Ammonia Oxidizers in High-Elevation Rivers of the Qinghai-Tibet Plateau Display Distinctive Distribution Patterns

ABSTRACT Ammonia-oxidizing bacteria (AOB) and archaea (AOA) as well as comammox catalyze ammonia oxidation. The distribution and biogeography of these ammonia oxidizers might be distinctive in high-elevation rivers, which are generally characterized by low temperature and low ammonium concentration but strong solar radiation; however, these characteristics have rarely been documented. This study explored the abundance, community, and activity of ammonia oxidizers in the overlying water of five rivers in the Qinghai-Tibet Plateau (QTP). Potential nitrification rates in these rivers ranged from 5.4 to 38.4 nmol N liter−1 h−1, and they were significantly correlated with ammonium concentration rather than temperature. Comammox were found in 25 of the total 28 samples, and they outnumbered AOA in three samples. Contrary to most studied low-elevation rivers, average AOB amoA gene abundance was significantly higher than that of AOA, and AOB/AOA ratios increased with decreasing water temperature. The Simpson index of the AOA community increased with elevation (P < 0.05), and AOA and AOB communities exhibited high dissimilarities with low-elevation rivers. Cold-adapted (Nitrosospira amoA cluster 1, 33.6%) and oligotrophic (Nitrosomonas amoA cluster 6a, 31.7%) groups accounted for large proportions in the AOB community. Suspended sediment concentration exerted significant effects on ammonia oxidizer abundance (r > 0.56), and owing to their elevational variations in source and concentration, suspended sediments facilitated distance-decay patterns for AOA and AOB community similarities. This study demonstrates distinctive biogeography and distribution patterns for ammonia oxidizers in high-elevation rivers of the QTP. Extensive research should be conducted to explore the role of these microbes in the nitrogen cycle of this zone. IMPORTANCE Ammonia-oxidizing archaea (AOA) and bacteria (AOB) as well as comammox contribute to ammonia oxidation, which plays significant roles in riverine nitrogen cycle and N2O production. Source regions of numerous rivers in the world lie in high-elevation zones, but the abundance, community, and activity of ammonia oxidizers in rivers in high-elevation regions have rarely been investigated. This study revealed distinctive distribution patterns and community structures for ammonia oxidizers in five high-elevation rivers of the Qinghai-Tibet Plateau, and the individual and combined effects of low temperature, low nutrients, and strong solar radiation on ammonia oxidizers were elucidated. The findings of this study are helpful to broaden our knowledge on the biogeography and distribution pattern of ammonia oxidizers in river systems. Moreover, this study provides some implications to predict the performance of ammonia oxidizers in high-elevation rivers and its variations under global climate warming.

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The Impact of Climate Change on the Surface Albedo over the Qinghai-Tibet Plateau

Remote Sensing ◽

10.3390/rs13122336 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2336

Author(s):

Chaonan Chen ◽

Li Tian ◽

Lianqi Zhu ◽

Yuanke Zhou

Keyword(s):

Climate Change ◽

Solar Radiation ◽

Land Surface ◽

Meteorological Data ◽

Growing Season ◽

High Elevation ◽

Tibet Plateau ◽

Decrease Rate ◽

The Impact ◽

Qinghai Tibet Plateau

Albedo is a characterization of the Earth’s surface ability to reflect solar radiation, and control the amount of solar radiation absorbed by the land surface. Within the context of global warming, the temporal and spatial changes of the albedo and its response to climate factors remain unclear. Based on MCD43A3 (V005) albedo and meteorological data (i.e., temperature and precipitation), we analyzed the spatiotemporal variations of albedo (2000–2016) and its responses to climate change during the growing season on the Qinghai-Tibet Plateau (QTP). The results indicated an overall downward trend in the annual albedo during the growing season, the decrease rate was 0.25%/decade, and the monthly albedo showed a similar trend, especially in May, when the decrease rate was 0.53%/decade. The changes also showed regional variations, such as for the annual albedo, the areas with significant decrease and increase in albedo were 181.52 × 103 km2 (13.10%) and 48.82 × 103 km2 (3.52%), respectively, and the intensity of albedo changes in low-elevation areas was more pronounced than in high-elevation areas. In addition, the annual albedo-temperature/precipitation relationships clearly differed at different elevations. The albedo below 2000 m and at 5000–6000 m was mainly negatively correlated with temperature, while at 2000–4000 m it was mainly negatively correlated with precipitation. The contemporaneous temperature could negatively impact the monthly albedo in significant ways at the beginning of the growing season (May and June), whereas in the middle of the growing season (July and August), the albedo was mainly negatively correlated with precipitation, and at the end of the growing season (September), the albedo showed a weak correlation with temperature/precipitation.

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Ammonia oxidizers in river sediments of the Qinghai-Tibet Plateau and their adaptations to high-elevation conditions

Water Research ◽

10.1016/j.watres.2020.115589 ◽

2020 ◽

Vol 173 ◽

pp. 115589 ◽

Cited By ~ 5

Author(s):

Sibo Zhang ◽

Wei Qin ◽

Xinghui Xia ◽

Lingzi Xia ◽

Siling Li ◽

...

Keyword(s):

River Sediments ◽

High Elevation ◽

Tibet Plateau ◽

Ammonia Oxidizers ◽

Qinghai Tibet Plateau

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Thaumarchaeal Ammonia Oxidation in an Acidic Forest Peat Soil Is Not Influenced by Ammonium Amendment

Applied and Environmental Microbiology ◽

10.1128/aem.00595-10 ◽

2010 ◽

Vol 76 (22) ◽

pp. 7626-7634 ◽

Cited By ~ 136

Author(s):

Nejc Stopnišek ◽

Cécile Gubry-Rangin ◽

Špela Höfferle ◽

Graeme W. Nicol ◽

Ines Mandič-Mulec ◽

...

Keyword(s):

Ammonia Oxidation ◽

Denaturing Gradient Gel Electrophoresis ◽

Inorganic Nitrogen ◽

Peat Soil ◽

Selective Advantage ◽

Ammonia Oxidizer ◽

Ammonium Concentration ◽

Rrna Gene ◽

Ammonia Oxidizers ◽

Ammonia Release

ABSTRACT Both bacteria and thaumarchaea contribute to ammonia oxidation, the first step in nitrification. The abundance of putative ammonia oxidizers is estimated by quantification of the functional gene amoA, which encodes ammonia monooxygenase subunit A. In soil, thaumarchaeal amoA genes often outnumber the equivalent bacterial genes. Ecophysiological studies indicate that thaumarchaeal ammonia oxidizers may have a selective advantage at low ammonia concentrations, with potential adaptation to soils in which mineralization is the major source of ammonia. To test this hypothesis, thaumarchaeal and bacterial ammonia oxidizers were investigated during nitrification in microcosms containing an organic, acidic forest peat soil (pH 4.1) with a low ammonium concentration but high potential for ammonia release during mineralization. Net nitrification rates were high but were not influenced by addition of ammonium. Bacterial amoA genes could not be detected, presumably because of low abundance of bacterial ammonia oxidizers. Phylogenetic analysis of thaumarchaeal 16S rRNA gene sequences indicated that dominant populations belonged to group 1.1c, 1.3, and “deep peat” lineages, while known amo-containing lineages (groups 1.1a and 1.1b) comprised only a small proportion of the total community. Growth of thaumarchaeal ammonia oxidizers was indicated by increased abundance of amoA genes during nitrification but was unaffected by addition of ammonium. Similarly, denaturing gradient gel electrophoresis analysis of amoA gene transcripts demonstrated small temporal changes in thaumarchaeal ammonia oxidizer communities but no effect of ammonium amendment. Thaumarchaea therefore appeared to dominate ammonia oxidation in this soil and oxidized ammonia arising from mineralization of organic matter rather than added inorganic nitrogen.

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Analysis on Thermal Stresses Adaptability to High Grade Asphalt Pavement Structure in Qinghai-Tibet Plateau

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.723.395 ◽

2015 ◽

Vol 723 ◽

pp. 395-399

Author(s):

Ning Li ◽

Xue Yan Zhou ◽

Yu Xiang Tian ◽

Peng Wei Liu

Keyword(s):

Low Temperature ◽

Thermal Stresses ◽

Asphalt Pavement ◽

Structure Type ◽

Climatic Conditions ◽

Tibet Plateau ◽

Large Temperature ◽

Climate Conditions ◽

Pavement Structure ◽

Qinghai Tibet Plateau

Permafrostregions have harsh climate conditions, continuous low temperature, abrupt cooling, large temperature difference, winds, etc. It has an extremely obvious influencetoasphalt pavement structures and materials. Take Lhasa-Gongga airport highway as an example to analyze the low temperature cracking problem of asphalt pavement caused by the climatic conditions. Using finite element method to contrast and analyze the thermal stresses variation of different asphalt layer, and recommend suitable asphalt pavement structure for Qinghai-Tibet plateau permafrost regions.The results indicate that the thermal stresses of asphalt layer gradually reduce along with the thickness direction of structure, moment of maximum and minimum value also been delayed and thermal stresses of base cause is fairly few. It can reduce thermal stresses of base cause and asphalt layer effectively while using the AC-25, and 4cmAC13 + 6cmAC20 + 8cmAC25 is recommended for Lhasa-Gonggaairport highway pavement structure type.

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Hydrometeorological Triggering of Periglacial Debris Flows Using a Bayesian Approach: A Case Study of the Hailuogou Gully Region, China

10.21203/rs.3.rs-673988/v1 ◽

2021 ◽

Author(s):

Zheng Wang ◽

Ningsheng Chen ◽

Guisheng Hu ◽

Yong Zhang ◽

Genxu Wang ◽

...

Keyword(s):

Debris Flow ◽

Debris Flows ◽

High Elevation ◽

Tibet Plateau ◽

Hydrological Characteristics ◽

Effects Of Temperature ◽

Qinghai Tibet Plateau ◽

Hydrometeorological Conditions ◽

Debris Flow Initiation

Abstract Mount Gonggais located in the east of the Qinghai–Tibet Plateau; many debris flows have occurred in small basins with a small glacier cover or snow cover in this area. The hydrometeorological conditions that caused debris flows in this region are complex, making forecasting and early warning difficult. Previous studies for these small-glacial-covered basins have primarily considered rainfall as the only inducing factor of debris flows, and often the effects of temperature are neglected. Thus, we carried out a probabilistic analysis of variables derived from hydrometeorological factors for the Mount Gongga region, Sichuan, China, where debris flows were recorded on 14 days between 1988 and 2019. By analyzing hydrological characteristics when debris flows occurred, three distinct dominant trigger types could be identified. The results show that 7 (50%) of the observed debris flow events during the study period, high-intensity rainfall was the dominant trigger, snowmelt by high temperature was identified as the dominant trigger for 2 (14%). Furthermore, 5 (36%) debris flow events could be attributed to the combined effects of long-lasting (or short-medium) rainfall and sustained higher temperatures. We find that the differences between the trigger types are statistically significant, and a susceptibility prediction differentiating between trigger types can outperform simple rainfall-only situations. This study contributes to an improved understanding of the hydrometeorological impact on debris flow initiation in high elevation watersheds.

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A new species of Genkalia (Bacillariophyta) from mountain lakes within the Sichuan Province of China

Phytotaxa ◽

10.11646/phytotaxa.372.3.7 ◽

2018 ◽

Vol 372 (3) ◽

pp. 236 ◽

Cited By ~ 1

Author(s):

F. LUO ◽

Q-M. YOU ◽

Q-X. WANG

Keyword(s):

Central Area ◽

High Elevation ◽

Sichuan Province ◽

Tibet Plateau ◽

Diatom Species ◽

Monsoon Climate ◽

The Sichuan Basin ◽

Qinghai Tibet Plateau ◽

Secondary Side ◽

A New Species

A new diatom species, Genkalia alpina sp. nov., was identified in high elevation lakes in the Mugecuo Scenic Area within the Sichuan Province of China. The area is located in the northern foot of the Hengduan Mountains between the western edge of the Sichuan Basin and the Qinghai-Tibet Plateau, belongs to the subtropical humid monsoon climate, at an altitude of 2600–3800m, with lake water originating mostly from the melting mountain snow. Light and scanning electron microscopy revealed that G. alpina valves are linear with two undulated margins and apices that are subcapitate in larger specimens, but slightly shorter in smaller specimens. The central area is elliptical, and the external proximal raphe ends are straight, or slightly deflected towards the primary valve side. Terminal raphe fissures are strongly bent towards the secondary side and they extend to mantle. Uniseriate striae continue uninterrupted from the valve face to the mantle. The present study is the first report of Genkalia species in China, and expands the geographical distribution of the genus, as well as the known diatom diversity of China.

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Distribution patterns and morphological classification of climbing dunes in the Qinghai-Tibet Plateau

Aeolian Research ◽

10.1016/j.aeolia.2018.09.002 ◽

2018 ◽

Vol 35 ◽

pp. 58-68 ◽

Cited By ~ 1

Author(s):

Miao Dong ◽

Ping Yan ◽

Baoli Liu ◽

Wei Wu ◽

Xiaonan Meng ◽

...

Keyword(s):

Distribution Patterns ◽

Tibet Plateau ◽

Morphological Classification ◽

Qinghai Tibet Plateau

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Impact of Short-Term Acidification on Nitrification and Nitrifying Bacterial Community Dynamics in Soilless Cultivation Media

Applied and Environmental Microbiology ◽

10.1128/aem.01545-12 ◽

2012 ◽

Vol 78 (18) ◽

pp. 6576-6582 ◽

Cited By ~ 21

Author(s):

Eddie Cytryn ◽

Irit Levkovitch ◽

Yael Negreanu ◽

Scot Dowd ◽

Sammy Frenk ◽

...

Keyword(s):

Bacterial Community ◽

Community Dynamics ◽

Ammonia Oxidation ◽

Ammonium Concentration ◽

Growth Media ◽

Ammonia Oxidizers ◽

Content Type ◽

Oxidation Rates ◽

Bacterial Community Dynamics ◽

The Impact

ABSTRACTSoilless medium-based horticulture systems are highly prevalent due to their capacity to optimize growth of high-cash crops. However, these systems are highly dynamic and more sensitive to physiochemical and pH perturbations than traditional soil-based systems, especially during nitrification associated with ammonia-based fertilization. The objective of this study was to assess the impact of nitrification-generated acidification on ammonia oxidation rates and nitrifying bacterial community dynamics in soilless growth media. To achieve this goal, perlite soilless growth medium from a commercial bell pepper greenhouse was incubated with ammonium in bench-scale microcosm experiments. Initial quantitative real-time PCR analysis indicated that betaproteobacterial ammonia oxidizers were significantly more abundant than ammonia-oxidizing archaea, and therefore, research focused on this group. Ammonia oxidation rates were highest between 0 and 9 days, when pH values dropped from 7.4 to 4.9. Pyrosequencing of betaproteobacterial ammonia-oxidizingamoAgene fragments indicated that r-strategist-likeNitrosomonaswas the dominant ammonia-oxidizing bacterial genus during this period, seemingly due to the high ammonium concentration and optimal growth conditions in the soilless media. Reduction of pH to levels below 4.8 resulted in a significant decrease in both ammonia oxidation rates and the diversity of ammonia-oxidizing bacteria, with increased relative abundance of the r-strategist-likeNitrosospira. Nitrite oxidizers (NitrospiraandNitrobacter) were on the whole more abundant and less sensitive to acidification than ammonia oxidizers. This study demonstrates that nitrification and nitrifying bacterial community dynamics in high-N-load intensive soilless growth media may be significantly different from those inin-terraagricultural systems.

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Different Driving Factors for Potential Activity of Ammonia-Oxidizing Archaea and Bacteria in Coastal Wetlands

10.21203/rs.3.rs-280386/v1 ◽

2021 ◽

Author(s):

Xianfang zhu ◽

Chen Wang ◽

Shuangyu Tang ◽

Guodong Ji

Keyword(s):

Nitrogen Cycle ◽

Coastal Wetlands ◽

Ammonia Oxidation ◽

Equation Model ◽

Ammonium Concentration ◽

Ammonia Oxidizing Archaea ◽

Soil Sediment ◽

Measured Activity ◽

Structure Equation Model ◽

Potential Activity

Abstract This study aimed to evaluate which environmental factors and genetic groups were important in explaining measured activity of Ammonia-oxidizing archaea (AOA) and bacteria (AOB), which play important roles in global nitrogen cycle, providing a new insight into the mechanism of archaeal and bacterial ammonia oxidation. We sampled 62 soil/sediment samples from coastal wetlands of the Bohai area of China and assessed the abundance of functional genes involved in the nitrogen cycle, soil/sediment characteristics and the potential activity of AOA (PAOA) and AOB (PAOB) using specific inhibitors. At last, we introduced the structure equation model (SEM) to infer direct and indirect effects of variables on potential activities. The results indicated that the change in AOA-amoA gene abundance may be more independent, while AOB-amoA was closely associated with the change in abundance of amx and denitrifier. PAOA was mainly defined by AOA-amoA abundance and partially influenced by the norA gene, suggesting coupling of archaeal ammonia oxidation with nitrite oxidation. PAOB was significantly defined by the abundance of amx and denitrifier, indirectly mediated by AOB-amoA. The activity of AOA seemed to be more independent of other microbial activities, while the activity of AOB varied closely with fluctuations of other microbial species. PAOA was mediated directly by the C/N ratio and indirectly by nitrite concentration and TOC value, while PAOB was mediated directly by ammonium concentration and TOC value and indirectly by C/N ratio. The activity of AOB may be determined by several other functional gene groups and had little correlation with AOB abundance while the activity of AOA was mostly controlled by itself.

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Competition of Ammonia-Oxidizing Archaea and Bacteria from Freshwater Environments

Applied and Environmental Microbiology ◽

10.1128/aem.01038-21 ◽

2021 ◽

Author(s):

Elizabeth French ◽

Jessica A. Kozlowski ◽

Annette Bollmann

Keyword(s):

Ammonia Oxidation ◽

Heterotrophic Bacteria ◽

Ammonia Oxidizer ◽

Ammonium Concentration ◽

Natural Environments ◽

Ammonia Oxidizing Bacteria ◽

Ammonia Oxidizers ◽

Batch Cultures ◽

Freshwater Systems ◽

Ammonia Oxidizing Archaea

In the environment, nutrients are rarely available in constant supply. Therefore, microorganisms require strategies to compete for limiting nutrients. In freshwater systems, ammonia-oxidizing archaea (AOA) and bacteria (AOB) compete with heterotrophic bacteria, photosynthetic microorganisms, and each other for ammonium, which AOA and AOB utilize as their sole source of energy and nitrogen. We investigated the competition between highly enriched cultures of an AOA (AOA-AC1) and an AOB (AOB-G5-7) for ammonium. Based on the amoA gene, the newly enriched archaeal ammonia oxidizer in AOA-AC1 was closely related to Nitrosotenuis spp. and the bacterial ammonia oxidizer in AOB-G5-7, Nitrosomonas sp. Is79, belonged to the Nitrosomonas oligotropha group ( Nitrosomonas cluster 6a). Growth experiments in batch cultures showed that AOB-G5-7 had higher growth rates than AOA-AC1 at higher ammonium concentrations. During chemostat competition experiments under ammonium-limiting conditions, AOA-AC1 dominated the cultures, while AOB-G5-7 decreased in abundance. In batch cultures, the outcome of the competition between AOA and AOB was determined by the initial ammonium concentrations. AOA-AC1 was the dominant ammonia oxidizer at an initial ammonium concentration of 50 μM and AOB-G5-7 at 500 μM. These findings indicate that, during direct competition, AOA-AC1 was able to use ammonium that was unavailable to AOB-G5-7, while AOB-G5-7 dominated at higher ammonium concentrations. The results are in strong accordance with environmental survey data suggesting that AOA are mainly responsible for ammonia oxidation under more oligotrophic conditions, whereas AOB dominate under eutrophic conditions. Importance Nitrification is an important process in the global nitrogen cycle. The first step - ammonia oxidation to nitrite – can be carried out by Ammonia-oxidizing Archaea (AOA) and Ammonia-oxidizing Bacteria (AOB). In many natural environments, these ammonia oxidizers coexist. Therefore, it is important to understand the population dynamics in response to increasing ammonium concentrations. Here, we study the competition between AOA and AOB enriched from freshwater systems. The results demonstrate that AOA are more abundant in systems with low ammonium availabilities and AOB when the ammonium availability increases. These results will help to predict potential shifts in community composition of ammonia oxidizers in the environment due to changes in ammonium availability.

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