scholarly journals Can water temperature impact litter decomposition under pollution of copper and zinc mixture

2018 ◽  
Vol 16 (1) ◽  
pp. 473-480
Author(s):  
Gaozhong Pu ◽  
Xingjun Tian
Keyword(s):  
Water Temperature ◽  
Litter Decomposition ◽  
Enzyme Activities ◽  
Extracellular Enzyme ◽  
Plant Litter ◽  
Microbial Decomposition ◽  
Litter Mass ◽  
Mass Losses ◽  
The Impact ◽  
Cu And Zn

AbstractTo better understand the impact of warming on heavy metals (HM) associated with plant litter decomposition in streams, we investigated the impact of high and low HM (Cu and Zn) levels and different water temperatures (10,15 and 20oC) on microbial decomposition of TyphaangustifoliaL.litter and the associated extracellular enzyme activities. During a 100-day incubation, changes in litter mass losses, chemical composition (lignin and total carbohydrate), and extracellular enzyme activity were determined. The decomposition rates were accelerated by the low HM levels at 20oC (0.0051 day–1 at CK vs 0.0061 day–1 at low HM levels). The negative effects of Cu and Zn on Typha litter decomposition were more pronounced at lower temperatures (10 and 15°C). The enhanced enzyme activities of cellulase and β-glucosidase and the higher lignin/litter weight loss and lignin/carbohydrate ratios were found at 20oC and low HM treatment. The enzyme activities of β-glucosidase and cellulase were positively correlated with litter mass losses at 20oC and low HM levels. These results suggest that a 5oC increase in water temperature may attenuate the inhibition of low HM level on litter decomposition.

scholarly journals Experimental evidence for the impact of soil viruses on carbon cycling during surface plant litter decomposition

2021 ◽  
Author(s):  
Michaeline BN Albright ◽  
La Verne Gallegos-Graves ◽  
Kelli L. Feeser ◽  
Kyana Montoya ◽  
Joanne B Emerson ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Carbon Cycling ◽  
Litter Decomposition ◽  
Indirect Evidence ◽  
Plant Litter ◽  
Fungal Community Composition ◽  
Live Virus ◽  
Plant Litter Decomposition ◽  
Combining Data ◽  
The Impact

To date, the potential impact of viral communities on biogeochemical cycles in soil has largely been inferred from indirect evidence, such as virus-driven changes in microbial abundances, viral auxiliary metabolic genes, and correlations with soil physiochemical properties. To more directly test the impact of soil viruses on carbon cycling during plant litter decomposition, we added concentrated viral community suspensions to complex litter decomposer communities in 40-day microcosm experiments. Microbial communities from two New Mexico alpine soils, Pajarito (PJ) and Santa Fe (SF), were inoculated onto grass litter on sand, and three treatments were applied in triplicate to each set of microcosms: addition of buffer (no added virus), addition of live virus (+virus), or killed virus (+killed-virus) fractions extracted from the same soil. Significant differences in respiration were observed between the +virus and +killed-virus treatments in the PJ, but not the SF microcosms. Bacterial and fungal community composition differed significantly by treatment in both PJ and SF microcosms. Combining data across both soils, viral addition altered links between bacterial and fungal diversity, dissolved organic carbon and total nitrogen. Overall, we demonstrate that increasing viral pressure in complex microbial communities can impact terrestrial biogeochemical cycling but is context-dependent.

The Impact of Uranium Mine Contamination of Soils on Plant Litter Decomposition

2014 ◽  
Vol 67 (4) ◽  
pp. 601-616 ◽  
Author(s):  
Ana C. Freitas ◽  
Dina Rodrigues ◽  
Teresa A. P. Rocha-Santos ◽  
Fernando Gonçalves ◽  
Armando C. Duarte ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Plant Litter ◽  
Uranium Mine ◽  
Plant Litter Decomposition ◽  
Contamination Of Soils ◽  
The Impact

Litter mass-loss rates and decomposition patterns in some needle and leaf litter types. Long-term decomposition in a Scots pine forest. VII

1991 ◽  
Vol 69 (7) ◽  
pp. 1449-1456 ◽  
Author(s):  
Björn Berg ◽  
Gunnar Ekbohm
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Nitrogen Concentration ◽  
White Birch ◽  
Litter Mass ◽  
Mass Losses ◽  
Litter Mass Loss

The decomposition dynamics of four types of needle litter and three types of leaf litter were followed for 4 years. Mass losses and certain chemical changes were studied. Most of the nutrient-rich litters appeared to decompose relatively quickly during the first 12–18 months. After 3–4 years, however, their accumulated mass losses were lower compared with litter types that intially had lower rates. Thus the more nutrient-rich litters had considerably lower mass-loss rates in the later stages. This pattern was even more pronouced for extract-free lignocellulose: its mass-loss rate was negatively related to the lignin concentration, which increased progressively as litter decomposition proceeded. During late stages in litter with a high nitrogen content, there was also a clear negative relation between nitrogen concentration and lignin mass-loss rate, as well as between nitrogen concentration and litter mass-loss rate. By extrapolation of measured mass-loss values, maximum values for accumulated litter–mass loss were estimated. A nonlinear statistical model predicted that the proportion of mass lost through decomposition should be 50% for grey alder leaves, 54% for green leaves of white birch, and 57% for brown leaves of white birch. For Scots pine the predicted maximums for accumulated mass loss were 68% for green needles and 89% for brown needles, whereas corresponding values for lodgepole pine needles were 81% (green) and 100% (brown). Lodgepole pine is an introduced species in this system. Key words: litter, decomposition, lignin, nitrogen, maxium mass loss.

scholarly journals Litter Quality Is a Stronger Driver than Temperature of Early Microbial Decomposition in Oligotrophic Streams: a Microcosm Study

2021 ◽  
Author(s):  
Javier Pérez ◽  
Verónica Ferreira ◽  
Manuel A. S. Graça ◽  
Luz Boyero
Keyword(s):  
Water Temperature ◽  
Litter Decomposition ◽  
Atmospheric Carbon Dioxide ◽  
Litter Quality ◽  
Aquatic Hyphomycetes ◽  
Microbial Decomposition ◽  
Microcosm Study ◽  
Stream Functioning ◽  
Two Factors ◽  
Sporulation Rate

AbstractLitter decomposition is an ecological process of key importance for forest headwater stream functioning, with repercussions for the global carbon cycle. The process is directly and indirectly mediated by microbial decomposers, mostly aquatic hyphomycetes, and influenced by environmental and biological factors such as water temperature and litter quality. These two factors are forecasted to change globally within the next few decades, in ways that may have contrasting effects on microbial-induced litter decomposition: while warming is expected to enhance microbial performance, the reduction in litter quality due to increased atmospheric carbon dioxide and community composition alteration may have the opposite outcome. We explored this issue through a microcosm experiment focused on early microbial-mediated litter decomposition under stream oligotrophic conditions, by simultaneously manipulating water temperature (10 °C and 15 °C) and litter quality (12 broadleaf plant species classified into 4 categories based on initial concentrations of nitrogen and tannins). We assessed potential changes in microbial-mediated litter decomposition and the performance of fungal decomposers (i.e., microbial respiration, biomass accrual, and sporulation rate) and species richness. We found stronger effects of litter quality, which enhanced the performance of microbial decomposers and decomposition rates, than temperature, which barely influenced any of the studied variables. Our results suggest that poorer litter quality associated with global change will have a major repercussion on stream ecosystem functioning.

scholarly journals Optimising methodology for determining the effect of ocean acidification on bacterial extracellular enzymes

2015 ◽  
Vol 12 (8) ◽  
pp. 5841-5870 ◽  
Author(s):  
T. J. Burrell ◽  
E. W. Maas ◽  
P. Teesdale-Spittle ◽  
C. S. Law
Keyword(s):  
Organic Matter ◽  
Ocean Acidification ◽  
Enzyme Activities ◽  
Extracellular Enzymes ◽  
Extracellular Enzyme ◽  
Labile Organic Matter ◽  
Glucosidase Activity ◽  
Effects Of Ph ◽  
The Impact ◽  
Silicon Tubing

Abstract. To fully understand the impact of ocean acidification on biogeochemical cycles, the response of bacterial extracellular enzymes needs to be considered as they play a central role in the degradation and distribution of labile organic matter. This study investigates the methodology, and potential artefacts involved in determining the response of bacterial extracellular glucosidase and protease to ocean acidification. The effect of pH on artificial fluorophores and substrates was examined, as well as the impact of three different acidification methods. The results indicate that pH has a significant effect on the fluorescence of the artificial fluorophore 4-methylumbeliferone for glucosidase activity, and 7-amino-4-methylcoumarin for protease activity, while artificial aminopeptidase substrate alters the pH of seawater, confirming previous observations. Before use in ocean acidification research these enzyme assay components must be buffered in order to stabilise sample pH. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5 h), while no significant response was detected for leucine aminopeptidase, highlighting the need for short-term direct effects of pH on enzyme activities. Bubbling with CO2 gas resulted in higher β-glucosidase activity when compared to acidification using gas-permeable silicon tubing and acidification with HCl. Although bubbling showed variable effects between two experiments conducted at different times of the year. In addition, bacterial cell numbers were 15–40% higher with bubbling relative to seawater acidified with gas-permeable silicon tubing and HCl. Artefacts associated with bubbling may lead to the overestimation of extracellular enzyme activities, and interpretation of the impacts of ocean acidification on organic matter cycling.

scholarly journals Light Pollution Changes the Toxicological Effects of Cadmium on Microbial Community Structure and Function Associated with Leaf Litter Decomposition

2020 ◽  
Vol 21 (2) ◽  
pp. 422 ◽  
Author(s):  
Zhuangzhuang Liu ◽  
Yanna Lv ◽  
Rongcai Ding ◽  
Xiaxia Chen ◽  
Gaozhong Pu
Keyword(s):  
Community Structure ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Aquatic Ecosystems ◽  
Negative Impact ◽  
Plant Litter ◽  
Leaf Litter Decomposition ◽  
Fungal Community Structure ◽  
Toxicological Effects ◽  
The Impact

Artificial light at night (ALAN/A) can not only alter the behavior and communication of biological organisms, it can also interact with other stressors. Despite its widespread use and the numerous potential ecological effects, little is known about the impact of ALAN on plant litter decomposition under cadmium (Cd) pollution in aquatic ecosystems. In an indoor microcosm experiment, we tested single and combined effects of ALAN and Cd on the activities and community structure of fungi associated with plant litter. The results showed that ALAN and/or Cd can change both water and leaf litter characteristics. ALAN exposure not only altered fungal community structure and their correlations, but also increased the activities of alkaline phosphatase, β-glucosidase, and cellobiohydrolase. The leaf litter decomposition rate was 71% higher in the A-Cd treatment than that in the N-Cd treatment, indicating that the presence of ALAN weakened the negative impact of Cd on leaf litter decomposition. These results suggested that ALAN exposure mitigated the negative effect of Cd on leaf litter decomposition, contributing to the duel effect of ALAN on leaf litter decomposition. Overall, the results expand our understanding of ALAN on the environment and highlight the contribution of ALAN to Cd toxicity in aquatic ecosystems.

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