Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Data and R code: Bioconversion efficiencies, greenhouse gas and ammonia emissions during black soldier fly rearing – a mass balance approach
    Parodi, Alejandro ; Boer, Imke de; Gerrits, Walter ; Loon, Joop van; Heetkamp, Marcel ; Schelt, Jeroen van; Bolhuis, Liesbeth ; Zanten, Hannah van - \ 2020
    Wageningen University & Research
    ammonia - bioconversion - emissions - GHG - Hermetia illucens - nitrogen
    Contains data and R code for analysis and visualizations of the study Bioconversion efficiencies, greenhouse gas and ammonia emissions during black soldier fly rearing.
    Monitoring emissions from the 2015 Indonesian fires using CO satellite data
    Nechita-Banda, Narcisa ; Krol, Maarten ; Werf, Guido R. Van Der; Kaiser, Johannes W. ; Pandey, Sudhanshu ; Huijnen, Vincent ; Clerbaux, Cathy ; Coheur, Pierre ; Deeter, Merritt N. ; Röckmann, Thomas - \ 2018
    Wageningen University and Research
    inverse modelling - biomass burning - emissions - atmosphere - data - peat
    Inverse modelling results for carbon monoxide (CO) emissions to the atmosphere from the 2015 Indonesian fires (1 August - 15 December 2015). The TM5-4DVAR model was used (http://tm5.sourceforge.net), together with satellite observations from either IASI or MOPITT instruments.
    Monitoring emissions from the 2015 Indonesian fires using CO satellite data
    Nechita-Banda, Narcisa ; Krol, Maarten ; Werf, Guido R. van der; Kaiser, Johannes W. ; Pandey, Sudhanshu ; Huijnen, Vincent ; Clerbaux, Cathy ; Coheur, Pierre ; Deeter, Merritt N. ; Röckmann, Thomas - \ 2018
    Philosophical Transactions of the Royal Society B. Biological sciences 373 (2018)1760. - ISSN 0962-8436 - 9 p.
    atmosphere - biomass burning - emissions - peat - satellite data

    Southeast Asia, in particular Indonesia, has periodically struggled with intense fire events. These events convert substantial amounts of carbon stored as peat to atmospheric carbon dioxide (CO2) and significantly affect atmospheric composition on a regional to global scale. During the recent 2015 El Niño event, peat fires led to strong enhancements of carbon monoxide (CO), an air pollutant and well-known tracer for biomass burning. These enhancements were clearly observed from space by the Infrared Atmospheric Sounding Interferometer (IASI) and the Measurements of Pollution in the Troposphere (MOPITT) instruments. We use these satellite observations to estimate CO fire emissions within an inverse modelling framework. We find that the derived CO emissions for each sub-region of Indonesia and Papua are substantially different from emission inventories, highlighting uncertainties in bottom-up estimates. CO fire emissions based on either MOPITT or IASI have a similar spatial pattern and evolution in time, and a 10% uncertainty based on a set of sensitivity tests we performed. Thus, CO satellite data have a high potential to complement existing operational fire emission estimates based on satellite observations of fire counts, fire radiative power and burned area, in better constraining fire occurrence and the associated conversion of peat carbon to atmospheric CO2 A total carbon release to the atmosphere of 0.35-0.60 Pg C can be estimated based on our results.This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.

    Spatial boundary of urban ‘acid islands’ in China
    Du, E. ; Vries, W. de; Liu, X. ; Fang, J. ; Galloway, J.N. ; Jiang, Y. - \ 2015
    Scientific Reports 5 (2015). - ISSN 2045-2322 - 9 p.
    atmospheric deposition - nitrogen deposition - air-pollution - soil acidification - emissions - canopy - forest - rain - ecosystems - cities
    Elevated emissions of sulfur dioxide, nitrogen oxides and ammonia in China have resulted in high levels of sulfur and nitrogen deposition, being contributors to soil acidification, especially in and near large cities. However, knowledge gaps still exist in the way that large cities shape spatial patterns of acid deposition. Here, we assessed the patterns of pH, sulfate, nitrate and ammonium in bulk precipitation and throughfall in southern China’s forests by synthesizing data from published literature. Concentrations and fluxes of sulfate, nitrate and ammonium in bulk precipitation and throughfall exhibited a power-law increase with a closer distance to the nearest large cities, and accordingly pH showed a logarithmic decline. Our findings indicate the occurrence of urban ‘acid islands’ with a critical radius of approximately 70¿km in southern China, receiving potential acid loads of more than 2 keq ha-1 yr-1. These urban acid islands covered an area of 0.70¿million km2, accounting for nearly 30% of the land area in southern China. Despite a significant capacity to neutralize acids in precipitation, our analysis highlights a substantial contribution of ammonium to potential acid load. Our results suggest a joint control on emissions of multiple acid precursors from urban areas in southern China
    Consumer-Related Food Waste: Causes and Potential for Action
    Aschemann-Witzel, J. ; Hooge, I.E. de; Amani, P. ; Bech-Larsen, T. ; Oostindjer, M. - \ 2015
    Sustainability 7 (2015). - ISSN 2071-1050 - p. 6457 - 6477.
    climate-change - behavior - consumption - households - separation - emissions - knowledge - attitude - impacts - system
    In the past decade, food waste has received increased attention on both academic and societal levels. As a cause of negative economic, environmental and social effects, food waste is considered to be one of the sustainability issues that needs to be addressed. In developed countries, consumers are one of the biggest sources of food waste. To successfully reduce consumer-related food waste, it is necessary to have a clear understanding of the factors influencing food waste-related consumer perceptions and behaviors. The present paper presents the results of a literature review and expert interviews on factors causing consumer-related food waste in households and supply chains. Results show that consumers’ motivation to avoid food waste, their management skills of food provisioning and food handling and their trade-offs between priorities have an extensive influence on their food waste behaviors. We identify actions that governments, societal stakeholders and retailers can undertake to reduce consumer-related food waste, highlighting that synergistic actions between all parties are most promising. Further research should focus on exploring specific food waste contexts and interactions more in-depth. Experiments and interventions in particular can contribute to a shift from analysis to solutions.
    Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses
    Cambra-Lopez, M. ; Winkel, A. ; Mosquera Losada, J. ; Ogink, N.W.M. ; Aarnink, A.J.A. - \ 2015
    Atmospheric Environment 111 (2015). - ISSN 1352-2310 - p. 20 - 27.
    particulate matter - aerosol monitors - indoor - dust - instruments - emissions - devices - pm2.5 - teom
    The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10 concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m-3 and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m-3 (P <0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m-3 and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses
    Relationship between in vitro and in vivo methane production measured simultaneously with different dietary starch sources and starch levels in dairy cattle
    Hatew, B. ; Cone, J.W. ; Pellikaan, W.F. ; Podesta, S.C. ; Bannink, A. ; Hendriks, W.H. ; Dijkstra, J. - \ 2015
    Animal Feed Science and Technology 202 (2015). - ISSN 0377-8401 - p. 20 - 31.
    gas-production technique - rumen microbial-population - volatile fatty-acids - fermentation characteristics - ruminal fermentation - production profiles - degradation - emissions - kinetics - protein
    To investigate the relationship between in vitro and in vivo methane (CH4) production measured simultaneously using the same rumen-fistulated cows in both experiments, four dietary treatments based on concentrate that accounted for 400 g/kg of the mixed diet DM, were formulated to contain starch varying in rate of fermentation (slowly (S) vs. rapidly (R): native vs. gelatinized maize grain) and level of inclusion (low (L) vs. high (H): 270 vs. 530 g/kg of concentrate DM). Sixteen rumen-fistulated lactating dairy cows were used in a complete randomized block design with these treatments replicated in four periods of 17 d each. In experiment 1, after 12 d of adaptation, the cows were housed in respiration chambers for 5 d to measure CH4 production. In experiment 2, in each period in vitro gas and CH4 production were measured (in duplicate per period) for mixed diet samples from the same diet as fed to the donor cows using rumen inocula adapted to the respective diets for an average of 16 d. In addition, samples of two concentrate ingredients, viz. grass silage and beet pulp, were incubated with four different inocula obtained from individual donor cows. Gas production (GP) was measured using automated GP system with CH4 measured at distinct time points. In vitro (24-h) CH4 production of mixed diet was lower with R than S (42.9 vs. 49.5 ml/g of incubated organic matter (OM); P=0.004), and higher with L than H (49.8 vs. 42.6 ml/g of incubated OM; P=0.002). A significant interaction effect between source and level of starch (P=0.015) was also found, indicating the CH4 production of the RH diet decreased in particular. In vivo, an increased rate of starch fermentation resulted in a lower CH4 per unit of estimated rumen-fermentable OM (eRFOM; 55.6 vs. 61.2 ml/g of eRFOM; P=0.007), and higher level of starch tended (P=0.089) to reduce CH4 per unit of eRFOM, but dietary starch level and source did not affect CH4 per unit of OM consumed. Across the diets tested, 24-h in vitro CH4 (ml/g of incubated OM) correlated well with in vivo CH4 expressed per unit of eRFOM (R2 = 0.54; P=0.040), but not when expressed per unit of OM ingested (R2 = 0.04; P=0.878). For grass silage (the same trend for beet pulp), inocula adapted to R- and H-based diets compared with S- and L-based diets resulted in a lower CH4 production (36.1 vs. 44.8 ml/g of incubated OM, R vs. S; and 37.4 vs. 43.4 ml/g of incubated OM, H vs. L; P
    Evaluation of a dry filter and an electrostatic precipitator for exhaust air cleaning at commercial non-cage laying hen houses
    Winkel, A. ; Mosquera Losada, J. ; Aarnink, A.J.A. ; Groot Koerkamp, P.W.G. ; Ogink, N.W.M. - \ 2015
    Biosystems Engineering 129 (2015). - ISSN 1537-5110 - p. 212 - 225.
    particulate matter - poultry houses - emissions - buildings - impaction - pm10
    The removal performance of two exhaust air cleaning systems for abatement of particulate matter (PM) emission in poultry houses were investigated: a commercially available dry filter (DF) and a full-scale prototype electrostatic precipitator (ESP). Each system was connected to two commercial, non-cage laying hen houses: one with aviary housing, the other with floor housing. At each house, six to nine 24-h measurements were carried out, spread over the year and the laying cycle. Upstream and downstream of the systems, we measured PM10, PM2.5, and carbon dioxide concentrations, temperature, and relative humidity. Additional measurements of particle size distribution only were carried out at the DF of another poultry house. The latter showed that removal of PM by the DF increased with increasing particle diameter. Mean removal efficiency of the DF for PM10 was 40.1%, whereas PM2.5 was not significantly removed. The ESP reduced concentrations of PM10 by an average of 57.0% and concentrations of PM2.5 by an average of 45.3%. For neither of the two systems an effect of upstream PM concentration on removal performance was found. Results of this study are compared with the available literature and possibilities to improve removal performance are discussed. The mean (SD between houses) untreated emissions rate from the non-cage layer houses was 7.81 (4.12) mg PM10 h-1 bird-1 and 0.44 (0.28) mg PM2.5 h-1 bird-1. In conclusion, the evaluated systems show potential to reduce PM emissions from poultry houses.
    Enteric methane production, rumen volatile fatty acid concentrations, and milk fatty acid composition in lactating Holstein-Friesian cows fed grass silage - or corn silage-based diets
    Gastelen, S. van; Antunes Fernandes, E.C. ; Hettinga, K.A. ; Klop, G. ; Alferink, S.J.J. ; Hendriks, W.H. ; Dijkstra, J. - \ 2015
    Journal of Dairy Science 98 (2015)3. - ISSN 0022-0302 - p. 1915 - 1927.
    dairy-cows - maize silage - ruminal fermentation - feed-intake - n balance - cattle - emissions - supplementation - digestibility - performance
    The objective of this study was to determine the effects of replacing grass silage (GS) with corn silage (CS) in dairy cow diets on enteric methane (CH4) production, rumen volatile fatty acid (FA) concentrations, and milk FA composition. A completely randomized block design experiment was conducted with 32 multiparous lactating Holstein-Friesian cows. Four dietary treatments were used, all having a roughage-to-concentrate ratio of 80:20 based on dry matter (DM). The roughage consisted of either 100% GS, 67% GS and 33% CS, 33% GS and 67% CS, or 100% CS (all DM basis). Feed intake was restricted (95% of ad libitum DM intake) to avoid confounding effects of DM intake on CH4 production. Nutrient intake, apparent digestibility, milk production and composition, nitrogen (N) and energy balance, and CH4 production were measured during a 5-d period in climate respiration chambers after adaptation to the diet for 12 d. Increasing CS proportion linearly decreased neutral detergent fiber and crude protein intake and linearly increased starch intake. Milk production and milk fat content (on average 23.4 kg/d and 4.68%, respectively) were not affected by increasing CS inclusion, whereas milk protein content increased quadratically. Rumen variables were unaffected by increasing CS inclusion, except the molar proportion of butyrate, which increased linearly. Methane production (expressed as grams per day, grams per kilogram of fat- and protein-corrected milk, and as a percent of gross energy intake) decreased quadratically with increasing CS inclusion, and decreased linearly when expressed as grams of CH4 per kilogram of DM intake. In comparison with 100% GS, CH4 production was 11 and 8% reduced for the 100% CS diet when expressed per unit of DM intake and per unit fat- and protein-corrected milk, respectively. Nitrogen efficiency increased linearly with increased inclusion of CS. The concentration of trans C18:1 FA, C18:1 cis-12, and total CLA increased quadratically, and iso C16:0, C18:1 cis-13, and C18:2n-6 increased linearly, whereas the concentration of C15:0, iso C15:0, C17:0, and C18:3n-3 decreased linearly with increasing inclusion of CS. No differences were found in short- and medium-straight, even-chain FA concentrations, with the exception of C4:0 which increased linearly with increased inclusion of CS. Replacing GS with CS in a common forage-based diet for dairy cattle offers an effective strategy to decrease enteric CH4 production without negatively affecting dairy cow performance, although a critical level of starch in the diet seems to be needed.
    Forest Carbon Offsets Revisited: Shedding Light on Darkwoods
    Kooten, G.C. van; Bogle, T. ; Vries, F.P. de - \ 2015
    Forest Science 61 (2015)2. - ISSN 0015-749X - p. 370 - 380.
    land management - policy design - sequestration - emissions - redd - implementation - deforestation - framework - prospects - programs
    This paper investigates the viability of carbon offset credits created through forest conservation and preservation. A detailed forest management model based on a case study of a forest estate in southeastern British Columbia, owned by The Nature Conservancy of Canada (NCC) is used to demonstrate the challenging nature of estimating forest carbon offsets. For example, the NCC management plan creates substantial carbon offset credits because the counterfactual is that of a private forest liquidator, but when sustainable management of the site is assumed, the commercial operator would sequester much more carbon than under the NCC plan. The broader message is that the creation of carbon offsets is highly sensitive to ex ante assumptions and whether physical carbon is discounted. We demonstrate that more carbon gets stored in wood products as the discount rate on carbon rises (addressing climate change is more urgent). A high discount rate on carbon favors greater harvests and processing of biomass into products, while a low rate favors reduced harvest intensity. Further, since carbon credits earned by protecting forests may find their way onto world carbon markets, they lower the costs of emitting CO2 while contributing little to mitigating climate change.
    No time for smokescreen skepticism: A rejoinder to Shani and Arad
    Hall, C.M. ; Amelung, B. ; Cohen, S. ; Leemans, R. ; Lamers, M.A.J. ; Nicholls, S. ; Richardson, R.B. - \ 2015
    Tourism Management 47 (2015). - ISSN 0261-5177 - p. 341 - 347.
    climate-change - environmental skepticism - scientific consensus - tourism - emissions - policy
    Shani and Arad (2014) claimed that tourism scholars tend to endorse the most pessimistic assessments regarding climate change, and that anthropogenic climate change was a “fashionable” and “highly controversial scientific topic”. This brief rejoinder provides the balance that is missing from such climate change denial and skepticism studies on climate change and tourism. Recent research provides substantial evidence that reports on anthropogenic climate change are accurate, and that human-induced greenhouse gas emissions, including from the tourism industry, play a significant role in climate change. Some positive net effects may be experienced by some destinations in the short-term, but in the long-term all elements of the tourism system will be impacted. The expansion of tourism emissions at a rate greater than efficiency gains means that it is increasingly urgent that the tourism sector acknowledge, accept and respond to climate change. Debate on tourism-related adaptation and mitigation measures is to be encouraged and welcomed. Climate change denial is not.
    Mapping Ecosystem Services for Land Use Planning, the Case of Central Kalimantan
    Sumarga, E. ; Hein, L.G. - \ 2014
    Environmental Management 54 (2014)1. - ISSN 0364-152X - p. 84 - 97.
    tropical forests - west kalimantan - southeast-asia - united-states - east-asia - indonesia - conservation - emissions - peat - deforestation
    Indonesia is subject to rapid land use change. One of the main causes for the conversion of land is the rapid expansion of the oil palm sector. Land use change involves a progressive loss of forest cover, with major impacts on biodiversity and global CO2 emissions. Ecosystem services have been proposed as a concept that would facilitate the identification of sustainable land management options, however, the scale of land conversion and its spatial diversity pose particular challenges in Indonesia. The objective of this paper is to analyze how ecosystem services can be mapped at the provincial scale, focusing on Central Kalimantan, and to examine how ecosystem services maps can be used for a land use planning. Central Kalimantan is subject to rapid deforestation including the loss of peatland forests and the provincial still lacks a comprehensive land use plan. We examine how seven key ecosystem services can be mapped and modeled at the provincial scale, using a variety of models, and how large scale ecosystem services maps can support the identification of options for sustainable expansion of palm oil production.
    Sustainability of meat production beyond carbon footprint: a synthesis of case studies from grazing systems in Uruguay
    Picasso, V.D. ; Modernel Hristoff, P.D. ; Becona, G. ; Salvo, L. ; Gutierrez, L. ; Astigarraga, L. - \ 2014
    Meat Science 98 (2014)3. - ISSN 0309-1740 - p. 346 - 354.
    life-cycle assessment - impact assessment - sequestration - emissions - climate - grasslands - balance
    Livestock production has been challenged as a large contributor to climate change, and carbon footprint has become a widely used measure of cattle environmental impact. This analysis of fifteen beef grazing systems in Uruguay quantifies the range of variation of carbon footprint, and the trade-offs with other relevant environmental variables, using a partial life cycle assessment (LCA) methodology. Using carbon footprint as the primary environmental indicator has several limitations: different metrics (GWP vs. GTP) may lead to different conclusions, carbon sequestration from soils may drastically affect the results, and systems with lower carbon footprint may have higher energy use, soil erosion, nutrient imbalance, pesticide ecotoxicity, and impact on biodiversity. A multidimensional assessment of sustainability of meat production is therefore needed to inform decision makers. There is great potential to improve grazing livestock systems productivity while reducing carbon footprint and other environmental impacts, and conserving biodiversity.
    Plant volatiles and the environment
    Loreto, F. ; Dicke, M. ; Schnitzler, J.P. ; Turlings, T.C.J. - \ 2014
    Plant, Cell & Environment 37 (2014)8. - ISSN 0140-7791 - p. 1905 - 1908.
    herbivorous insects - floral scent - isoprene - perception - evolution - emissions - aerosols - defense - enemies - stress
    Volatile organic compounds emitted by plants represent the largest part of biogenic volatile organic compounds (BVOCs) released into our atmosphere. Plant volatiles are formed through many biochemical pathways, constitutively and after stress induction. In recent years, our understanding of the functions of these molecules has made constant and rapid progress. From being considered in the past as a mere waste of carbon, BVOCs have now emerged as an essential element of an invisible language that is perceived and exploited by the plants' enemies, the enemies of plant enemies, and neighbouring plants. In addition, BVOCs have important functions in protecting plants from abiotic stresses. Recent advances in our understanding of the role of BVOC in direct and indirect defences are driving further attention to these emissions. This special issue gathers some of the latest and most original research that further expands our knowledge of BVOC. BVOC emissions and functions in (1) unexplored terrestrial (including the soil) and marine environments, (2) in changing climate conditions, and (3) under anthropic pressures, or (4) in complex trophic communities are comprehensively reviewed. Stepping up from scientific awareness, the presented information shows that the manipulation and exploitation of BVOC is a realistic and promising strategy for agricultural applications and biotechnological exploitations.
    The seasonal variation of the CO2 flux over Tropical Asia estimated from GOSAT, CONTRAIL, and IASI
    Basu, S. ; Krol, M.C. ; Butz, A. ; Clerbaux, C. ; Sawa, Y. ; Machida, T. ; Matsueda, H. ; Frankenberg, C. ; Hasekamp, O.P. ; Aben, I. - \ 2014
    Geophysical Research Letters 41 (2014)5. - ISSN 0094-8276 - p. 1809 - 1815.
    atmospheric co2 - carbon balance - emissions - gosat - retrievals - aerosol - fires
    We estimate the CO2 flux over Tropical Asia in 2009, 2010, and 2011 using Greenhouse Gases Observing Satellite (GOSAT) total column CO2(XCO2) and in situ measurements of CO2. Compared to flux estimates from assimilating surface measurements of CO2, GOSAT XCO2 estimates a more dynamic seasonal cycle and a large source in March–May 2010. The more dynamic seasonal cycle is consistent with earlier work by Patra et al. (2011), and the enhanced 2010 source is supported by independent upper air CO2 measurements from the Comprehensive Observation Network for Trace gases by Airliner (CONTRAIL) project. Using Infrared Atmospheric Sounding Interferometer (IASI) measurements of total column CO (XCO), we show that biomass burning CO2 can explain neither the dynamic seasonal cycle nor the 2010 source. We conclude that both features must come from the terrestrial biosphere. In particular, the 2010 source points to biosphere response to above-average temperatures that year.
    A multi-year methane inversion using SCIAMACHY, accounting for systematic errors using TCCON measurements
    Houweling, S. ; Krol, M.C. ; Bergamaschi, P. ; Frankenberg, C. ; Dlugokencky, E.J. ; Morino, I. - \ 2014
    Atmospheric Chemistry and Physics 14 (2014). - ISSN 1680-7316 - p. 3991 - 4012.
    column observing network - atmospheric methane - carbon-dioxide - tropospheric methane - lower stratosphere - data assimilation - transport model - emissions - ch4 - gosat
    This study investigates the use of total column CH4 (XCH4) retrievals from the SCIAMACHY satellite instrument for quantifying large-scale emissions of methane. A unique data set from SCIAMACHY is available spanning almost a decade of measurements, covering a period when the global CH4 growth rate showed a marked transition from stable to increasing mixing ratios. The TM5 4DVAR inverse modelling system has been used to infer CH4 emissions from a combination of satellite and surface measurements for the period 2003–2010. In contrast to earlier inverse modelling studies, the SCIAMACHY retrievals have been corrected for systematic errors using the TCCON network of ground-based Fourier transform spectrometers. The aim is to further investigate the role of bias correction of satellite data in inversions. Methods for bias correction are discussed, and the sensitivity of the optimized emissions to alternative bias correction functions is quantified. It is found that the use of SCIAMACHY retrievals in TM5 4DVAR increases the estimated inter-annual variability of large-scale fluxes by 22% compared with the use of only surface observations. The difference in global methane emissions between 2-year periods before and after July 2006 is estimated at 27–35 Tg yr-1. The use of SCIAMACHY retrievals causes a shift in the emissions from the extra-tropics to the tropics of 50 ± 25 Tg yr-1. The large uncertainty in this value arises from the uncertainty in the bias correction functions. Using measurements from the HIPPO and BARCA aircraft campaigns, we show that systematic errors in the SCIAMACHY measurements are a main factor limiting the performance of the inversions. To further constrain tropical emissions of methane using current and future satellite missions, extended validation capabilities in the tropics are of critical importance.
    Spatio-temporal trends of nitrogen deposition and climate effects on Sphagnum productivity in European peatlands
    Granath, G. ; Limpens, J. ; Posch, M. ; Mücher, S. ; Vries, W. de - \ 2014
    Environmental Pollution 187 (2014). - ISSN 0269-7491 - p. 73 - 80.
    carbon accumulation - n deposition - boreal mire - bogs - growth - vegetation - impact - mosses - forest - emissions
    To quantify potential nitrogen (N) deposition impacts on peatland carbon (C) uptake, we explored temporal and spatial trends in N deposition and climate impacts on the production of the key peat forming functional group (Sphagnum mosses) across European peatlands for the period 1900–2050. Using a modelling approach we estimated that between 1900 and 1950 N deposition impacts remained limited irrespective of geographical position. Between 1950 and 2000 N deposition depressed production between 0 and 25% relative to 1900, particularly in temperate regions. Future scenarios indicate this trend will continue and become more pronounced with climate warming. At the European scale, the consequences for Sphagnum net C-uptake remained small relative to 1900 due to the low peatland cover in high-N areas. The predicted impacts of likely changes in N deposition on Sphagnum productivity appeared to be less than those of climate. Nevertheless, current critical loads for peatlands are likely to hold under a future climate.
    Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites
    Mitchard, E.T.A. ; Feldpausch, T.R. ; Brienen, R.J.W. ; Lopez-Gonzalez, G. ; Monteagudo, A. ; Baker, T.R. ; Lewis, S.L. ; Poorter, L. ; Peña-Claros, M. - \ 2014
    Global Ecology and Biogeography 23 (2014)8. - ISSN 1466-822X - p. 935 - 946.
    aboveground live biomass - stocks - deforestation - emissions - allometry - patterns - basin - soils
    Aim The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset. Location Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1 Methods Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons. Results The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by >¿25%, whereas regional uncertainties for the maps were reported to be
    Rumen degradation characteristics of ryegrass herbage and ryegrass silage are affected by interactions between stage of maturity and nitrogen fertilisation rate
    Heeren, J.A.H. ; Podesta, S.C. ; Hatew, B. ; Klop, G. ; Laar, H. van; Bannink, A. ; Warner, D. ; Jonge, L.H. de; Dijkstra, J. - \ 2014
    Animal Production Science 54 (2014)9. - ISSN 1836-0939 - p. 1263 - 1267.
    neutral detergent fiber - phleum-pratense l. - dairy-cows - nutritive-value - grass - timothy - protein - digestibility - emissions - matter
    The objective of this experiment was to evaluate interaction effects between stage of maturity and N fertilization rate on rumen degradation characteristics determined with nylon bag incubations of ryegrass herbages and ryegrass silage. Grass herbage (n = 4) was cut after 3 or 5 weeks of regrowth and received a low (20 kg N/ha) or a high (90 kg N/ha) fertilization rate. Grass silage (n = 6) received a low (65 kg N/ha) or high (150 kg N/ha) fertilization rate and was harvested at early (c 2000 kg DM/ha), mid (harvested 13 d later), or late (harvested 34 d later) maturity stage and ensiled in big bales. All grasses were incubated in the rumen of three lactating rumen-cannulated Holstein Friesian cows. Rumen degradation characteristics of organic matter (OM), nitrogen (N) and neutral detergent fibre (NDF) and the extent of effective degradation (ED) were evaluated. In grass herbage, NDF content varied between 390 and 454 g/kg DM and N content between 12.1 and 25.8 g/kg DM. In grass silage, NDF content varied between 438 and 593 g/kg DM and N content between 13.4 and 34.8 g/kg DM. In general, rumen degradation of grass herbage and grass silage decreased with increased maturity, and increased with increased fertilization rate. Significant interaction between maturity and fertilization rate was observed for ED of OM, N and NDF, except for ED of N in grass herbage. These results indicate that the effect of the rate of N fertilization on degradation of nutrients in the rumen of dairy cattle and on nutritional value depends on the grass maturity stage.
    Climate change and deforestation: the evolution of an intersecting policy domain
    Buizer, I.M. ; Humphreys, D. ; Jong, W. de - \ 2014
    Environmental Science & Policy 35 (2014). - ISSN 1462-9011 - p. 1 - 11.
    forest governance - redd plus - land-use - biodiversity - emissions - countries - services - regime
    Forests and climate change are increasingly dealt with as interconnected policy issues. Both the potential synergies and policy conflicts between forest conservation and restoration and climate change mitigation now receive sustained and high level attention from academic, policy analysis and practitioner communities across the globe. Arguably the most pronounced contemporary policy manifestation of this is the debate on Reducing Emissions from Deforestation and Forest Degradation in Developing Countries (or REDD+) by which governments and private investors from developed countries may compensate actors in tropical forest countries for reducing forest loss beneath an agreed baseline. Problems of climate–forest policies implementation and governance, however, can also be found in countries such as Canada, the USA, the UK and Australia. The future of instruments like REDD+ is uncertain with growing critiques on payment and performance-based mechanisms and unresolved issues of governance, government and accountability. This paper, and the special issue it introduces, illustrates that in the REDD+ debate many contentious issues have resurfaced from past debates. These issues include the participation and rights of local communities in forest policy and management; the relationship between internationally agreed payment and performance-based programmes and formal democratic decision-making processes and structures; the complexities of rights to carbon versus tenure rights; and the ways in which – in spite of the high expectations of both developing and developed countries to combat carbon emissions from deforestation and forest degradation through the REDD+ mechanism – effective climate-focused forestry policies are seldom found in most tropical forest-rich countries. REDD+ is now very much the dominant discourse at the forest–climate interface, and one with a primary focus on measurability to communicate carbon mitigation results across various levels. However, this serves to disperse and displace, rather than resolve, policy-making on non-carbon values.
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