scholarly journals Different mechanisms underlying divergent responses of autotrophic and heterotrophic respiration to long-term throughfall reduction in a warm-temperate oak forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jinglei Zhang ◽  
Shirong Liu ◽  
Cuiju Liu ◽  
Hui Wang ◽  
Junwei Luan ◽  
...  
Keyword(s):  
Soil Microorganisms ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Oak Forest ◽  
Prolonged Drought ◽  
Bacterial Richness ◽  
The Impact ◽  
Warm Temperate ◽  
Throughfall Reduction

Abstract Background There are many studies on disentangling the responses of autotrophic (AR) and heterotrophic (HR) respiration components of soil respiration (SR) to long-term drought, but few studies have focused on the mechanisms underlying its responses. Methods To explore the impact of prolonged drought on AR and HR, we conducted the 2-year measurements on soil CO2 effluxes in the 7th and 8th year of manipulated throughfall reduction (TFR) in a warm-temperate oak forest. Results Our results showed long-term TFR decreased HR, which was positively related to bacterial richness. More importantly, some bacterial taxa such as Novosphingobium and norank Acidimicrobiia, and fungal Leptobacillium were identified as major drivers of HR. In contrast, long-term TFR increased AR due to the increased fine root biomass and production. The increased AR accompanied by decreased HR appeared to counteract each other, and subsequently resulted in the unchanged SR under the TFR. Conclusions Our study shows that HR and AR respond in the opposite directions to long-term TFR. Soil microorganisms and fine roots account for the respective mechanisms underlying the divergent responses of HR and AR to long-term TFR. This highlights the contrasting responses of AR and HR to prolonged drought should be taken into account when predicting soil CO2 effluxes under future droughts.

scholarly journals Different mechanisms underlying divergent responses of autotrophic and heterotrophic respiration to long-term throughfall reduction in a warm-temperate oak forest

2021 ◽  
Author(s):  
Jinglei Zhang ◽  
Shirong Liu ◽  
Cuiju Liu ◽  
Hui Wang ◽  
Junwei Luan ◽  
...  
Keyword(s):  
Soil Microorganisms ◽  
Fine Root ◽  
Fine Root Biomass ◽  
Oak Forest ◽  
Prolonged Drought ◽  
Bacterial Richness ◽  
The Impact ◽  
Warm Temperate ◽  
Throughfall Reduction

Abstract Background: There are many studies on disentangling the responses of autotrophic (AR) and heterotrophic (HR) respiration components of soil respiration (SR) to long-term drought, but few studies have focused on the mechanisms underlying its responses.Methods: To explore the impact of prolonged drought on AR and HR, We conducted the 2-year measurements on soil CO2 effluxes in the 7th and 8th year of manipulated throughfall reduction (TFR) in a warm-temperate oak forest. Results: Our results showed long-term TFR decreased HR, which was positively related to bacterial richness. More importantly, some bacterial taxa such as Novosphingobium and norank Acidimicrobiia, and fungal Leptobacillium were identified as major drivers of HR. In contrast, long-term TFR increased AR due to the increased fine root biomass and production. The increased AR accompanied by decreased HR appeared to counteract each other, and subsequently resulted in the unchanged SR under the TFR. Conclusions: Our study shows that HR and AR respond in the opposite directions to long-term TFR. Soil microorganisms and fine roots account for the respective mechanisms underlying the divergent responses of HR and AR to long-term TFR. This highlights the contrasting responses of AR and HR to prolonged drought should be taken into account when predicting soil CO2 effluxes under future droughts.

scholarly journals Soil Bacterial and Fungal Richness and Network Exhibit Different Responses to Long-Term Throughfall Reduction in a Warm-Temperate Oak Forest

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 165
Author(s):  
Jinglei Zhang ◽  
Shirong Liu ◽  
Cuiju Liu ◽  
Hui Wang ◽  
Junwei Luan ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Bacterial Species ◽  
Soil Microbial Communities ◽  
Fine Root Biomass ◽  
Oak Forest ◽  
Soil Microbial ◽  
Soil Bacterial ◽  
Warm Temperate ◽  
Throughfall Reduction

Prolonged drought results in serious ecological consequences in forest ecosystems, particularly for soil microbial communities. However, much is unknown about soil microbial communities in their response to long-term consecutive droughts in warm-temperate forests. Here, we conducted a 7-year manipulated throughfall reduction experiment (TFR) to examine the responses of bacterial and fungal communities in terms of richness and networks. Our results show that long-term TFR reduced bacterial, but not fungal, richness, with rare bacterial taxa being more sensitive to TFR than dominant taxa. The bacterial network under the TFR treatment featured a simpler network structure and fewer competitive links compared to the control, implying weakened interactions among bacterial species. Bacterial genes involved in xenobiotic biodegradation and metabolism, and lignin-degrading enzymes were enhanced under TFR treatment, which may be attributed to TFR-induced increases in fine root biomass and turnover. Our results indicate that soil bacterial communities are more responsive than fungi to long-term TFR in a warm-temperate oak forest, leading to potential consequences such as the degradation of recalcitrant organics in soil.

Soil respiration and its components respond asymmetrically to throughfall reduction and nitrogen additions in a subtropical Moso bamboo forest in the Southwest China

2020 ◽  
Author(s):  
Yi Wang ◽  
Shirong Liu ◽  
Junwei Luan
Keyword(s):  
Global Change ◽  
Soil Respiration ◽  
Southwest China ◽  
Fine Root ◽  
Global Climate ◽  
Moso Bamboo ◽  
Change Factors ◽  
The Impact ◽  
Throughfall Reduction ◽  
Nitrogen Additions

<p>The roles of multiple global change are expected for many terrestrial ecosystems in future. As two main global change factors, the impact of drought and nitrogen deposition and their interaction on soil respiration and its components (R) remains unclear. To explore the responses of soil respiration (R<sub>s</sub>), autotrophic respiration (R<sub>a</sub>) and heterotrophic respiration (R<sub>h</sub>) to multiple global change factors, we established a field experiment of throughfall reduction and nitrogen additions in a subtropical Moso bamboo (<em>Phyllostachys heterocycla</em>) forest in the Southwest China, using a 4 × 4 completely randomized design. Results showed that bivariate exponential equation with soil temperature (T) and soil moisture (SWC) (R=a.e<sup>bT</sup>.SWC<sup>c</sup>) was fitted to predict R<sub>s</sub>, R<sub>a</sub> and R<sub>h</sub>. Throughfall reduction, nitrogen additions and their interaction had no effect on annual mean R<sub>s</sub> and R<sub>a</sub>, but nitrogen additions significantly depressed annual mean R<sub>h</sub>. Nitrogen additions significantly decreased contribution of R<sub>h</sub> to R<sub>s</sub> and increased contribution of R<sub>a</sub> to R<sub>s</sub>, however, the contributions were non-responsive under throughfall reduction. The more positive effect of nitrogen additions on the contribution of R<sub>a</sub> to R<sub>s</sub> was appeared compared with that of throughfall reduction, thereby more negative effect on the contribution of R<sub>h</sub> to R<sub>s</sub>. The fine root biomass, fine root carbon and nitrogen storage regulated R<sub>s</sub>, while fine root phosphorus storage determined R<sub>a</sub>. The R<sub>h</sub> was negatively correlated with vector lengths, thus suggesting that microbial carbon limitation caused the decline of R<sub>h</sub>. Our findings demonstrate that the nitrogen additions played overriding role than throughfall reduction in affecting the contribution of R<sub>a</sub> and R<sub>h</sub> to R<sub>s</sub>. Moreover, the negative response of temperature sensitivity of R<sub>s</sub> and R<sub>h</sub> to nitrogen additions, suggesting that that the nitrogen additions may weaken the positive response of soil CO<sub>2</sub> emission to global climate warming. Our study highlights asymmetrical responses of R<sub>s</sub>, R<sub>a</sub> and R<sub>h </sub>to throughfall reduction and nitrogen additions and could enhance accurate predictions of soil carbon dynamics in response to multiple global climate change in future.</p>

scholarly journals The impact of copper-containing pesticides on ecological attributes and agricultural value of soils. The need for monitoring and assessment

2020 ◽  
Author(s):  
V.V. Gabechaya ◽  
◽  
I.V. Andreeva ◽  
I.I. Vasenev ◽  
A.A. Neaman ◽  
...  
Keyword(s):  
Copper Content ◽  
Soil Microorganisms ◽  
Soil Surface ◽  
Ecological Attributes ◽  
Decomposition Processes ◽  
The World ◽  
Vineyard Soil ◽  
Vineyard Soils ◽  
The Impact

Copper-based pesticides have been used around the world for more than 200 years to control bacterial and fungal diseases in a variety of crops. In our review, we found that copper content from cupric fungicides in vineyard soil surface horizons often exceeds 200 mg/kg. However, there are few studies on copper content in vineyard soils in Russia. The fact of the matter is that soil microorganisms have greater metal sensitivity than plants. Therefore, the use of copper-based pesticides may damage microbial communities in vineyard soils and disrupt litter decomposition processes, thus leading to a long-term deterioration of ecological attributes and agricultural value of soils. It is this fact that makes the need for constant monitoring and assessment of the impact of copper-based pesticides on vineyard soils in Russia so paramount.

scholarly journals Spatial and Temporal Variation in Fine Root Biomass, Productivity and Turnover in Shorea Robusta Along the Gradient of Tree Girth Size

2021 ◽  
Author(s):  
Rachita Pandey ◽  
Surendra Singh Bargali ◽  
Kiran Bargali
Keyword(s):  
Fine Roots ◽  
Root Biomass ◽  
Fine Root ◽  
Soil Depth ◽  
Winter Season ◽  
Fine Root Biomass ◽  
Spatial And Temporal Variation ◽  
Root Dynamics ◽  
Bottom Line ◽  
The Impact

Abstract Fine roots (≤ 2 mm of diameter) contribute diminutive fractions of the overall tree biomass but are highly zestful and functionally remarkable component for assessing forest carbon and nutrient budgets. This study assessed how tree girth influenced fine root biomass (FRB), production (FRP) and turnover rate (FRT) in sub tropical sal forest.Four sites (S1, S2, S3, S4) were established in the bhabhar region of Nainital district, Uttarakhand, India within an elevational range of 405m and 580m. On the basis of girth size, sal trees were categorized in five girth size classes. Fine roots were sampled seasonally to a depth of 60 cm and divided into 3 layers (0-20, 20-40 and 40-60 cm).FRB was significantly affected by tree girth size (p< 0.05) while FRP and FRT showed insignificant effect. FRB was higher in lower girth classes (A-C) as compared to higher girth classes (D-E).Seasonal variation of FRB in all girth sizes showed a keen resemblance as the standing FRB reached pinnacle during rainy season and reached bottom-line in the winter season. Maximum FRB was reported for uppermost organo-mineralic soil depth (0-20 cm) at 1 m distance from tree bole and decreased with increasing soil depth and distance from tree bole while FRT showed a reverse trend. The present study will provide a holistic outlook on variations in FRB, FRP and FRT and the impact of edaphic characteristics and tree girth on fine root dynamics with respect to the studied forest stands.

scholarly journals Experimental throughfall reduction barely affects soil carbon dynamics in a warm-temperate oak forest, central China

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Haibo Lu ◽  
Shirong Liu ◽  
Hui Wang ◽  
Junwei Luan ◽  
Andreas Schindlbacher ◽  
...  
Keyword(s):  
Soil Carbon ◽  
Carbon Dynamics ◽  
Central China ◽  
Oak Forest ◽  
Soil Carbon Dynamics ◽  
Warm Temperate ◽  
Throughfall Reduction

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

Sign in / Sign up

Export Citation Format

Share Document