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LPJmL4 model output for the publications in GMD: LPJmL4 - a dynamic global vegetation model with managed land: Part I – Model description and Part II – Model evaluation
Schaphoff, Sibyll ; Bloh, Werner von; Rammig, Anja ; Thonicke, Kirsten ; Biemans, H. ; Forkel, Matthias ; Gerten, Dieter ; Heinke, Jens ; Jägermeyr, Jonas ; Knauer, Jürgen ; Langerwisch, Fanny ; Lucht, Wolfgang ; Müller, Christoph ; Rolinski, Susanne ; Waha, Katharina - \ 2018
soil carbon - vegetation carbon - global carbon balance - permafrost distribution - discharge - fractional burned area - crop yields - global dynamic vegetation model - vegetation dynamics
LPJmL4 is a process-based model that simulates climate and land-use change impacts on the terrestrial biosphere, the water and carbon cycle and on agricultural production. The LPJmL4 model combines plant physiological relations, generalized empirically established functions and plant trait parameters. The model incorporates dynamic land use at the global scale and is also able to simulate the production of woody and herbaceous short-rotation bio-energy plantations. Grid cells may contain one or several types of natural or agricultural vegetation. A comprehensive description of the model is given by Schaphoff et al. (2017a, http://doi.org/10.5194/gmd-2017-145). The data presented here represent some standard LPJmL4 model results for the land surface described in Schaphoff et al. (2017a,). Additionally, these results are evaluated in the companion paper of Schaphoff et al. (2017b, http://doi.org/10.5194/gmd-2017-146). The data collection includes some key output variables made with different model setups described by Schaphoff et al. (2017b). The data cover the entire globe with a spatial resolution of 0.5° and temporal coverage from 1901-2011 on an annual basis for soil, vegetation, aboveground and litter carbon as well as for vegetation distribution, crop yields, sowing dates, maximum thawing depth, and fire carbon emissions. Vegetation distribution is given for each plant functional type (PFT), crop yields, and sowing dates are given for each crop functional type (CFT), respectively. Monthly data are provided for the carbon fluxes (net primary production, gross primary production, soil respiration) and the water fluxes (transpiration, evaporation, interception, runoff, and discharge) and for absorbed photosynthetically active radiation (FAPAR) and albedo.
LPJmL4 Model Code
Schaphoff, Sibyll ; Bloh, Werner von; Thonicke, Kirsten ; Biemans, H. ; Forkel, Matthias ; Gerten, Dieter ; Heinke, Jens ; Jägermeyr, Jonas ; Müller, Christoph ; Rolinski, Susanne ; Waha, Katharina ; Stehfest, Elke ; Waal, Liesbeth de; Heyder, Ursula ; Gumpenberger, Marlies ; Beringer, Tim - \ 2018
Potsdam Institute for Climate Impact Research (PIK)
soil carbon - vegetation carbon - global carbon balance - permafrost distribution - discharge - fractional burned area - crop yields - global dynamic vegetation model - vegetation dynamics
LPJmL4 is a process-based model that simulates climate and land-use change impacts on the terrestrial biosphere, the water and carbon cycle and on agricultural production. The LPJmL4 model combines plant physiological relations, generalized empirically established functions and plant trait parameters. The model incorporates dynamic land use at the global scale and is also able to simulate the production of woody and herbaceous short-rotation bio-energy plantations. Grid cells may contain one or several types of natural or agricultural vegetation.
Climate change impact and adaptation research requires integrated assessment and farming systems analysis: a case study in the Netherlands
Reidsma, P. ; Wolf, J. ; Kanellopoulos, A. ; Schaap, B.F. ; Mandryk, M. ; Verhagen, J. ; Ittersum, M.K. van - \ 2015
Environmental Research Letters 10 (2015)4. - ISSN 1748-9326
european-union - crop yields - agriculture - responses - models - wheat - variability - improvement - strategies - scenarios
Rather than on crop modelling only, climate change impact assessments in agriculture need to be based on integrated assessment and farming systems analysis, and account for adaptation at different levels. With a case study for Flevoland, the Netherlands, we illustrate that (1) crop models cannot account for all relevant climate change impacts and adaptation options, and (2) changes in technology, policy and prices have had and are likely to have larger impacts on farms than climate change. While crop modelling indicates positive impacts of climate change on yields of major crops in 2050, a semiquantitative and participatory method assessing impacts of extreme events shows that there are nevertheless several climate risks. A range of adaptation measures are, however, available to reduce possible negative effects at crop level. In addition, at farm level farmers can change cropping patterns, and adjust inputs and outputs. Also farm structural change will influence impacts and adaptation. While the 5th IPCC report is more negative regarding impacts of climate change on agriculture compared to the previous report, also for temperate regions, our results show that when putting climate change in context of other drivers, and when explicitly accounting for adaptation at crop and farm level, impacts may be less negative in some regions and opportunities are revealed. These results refer to a temperate region, but an integrated assessment may also change perspectives on climate change for other parts of the world.
From field to atlas: Upscaling of location-specific yield gap estimates
Bussel, L.G.J. van; Grassini, P. ; Wart, J. van; Wolf, J. ; Claessens, L. ; Yang, H. ; Boogaard, H.L. ; Groot, H.L.E. de; Saito, K. ; Cassman, K.G. ; Ittersum, M.K. van - \ 2015
Field Crops Research 177 (2015). - ISSN 0378-4290 - p. 98 - 108.
climate-change - weather data - crop yields - input data - resolution - model - scale - impact - maize - systems
Accurate estimation of yield gaps is only possible for locations where high quality local data are available,which are, however, lacking in many regions of the world. The challenge is how yield gap estimates basedon location-specific input data can be used to obtain yield gap estimates for larger spatial areas. Hence,insight about the minimum number of locations required to achieve robust estimates of yield gaps atlarger spatial scales is essential because data collection at a large number of locations is expensive andtime consuming. In this paper we describe an approach that consists of a climate zonation scheme supple-mented by agronomical and locally relevant weather, soil and cropping system data. Two elements of thismethodology are evaluated here: the effects on simulated national crop yield potentials attributable tomissing and/or poor quality data and the error that might be introduced in scaled up yield gap estimatesdue to the selected climate zonation scheme. Variation in simulated yield potentials among weatherstations located within the same climate zone, represented by the coefficient of variation, served as ameasure of the performance of the climate zonation scheme for upscaling of yield potentials.We found that our approach was most appropriate for countries with homogeneous topography andlarge climate zones, and that local up-to-date knowledge of crop area distribution is required for selectingrelevant locations for data collection. Estimated national water-limited yield potentials were found to berobust if data could be collected that are representative for approximately 50% of the national harvestedarea of a crop. In a sensitivity analysis for rainfed maize in four countries, assuming only 25% coverageof the national harvested crop area (to represent countries with poor data availability), national water-limited yield potentials were found to be over- or underestimated by 3 to 27% compared to estimateswith the recommended crop area coverage of =50%. It was shown that the variation of simulated yieldpotentials within the same climate zone is small. Water-limited potentials in semi-arid areas are anexception, because the climate zones in these semi-arid areas represent aridity limits of crop productionfor the studied crops. We conclude that the developed approach is robust for scaling up yield gap estimatesfrom field, i.e. weather station data supplemented by local soil and cropping system data, to regional andnational levels. Possible errors occur in semi-arid areas with large variability in rainfall and in countrieswith more heterogeneous topography and climatic conditions in which data availability hindered full application of the approach.
Can exploiting natural genetic variation in leaf photosynthesis contribute to increasing rice productivity? A simulation analysis
Gu, J. ; Yin, X. ; Stomph, T.J. ; Struik, P.C. - \ 2014
Plant, Cell & Environment 37 (2014)1. - ISSN 0140-7791 - p. 22 - 34.
oryza-sativa l. - introgression lines - physiological traits - critical-appraisal - co2 assimilation - plant-growth - crop yields - leaves - model - rubisco
Rice productivity can be limited by available photosynthetic assimilates from leaves. However, the lack of significant correlation between crop yield and leaf photosynthetic rate (A) is noted frequently. Engineering for improved leaf photosynthesis has been argued to yield little increase in crop productivity because of complicated constraints and feedback mechanisms whenmoving up from leaf to crop level.Herewe examined the extent to which natural genetic variation in A can contribute to increasing rice productivity. Using the mechanistic model GECROS,we analysed the impact of genetic variation inAon crop biomass production, based on the quantitative trait loci for various photosynthetic components within a rice introgression line population.We showed that genetic variation in A of 25% can be scaled up equally to crop level, resulting in an increase in biomass of 22–29% across different locations and years. This was probably because the genetic variation in A resulted not only from Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase)-limited photosynthesis but also from electron transport-limited photosynthesis; as a result, photosynthetic rates could be improved for both light-saturated and light-limited leaves in the canopy. Rice productivity could be significantly improved by mining the natural variation in existing germ-plasm, especially the variation in parameters determining light-limited photosynthesis.
Meristem temperature substantially deviates from air temperature, even in moderate environments: Is the magnitude of this deviation species-specific?
Savvides, A. ; Ieperen, W. van; Dieleman, J.A. ; Marcelis, L.F.M. - \ 2013
Plant, Cell & Environment 36 (2013)1. - ISSN 0140-7791 - p. 1950 - 1960.
shoot-tip temperature - climate-change - leaf development - effective thickness - light interception - boundary-layers - heat-transfer - crop yields - maize apex - plant
Meristem temperature (Tmeristem) drives plant development but is hardly ever quantified. Instead, air temperature (Tair) is usually used as its approximation. Meristems are enclosed within apical buds. Bud structure and function may differ across species. Therefore, Tmeristem may deviate from Tair in a species-specific way. Environmental variables (air temperature, vapour pressure deficit, radiation, and wind speed) were systematically varied to quantify the response of Tmeristem. This response was related to observations of bud structure and transpiration. Tomato and cucumber plants were used as model plants as they are morphologically distinct and usually growing in similar environments. Tmeristem substantially deviated from Tair in a species-specific manner under moderate environments. This deviation ranged between -2.6 and 3.8¿°C in tomato and between -4.1 and 3.0¿°C in cucumber. The lower Tmeristem observed in cucumber was linked with the higher transpiration of the bud foliage sheltering the meristem when compared with tomato plants. We here indicate that for properly linking growth and development of plants to temperature in future applications, for instance in climate change scenarios studies, Tmeristem should be used instead of Tair, as a species-specific trait highly reliant on various environmental factors
Climate Change and Potato Production in Contrasting South African Agro-ecosystems 1. Effects on Land and Water Use Efficiencies
Haverkort, A.J. ; Franke, A.C. ; Engelbrecht, F.A. ; Steyn, J.M. - \ 2013
Potato Research 56 (2013)1. - ISSN 0014-3065 - p. 31 - 50.
elevated carbon-dioxide - solanum-tuberosum l. - co2 concentration - atmospheric co2 - crop yields - model - growth - simulation - enrichment - quality
Explorations of the impact of climate change on potential potato yields were obtained by downscaling the projections of six different coupled climate models to high spatial resolution over southern Africa. The simulations of daily maximum and minimum temperatures, precipitation, wind speed, and solar radiation were used as input to run the crop growth model LINTUL-Potato. Pixels representative for potato growing areas were selected for four globally occurring agro-ecosystems: rainy and dry winter and summer crops. The simulated inter-annual variability is much greater for rainfall than for temperature. Reference evapotranspiration and radiation are projected to hardly decline over the 90-year period, whilst temperatures are projected to rise significantly by about 1.9 °C. From literature, it was found that radiation use efficiency of potato increased with elevated CO2 concentrations by almost 0.002 g¿MJ-1¿ppm-1. This ratio was used to calculate the CO2 effect on yields between 1960 and 2050, when CO2 concentration increases from 315 to 550 ppm. Within this range, evapotranspiration by the potato crop was reduced by about 13% according to literature. Simulated yield increase was strongest in the Mediterranean-type winter crop (+37%) and least under Mediterranean summer (+12%) and relatively warm winter conditions (+14%) closer to the equator. Water use efficiency also increased most in the cool rainy Mediterranean winter (+45%) and least so in the winter crop closer to the equator (+14%). It is concluded from the simulations that for all four agro-ecosystems possible negative effects of rising temperatures and reduced availability of water for potato are more than compensated for by the positive effect of increased CO2 levels on water use efficiency and crop productivity.
Climate hotspots: key vulnerable regions, climate change and limits to warming
Hare, W. ; Cramer, W. ; Schaeffer, M. ; Battaglini, A. ; Jaeger, C. - \ 2011
Regional Environmental Change 11 (2011)S1. - ISSN 1436-3798 - p. S1 - S13.
sea-level rise - declining coral calcification - southern beaufort sea - china food security - great-barrier-reef - ocean acidification - carbon-dioxide - polar bears - tipping point - crop yields
Defining and operationalizing Article 2 of the UNFCCC remains a challenge. The question of what is dangerous climate change is not a purely scientific one, as danger necessarily has a subjective dimension and its definition requires judgment and precaution. The papers in this special issue of Regional Environmental Change attempt to navigate this problem, by offering an overview of the latest scientific findings in the context of risks and uncertainties, and assess some key vulnerabilities that might lead to dangerous climate change. This synthesis provides an overview of the papers in this issue and looks at four areas of possible dangerous climate change—adverse declines in regional food and water security, loss of arctic sea ice with projected extinction of species, large-scale sea-level rise and loss of coral reef systems. These issues affect a number of different regions including Africa, South Asia, and Small Island Developing States. Significant risks to vulnerable regions and systems at warming levels of 1.5–2°C above pre-industrial are identified. The direct effects of CO2 concentration increases in terms of ocean acidification are identified as relevant to Article 2 because of the risks posed to coral reefs. Ultimate CO2 stabilization levels that allow for the long-term viability of coral reefs likely are below 350 ppm. The paper concludes by arguing that the emission reduction pledges made by countries under the Copenhagen Accord will not suffice to prevent dangerous climate change.
Will higher minimum temperatures increase corn production in Northeast China? An analysis of historical data over 1965-2008
Chen Changqing, ; Lei Chengxia, ; Deng Aixing, ; Qian Chunrong, ; Hoogmoed, W.B. ; Zhang Weijian, - \ 2011
Agricultural and Forest Meteorology 151 (2011)12. - ISSN 0168-1923 - p. 1580 - 1588.
climate-change - phasic development - potential impact - soybean yield - winter-wheat - crop yields - rice - sensitivity - growth - trends
Recent crop model projections have shown that crop production may benefit from warming, especially in the high latitudes, but hard evidence is limited. In this study we conducted correlation and regression analyses of climate records of seventy-two meteorological stations and records of corn yield over the period 1965–2008 in Northeast China. It was found that over these forty-four years, the diurnal mean, minimum and maximum temperatures during corn growing season increased on average by 0.31 °C, 0.42 °C and 0.23 °C every ten years, respectively. No significant change in precipitation was found, although differences between years were large. The daily minimum temperature was the dominant factor to corn production. Corn yield was significantly correlated with the daily minimum temperature in May and September. According to a regression analysis of the anomalies of corn yield and air temperature, a 1.0 °C increase in daily minimum temperature in May or September will lead to an increment of 303 kg ha-1 or 284 kg ha-1 in corn yield, respectively. Corn varieties with longer growth duration will profit most from the climatic changes but agronomic practices may have to be modified to address expected weather extremes such as droughts and periods with heavy rainfall
Assessing denitrification and N leaching in a field with organic amendments
Radersma, S. ; Smit, A.L. - \ 2011
NJAS Wageningen Journal of Life Sciences 58 (2011)1-2. - ISSN 1573-5214 - p. 21 - 29.
nitrate vulnerable zone - paper-mill sludge - crop yields - nitrogen mineralization - plant residues - barley straw - forest soils - decomposition - management - release
Denitrification and leaching of nitrogen (N) from agriculture are a loss of nutrients to farmers and sources of pollution to water and air, and should therefore be minimized. In a field experiment on loamy soil, denitrification and N leaching were measured after late summer incorporation of fodder radish residues with or without paper pulp as N-immobilizing organic material. A set of relatively simple methods were used to measure and calculate denitrification and N leaching during the first two weeks after application and during the rest of the winter period. The methods were acetylene inhibition of nitrification, anion-exchange resin, the mineralization model MINIP, and inorganic-N balance calculations. Paper pulp increased N immobilization after the first day of application throughout the winter. This led to a 63–70% reduction in N losses compared with the sole fodder radish field and with the control. Denitrification was highest in the sole fodder radish treatment, at 65% of its total N losses. N leaching during the winter period was highest in the control, at 70% of its total N losses. This N was mainly liberated by mineralization of soil organic matter after ploughing in late summer. The application of paper pulp plus fodder radish did not affect sugar beet yields in the next year. The methodology for determining leaching and denitrification enabled the assessment of differences among treatments. It showed clearly that paper pulp strongly reduced N losses on this type of soil. The anion resin method that was used to measure leaching during the winter period showed clear and consistent differences between treatments, but may need additional calibration before fully relying on the absolute amounts of N leached
Eucalyptus-wheat interaction on Ethiopian Nitosols
Kidanu, S. ; Mamo, T. ; Stroosnijder, L. - \ 2004
Agricultural Systems 80 (2004)2. - ISSN 0308-521X - p. 151 - 170.
root-growth - crop yields - soil - tree - agroforestry - plantations - shelterbelt
Over the past few years a single row of Eucalyptus globulus trees planted along the borders of cropland has come to dominate central highland agroforestry practices. Although evidence is scanty, there is a perception that this practice adversely affects crop productivity. An on-farm trial was therefore conducted at Ginchi to determine the biomass production potential of eucalypt boundaries and their effect on the productivity of the adjacent wheat crop (Triticum aestivum) on highland Nitosols. Three rotation cycles of 4 years each, two stand ages within each rotation, four field aspects and six yield strata perpendicular to the tree-crop interface were arranged in a split-split plot design with three replications. The annual wood production rate, which was 345-903 kg ha-1 yr-1 with two- and four-year-old stands in the first cycle, was increased more than 2-fold in the subsequent two rotation cycles. With these productivities, eucalypt boundaries on a hectare of land in the second and third cycle would satisfy about 70% of the annual biomass energy requirement of a rural household with a family size of five people for four consecutive years. However, adjacent wheat yields were substantially reduced because of the combined effects of water, light and nutrient competition. In the last two rotation cycles, significant yield depressions occurred over the first 16 m from the line of trees as opposed to only the first 8 m in the first cycle. The yield drop was 4.5-8.1%, and 8.1-10.4% in the first and last two rotation cycles, respectively. Nevertheless, the benefit accrued from the tree component adequately compensated for this reduction in wheat yield and generated additional income. The implications of these results are discussed in the context of the suitability of the practice in the region and its role in relieving the increasing pressure on indigenous forest and woodland.