Decline in the contribution of microbial residues to soil organic carbon along a subtropical elevation gradient

Yang, Liuming; Lyu, Maokui; Li, Xiaojie; Xiong, Xiaoling; Lin, Wenxiong; Yang, Yusheng; Xie, Jinsheng

doi:10.1016/j.scitotenv.2020.141583

Cited by 34 publications

(12 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Foremost, absorptive roots can efficiently fuel the proliferation of microbes and promote the subsequent accumulation of microbial necromass in the rhizosphere via continuous high‐quality substrate inputs (Finzi et al, 2015). This can be supported by the stronger positive correlation between microbial biomass and amino sugar (Figure S3), which is consistent with previous studies (Ni, Liao, Tan, Wang, et al, 2020; Yang et al, 2020). In addition, the increase in microbial necromass in the rhizosphere of absorptive roots was mainly driven by the accumulation of fungal necromass (Figure 2B; Nakas & Klein, 1979; Six et al, 2006).…”

Section: Discussionsupporting

confidence: 92%

Absorptive roots drive a larger microbial carbon pump efficacy than transport roots in alpine coniferous forests

et al. 2022

View full text Add to dashboard Cite

1. Root activity creates a unique microbial hotspot in the rhizosphere and profoundly regulates soil carbon (C) dynamics, but empirical assessments of the soil microbial carbon pump (MCP, the iterative accumulation of necromass after microbial anabolism) and associated ecological consequences on soil C storage based on insight of the rhizosphere are still neglected, especially for different root functional modules.2. We assessed the soil MCP efficacy (i.e. the contribution of microbial necromass to SOC) by investigating the divergent contribution of microbial necromass based on amino sugar extrapolations to soil organic C (SOC) in the rhizosphere of two root functional modules (i.e. absorptive roots and transport roots) and the bulk soil in an alpine coniferous forest.3. The results showed that the MCP efficacy in both rhizosphere and bulk soil was more than 50%, suggesting that microbial necromass plays a key role in SOC formation. More importantly, absorptive roots drove a greater rhizosphere MCP efficacy (56%) than transport roots (51%). 4. Synthesis. These observations suggest that the microbial necromass is a major contributor to SOC storage in both rhizosphere and bulk soil in alpine coniferous forests. The magnitude of the contribution of microbial necromass to rhizosphere SOC depends on root functional differentiation. Our study provides novel and direct empirical evidence for the active soil MCP functions in SOC sequestration from the perspective of the rhizosphere.

show abstract

Section: Discussionsupporting

confidence: 92%

Absorptive roots drive a larger microbial carbon pump efficacy than transport roots in alpine coniferous forests

et al. 2022

View full text Add to dashboard Cite

show abstract

“…We do note that despite large changes in C and nutrient fluxes (Giardina et al, 2014; Litton et al, 2020), soil bacterial community composition is relatively stable across our MAT gradient (Selmants et al, 2016). And in line with data from forested sites across a subtropical elevational gradient (Yang et al, 2020), unpublished data from our MAT gradient also reveal little variation in fungal biomass with MAT (unpublished data of D. Leopold). Regarding the fourth alternative explanation, increases in AR above a long‐term mean could affect nutrient cycling rates by alleviating water constraints on decomposition rates, or conversely by reducing belowground O 2 supply thereby limiting nutrient availability and uptake for plant growth (Fahey et al, 2016; Rustad et al, 2001; Taylor et al, 2017).…”

Section: Discussionsupporting

confidence: 89%

Interannual variation in rainfall modulates temperature sensitivity of carbon allocation and flux in a tropical montane wet forest

Lyu

Giardina

Litton

2021

Global Change Biology

Self Cite

View full text Add to dashboard Cite

Tropical forests exert a disproportionately large influence on terrestrial carbon (C) balance but projecting the effects of climate change on C cycling in tropical forests remains uncertain. Reducing this uncertainty requires improved quantification of the independent and interactive effects of variable and changing temperature and precipitation regimes on C inputs to, cycling within and loss from tropical forests. Here, we quantified aboveground litterfall and soil‐surface CO2 efflux (“soil respiration”; FS) in nine plots organized across a highly constrained 5.2°C mean annual temperature (MAT) gradient in tropical montane wet forest. We used five consecutive years of these measurements, during which annual rainfall (AR) steadily increased, in order to: (a) estimate total belowground C flux (TBCF); (b) examine how interannual variation in AR alters the apparent temperature dependency (Q10) of above‐ and belowground C fluxes; and (c) quantify stand‐level C allocation responses to MAT and AR. Averaged across all years, FS, litterfall, and TBCF increased positively and linearly with MAT, which accounted for 49, 47, and 46% of flux rate variation, respectively. Rising AR lowered TBCF and FS, but increased litterfall, with patterns representing interacting responses to declining light. The Q10 of FS, litterfall, and TBCF all decreased with increasing AR, with peak sensitivity to MAT in the driest year and lowest sensitivity in the wettest. These findings support the conclusion that for this tropical montane wet forest, variations in light, water, and nutrient availability interact to strongly influence productivity (litterfall+TBCF), the sensitivity of above‐ and belowground C fluxes to rising MAT (Q10 of FS, litterfall, and TBCF), and C allocation patterns (TBCF:[litterfall+TBCF]).

show abstract

“…In this study, the low decay conditions (lower temperature and litter quality) at high elevation could promote soil C accumulation, especially recalcitrant plant-derived C (i.e., lignin) accumulation (Craig et al, 2018). In contrast, the fast decay conditions (higher temperature and litter quality) at low elevation could reduce soil C accumulation (Prietzel and Christophel, 2014) but promote labile microbial-derived C (i.e., polysaccharides) accumulation (Yang et al, 2020). In this way, soils from medium elevations had higher SOC content and labile C fractions and higher bacterial diversity.…”

Section: Effects Of Soil Organic Carbon Properties In Shaping Bacterial Diversity and Compositionmentioning

confidence: 75%

Soil pH and Organic Carbon Properties Drive Soil Bacterial Communities in Surface and Deep Layers Along an Elevational Gradient

et al. 2021

View full text Add to dashboard Cite

Elevational gradients strongly affect the spatial distribution and structure of soil bacterial communities. However, our understanding of the effects and determining factors is still limited, especially in the deep soil layer. Here, we investigated the diversity and composition of soil bacterial communities in different soil layers along a 1,500-m elevational gradient in the Taibai Mountain. The variables associated with climate conditions, plant communities, and soil properties were analyzed to assess their contributions to the variations in bacterial communities. Soil bacterial richness and α-diversity showed a hump-shaped trend with elevation in both surface and deep layers. In the surface layer, pH was the main factor driving the elevational pattern in bacterial diversity, while in the deep layer, pH and soil carbon (C) availability were the two main predictors. Bacterial community composition differed significantly along the elevational gradient in all soil layers. In the surface layer, Acidobacteria, Delta-proteobacteria, and Planctomycetes were significantly more abundant in the lower elevation sites than in the higher elevation sites; and Gemmatimonadetes, Chloroflexi, and Beta-proteobacteria were more abundant in the higher elevation sites. In the deep layer, AD3 was most abundant in the highest elevation site. The elevational pattern of community composition co-varied with mean annual temperature, mean annual precipitation, diversity and basal area of trees, pH, soil C availability, and soil C fractions. Statistical results showed that pH was the main driver of the elevational pattern of the bacterial community composition in the surface soil layer, while soil C fractions contributed more to the variance of the bacterial composition in the deep soil layer. These results indicated that changes in soil bacterial communities along the elevational gradient were driven by soil properties in both surface and deep soil layers, which are critical for predicting ecosystem functions under future climate change scenarios.

show abstract

Decline in the contribution of microbial residues to soil organic carbon along a subtropical elevation gradient

Cited by 34 publications

References 47 publications

Absorptive roots drive a larger microbial carbon pump efficacy than transport roots in alpine coniferous forests

Absorptive roots drive a larger microbial carbon pump efficacy than transport roots in alpine coniferous forests

Interannual variation in rainfall modulates temperature sensitivity of carbon allocation and flux in a tropical montane wet forest

Soil pH and Organic Carbon Properties Drive Soil Bacterial Communities in Surface and Deep Layers Along an Elevational Gradient

Contact Info

Product

Resources

About