scholarly journals Early Spring Snowmelt and Summer Droughts Strongly Impair the Resilience of Key Microbial Communities in Subalpine Grassland Ecosystems

2021 ◽  
Author(s):  
Farhan Hafeez ◽  
Lionel Bernard ◽  
Jean-Christophe Clement ◽  
Franck Poly ◽  
Thomas Pommier
Keyword(s):  
Microbial Communities ◽  
Plant Biomass ◽  
Early Spring ◽  
Climatic Extremes ◽  
Soil Microbial ◽  
Cascading Effect ◽  
Growing Seasons ◽  
Grassland Ecosystems ◽  
Microbial Responses ◽  
Early Snowmelt

Subalpine grassland ecosystems are important from biodiversity, agriculture, and touristic perspectives but their resilience to seasonally occurring climatic extremes is increasingly challenged with climate change, accelerating their vulnerability to tipping points. Microbial communities, which are central in ecosystem functioning, are usually considered as more resistant and highly resilient to such extreme events due to their functional redundancy and strong selection in residing habitats. To investigate this, we explored the soil microbial responses upon recurrent summer droughts associated with early snowmelt in grasslands mesocosms set-up at the Lautaret Pass (French Alps). Potential respiration, nitrification and denitrification were monitored over a period of two growing seasons along with quantification of community gene abundances of total bacteria as well as (de)nitrifiers. Results revealed that droughts had a low and short-term impact on bacterial total respiration supporting their hypothesized high resistance and ability to recover. Nitrification and abundances of the corresponding functional guilds showed relatively strong resistance to summer droughts but declined in response to early snowmelt. This triggered a cascading effect on denitrification but also on the abundances of denitrifying communities which could recover from all climatic extremes except from the summer droughts where nitrifiers were collapsed. Denitrification and the respective functional groups faced high impact of applied stresses with strong reduction in the abundance and activity of this specialized community. Although, the consequently lower microbial competition for nitrate may be positive for plant biomass production, warnings exist when considering the potential nitrogen leaching from these ecosystems as well as risks of greenhouses gases emission such as N2O

scholarly journals Resilience and Assemblage of Soil Microbiome in Response to Chemical Contamination Combined with Plant Growth

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
Shuo Jiao ◽  
Weimin Chen ◽  
Gehong Wei
Keyword(s):  
Microbial Communities ◽  
Soil Microbial Communities ◽  
Soil Microbiome ◽  
Chemical Contamination ◽  
Plant Interactions ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Microbial Responses ◽  
Legume Plants ◽  
Functional Profiles

ABSTRACT A lack of knowledge of the microbial responses to environmental change at the species and functional levels hinders our ability to understand the intrinsic mechanisms underlying the maintenance of microbial ecosystems. Here, we present results from temporal microcosms that introduced inorganic and organic contaminants into agro-soils for 90 days, with three common legume plants. Temporal dynamics and assemblage of soil microbial communities and functions in response to contamination under the influence of growth of different plants were explored via sequencing of the 16S rRNA amplicon and by shotgun metagenomics. Soil microbial alpha diversity and structure at the taxonomic and functional levels exhibited resilience patterns. Functional profiles showed greater resilience than did taxonomic ones. Different legume plants imposed stronger selection on taxonomic profiles than on functional ones. Network and random forest analyses revealed that the functional potential of soil microbial communities was fostered by various taxonomic groups. Betaproteobacteria were important predictors of key functional traits such as amino acid metabolism, nucleic acid metabolism, and hydrocarbon degradation. Our study reveals the strong resilience of the soil microbiome to chemical contamination and sensitive responses of taxonomic rather than functional profiles to selection processes induced by different legume plants. This is pivotal to develop approaches and policies for the protection of soil microbial diversity and functions in agro-ecosystems with different response strategies from global environmental drivers, such as soil contamination and plant invasion. IMPORTANCE Exploring the microbial responses to environmental disturbances is a central issue in microbial ecology. Understanding the dynamic responses of soil microbial communities to chemical contamination and the microbe-soil-plant interactions is essential for forecasting the long-term changes in soil ecosystems. Nevertheless, few studies have applied multi-omics approaches to assess the microbial responses to soil contamination and the microbe-soil-plant interactions at the taxonomic and functional levels simultaneously. Our study reveals clear succession and resilience patterns of soil microbial diversity and structure in response to chemical contamination. Different legume plants exerted stronger selection processes on taxonomic than on functional profiles in contaminated soils, which could benefit plant growth and fitness as well as foster the potential abilities of hydrocarbon degradation and metal tolerance. These results provide new insight into the resilience and assemblage of soil microbiome in response to environmental disturbances in agro-ecosystems at the species and functional levels.

scholarly journals Annual Removal of Aboveground Plant Biomass Alters Soil Microbial Responses to Warming

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Kai Xue ◽  
Mengting M. Yuan ◽  
Jianping Xie ◽  
Dejun Li ◽  
Yujia Qin ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Soil Carbon ◽  
Plant Biomass ◽  
Biofuel Production ◽  
Interactive Effects ◽  
Functional Genes ◽  
Soil Microbial ◽  
Recalcitrant Carbon ◽  
Microbial Responses

ABSTRACT Clipping (i.e., harvesting aboveground plant biomass) is common in agriculture and for bioenergy production. However, microbial responses to clipping in the context of climate warming are poorly understood. We investigated the interactive effects of grassland warming and clipping on soil properties and plant and microbial communities, in particular, on microbial functional genes. Clipping alone did not change the plant biomass production, but warming and clipping combined increased the C 4 peak biomass by 47% and belowground net primary production by 110%. Clipping alone and in combination with warming decreased the soil carbon input from litter by 81% and 75%, respectively. With less carbon input, the abundances of genes involved in degrading relatively recalcitrant carbon increased by 38% to 137% in response to either clipping or the combined treatment, which could weaken long-term soil carbon stability and trigger positive feedback with respect to warming. Clipping alone also increased the abundance of genes for nitrogen fixation, mineralization, and denitrification by 32% to 39%. Such potentially stimulated nitrogen fixation could help compensate for the 20% decline in soil ammonium levels caused by clipping alone and could contribute to unchanged plant biomass levels. Moreover, clipping tended to interact antagonistically with warming, especially with respect to effects on nitrogen cycling genes, demonstrating that single-factor studies cannot predict multifactorial changes. These results revealed that clipping alone or in combination with warming altered soil and plant properties as well as the abundance and structure of soil microbial functional genes. Aboveground biomass removal for biofuel production needs to be reconsidered, as the long-term soil carbon stability may be weakened. IMPORTANCE Global change involves simultaneous alterations, including those caused by climate warming and land management practices (e.g., clipping). Data on the interactive effects of warming and clipping on ecosystems remain elusive, particularly in microbial ecology. This study found that clipping alters microbial responses to warming and demonstrated the effects of antagonistic interactions between clipping and warming on microbial functional genes. Clipping alone or combined with warming enriched genes degrading relatively recalcitrant carbon, likely reflecting the decreased quantity of soil carbon input from litter, which could weaken long-term soil C stability and trigger positive warming feedback. These results have important implications in assessing and predicting the consequences of global climate change and indicate that the removal of aboveground biomass for biofuel production may need to be reconsidered.

Microbial Dynamic Changes under Different Grazing Intensities in Growing Seasons of Desert Steppe

2013 ◽  
Vol 864-867 ◽  
pp. 2635-2638
Author(s):  
Jing He ◽  
Ting Ting Yang ◽  
Tao Shi ◽  
Guo Zheng Yao
Keyword(s):  
Soil Bacteria ◽  
Measured Data ◽  
Desert Steppe ◽  
Dynamic Changes ◽  
Soil Microbial ◽  
Growing Seasons ◽  
Grassland Ecosystems ◽  
Ground Survey ◽  
Grazing Intensities ◽  
Microbial Dynamic

Soil microbial plays a very important role in the grassland ecosystems, but measured data is very lack. In this paper, based on the ground survey data microbial dynamic changes in growing seasons of Desert steppe in 2012 was estimated. The main conclusions are as follows: soil bacteria number began to increase in May, reached to highest value in July and then began to decrease. Actinomycetes population increased first and then decreased. Fungus amount decreased in beginning and then increased. Grazing significantly affect the number of soil microbial, shown as soil microbial of very severe grazing fences are significantly lower than other fences.

scholarly journals Soil Microbial Activity and Diversity in Response to Soil Chemical Factors in Agricultural Soils

2019 ◽  
Vol 24 (1) ◽  
pp. 43
Author(s):  
Lily Ishak ◽  
Philip Hugh Brown
Keyword(s):  
Microbial Communities ◽  
Agricultural Soils ◽  
Soil Health ◽  
Soil Microbial Communities ◽  
Soil Microbial Activity ◽  
Soil Microbial Diversity ◽  
Soil Microbial ◽  
Microbial Responses ◽  
Chemical Factors ◽  
Microbial Groups

The role of microbial communities in maintaining soil health is mostly influenced by chemical condition of soil. Microbial communities vary in response to soil chemical factors. The contradictive results from previous findings emphasise that it is difficult to define a pattern of the influence of soil chemical factors on soil microbial diversity and activity. The aim of the study was to assess soil microbial responses to soil chemical factors in agricultural soils. Composite soil (Dermosol order) samples taken from 16 commercial crop sites in Bundaberg, Queensland, Australia, were chemically and biologically analysed. It was found that bacterial and fungal activity and diversity were significantly affected by soil EC, SOM and NO3-N content, but were not influenced by soil pH, CEC, and Ca:Mg ratio. The diversity of bacterial and fungal communities displayed a positive linear relationship with soil EC, whereas the activity and diversity of these two microbial groups and SOM displayed a significant quadratic relationship. The finding suggested that microbial community was predominantly influenced by SOM content.

scholarly journals Impact of Metal Pollution and Thlaspi caerulescens Growth on Soil Microbial Communities

2010 ◽  
Vol 76 (23) ◽  
pp. 7843-7853 ◽  
Author(s):  
Lur Epelde ◽  
Jos� M. Becerril ◽  
George A. Kowalchuk ◽  
Ye Deng ◽  
Jizhong Zhou ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Microbial Communities ◽  
Metal Pollution ◽  
Basal Respiration ◽  
Ammonia Oxidizing Bacteria ◽  
Microbial Properties ◽  
Soil Microbial ◽  
Microbial Responses ◽  
Substrate Induced Respiration ◽  
Total Bacteria

ABSTRACT Soil microorganisms drive critical functions in plant-soil systems. As such, various microbial properties have been proposed as indicators of soil functioning, making them potentially useful in evaluating the recovery of polluted soils via phytoremediation strategies. To evaluate microbial responses to metal phytoextraction using hyperaccumulators, a microcosm experiment was carried out to study the impacts of Zn and/or Cd pollution and Thlaspi caerulescens growth on key soil microbial properties: basal respiration; substrate-induced respiration (SIR); bacterial community structure as assessed by PCR-denaturing gradient gel electrophoresis (DGGE); community sizes of total bacteria, ammonia-oxidizing bacteria, and chitin-degrading bacteria as assessed by quantitative PCR (Q-PCR); and functional gene distributions as determined by functional gene arrays (GeoChip). T. caerulescens proved to be suitable for Zn and Cd phytoextraction: shoots accumulated up to 8,211 and 1,763 mg kg−1 (dry weight [DW]) of Zn and Cd, respectively. In general, Zn pollution led to decreased levels of basal respiration and ammonia-oxidizing bacteria, while T. caerulescens growth increased the values of substrate-induced respiration (SIR) and total bacteria. In soils polluted with 1,000 mg Zn kg−1 and 250 mg Cd kg−1 (DW), soil bacterial community profiles and the distribution of microbial functional genes were most affected by the presence of metals. Metal-polluted and planted soils had the highest percentage of unique genes detected via the GeoChip (35%). It was possible to track microbial responses to planting with T. caerulescens and to gain insight into the effects of metal pollution on soilborne microbial communities.

scholarly journals Responses of tundra soil microbial communities to half a decade of experimental warming at two critical depths

2019 ◽  
Vol 116 (30) ◽  
pp. 15096-15105 ◽  
Author(s):  
Eric R. Johnston ◽  
Janet K. Hatt ◽  
Zhili He ◽  
Liyou Wu ◽  
Xue Guo ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Active Layer ◽  
Soil Microbial Communities ◽  
Fold Increase ◽  
Tundra Soil ◽  
Tundra Soils ◽  
Carbohydrate Utilization ◽  
Soil Microbial ◽  
C Stocks ◽  
Microbial Responses

Northern-latitude tundra soils harbor substantial carbon (C) stocks that are highly susceptible to microbial degradation with rising global temperatures. Understanding the magnitude and direction (e.g., C release or sequestration) of the microbial responses to warming is necessary to accurately model climate change. In this study, Alaskan tundra soils were subjected to experimental in situ warming by ∼1.1 °C above ambient temperature, and the microbial communities were evaluated using metagenomics after 4.5 years, at 2 depths: 15 to 25 cm (active layer at outset of the experiment) and 45 to 55 cm (transition zone at the permafrost/active layer boundary at the outset of the experiment). In contrast to small or insignificant shifts after 1.5 years of warming, 4.5 years of warming resulted in significant changes to the abundances of functional traits and the corresponding taxa relative to control plots (no warming), and microbial shifts differed qualitatively between the two soil depths. At 15 to 25 cm, increased abundances of carbohydrate utilization genes were observed that correlated with (increased) measured ecosystem carbon respiration. At the 45- to 55-cm layer, increased methanogenesis potential was observed, which corresponded with a 3-fold increase in abundance of a single archaeal clade of the Methanosarcinales order, increased annual thaw duration (45.3 vs. 79.3 days), and increased CH4 emissions. Collectively, these data demonstrate that the microbial responses to warming in tundra soil are rapid and markedly different between the 2 critical soil layers evaluated, and identify potential biomarkers for the corresponding microbial processes that could be important in modeling.

scholarly journals Plant And Soil Microbial Communities Regulate Soil Respiration In Response To Precipitation And Land Use In An Inner Mongolian Grassland

2021 ◽  
Author(s):  
Chi Zhang ◽  
Chao Song ◽  
Donghui Wang ◽  
Wenkuan Qin ◽  
Biao Zhu ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Respiration ◽  
Microbial Communities ◽  
Precipitation Amount ◽  
Soil Microbial Communities ◽  
Soil Microbial ◽  
Altered Precipitation ◽  
Grassland Ecosystems ◽  
Mongolian Grassland

Abstract Purpose: Changes in precipitation amount and land use are expected to greatly impact soil respiration (Rs) of grassland ecosystems. However, little is known about whether they can interactively impact Rs and how plant and soil microbial communities regulate the response of Rs. Methods: Here, we investigated the impacts of altered precipitation amount (–50%, ambient and +50%) and land-use regime (fencing, mowing and grazing) on Rs with a field experiment in the Inner Mongolian grassland.Results: We found that altered precipitation amount impacted Rs and its components across the 3-year study period, while land-use regime alone or its interaction with precipitation amount impacted them in certain years. In addition, changed soil microclimate, especially soil moisture, under altered precipitation amount and land-use regime can impact the components of Rs either directly or indirectly via influencing plant and soil microbial communities.Conclusions: Integrating changing precipitation amount and land-use regime within experiment can produce more accurate insights into grassland Rs, and chronically shifted plant and soil microbial communities under these changes may result in distinct long-term impacts on Rs.

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