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  1. Book ; Conference proceedings: Development of a kenaf industry in Australia

    Kirschbaum, Miko U. F.

    [Kenaf Workshop] ; Brisbane, 6 - 7 February 1990

    (Proceedings / Department of Primary Industries and Energy, Bureau of Rural Resources ; 9)

    1990  

    Institution Australian Special Rural Research Council
    Event/congress Kenaf Workshop (1990, Brisbane)
    Author's details Australian Special Rural Research Council ... Ed.: Miko U. F. Kirschbaum
    Series title Proceedings / Department of Primary Industries and Energy, Bureau of Rural Resources ; 9
    Proceedings / Australia, Department of Primary Industries and Energy, Bureau of Rural Resources
    Collection Proceedings / Australia, Department of Primary Industries and Energy, Bureau of Rural Resources
    Keywords Australien ; Kenaf ; Faserpflanzenanbau ; Faserpflanzenverarbeitung
    Subject Faserpflanzen ; Gambohanf ; Hanfeibisch ; Hibiscus cannabinus ; Dekkanhanf ; Ambari ; Bimlijute ; Javajute ; Bombayhanf ; Bimli ; Faserpflanzenbau
    Size VI, 129 S. : graph. Darst., Kt.
    Publisher Australian Gov. Publ. Service
    Publishing place Canberra
    Publishing country Australia
    Document type Book ; Conference proceedings
    HBZ-ID HT006639821
    ISBN 0-644-13239-6 ; 978-0-644-13239-8
    Database Catalogue ZB MED Nutrition, Environment, Agriculture

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  2. Article ; Online: The carbon‐quality temperature hypothesis: Fact or artefact?

    Liáng, Lìyǐn L. / Kirschbaum, Miko U. F. / Arcus, Vickery L. / Schipper, Louis A.

    Global Change Biology. 2023 Feb., v. 29, no. 4 p.935-942

    2023  

    Abstract: Climate warming can reduce global soil carbon stocks by enhancing microbial decomposition. However, the magnitude of this loss remains uncertain because the temperature sensitivity of the decomposition of the major fraction of soil carbon, namely ... ...

    Abstract Climate warming can reduce global soil carbon stocks by enhancing microbial decomposition. However, the magnitude of this loss remains uncertain because the temperature sensitivity of the decomposition of the major fraction of soil carbon, namely resistant carbon, is not fully known. It is now believed that the resistance of soil carbon mostly depends on microbial accessibility of soil carbon with physical protection being the primary control of the decomposition of protected carbon, which is insensitive to temperature changes. However, it is still unclear whether the temperature sensitivity of the decomposition of unprotected carbon, for example, carbon that is not protected by the soil mineral matrix, may depend on the chemical recalcitrance of carbon compounds. In particular, the carbon‐quality temperature (CQT) hypothesis asserts that recalcitrant low‐quality carbon is more temperature‐sensitive to decomposition than labile high‐quality carbon. If the hypothesis is correct, climate warming could amplify the loss of unprotected, but chemically recalcitrant, carbon and the resultant CO₂ release from soils to the atmosphere. Previous research has supported this hypothesis based on reported negative relationships between temperature sensitivity and carbon quality, defined as the decomposition rate at a reference temperature. Here we show that negative relationships can arise simply from the arbitrary choice of reference temperature, inherently invalidating those tests. To avoid this artefact, we defined the carbon quality of different compounds as their uncatalysed reaction rates in the absence of enzymes. Taking the uncatalysed rate as the carbon quality index, we found that the CQT hypothesis is not supported for enzyme‐catalysed reactions, which showed no relationship between carbon quality and temperature sensitivity. The lack of correlation in enzyme‐catalysed reactions implies similar temperature sensitivity for microbial decomposition of soil carbon, regardless of its quality, thereby allaying concerns of acceleration of warming‐induced decomposition of recalcitrant carbon.
    Keywords Biological Sciences ; biodegradation ; carbon ; carbon dioxide ; climate ; global change ; soil carbon ; soil minerals ; temperature
    Language English
    Dates of publication 2023-02
    Size p. 935-942.
    Publishing place John Wiley & Sons, Ltd
    Document type Article ; Online
    Note JOURNAL ARTICLE
    ZDB-ID 1281439-8
    ISSN 1365-2486 ; 1354-1013
    ISSN (online) 1365-2486
    ISSN 1354-1013
    DOI 10.1111/gcb.16539
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: The effect of land-use change on soil C, N, P, and their stoichiometries: A global synthesis

    Kim, Dong-Gill / Kirschbaum, Miko U.F. / Eichler-Löbermann, Bettina / Gifford, Roger M. / Liáng, Lìyǐn L.

    Agriculture, Ecosystems and Environment. 2023 June, v. 348 p.108402-

    2023  

    Abstract: Land-use change (LUC) can lead to the uptake or release of carbon (C), nitrogen (N) and phosphorus (P). Here we summarize and statistically analyze available observations on changes in soil organic C (SOC), total N (TN), total P (TP), and their ... ...

    Abstract Land-use change (LUC) can lead to the uptake or release of carbon (C), nitrogen (N) and phosphorus (P). Here we summarize and statistically analyze available observations on changes in soil organic C (SOC), total N (TN), total P (TP), and their stoichiometries (C:N, C:P, and N:P) after LUC and try to identify any controlling factors. We analyzed 1110 published data sets of changes in SOC, TN, and TP and their stoichiometries. Conversion of forest to cropland greatly decreased SOC (-33.1%) and TN (-27.8%), but forest to grassland conversion increased both slightly (SOC: 5.6%, TN: 15.9%). Conversion of cropland to forest increased SOC (193%) and TN (102%). Conversion of grassland to forest did not change SOC but decreased TN (-17.0%). Converting forest to cropland or grassland increased TP by 10.6% and 14.9%, respectively, and forestation of cropland or grassland decreased TP by 39.7% and 48.3%, respectively. Across all LUCs, changes in SOC and TN were generally linearly correlated, with a ratio close to 1, except after forestation, when large SOC increases sometimes exceeded TN increases. Changes in TP following LUC were positively correlated with changes in P fertilizer application rates. Following some LUCs, changes in SOC, TN, and TP and their stoichiometries were correlated with temperature or rainfall, but few generalities emerged. Forestation with deciduous trees increased SOC (29.9%), TN (22.2%), and TP (14.4%), but forestation with conifers reduced SOC (-27.0%), TN (-35.5%), and TP (-6.7%). After converting forest to cropland or grassland, C:N, C:P, and N:P all decreased, whereas forestation of cropland or grassland increased C:N, C:P, and N:P. This suggests that SOC enhancements following LUC could be constrained by TN and TP availability, which might need to be overcome through extra nutrient additions to achieve maximal C storage.
    Keywords agriculture ; carbon sequestration ; cropland ; environment ; fertilizer application ; forests ; grasslands ; land use change ; nitrogen ; phosphorus ; phosphorus fertilizers ; rain ; soil ; soil organic carbon ; temperature ; total nitrogen ; Land-use change ; Greenhouse gas emissions ; Carbon ; Stoichiometry ; Time ; Rainfall ; Forest type
    Language English
    Dates of publication 2023-06
    Publishing place Elsevier B.V.
    Document type Article ; Online
    ZDB-ID 602345-9
    ISSN 1873-2305 ; 0167-8809
    ISSN (online) 1873-2305
    ISSN 0167-8809
    DOI 10.1016/j.agee.2023.108402
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Re-analysis of plant CO

    Kirschbaum, Miko U F / Lambie, Suzanne M

    Functional plant biology : FPB

    2020  Volume 42, Issue 10, Page(s) 989–1000

    Abstract: Many short-term experiments have been conducted under increasing CO2 but results have been varied and have not yet led to a conclusive quantitative understanding of the CO2 response of plant growth. This may have been partly due to a lack of explicit ... ...

    Abstract Many short-term experiments have been conducted under increasing CO2 but results have been varied and have not yet led to a conclusive quantitative understanding of the CO2 response of plant growth. This may have been partly due to a lack of explicit consideration of the positive feedback inherent in plant growth during periods of exponential growth. This feedback can increase an initial physiological enhancement of relative growth rate (RGR) into a much larger biomass enhancement. To overcome this problem, we re-analysed existing experimental data from 78 publications. We calculated the RGRs of C3 plants and their relative enhancement under elevated CO2 and derived response indices that were independent of the duration of experiments and the RGR at normal atmospheric CO2. The RGR of unstressed plants increased by 14±2% under doubled CO2, with observed RGR enhancement linearly correlated with calculated photosynthetic enhancements (based on the Farquhar-von Caemmerer-Berry photosynthesis model), but at only half their numeric values. Calculated RGR enhancements did not change significantly for temperatures from 12 to 40°C, but were reduced under nutrient limitation, and were increased under water stress or low irradiance. We concluded that short-term experiments can offer simple and cost-effective insights into plant CO2 responses, provided they are analysed by calculating relative changes in RGR during the strictly exponential initial growth phase.
    Language English
    Publishing date 2020-06-02
    Publishing country Australia
    Document type Journal Article
    ZDB-ID 2071582-1
    ISSN 1445-4416 ; 1445-4408
    ISSN (online) 1445-4416
    ISSN 1445-4408
    DOI 10.1071/FP15103
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: The carbon-quality temperature hypothesis: Fact or artefact?

    Liáng, Lìyǐn L / Kirschbaum, Miko U F / Arcus, Vickery L / Schipper, Louis A

    Global change biology

    2022  Volume 29, Issue 4, Page(s) 935–942

    Abstract: Climate warming can reduce global soil carbon stocks by enhancing microbial decomposition. However, the magnitude of this loss remains uncertain because the temperature sensitivity of the decomposition of the major fraction of soil carbon, namely ... ...

    Abstract Climate warming can reduce global soil carbon stocks by enhancing microbial decomposition. However, the magnitude of this loss remains uncertain because the temperature sensitivity of the decomposition of the major fraction of soil carbon, namely resistant carbon, is not fully known. It is now believed that the resistance of soil carbon mostly depends on microbial accessibility of soil carbon with physical protection being the primary control of the decomposition of protected carbon, which is insensitive to temperature changes. However, it is still unclear whether the temperature sensitivity of the decomposition of unprotected carbon, for example, carbon that is not protected by the soil mineral matrix, may depend on the chemical recalcitrance of carbon compounds. In particular, the carbon-quality temperature (CQT) hypothesis asserts that recalcitrant low-quality carbon is more temperature-sensitive to decomposition than labile high-quality carbon. If the hypothesis is correct, climate warming could amplify the loss of unprotected, but chemically recalcitrant, carbon and the resultant CO
    MeSH term(s) Temperature ; Carbon/chemistry ; Artifacts ; Soil Microbiology ; Soil/chemistry
    Chemical Substances Carbon (7440-44-0) ; Soil
    Language English
    Publishing date 2022-11-30
    Publishing country England
    Document type Journal Article
    ZDB-ID 1281439-8
    ISSN 1365-2486 ; 1354-1013
    ISSN (online) 1365-2486
    ISSN 1354-1013
    DOI 10.1111/gcb.16539
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Assessing the merits of bioenergy by estimating marginal climate-change impacts

    Kirschbaum, Miko U.F

    international journal of life cycle assessment. 2017 June, v. 22, no. 6

    2017  

    Abstract: PURPOSE: Climate-change impacts can be mitigated through greater use of bioenergy, but the extent to which specific options actually reduce overall impacts needs to be assessed. Most bioenergy assessments have used proxy measures for assessing its merits. ...

    Abstract PURPOSE: Climate-change impacts can be mitigated through greater use of bioenergy, but the extent to which specific options actually reduce overall impacts needs to be assessed. Most bioenergy assessments have used proxy measures for assessing its merits. Here, a new approach is presented, whereby the contribution of bioenergy use is assessed through quantifying marginal changes in climate-change impacts that result from the implementation of a bioenergy option. METHODS: Marginal climate-change impacts were calculated for one specific example of a bioenergy option, conversion of an unutilised mature forest into a production forest harvested repeatedly for bioenergy over successive 25-year rotations. The overall benefit of the option was assessed by including stand-level carbon dynamics, global carbon-cycle feedback, progressively changing radiative efficiency and marginal impact sensitivity of warming. It also includes a differentiated assessment of three kinds of climatic impacts: direct-warming, rate-of-warming and cumulative-warming impacts. Marginal impacts were calculated and summed over 100 years to assess the overall marginal impact of this bioenergy option. RESULTS AND DISCUSSION: Bioenergy use in this specific example led to a large initial loss of biomass carbon followed by an ongoing and accumulating benefit through fossil-fuel substitution. This caused adverse climatic impacts over the first two rotations as the effects of the on-site carbon loss dominated the overall impact, but the option became increasingly beneficial over longer time frames as the benefit of fossil-fuel substitution accrued and eventually dominated. Summed over 100 years, the bioenergy option reduced direct-temperature and rate-of-warming impacts whilst increasing cumulative-warming impacts. The average of the three kinds of impacts showed a slight mitigation benefit by reducing overall impacts. In the particular example, bioenergy use was assessed to have a more beneficial effect if the analysis was carried out under the assumption of higher-emission concentrations pathways, or if it assumed a steeper relationship between climate perturbations and impacts. CONCLUSIONS: The usefulness of any climate-change mitigation option ultimately relates to the marginal climate-change impacts it can avert. It is shown here that marginal impacts can be calculated in routine operation and that they can provide an objective and methodologically consistent assessment of the mitigation potential of bioenergy use.
    Keywords bioenergy ; biomass ; carbon ; climate ; climate change ; forests ; fossil fuels
    Language English
    Dates of publication 2017-06
    Size p. 841-852.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    ZDB-ID 2009386-X
    ISSN 1614-7502 ; 0948-3349
    ISSN (online) 1614-7502
    ISSN 0948-3349
    DOI 10.1007/s11367-016-1196-4
    Database NAL-Catalogue (AGRICOLA)

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  7. Article: The potential effectiveness of four different options to reduce environmental impacts of grazed pastures. A model-based assessment

    Giltrap, Donna L / Kirschbaum, Miko U.F / Liáng, Lìyǐn L

    Agricultural systems. 2021 Jan., v. 186

    2021  

    Abstract: Pastoral agriculture can have negative environmental impacts. These include greenhouse gas emissions (such as enteric CH₄ and soil N₂O emissions), NH₃ volatilisation, and leaching of nitrogen into waterways. We used a modelling approach to assess the ... ...

    Abstract Pastoral agriculture can have negative environmental impacts. These include greenhouse gas emissions (such as enteric CH₄ and soil N₂O emissions), NH₃ volatilisation, and leaching of nitrogen into waterways. We used a modelling approach to assess the effect of three plant traits and one management practice on N₂O emissions, nitrogen (N) losses via leaching and NH₃ volatilisation, pasture production and soil organic carbon (SOC) changes (as applicable). The aim was to identify traits/management practices that could potentially be environmentally beneficial and could then inform future research to find or breed plants with those traits.The traits and practice investigated were: 1) N content in animal feed; 2) plant-excreted nitrification inhibitors; 3) deep rooting; and 4) frequency of pasture renewal. Of these, the N content in animal feed provided the most promising results, with low N content resulting in lower urine N excretion, and consequently reduced leaching losses and emissions of N₂O and NH₃. Modelling the effect of plant-excreted nitrification inhibitors showed mixed results, with reduced leaching rates but increased NH₃ emissions. N₂O emissions could be reduced if nitrification rates were strongly reduced. However, at lower rates of inhibition, there was little effect on N₂O emissions. In the deep rooting scenarios, we found that N leaching losses were minimised if roots grew predominantly in upper soil layers where any mineral N was likely to spend more time before being leached. Nitrogen was, therefore, more effectively intercepted and prevented from leaching by greater root proliferation in the upper rather than deeper layers. For pasture renewal, we unexpectedly found that SOC could be increased by more frequent pasture renewal. However, this would come at the cost of reduced pasture production as renewal events reduced grazing off-takes proportionately more than the reduction in carbon gain by pasture plants. A renewal period of about 10 years was found to be optimal for pasture production and could be maintained with minimal SOC changes.
    Keywords excretion ; feeds ; greenhouse gases ; nitrification ; nitrogen ; nitrogen content ; pastoralism ; pastures ; soil ; soil organic carbon ; urine ; volatilization
    Language English
    Dates of publication 2021-01
    Publishing place Elsevier Ltd
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 413255-5
    ISSN 0308-521X
    ISSN 0308-521X
    DOI 10.1016/j.agsy.2020.102960
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Short-Term Temperature Response of Leaf Respiration in Different Subtropical Urban Tree Species.

    Xu, Man / Liáng, Lìyǐn L / Kirschbaum, Miko U F / Fang, Shuyi / Yu, Yina

    Frontiers in plant science

    2021  Volume 11, Page(s) 628995

    Abstract: Plant leaf respiration is one of the critical components of the carbon cycle in terrestrial ecosystems. To predict changes of carbon emissions from leaves to the atmosphere under a warming climate, it is, therefore, important to understand the ... ...

    Abstract Plant leaf respiration is one of the critical components of the carbon cycle in terrestrial ecosystems. To predict changes of carbon emissions from leaves to the atmosphere under a warming climate, it is, therefore, important to understand the thermodynamics of the temperature response of leaf respiration. In this study, we measured the short-term temperature response of leaf respiration from five different urban tree species in a subtropical region of southern China. We applied two models, including an empirical model (the Kavanau model) and a mechanistic model (Macromolecular Rate Theory, MMRT), to investigate the thermodynamic properties in different plant species. Both models are equivalent in fitting measurements of the temperature response of leaf respiration with no significant difference (
    Language English
    Publishing date 2021-01-14
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2711035-7
    ISSN 1664-462X
    ISSN 1664-462X
    DOI 10.3389/fpls.2020.628995
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Could patterns of animal behaviour cause the observed differences in soil carbon between adjacent irrigated and unirrigated pastures?

    Liáng, Lìyǐn L / Kirschbaum, Miko U F / Giltrap, Donna L / Hunt, John E / Laubach, Johannes

    The Science of the total environment

    2021  Volume 772, Page(s) 145033

    Abstract: Previous soil sampling from grazed pastures in New Zealand compared the changes of soil organic carbon (SOC) in adjacent irrigated and unirrigated portions of the same paddocks. It showed that irrigated portions had lower SOC stocks than unirrigated ... ...

    Abstract Previous soil sampling from grazed pastures in New Zealand compared the changes of soil organic carbon (SOC) in adjacent irrigated and unirrigated portions of the same paddocks. It showed that irrigated portions had lower SOC stocks than unirrigated portions, with an average difference of 7.0 tC ha
    MeSH term(s) Animals ; Behavior, Animal ; Biomass ; Carbon/analysis ; Cattle ; New Zealand ; Soil
    Chemical Substances Soil ; Carbon (7440-44-0)
    Language English
    Publishing date 2021-01-29
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2021.145033
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Could patterns of animal behaviour cause the observed differences in soil carbon between adjacent irrigated and unirrigated pastures?

    Liáng, Lìyǐn L / Kirschbaum, Miko U.F / Giltrap, Donna L / Hunt, John E / Laubach, Johannes

    Science of the total environment. 2021 June 10, v. 772

    2021  

    Abstract: Previous soil sampling from grazed pastures in New Zealand compared the changes of soil organic carbon (SOC) in adjacent irrigated and unirrigated portions of the same paddocks. It showed that irrigated portions had lower SOC stocks than unirrigated ... ...

    Abstract Previous soil sampling from grazed pastures in New Zealand compared the changes of soil organic carbon (SOC) in adjacent irrigated and unirrigated portions of the same paddocks. It showed that irrigated portions had lower SOC stocks than unirrigated portions, with an average difference of 7.0 tC ha⁻¹ or 0.6 tC ha⁻¹ yr⁻¹. These findings have formed the basis of an assessment for the net effect of conversion of New Zealand's grazed pastures to irrigation. However, since cattle could move freely between irrigated and unirrigated portions of the studied paddocks, there could have been different grazing intensities and/or excreta transfer between the irrigated and unirrigated portions of the same paddocks. Both these factors could have affected SOC stocks. In this study, we used the process-based model, CenW, to simulate the consequences of this possible carbon transfer via animal excreta and different grazing intensities. We found that the observed increase of 0.6 tC ha⁻¹ yr⁻¹ in SOC stock in the unirrigated portions could result from a transfer of 20% excreta from the irrigated to unirrigated portions (with an area ratio of 6:1) of a paddock and with the unirrigated portions being grazed only lightly with 2.0 tDM ha⁻¹ in foliage biomass residuals remaining after grazing. That means that the observed higher SOC stocks in the unirrigated portions could potentially be attributable to the behaviour of grazing animals. We suggest that a realistic extent of carbon transfer and/or differences in grazing intensities could be sufficient to account for the observed differences in SOC stocks even if irrigation per se caused no differences in carbon stocks. It is therefore inappropriate to ascribe the change of SOC to irrigation effects based on experimental findings where SOC changes can be affected by the behaviour of grazing animals.
    Keywords animal behavior ; biomass ; cattle ; environment ; excreta ; irrigation ; leaves ; models ; pastures ; soil ; soil organic carbon ; New Zealand
    Language English
    Dates of publication 2021-0610
    Publishing place Elsevier B.V.
    Document type Article
    Note NAL-AP-2-clean
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2021.145033
    Database NAL-Catalogue (AGRICOLA)

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