA). These genotypes were detected at a high frequency in both contaminated (41.7 to 75%) and pristine (37.5 to 50%) soils, indicating that they are already present in substantial numbers before a contamination event. No correlation was found between the prevalence of hydrocarbon-degradative genotypes and biological activities (respiration, fluorescein diacetate hydrolysis, lipase activity) or numbers of culturable hydrocarbon-degrading soil microorganisms; there also was no correlation between the numbers of hydrocarbon degraders and the contamination level. The measured biological activities showed significant positive correlation with each other, with the organic matter content, and partially with the TPH content and a significant negative correlation with the soil dry-mass content (P < 0.05 to 0.001).
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Churchill, Amber, and William Bowman. "Alpine Moist Meadow Response to Nitrogen Deposition in the Greater Yellowstone Ecosystem." UW National Parks Service Research Station Annual Reports 36 (January 1, 2013): 128–33. http://dx.doi.org/10.13001/uwnpsrc.2013.4001.
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The deposition of anthropogenic reactive nitrogen (N) in alpine ecosystems can have multiple deleterious effects on plants, soils and hydrology in both the alpine and areas downstream through leaching and export. Thresholds for ecological responses to N deposition have been established for lakes, soils and changes in plant community composition in some areas of the Rocky Mountains. These thresholds offer a target for land and air resource managers to prevent significant changes in ecosystem function, however the underlying feedbacks controlling ecosystem response have not been fully examined. Research originally proposed in association with our UW NPS Small Grant aimed to examine plant to ecosystem interactions within alpine moist meadows between two sites receiving different levels of N deposition. This focus has been modified, in response to site limitations, to examine the mediation of the N cycle by the alpine moist meadow plant community.
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Chueva, Natalya V., Galina M. Kashulina, and Natalya M. Korobeynikova. "Agrochemical properties of soil of the Polar-Alpine Botanical Garden-Institute." Transaction Kola Science Centre 12, no. 6-2021 (December 31, 2021): 287–91. http://dx.doi.org/10.37614/2307-5252.2021.6.12.9.043.
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The current state of soil fertility was estimated at 2 sites of experimental fields of the Polar-Alpine Botanical Garden. Soils in both areas are characterized by a light granulometric composition. The sites vary in the content of organic matter in the soils, as well as the acidity and proportion of the sites where the liming is needed. The availability of phosphorus at all sites in both areas is characterized as high, potassium — from medium to high, mineral forms of nitrogen — as very low.
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Wang, Xin, Ting Liu, Liang Wang, Zongguang Liu, Erxiong Zhu, Simin Wang, Yue Cai, Shanshan Zhu, and Xiaojuan Feng. "Spatial–temporal variations in riverine carbon strongly influenced by local hydrological events in an alpine catchment." Biogeosciences 18, no. 10 (May 20, 2021): 3015–28. http://dx.doi.org/10.5194/bg-18-3015-2021.
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Abstract. Headwater streams drain >70 % of global land areas but are poorly monitored compared with large rivers. The small size and low water buffering capacity of headwater streams may result in a high sensitivity to local hydrological alterations and different carbon transport patterns from large rivers. Furthermore, alpine headwater streams on the “Asian water tower”, i.e., Qinghai–Tibetan Plateau, are heavily affected by thawing of frozen soils in spring as well as monsoonal precipitation in summer, which may present contrasting spatial–temporal variations in carbon transport compared to tropical and temperate streams and strongly influence the export of carbon locked in seasonally frozen soils. To illustrate the unique hydro-biogeochemistry of riverine carbon in Qinghai–Tibetan headwater streams, here we carry out a benchmark investigation on the riverine carbon transport in the Shaliu River (a small alpine river integrating headwater streams) based on annual flux monitoring, sampling at a high spatial resolution in two different seasons and hydrological event monitoring. We show that riverine carbon fluxes in the Shaliu River were dominated by dissolved inorganic carbon, peaking in the summer due to high discharge brought by the monsoon. Combining seasonal sampling along the river and monitoring of soil–river carbon transfer during spring thaw, we also show that both dissolved and particulate forms of riverine carbon increased downstream in the pre-monsoon season due to increasing contribution of organic matter derived from thawed soils along the river. By comparison, riverine carbon fluctuated in the summer, likely associated with sporadic inputs of organic matter supplied by local precipitation events during the monsoon season. Furthermore, using lignin phenol analysis for both riverine organic matter and soils in the basin, we show that the higher acid-to-aldehyde (Ad/Al) ratios of riverine lignin in the monsoon season reflect a larger contribution of topsoil likely via increased surface runoff compared with the pre-monsoon season when soil leachate lignin Ad/Al ratios were closer to those in the subsoil than topsoil solutions. Overall, these findings highlight the unique patterns and strong links of carbon transport in alpine headwater catchments with local hydrological events. Given the projected climate warming on the Qinghai–Tibetan Plateau, thawing of frozen soils and alterations of precipitation regimes may significantly influence the alpine headwater carbon transport, with critical effects on the biogeochemical cycles of the downstream rivers. The alpine headwater catchments may also be utilized as sentinels for climate-induced changes in the hydrological pathways and/or biogeochemistry of the small basin.
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Chen, Luyun, and Yongheng Gao. "Global Climate Change Effects on Soil Microbial Biomass Stoichiometry in Alpine Ecosystems." Land 11, no. 10 (September 26, 2022): 1661. http://dx.doi.org/10.3390/land11101661.
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Alpine ecosystems are sensitive to global climate change-factors, which directly or indirectly affect the soil microbial biomass stoichiometry. In this paper, we have compared the soil microbial biomass stoichiometry ratios of alpine ecosystems using the global average values. In the comparison, the responses and mechanisms of soil microbial biomass stoichiometry to nitrogen deposition, altered precipitation, warming, and elevated atmospheric carbon dioxide (CO2) concentration in the alpine ecosystem were considered. The alpine ecosystem has a higher soil microbial-biomass-carbon-to-nitrogen ratio (MBC:MBN) than the global average. In contrast, the soil microbial-biomass-nitrogen-to-phosphorus (MBN:MBP) and carbon-to-phosphorus ratios (MBC:MBP) varied considerably in different types of alpine ecosystems. When compared with the global average values of these ratios, no uniform pattern was found. In response to the increase in nitrogen (N) deposition, on the one hand, microbes will adopt strategies to regulate extracellular enzyme synthesis and excrete excess elements to maintain stoichiometric balance. On the other hand, microbes may also alter their stoichiometry by storing excess N in their bodies to adapt to the increased N in the environment. Thus, a decrease in MBC:MBN and an increase in MBN:MBP are observed. In addition, N deposition directly and indirectly affects the soil fungal-to-bacterial ratio (F:B), which in turn changes the soil microbial biomass stoichiometry. For warming, there is no clear pattern in the response of soil microbial biomass stoichiometry in alpine ecosystems. The results show diverse decreasing, increasing, and unchanging patterns. Under reduced precipitation, microbial communities in alpine ecosystems typically shift to a fungal dominance. The latter community supports a greater carbon-to-nitrogen ratio (C:N) and thus an increased soil MBC:MBN. However, increased precipitation enhances N effectiveness and exacerbates the leaching of dissolved organic carbon (DOC) and phosphorus (P) from alpine ecosystem soils. As a result, a decrease in the soil MBC:MBN and an increase in the soil MBN:MBP are evident. Elevated atmospheric CO2 usually has little effect on the soil MBC:MBN in alpine ecosystems, mainly because of two reasons. These are: (i) N is the main limiting factor in alpine ecosystems, and (ii) alpine ecosystems accumulate higher soil organic carbon (SOC) and microbes and preferentially decompose “old” carbon (C) stocks. The response of soil microbial stoichiometry to global climate change factors in alpine ecosystems is diverse, and the impact pathways are complex. Future studies need to focus on the combined effects of multiple global climate change factors on microbial stoichiometry and the mechanism of microbial stoichiometric balance.
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Kershaw, G. Peter, and Linda J. Kershaw. "Ecological characteristics of 35-year-old crude-oil spills in tundra plant communities of the Mackenzie Mountains, N.W.T." Canadian Journal of Botany 64, no. 12 (December 1, 1986): 2935–47. http://dx.doi.org/10.1139/b86-388.
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In June 1945 the CANOL Crude Oil Pipeline No. 1 from Norman Wells, Northwest Territories, to Whitehorse, Yukon Territory, was abandoned. During its short history, approximately 17 838 500 L of oil was lost through spills and 9 864 400 L was left in the line and storage tanks. Although some burning was done during salvage operations, most residual oil was drained onto the soil surface. Studies in alpine tundra indicate that this oil penetrated up to 60 cm in dry, coarse-textured soils and 8 cm in wet, clay-rich soils. Oil decomposition ranged from complete utilization of n-alkanes to selective metabolism of n-alkanes C12 to C19. Contaminated soils were drier than control soils. This, plus surface blackening and thinning or organic surface layers, resulted in subsurface warming. Floristic similarity coefficients comparing control sites and 27 crude-oil spills varied from 19 to 52. Plant cover was substantially lower on oil spills and in only one community was floristic diversity greater on oil spills than on associated control sites. Dominant colonizers included Cladonia pocillum, Cladonia pyxidata, Rinodina roscida, Carex aquatilis, Carex membranacea, Carex scirpoidea, Epilobium angustifolium, Eriophorum angustifolium, Festuca altaica, Juncus albescens, Poa alpina, Salix planifolia, Solidago multiradiata, and Trisetum spicatum.
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D'Alò, Federica, Iñaki Odriozola, Petr Baldrian, Laura Zucconi, Caterina Ripa, Nicoletta Cannone, Francesco Malfasi, Lisa Brancaleoni, and Silvano Onofri. "Microbial activity in alpine soils under climate change." Science of The Total Environment 783 (August 2021): 147012. http://dx.doi.org/10.1016/j.scitotenv.2021.147012.
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Falsone, Gloria, Luisella Celi, and Eleonora Bonifacio. "AGGREGATE FORMATION IN CHLORITIC AND SERPENTINITIC ALPINE SOILS." Soil Science 172, no. 12 (December 2007): 1019–30. http://dx.doi.org/10.1097/ss.0b013e31815778a0.
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Liu, Biying, Jian Sun, Miao Liu, Tao Zeng, and Juntao Zhu. "The aridity index governs the variation of vegetation characteristics in alpine grassland, Northern Tibet Plateau." PeerJ 7 (July 15, 2019): e7272. http://dx.doi.org/10.7717/peerj.7272.
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The vegetation dynamic (e.g., community productivity) is an important index used to evaluate the ecosystem function of grassland ecosystem. However, the critical factors that affect vegetation biomass are disputed continuously, and most of the debates focus on mean annual precipitation (MAP) or temperature (MAT). This article integrated these two factors, used the aridity index (AI) to describe the dynamics of MAP and MAT, and tested the hypothesis that vegetation traits are influenced primarily by the AI. We sampled 275 plots at 55 sites (five plots at each site, including alpine steppe and meadow) across an alpine grassland of the northern Tibet Plateau, used correlation analysis and redundancy analysis (RDA) to explore which key factors determine the biomass dynamic, and explained the mechanism by which they affect the vegetation biomass in different vegetation types via structural equation modelling (SEM). The results supported our hypothesis, in all of the environmental factors collected, the AI made the greatest contribution to biomass variations in RDA , and the correlation between the AI and biomass was the largest (R = 0.85, p < 0.05). The final SEM also validated our hypothesis that the AI explained 79.3% and 84.4% of the biomass variations in the alpine steppe and the meadow, respectively. Furthermore, we found that the soils with higher carbon to nitrogen ratio and soil total nitrogen had larger biomass, whereas soil organic carbon had a negative effect on biomass in alpine steppe; however, opposite effects of soil factors on biomass were observed in an alpine meadow. The findings demonstrated that the AI was the most critical factor affecting biomass in the alpine grasslands, and different reaction mechanisms of biomass response to the AI existed in the alpine steppe and alpine meadow.
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Fu, Gang, Xianzhou Zhang, Chengqun Yu, Peili Shi, Yuting Zhou, Yunlong Li, Pengwan Yang, and Zhenxi Shen. "Response of Soil Respiration to Grazing in an Alpine Meadow at Three Elevations in Tibet." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/265142.
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Alpine meadows are one major type of pastureland on the Tibetan Plateau. However, few studies have evaluated the response of soil respiration (Rs) to grazing along an elevation gradient in an alpine meadow on the Tibetan Plateau. Here three fenced enclosures were established in an alpine meadow at three elevations (i.e., 4313 m, 4513 m, and 4693 m) in July 2008. We measuredRsinside and outside the three fenced enclosures in July–September, 2010-2011. Topsoil (0–20 cm) samples were gathered in July, August, and September, 2011. There were no significant differences forRs, dissolved organic C (DOC), and belowground root biomass (BGB) between the grazed and ungrazed soils. Soil respiration was positively correlated with soil organic C (SOC), microbial biomass (MBC), DOC, and BGB. In addition, bothRsand BGB increased with total N (TN), the ratio of SOC to TN, ammonium N (NH4+-N), and the ratio ofNH4+-N to nitrate N. Our findings suggested that the negligible response ofRsto grazing could be directly attributed to that of respiration substrate and that soil N may indirectly affectRsby its effect on BGB.
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van, Rees H., and RC Boston. "Evaluation of Factors Affecting Surface Runoff on Alpine Rangeland in Victoria." Rangeland Journal 8, no. 2 (1986): 97. http://dx.doi.org/10.1071/rj9860097.
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A 'portable' rainfall simulator was used on alpine soils on the Bogong High Plains in Victoria, to determine the relationship of surface runoff to soil moisture, rainfall intensity, slope and the percentage of the area lacking vegetation cover (bare ground). A strong inverse relationship (R' = 0.64) existed between total runoff and antecedent soil moisture conditions. The other factors, within the range evaluated in these experiments (bare ground 0 to 33'70, rainfall intensity 37 to 97 mm/hr and slope 6 to 23%) had no significant influence on runoff. Time to runoff initiation was influenced by antecedent soil moisture, slope and rainfall intensity ( ~ ~ ~ 0 . 7 1 ) . It was found that time to runoff decreased as the soils dried, and the slope and rainfall intensity increased. The percentage of bare ground had little influence on the time to runoff initiation. These results show that differences in grassland condition, including large differences in the percentage of bare ground, had little influence on either surface runoff or on the time to runoff initiation. The single most important factor influencing runoff rates was the antecedent moisture content of the soil. This factor is generally outside management control.
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Egli, M., A. Mirabella, G. Sartori, D. Giaccai, R. Zanelli, and M. Plötze. "Effect of slope aspect on transformation of clay minerals in Alpine soils." Clay Minerals 42, no. 3 (September 2007): 373–98. http://dx.doi.org/10.1180/claymin.2007.042.3.09.
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AbstractTwo soil profile sequences on paragneiss debris in the Val di Rabbi (Northern Italy) along an altitude gradient ranging from 1200 to 2400 m a.s.l. were studied to evaluate the effect of aspect on the weathering of clay minerals. All the soils had a coarse structure, a sandy texture and a low pH. Greater weathering intensities of clay-sized phyllosilicates (greater content of smectites) were observed in soils on the north-facing slope. On the south-facing slope, smectite was found only in the surface horizon of the soil profile at the highest altitude. Hot citrate treatment of north-facing soils revealed the presence of low-charged 2:1 clay minerals, the expansion of which was hindered in the untreated state by interlayered polymers. However, the hot citrate treatment encountered some problems with the samples of the south-facing soils: as confirmed by Fourier transform infrared spectroscopy, the hot citrate treatment was unable to remove all interlayer Al polymers. The 2:1 phyllosilicates were not expanded by ethylene glycol solvation in several samples, although thermogravimetric analyses indicated the presence of clay minerals with interlayer H2O. At the same time, the collapse of clay minerals to 1.0 nm following K-saturation was evident. Theoretically, this should indicate that 2:1 phyllosilicates had no evident substitution of trioctahedral cations (Mg2+, Fe2+) by dioctahedral cations (Al3+ and Fe3+). X-ray diffraction analysis of the d060 region and determination of the layer charge of clay minerals by the long-chain (C18) alkylammonium ion, however, did not confirm this. A transformation from trioctahedral to dioctahedral species was observed and low-charge clay minerals (ξ ~0.30) were identified in the surface horizons of the south-facing sites. In the south-facing soils, the podzolization process was less pronounced because of a lower water flux through the soil and probably less complexing organic molecules that would remove the interlayer polymers. Besides the eluviation process, clay minerals underwent a process of ionic substitutions in the octahedral sheet that led to the reduction of the layer charge. This process was more obvious in the north-facing sites.
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Lokupitiya, E., N. L. Stanton, R. S. Seville, and J. R. Snider. "Effects of increased nitrogen deposition on soil nematodes in alpine tundra soils." Pedobiologia 44, no. 5 (January 2000): 591–608. http://dx.doi.org/10.1078/s0031-4056(04)70074-8.
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Johnston, Stuart William. "The influence of aeolian dust deposits on alpine soils in south-eastern Australia." Soil Research 39, no. 1 (2001): 81. http://dx.doi.org/10.1071/sr99121.
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Aeolian sediment collected from 2 locations across the ‘Main Range’ of Kosciuszko National Park, along with a series of soil profiles that were analysed for particle size, were used as a baseline from which to estimate the effects of aeolian sedimentation in this region. Laboratory analysis of the soil profiles indicated that the properties of the surface horizons of the alpine humus soils were heavily influenced by aeolian dust accumulation; however, the sub-surface horizons were mainly derived from the natural bedrock. The surface and subsurface horizons differed in texture bulk density, pH, electrical conductivity, exchangeable cations, and clay mineralogy. This study confirmed that the snow patch meadow soils exhibited particle size and mineralogy consistent with dust enrichment, with distinct bands being found in some profiles.
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Bai, Junhong, Qiongqiong Lu, Qingqing Zhao, Junjing Wang, and Hua Ouyang. "Effects of Alpine Wetland Landscapes on Regional Climate on the Zoige Plateau of China." Advances in Meteorology 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/972430.
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The differences in the air temperature, precipitation, evaporation, and relative humidity between wetlands and nonwetlands were analyzed to investigate the effects of alpine wetlands on regional climate. Meanwhile, the changes in precipitation and surface runoff fluxes before and after the typical wetland degradation were discussed, and the effects of wetland degradation on soil organic carbon were assessed. Correlation and regression analyses were applied to exhibit the relationships between wetland landscape areas and meteorological factors. Our results showed that the cooling effects of wetlands on ambient environment were very obvious, and soil temperature could be higher in the area with less surrounding wetland area. The evaporation capacity and relative humidity in wetlands were higher compared to the surrounding non-wetlands. Precipitation and surface runoff flux decreased due to serious wetland degradation, indicating that wetland degradation or expansion had close relation with regional precipitation. Once peat soils were converted to meadow soils or Aeolian sandy soils, soil organic carbon (SOC) would decline linearly. Correlation and regression analyses showed that there were significant correlations between wetland landscape areas and the annual average air temperature, the average air temperature in growing seasons, and the evaporation in growing seasons (P<0.05).
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Jolokhava, Tamar, Otar Abdaladze, Khatuna Gigauri, and Zaal Kikvidze. "Gradient analysis of soil-plant interactions from the alpine-nival ecotone to the snowline on slopes of the Central Great Caucasus (Kazbegi Region, Georgia)." Ukrainian Botanical Journal 78, no. 3 (June 29, 2021): 163–75. http://dx.doi.org/10.15407/ukrbotj78.03.163.
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Alpine ecosystems are especially sensitive to climatic changes which affect the relationships among glaciers, snow, vegetation and soils. Our aim was to examine how the variation in the abiotic environment affected soil properties and plant species distribution at regional and local scales. We sampled soil and vegetation along two transects set on the opposite-facing slopes (North versus South), from the alpine-nival ecotone to the snowline (Central Great Caucasus, Kazbegi, Georgia). We measured also soil temperature and controlled for the slope inclination. Multivariate ordination methods were used to link abiotic factors, soil properties and plant species distribution along the gradients. We found that ordination models were better resolved when soil properties were used as environmental variables instead of abiotic ones such as elevation, inclination and slope aspect. Soil pH and plant available potassium were the best predictors of plant species distribution in these habitats. We conclude that the models that account for the role of soils as a mediator between the abiotic environment and vegetation can more accurately describe plant species distribution at local and regional scales: a potentially important amendment with implications for the monitoring of the effects of climate change on vegetation at least in high mountain systems.
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Kryuchenko, Nataliya O., Edward Ya Zhovinsky, and Petr S. Paparyga. "Biogeochemical peculiarities of accumulation of chemical elements by plants of the Svydovets Massif of the Ukrainian Carpathians." Journal of Geology, Geography and Geoecology 30, no. 1 (April 8, 2021): 78–89. http://dx.doi.org/10.15421/112108.
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he objective of the paper was determining biogeochemical peculiarities of ac- cumulation of chemical elements (Mn, Ni, Сo, V, Cr, Zr, Cu, Pb, Zn, Ba, P) by wild-grow- ing shrubs (stems and leaves) – bog bilberry (Vaccіnium uliginоsum), European blueberry (Vaccinium myrtillus L.), alpine juniper (J. communis subsp. alpina); perennial herbaceous plants (flowers and leaves) – common tormentil (Potentіlla erecta (L.) Hampe), willow gentian (Gentiana asclepiadea), true sedges (Carex); and trees (needles) of European silver fir (Abies alba) on nine plots in the Svy- dovets Massif of the Ukrainian Carpathians. The results we obtained based on field surveys (selection of samples of soil and vegeta- tion) and interpretation of their analysis allowed us to determine the total regional background of chemical elements in soils and ash of plants using emission spectral analysis. We assessed the total concentration of chemical elements in soils of the plots (least to highest): the Apshynets Ridge – the Herashaska Polonyna – Drahobratske Lake – the Svydovets stream – Apshynets Lake – Herashaske Lake – the Zhuravlyne Bog – Vorozheske Lake (group of small lakes) – Vorozheske Lake (large) and determined the dependence on type of soil and pH. We determined that for wild-growing herbaceous plants the biogeochemical activity of species increases in the following sequence: true sedges - willow gentian - common tormentil; for wild-growing shrubs (bog bilberry, European blueberry, alpine juniper) such a sequence is impossible to determine due to the great difference between the values on different plots. We determined the role of each plant as medicinal for treating microelement deficiency in Cu, Zn, Co. We determined that in the plot of the Herashaska Polonyna, the needles of alpine juniper contain a maximum amount of Zn and Co, the needles and leaves of bog bilberry – Cu, Zn, Co; the flowers and leaves of common tormentil by Apshynets Lake and European silver fir near the area of the Svydovets stream – Cu. We calculated the daily dose of each element according to species of plants to overcome microelementosis. The results of biogeochemical surveys may be the basis for determining and recommending plants as medicinal, and also of geochemical and biogeochemical monitoring studies.
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Bai, Junhong, Hua Ouyang, Rong Xiao, Junqin Gao, Haifeng Gao, Baoshan Cui, and Laibin Huang. "Spatial variability of soil carbon, nitrogen, and phosphorus content and storage in an alpine wetland in the Qinghai - Tibet Plateau, China." Soil Research 48, no. 8 (2010): 730. http://dx.doi.org/10.1071/sr09171.
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This study considers the spatial variability of soil organic carbon, nitrogen, and phosphorus storage in a drained alpine wetland and the possible relationships with soil properties. Top 0–0.30 m soil samples were collected in a typical alpine wetland in the south-eastern Qinghai–Tibet plateau using grid sampling. There was high spatial variability for soil organic carbon density (SOCD), soil total nitrogen density (STND), and soil total phosphorous density (STPD) in the drained alpine wetland. Spherical models best described the structure of the semivariograms for SOCD and STPD, and an exponential model for STND, with the range parameter of <4 m. Similar spatial distribution with lower or higher patches of C, N, and P storage were observed. SOCD, STND, and STPD were significantly negatively correlated with soil moisture (P < 0.01), and significantly positively correlated with bulk density (P < 0.01). However, no significant correlations were observed between SOCD, STND, and STPD and soil pH values. Wetland drainage might lead to higher C, N, and P densities in top 0.30 m soils due to peat compaction; thus, it is necessary to incorporate water table fluctuations or the whole depth of peat layers to estimating precisely C, N and P storage.
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Poonam, Rajan Bawa, D. Nayak, H. Sankhyan, and S. S. Sharma. "Soil Nutrient Storage Under Major Ecosystems of Cold Deserts of Himachal Pradesh." Indian Journal of Forestry 40, no. 2 (June 1, 2017): 127–32. http://dx.doi.org/10.54207/bsmps1000-2017-8z33wr.
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The present investigation was carried out at village Goshal of Lahaul and Spiti cold desert district of Himachal Pradesh during the year 2010 to 2013 to compare soil physical and chemical properties by demarcating the study area into three main ecosystems viz; forest ecosystem, alpine pasture ecosystem and agro ecosystem. The soil physical properties of all the three ecosystems revealed that the soils were found nearly neutral in reaction, having no salt problem and were medium in physical status. Bulk density was more in alpine and forest ecosystem due to grazing and soil was more compact as compared to agro ecosystem. The average soil moisture was maximum in agro ecosystem. Average soil nutrient status for all the three ecosystems depicted that the fields where peas and pulses were planted were found to be possessing higher nitrogen contents than other areas due to the fixation of atmospheric nitrogen.
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Stassen, P. J. C., J. Wooldridge, and M. Booyse. "ROOTSTOCKS FOR 'ALPINE' NECTARINES ON SANDY, NEMATODE-INFESTED SOILS." Acta Horticulturae, no. 1058 (December 2014): 499–506. http://dx.doi.org/10.17660/actahortic.2014.1058.62.
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Seastedt, T. R., and Gina A. Adams. "EFFECTS OF MOBILE TREE ISLANDS ON ALPINE TUNDRA SOILS." Ecology 82, no. 1 (January 2001): 8–17. http://dx.doi.org/10.1890/0012-9658(2001)082[0008:eomtio]2.0.co;2.
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Allen, Charles E., and Scott F. Burns. "CHARACTERIZATION OF ALPINE SOILS, EAGLE CAP, WALLOWA MOUNTAINS, OREGON." Physical Geography 21, no. 3 (May 2000): 212–22. http://dx.doi.org/10.1080/02723646.2000.10642706.
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Margesin, Rosa, Melanie Jud, Dagmar Tscherko, and Franz Schinner. "Microbial communities and activities in alpine and subalpine soils." FEMS Microbiology Ecology 67, no. 2 (February 2009): 208–18. http://dx.doi.org/10.1111/j.1574-6941.2008.00620.x.
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Corcho Alvarado, J. A., F. Chawla, and P. Froidevaux. "Determining241Pu in environmental samples: case studies in alpine soils." Radiochimica Acta 99, no. 2 (February 2011): 121–29. http://dx.doi.org/10.1524/ract.2011.1803.
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Mladenov, N., M. W. Williams, S. K. Schmidt, and K. Cawley. "Atmospheric deposition as a source of carbon and nutrients to barren, alpine soils of the Colorado Rocky Mountains." Biogeosciences Discussions 9, no. 3 (March 1, 2012): 2375–424. http://dx.doi.org/10.5194/bgd-9-2375-2012.
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Abstract. Many alpine areas are experiencing intense 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, we evaluated the magnitude and chemical quality 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 (2002–2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were approximately 1.0 mg L−1and 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. Relationships among DOC concentration, dissolved organic matter (DOM) fluorescence properties, 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. 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 and, therefore, likely to be more bioavailable to microbes in barren alpine soils. Bioavailability experiments with different types of atmospheric C sources are needed to better evaluate the substrate quality of atmospheric C inputs. Our C budget estimates for the Green Lake 4 catchment suggest that atmospheric deposition represents an average input of approximately 13 kg C ha−1 yr−1 that could be as high as 24 kg C ha−1 yr−1 in high dust years and approaches that of autotrophic C fixation in barren soils.
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Angert, A., D. Yakir, M. Rodeghiero, Y. Preisler, E. A. Davidson, and T. Weiner. "Using O<sub>2</sub> to study the relationships between soil CO<sub>2</sub> efflux and soil respiration." Biogeosciences 12, no. 7 (April 7, 2015): 2089–99. http://dx.doi.org/10.5194/bg-12-2089-2015.
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Abstract. Soil respiration is the sum of respiration processes in the soil and is a major flux in the global carbon cycle. It is usually assumed that the CO2 efflux is equal to the soil respiration rate. Here we challenge this assumption by combining measurements of CO2 with high-precision measurements of O2. These measurements were conducted on different ecosystems and soil types and included measurements of air samples taken from the soil profile of three Mediterranean sites: a temperate forest and two alpine forests. Root-free soils from the alpine sites were also incubated in the lab. We found that the ratio between the CO2 efflux and the O2 influx (defined as apparent respiratory quotient, ARQ) was in the range of 0.14 to 1.23 and considerably deviated from the value of 0.9 ± 0.1 expected from the elemental composition of average plants and soil organic matter. At the Mediterranean sites, these deviations are explained as a result of CO2 dissolution in the soil water and transformation to bicarbonate ions in these high-pH soils, as well as by carbonate mineral dissolution and precipitation processes. Thus, a correct estimate of the short-term, chamber-based biological respiratory flux in such soils can only be made by dividing the measured soil CO2 efflux by the average (efflux-weighted) soil profile ARQ. Applying this approach to a semiarid pine forest resulted in an estimated short-term biological respiration rate that is 3.8 times higher than the chamber-measured surface CO2. The ARQ values often observed in the more acidic soils were unexpectedly low (< 0.7). These values probably result from the oxidation of reduced iron, which has been formed previously during times of high soil moisture and local anaerobic conditions inside soil aggregates. The results reported here provide direct quantitative evidence of a large temporal decoupling between soil–gas exchange fluxes and biological soil respiration.
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Budge, K., J. Leifeld, E. Hiltbrunner, and J. Fuhrer. "Alpine grassland soils contain large proportion of labile carbon but indicate long turnover times." Biogeosciences 8, no. 7 (July 19, 2011): 1911–23. http://dx.doi.org/10.5194/bg-8-1911-2011.
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Abstract. Alpine soils are expected to contain large amounts of labile carbon (C) which may become a further source of atmospheric carbon dioxide (CO2) as a result of global warming. However, there is little data available on these soils, and understanding of the influence of environmental factors on soil organic matter (SOM) turnover is limited. We extracted 30 cm deep cores from five grassland sites along a small elevation gradient from 2285 to 2653 m a.s.l. in the central Swiss Alps. Our aim was to determine the quantity, allocation, degree of stabilization and mean residence time (MRT) of SOM in relation to site factors such as soil pH, vegetation, and SOM composition. Soil fractions obtained by size and density fractionation revealed a high proportion of labile C in SOM, mostly in the uppermost soil layers. Labile C in the top 20 cm across the gradient ranged from 39.6–57.6 % in comparison to 7.2–29.6 % reported in previous studies for lower elevation soils (810–1960 m a.s.l.). At the highest elevation, MRTs measured by means of radiocarbon dating and turnover modelling, increased between fractions of growing stability from 90 years in free POM (fPOM) to 534 years in the mineral associated fraction (mOM). Depending on elevation and pH, plant community data suggested considerable variation in the quantity and quality of organic matter input, and these patterns could be reflected in the dynamics of soil C. 13C NMR data confirmed a relationship of SOM composition to MRT. While low temperature in alpine environments is likely to be a major cause for the slow turnover rate observed, other factors such as residue quality and soil pH, as well as the combination of all factors, play an important role in causing small scale variability of SOM turnover. Failing to incorporate this interplay of controlling factors into models may impair the performance of models to project SOM responses to environmental change.
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Angert, A., D. Yakir, M. Rodeghiero, Y. Preisler, E. A. Davidson, and T. Weiner. "Using O<sub>2</sub> to study the relationships between soil CO<sub>2</sub> efflux and soil respiration." Biogeosciences Discussions 11, no. 8 (August 7, 2014): 12039–68. http://dx.doi.org/10.5194/bgd-11-12039-2014.
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Abstract. Soil respiration, is the sum of respiration processes in the soil, and is a major flux in the global carbon cycle. It is usually assumed that the CO2 efflux is equal to the soil respiration rate. Here we challenge this assumption by combining measurements of CO2 with high-precision measurements of O2. These measurements were conducted on different ecosystems and soil types, and included measurements of air-samples taken from the soil profile of three Mediterranean sites, a temperate forest, and two alpine forests. Root-free soils from the alpine sites were also incubated at the lab. We found that the ratio between the CO2 efflux to the O2 influx (which we defined as apparent respiratory quotient, ARQ) was in the range of 0.14 to 1.23, which strongly deviates from 0.9 ± 0.1, which is the ratio expected from the elemental composition of average plants and soil organic matter. At the Mediterranean sites these deviations were explained as a result of CO2 dissolution in the soil water and transformation to bi-carbonate in these high pH soils, and by carbonates dissolution and precipitation processes. Thus, correct estimate of the short-term, chamber-based biological respiratory flux in such soils can only be made by dividing the measured CO2 efflux by the average (efflux weighted) soil profile ARQ. We demonstrated that applying this approach to a semiarid pine forest resulted in estimated short-term respiration rate 3.8 times higher than the chamber-measured surface CO2 efflux (8.8 μmol CO2 m−2 s−1 instead of 2.3 μmol CO2 m−2 s−1, at the time of measurement). The ARQ values that were often found for the more acidic soils were lower than 0.7, and hence surprising. These values might be the result of the oxidation of reduced iron, which could previously form during times of high soil moisture and local anaerobic conditions inside aggregates. Further research is needed to confirm that low ARQ found in non-calcareous soils, is the result of this process, which can cause additional temporal decoupling between gas fluxes and soil respiration.
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Makarov, M. I., M. S. Kadulin, and T. I. Malysheva. "15N Natural Abundance of Soil Microbial Biomass in Alpine and Tundra Ecosystems." Eurasian Soil Science 54, no. 6 (June 2021): 907–17. http://dx.doi.org/10.1134/s1064229321060107.
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Abstract Isotopic composition of nitrogen in soil microbial biomass (δ15Nmicr) is connected with the transformation of nitrogen compounds and with the balance of carbon and nitrogen availability for microorganisms. We have studied the dependence of δ15Nmicr on nitrogen isotopic composition in the substrate (δ15N of total and extractable nitrogen), as well as the dependence of δ15Nmicr and 15N-enrichment of microbial biomass (Δ15Nmicr = δ15Nmicr – δ15Nsubstr) on nitrogen availability parameters (the C/N ratio in soil, the N-mineralization activity, the content of extractable nitrogen, and the nitrogen use efficiency) in soils of four alpine ecosystems in the North Caucasus and four tundra ecosystems in the Khibiny Mountains. It has been shown that δ15Nmiсr varies from –0.2 to +8.4‰ and may be characterized by both 15N-enrichment and depletion (negative Δ15Nmiсr values) relative to the total and extractable soil nitrogen. As a rule, Δ15Nmicr is 1.5–3.1‰ relative to 15Ntotal and 0.6–4.8‰ relative to 15Nextr. However, under the most N-deficiency conditions in soils of mountain tundra lichen and shrub heaths, Nmicr does not accumulate an increased amount of 15N. We have not revealed a close correlation of δ15Nmicr and Δ15Nmicr with the C/N ratio. The accumulation of 15N in microbial biomass is much stronger related to N-mineralization (positively) and the nitrogen use efficiency (negatively). This testifies to the important role of microbial nitrogen dissimilation in controlling the isotopic composition of soil microbial biomass nitrogen.
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Quinton, W. L., S. K. Carey, and N. T. Goeller. "Snowmelt runoff from northern alpine tundra hillslopes: major processes and methods of simulation." Hydrology and Earth System Sciences 8, no. 5 (October 31, 2004): 877–90. http://dx.doi.org/10.5194/hess-8-877-2004.
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Abstract. In northern alpine tundra, large slope gradients, late-lying snow drifts and shallow soils overlying impermeable substrates all contribute to large hillslope runoff volumes during the spring freshet. Understanding the processes and pathways of hillslope runoff in this environment is, therefore, critical to understanding the water cycle within northern alpine tundra ecosystems. This study: (a) presents the results of a field study on runoff from a sub-alpine tundra hillslope with a large snow drift during the spring melt period; (b) identifies the major runoff processes that must be represented in simulations of snowmelt runoff from sub-alpine tundra hillslopes; (c) describes how these processes can be represented in a numerical simulation model; and d) compares field measurements with modelled output to validate or refute the conceptual understanding of runoff generation embodied in the process simulations. The study was conducted at Granger Creek catchment, 15 km south of Whitehorse, Yukon Territory, Canada, on a north-facing slope below a late-lying snow drift. For the freshet period, the major processes to be represented in a runoff model include the rate of meltwater release from the late-lying snowdrift, the elevation and thickness of the saturated layer, the magnitude of the soil permeability and its variation with depth. The daily cycle of net all-wave radiation was observed to drive the diurnal pulses of melt water from the drift; this, in turn, was found to control the daily pulses of flow through the hillslope subsurface and in the stream channel. The computed rate of frost table lowering fell within the observed values; however, there was wide variation among the measured frost table depths. Spatial variability in frost table depth would result in spatial variabilities in saturated layer depth and thickness, which would, in turn, produce variations in subsurface flow rates over the slope, including preferential flowpaths. Keywords: subsurface runoff, alpine tundra, permafrost, organic soils, model simulation
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Pérez, Francisco L. "Plant Organic Matter Really Matters: Pedological Effects of Kūpaoa (Dubautia menziesii) Shrubs in a Volcanic Alpine Area, Maui, Hawai’i." Soil Systems 3, no. 2 (April 19, 2019): 31. http://dx.doi.org/10.3390/soilsystems3020031.
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This study examines litter accumulation and associated soil fertility islands under kūpaoa (Dubautia menziesii) shrubs, common at high elevations in Haleakalā National Park (Maui, Hawai’i). The main purposes were to: (i) Analyze chemical and physical properties of kūpaoa leaf-litter, (ii) determine soil changes caused by organic-matter accumulation under plants, and (iii) compare these with the known pedological effects of silversword (Argyroxiphium sandwicense) rosettes in the same area. Surface soil samples were gathered below shrubs, and compared with paired adjacent, bare sandy soils; two soil profiles were also contrasted. Litter patches under kūpaoa covered 0.57–3.61 m2 area and were 22–73 mm thick. A cohesive, 5–30-mm-thick soil crust with moderate aggregate stability developed underneath litter horizons; grain aggregation was presumably related to high organic-matter accumulation. Shear strength and compressibility measurements showed crusts opposed significantly greater resistance to physical removal and erosion than adjacent bare soils. As compared to contiguous bare ground areas, soils below shrubs had higher organic matter percentages, darker colors, faster infiltration rates, and greater water-retention capacity. Chemical soil properties were greatly altered by organic matter: Cations (Ca2+, Mg2+, K+), N, P, and cation-exchange capacity, were higher below plants. Further processes affecting soils under kūpaoa included microclimatic amelioration, and additional water input by fog-drip beneath its dense canopy. Substrate modifications were more pronounced below D. menziesii than A. sandwicense. Organic matter and available nutrient contents were higher under shrubs, where soils also showed greater infiltration and water-retention capacity. These trends resulted from contrasting litter properties between plant species, as kūpaoa leaves have higher nutrient content than silversword foliage. Different litter dynamics and reproduction strategies may also explain contrasting soil properties between the monocarpic rosettes and polycarpic kūpaoa. By inducing substantial substrate changes, Dubautia shrubs alter—or even create—different microhabitats and exert critical control on alpine soil development at Haleakalā.
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Fox, Catherine, and Charles Tarnocai. "Organic soils of Canada: Part 2. Upland Organic soils." Canadian Journal of Soil Science 91, no. 5 (October 2011): 823–42. http://dx.doi.org/10.4141/cjss10032.
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Fox, C. A. and Tarnocai, C. 2011. Organic soils of Canada: Part 2. Upland Organic soils. Can. J. Soil Sci. 91: 823–842. Soils from upland moderately well-drained environments with thick accumulations (>10 cm over lithic contact; >40 cm over mineral soil) of folic materials (forest materials, branches, roots, and other non-wetland materials) are classified within the Folisol great group in the Organic Order since the 1987 revision of the Canadian System of Soil Classification. The Folisol great group correlates to Folist in Keys to Soil Taxonomy and Folic Histosol in World Reference Base for Soil Resources (FAO). Two subgroups – Hemic and Humic Folisol – account for most Folisols addressing the state of decomposition of folic materials. The Lignic and Histic Folisol subgroups identify specific kinds of folic accumulations. Folisolic soils can occur throughout Canada, in forest, heath, and alpine ecosytems with cool, moist, humid environments, but are most prominent within the Pacific Maritime Ecozone; areal extent in Canada is ∼12 505 km2. The main genetic process is the accumulation and decomposition of the folic materials that lead to distinct F and H horizons. Recommendations for research needs are presented to address outstanding taxonomic questions for: 1. Classification of Folisols as a separate soil order; and 2. Taxonomic protocols for lowercase suffixes for the L, F and H horizons and the need for enhanced humus form classifications. Some of the historical proposals to address these issues are discussed. Folisols should be considered extremely sensitive environmentally because of their markedly different genetic development being dependent on thick accumulations of folic materials, their limited and unique distribution in Canada, and their importance for forest sustainability.
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Kirkpatrick, J. B., K. L. Bridle, and K. J. M. Dickinson. "Decades-scale vegetation change in burned and unburned alpine coniferous heath." Australian Journal of Botany 58, no. 6 (2010): 453. http://dx.doi.org/10.1071/bt10138.
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Fire appears to be a rare event in alpine vegetation, suggesting that its effects might be more persistent than in most lowland vegetation types. However, it has been suggested that the Australian alpine biota is resilient to infrequent large fires. This paper describes decades-scale vegetation and soil change after fire in paired plots over fire boundaries in Tasmanian alpine coniferous heath. The effect of fire on soils persisted for decades. Recovery of vegetation was extremely slow by global standards, with delayed reinvasion of previously dominant species. There was low cover of the most fire-sensitive species 43–69 years after fire and much bare ground still evident, with the rate of revegetation declining through time. Gymnosperm shrubs increased at the expense of angiosperms in the unburned plots in the same period and cryptogams declined in both burned and unburned plots. These results suggest that the Tasmanian alpine flora cannot be characterised as resilient to infrequent large fire, although most species survive its incidence. The many centuries that it appears are necessary for coniferous heath to recover to its pre-burn state suggest that fires caused by increased ignitions from lightning and arsonists are the major issue for conservation of the vegetation type.
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Yang, Songyu, Boris Jansen, Samira Absalah, Rutger L. van Hall, Karsten Kalbitz, and Erik L. H. Cammeraat. "Lithology- and climate-controlled soil aggregate-size distribution and organic carbon stability in the Peruvian Andes." SOIL 6, no. 1 (January 27, 2020): 1–15. http://dx.doi.org/10.5194/soil-6-1-2020.
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Abstract. Recent studies indicate that climate change influences soil mineralogy by altering weathering processes and thus impacts soil aggregation and organic carbon (SOC) stability. Alpine ecosystems of the Neotropical Andes are characterized by high SOC stocks, which are important for sustaining ecosystem services. However, climate change in the form of altered precipitation patterns can potentially affect soil aggregation and SOC stability with potentially significant effects on the soil's ecosystem services. This study aimed to investigate the effects of precipitation and lithology on soil aggregation and SOC stability in the Peruvian Andean grasslands, and it assessed whether occlusion of organic matter (OM) in aggregates controls SOC stability. For this, samples were collected from soils on limestone and soils on acid igneous rocks from two sites with contrasting precipitation levels. We used a dry-sieving method to quantify aggregate-size distribution and applied a 76 d soil incubation with intact and crushed aggregates to investigate SOC stability's dependence on aggregation. SOC stocks ranged from 153±27 to 405±42 Mg ha−1, and the highest stocks were found in the limestone soils of the wet site. We found lithology rather than precipitation to be the key factor regulating soil aggregate-size distribution, as indicated by coarse aggregates in the limestone soils and fine aggregates in the acid igneous rock soils. SOC stability estimated by specific SOC mineralization rates decreased with precipitation in the limestone soils, but only minor differences were found between wet and dry sites in the acid igneous rock soils. Aggregate destruction had a limited effect on SOC mineralization, which indicates that occlusion of OM in aggregates played a minor role in OM stabilization. This was further supported by the inconsistent patterns of aggregate-size distribution compared to the patterns of SOC stability. We propose that OM adsorption on mineral surfaces is the main OM stabilization mechanism controlling SOC stocks and stability. The results highlight the interactions between precipitation and lithology on SOC stability, which are likely controlled by soil mineralogy in relation to OM input.
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Munn, L. C. "Comments on “The Influence of Eolian Dust on Alpine Soils”." Soil Science Society of America Journal 52, no. 1 (January 1988): 301. http://dx.doi.org/10.2136/sssaj1988.03615995005200010056x.
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