Separating microbial respiration of exudates from root respiration in non-sterile soils: a comparison of four methods

Kuzyakov, Yakov

doi:10.1016/s0038-0717(02)00146-3

Cited by 143 publications

(101 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…α is the ratio of heterotrophic respiration to soil apparent respiration, assuming a value of 0.55 [22,23]. GWP 100 is Global Warming Potential over 100-year time-span, which was taken as 34 and 298 for CH 4 and N 2 O respectively [24].…”

Section: Greenhouse Gases Balance Assessmentmentioning

confidence: 99%

Carbon Dioxide Emissions from the Littoral Zone of a Chinese Reservoir

Yang

Grace

Geng

et al. 2017

Water

View full text Add to dashboard Cite

Abstract:The continuous increase in the number of reservoirs globally has raised important questions about the environmental impact of their greenhouse gases emissions. In particular, the littoral zone may be a hotspot for production of greenhouse gases. We investigated the spatiotemporal variation of CO 2 flux at the littoral zone of a Chinese reservoir along a wet-to-dry transect from permanently flooded land, seasonally flooded land to non-flooded dry land, using the static dark chamber technique. The mean total CO 2 emission was 346 mg m −2 h −1 and the rate varied significantly by water levels, months and time of day. The spatiotemporal variation of flux was highly correlated with biomass, temperature and water level. Flooding could play a positive role in carbon balance if water recession occurs at the time when carbon gains associated with plant growth overcomes the carbon loss of ecosystem. The overall carbon balance was analysed using cumulative greenhouse gases fluxes and biomass, bringing the data of the present study alongside previously published, simultaneously measured CH 4 and N 2 O fluxes. For the growing season, 12.8 g C m −2 was absorbed by the littoral zone. Taking CH 4 and N 2 O into the calculation showed that permanently flooded sites were a source of greenhouse gases, rather than a sink. Our study emphasises how water level fluctuation influenced CO 2 , CH 4 and N 2 O in different ways, which greatly affected the spatiotemporal variation and emission rate of greenhouse gases from the littoral zone.

show abstract

Section: Greenhouse Gases Balance Assessmentmentioning

confidence: 99%

Carbon Dioxide Emissions from the Littoral Zone of a Chinese Reservoir

Yang

Grace

Geng

et al. 2017

Water

View full text Add to dashboard Cite

show abstract

“…Further investigations can play an important role in assessing the effect of soil K depletion on longterm crop production. The reliability of our total C balances is severely hampered by the lack of reliable data on root C contributions which has been the subject of much recent research (Kuzyakov et al 2001;Kuzyakov 2002;Werth and Kuzyakov 2008;Pumpanen et al 2009). From their comprehensive studies under controlled conditions Kuzyakov and Larionova (2006), concluded that root respiration contributed approximately 40% to the total CO 2 efflux from soils.…”

Section: Discussionmentioning

confidence: 99%

Carbon and nutrient balances in three mountain oases in Northern Oman

Buerkert

Al-Rawahi

Melapie

et al. 2018

Jour. Agri. & Mar. Scie.

View full text Add to dashboard Cite

Carbon (C) and nitrogen (N) fluxes of two cropping systems in three mountain oases of Al Jabal Al-Akhdar mountains of northern Oman were determined in 2008/09 and 2009/10. These comprised garlic at Ash Sharayjah (1,900 m asl) and Masayrat (1,030 m asl), pomegranate in Ash Sharayjah and Qasha’ (1,640 m asl), and date palm groves at Masayrat. Goat manure was applied to garlic fields at 47 and 40 t dry matter (DM) ha-1 at Ash Sharayjah and 42 and 37 t DM ha-1 at Masayrat. Pomegranates at Ash Sharayjah and Qasha’ received cattle dairy manure at 66 and 60 t DM ha-1 yr-1. Annual total gaseous C losses varied from 20.9 to 61.2 t C ha-1 to which CH4-C contributed < 2%. Total annual C surpluses were 12.5 t ha-1 in garlic fields at Ash Sharayjah, while C deficits of -5.5 t ha-1 were obtained at Masayrat. Annual C surpluses in pomegranate and date palm were 16.7, 7.5, and 1.7 t ha-1 in Ash Sharayjah, Qasha’, and Masayrat. Date palm groves had total annual N surpluses of 1857 kg N ha-1 while pomegranate fields at Ash Sharayjah and Qasha’ had annual surpluses of 1414 and 1500 kg N ha-1.

show abstract

“…A priming effect is defined as a short-term change in the soil organic matter decay rate caused by a perturbation of the supply of nutrients, organic carbon, or other chemical and biological factors (Kuzyakov et al 2000, Kuzyakov 2002). In the case of elevated CO 2 responses, priming effects occur when the CO 2 treatments change the rate of pre-treatment or 'old' soil organic matter decomposition.…”

Section: B3 Priming Effects On Soil Organic Matter Decompositionmentioning

confidence: 99%

Final Report on "Rising CO2 and Long-term Carbon Storage in Terrestrial Ecosystems: An Empirical Carbon Budget Validation"

Megonigal¹,

Drake²

2010

View full text Add to dashboard Cite

funded through the TECO program. However, this project has a longer history because DOE also funded this study from its inception in 1985 through 1997. The original grant was focused on plant responses to elevated CO 2 in an intact ecosystem, while the latter grant was focused on belowground responses. Here we summarize the major findings across the 25 years this study has operated, and note that the experiment will continue to run through 2020 with NSF support. The major conclusions of the study to date are: Elevated CO 2 stimulated plant productivity in the C3 plant community by ~30% during the 25 year study. The magnitude of the increase in productivity varied interannually and was sometime absent altogether. There is some evidence of down-regulation at the ecosystem level across the 25 year record that may be due to interactions with other factors such as sea-level rise or long-term changes in N supply. Elevated CO 2 stimulated C 4 productivity by <10%, perhaps due to more efficient water use, but C 3 plants at elevated CO 2 did not displace C 4 plants as predicted. Increased primary production caused a general stimulation of microbial processes, but there were both increases and decreases in activity depending on the specific organisms considered. An increase in methanogenesis and methane emissions implies elevated CO 2 may amplify radiative forcing in the case of wetland ecosystems. Elevated CO 2 stimulated soil carbon sequestration in the form of an increase in elevation. The increase in elevation is 50-100% of the increase in net ecosystem production caused by elevated CO 2 (still under analysis). The increase in soil elevation suggests the elevated CO 2 may have a positive outcome for the ability of coastal wetlands to persist despite accelerated sea level rise. Crossing elevated CO 2 with elevated N causes the elevated CO 2 effect to diminish, with consequences for change in soil elevation. I. RationaleThe possibility that terrestrial ecosystems may be able to slow the rate of CO 2 rise is both intriguing and important to pursue as the world struggles to address the challenges of climatic change. When this work began in 1986, the pressing question was whether rising CO 2 would stimulate CO 2 assimilation and carbon sequestration in terrestrial ecosystems through direct effects on photosynthesis. Later we tackled the far more difficult question of whether this increase in CO 2 assimilation would ripple through the ecosystem carbon cycle to cause a longterm increase in carbon sequestration. As the DOE funding of this project ends, there are now thousands of studies that have demonstrated that elevated CO 2 elicits a sustained increase in photosynthesis (Ainsworth and Long, 2005), and we have evidence that a substantial portion of this carbon is sequestered as soil organic matter in our tidal wetland ecosystem.There are myriad feedbacks on carbon cycling that involve plant and microbial physiology, biogeochemistry and other physical and ecological interactions. As a result, increases in photosynthesis can...

show abstract

Separating microbial respiration of exudates from root respiration in non-sterile soils: a comparison of four methods

Cited by 143 publications

References 35 publications

Carbon Dioxide Emissions from the Littoral Zone of a Chinese Reservoir

Carbon Dioxide Emissions from the Littoral Zone of a Chinese Reservoir

Carbon and nutrient balances in three mountain oases in Northern Oman

Final Report on "Rising CO2 and Long-term Carbon Storage in Terrestrial Ecosystems: An Empirical Carbon Budget Validation"

Contact Info

Product

Resources

About