Lund-Potsdam-Jena managed land (LPJmL) Process-based agriculture, vegetation and hydrology model

Transcription

1 Lund-Potsdam-Jena managed land (LPJmL) Process-based agriculture, vegetation and hydrology model A short, simple and informal introduction June

2 One grid-cell in LPJmL Climate, CO 2 concentration, soil structure, land use Interception Irrigated and rainfed agriculture, grasslands, natural vegetation Evaporation Surface runoff 0.5 C, H 2 O exchange AET Photosynthesis Water availability Infiltration C i Phenology Management Production River discharge (Gerten et al., 2004; Biemans et al., 2009) Irrigation water requirements (Rost et al., 2008) Water consumption of crops (Fader et al., 2010) Etc. 2

3 Model inputs & availability Monthly climate (temperature, precipitation, rainy days, cloud cover). Global, 0.5 arc degrees. CRU Climate models until Soil structure (not type!). Static. Global atm. CO 2 -concentrations Land use dataset: irrigated and rainfed (separated!) sowing areas for each class. Global, 0.5 arc degrees. M.Fader s dataset from Weather generator: daily climate. Secondary inputs: potential evapotranspiration and soil temperature 3

4 Plant classes & parametrisation Natural vegetation (pft) Sitch et al., tropical broad-leaved evergreen; 2. tropical broad-leaved raingreen; 3. temperate needle-leaved evergreen; 4. temperate broad-leaved evergreen; 5. temperate broad-leaved summer green; 6. boreal summer green; 7. boreal needle-leaved evergreen; 8. C3 herbaceous; 9. C4 herbaceous. Agricultural trees & others Med Fader et al., Citrus (orange) 2.Nuts (almonds) 3.Orchards (apple) 4.Olives 5.Cotton 6.Date palms 7.Grapes 8.Fodder grass 9.Vegetables (grass!!) 10.Potatoes Annual crops (cft) Bondeau et al., Temperate cereals (wheat) 2.Maize 3.Rice 4.Tropical cereals (millet) 5.Temperate roots (sugar beets) 6.Tropical roots (cassava) 7.Pulses (beans) 8.Sunflower 9.Groundnuts 10.Soybeans 11.Sucar Cane 12.Managed grasslands Bioenergy Behringer et al., Tropical bioenergy tree 2.Temperate bioenergy tree 3.Bioenergy grasses Inclusion of others or re-parametrisation possible but literature work needed 4

5 Main model outputs Carbon cycle: GPP, NPP, Net ecosystem exchange, autotrohic and heterotrophic respiration, Vegetation carbon, soil carbon. Agriculture: yields (t/ha), production (t), growing period. Water: soil evaporation, plant transpiration, plant interception, surface runoff, percolation/infiltration, irrigation requirements, soil water content, surface water availability. 5

6 Processes considered & considered simply Photosynthesis Phenology & LAI development Carbon allocation to different plant s parts & allometry Root distribution & soil biochemistry Fire disturbance in natural vegetation Tree mortality Light and water competition between different types of natural vegetation Bioclimatic limits (parametrised) Crop & fruit ripeness & harvest Residues of agriculture Dynamic sowing dates and growing periods Coupling between CO2 and photosynthesis Water stress & heat stress Agricultural management 6

7 Processes not considered Among others: Management of forests Nitrogen cycle (it s being done at PIK) Erosion Pollution Fire disturbance in agriculture Age classes in natural vegetation Fossil groundwater availability Salinization 7

8 Applications Impacts of climate change Impacts of land use change Potential agricultural production Past & future evolution of carbon cycle Past & future changes in hydrological cycle Potential growing areas Impacts of agric. management 8

9 Agricultural management I Represents level of inputs and control of production (fertilizers, technology, work, weed and pest control, etc.) Three parameters are coupled: LAI max = plant productivity HI max = proportion of aboveground biomass that goes into storage organ -a = scales leave productivity to field productivity (represent homogeneity/heterogeneity of fields) 9

10 Agricultural management II Coupling: LAI max : 1 HI MAX : : 80% -a: 0,4 LAI max : 2 HI MAX : 83,3 -a: 0,5 LAI max : 3 HI MAX : 86,7 -a: 0,6 LAI max : 4 HI MAX : 90,0 -a: 0.7 LAI max : 5 HI MAX : 93,3 -a: 0,8 LAI max : 6 HI MAX : 96,7 -a: 0,9 LAI max : 7 HI MAX : 100 -a: 1 LAI max callibrated to best fit FAO yields 10

11 Example of management (LAI max ) wheat Maize Mean

12 Literature The LPJmL paper: Bondeau, A., Smith, P., Zaehle, S., Schaphoff, S., Lucht, W., Cramer, W., Gerten, D., Lotze- Campen, H., Müller, C., Reichstein, M., Smith, B Modelling the role of agriculture for the 20th century global terrestrial carbon balance. Global Change Biology 13, The LPJ paper: Sitch S, Smith B, Prentice IC, Arneth A, Bondeau A, Cramer W, Kaplan J, Levis S, Lucht, W, Sykes M, Thonicke K, Venevsky S Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ Dynamic Vegetation Model. Global Change Biology 9: Description of the water routing scheme: Rost, S., Gerten, D., Bondeau, A., Lucht, W., Rohwer, J., Schaphoff, S. 2008: Agricultural green and blue water consumption and its influence on the global water system. Water Resources Research 44, W09405, doi: /2007wr And the technical implementation of river routing: von Bloh, W., Rost, S., Gerten, D., Lucht, W Efficient parallelization of a dynamical global vegetation model with river routing. Environ. Model. Softw. 25, This is the permafrost and soil hydrology paper: Schaphoff, S., Heyder, U., Ostberg, S., Gerten, D., Heinke, J., Lucht, W Contribution of permafrost soils to the global carbon budget. Environ. Res. Lett. 8, This is the bioenergy paper: Beringer T, Lucht W, Schaphoff S Bioenergy production potential of global biomass plantations under environmental and agricultural constraints. Glob. Change Biol. Bioen. 3, This is the SPITFIRE paper: Thonicke K, Spessa A, Prentice IC, Harrison SP, Dong L & Carmona-Moreno C The influence of vegetation, fire spread and fire behaviour on biomass burning and trace gas emissions: results from a process-based model. Biogeoscience 7(6): This is the sowing date paper: Waha K, van Bussel LGJ, Müller C, Bondeau A (2012): Climate-driven simulation of global crop sowing dates. Global Ecology and Biogeography, 21,2, pp , doi: /j x The implementation of agricultural trees is submitted to GMD: Fader, M., von Bloh, W., Shi, S., Bondeau, A., Cramer, W. : Modelling Mediterranean agro-ecosystems by including agricultural trees in the LPJmL model. 12

13 C est tout! June