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671 | werner | 2 | /******************************************************************************************** |
3 | ** iLand - an individual based forest landscape and disturbance model |
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4 | ** http://iland.boku.ac.at |
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5 | ** Copyright (C) 2009- Werner Rammer, Rupert Seidl |
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6 | ** |
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7 | ** This program is free software: you can redistribute it and/or modify |
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8 | ** it under the terms of the GNU General Public License as published by |
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9 | ** the Free Software Foundation, either version 3 of the License, or |
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10 | ** (at your option) any later version. |
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11 | ** |
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12 | ** This program is distributed in the hope that it will be useful, |
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13 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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15 | ** GNU General Public License for more details. |
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16 | ** |
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17 | ** You should have received a copy of the GNU General Public License |
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18 | ** along with this program. If not, see <http://www.gnu.org/licenses/>. |
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19 | ********************************************************************************************/ |
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20 | |||
113 | Werner | 21 | #include "global.h" |
22 | #include "production3pg.h" |
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23 | |||
189 | iland | 24 | #include "resourceunit.h" |
113 | Werner | 25 | #include "species.h" |
226 | werner | 26 | #include "speciesresponse.h" |
27 | #include "model.h" |
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113 | Werner | 28 | |
29 | Production3PG::Production3PG() |
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30 | { |
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226 | werner | 31 | mResponse=0; |
440 | werner | 32 | mEnvYear = 0.; |
113 | Werner | 33 | } |
34 | |||
226 | werner | 35 | /** |
36 | This is based on the utilizable photosynthetic active radiation. |
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37 | @sa http://iland.boku.ac.at/primary+production |
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227 | werner | 38 | The resulting radiation is MJ/m2 */ |
39 | inline double Production3PG::calculateUtilizablePAR(const int month) const |
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226 | werner | 40 | { |
327 | werner | 41 | // calculate the available radiation. This is done at SpeciesResponse-Level |
226 | werner | 42 | // see Equation (3) |
273 | werner | 43 | // multiplicative approach: responses are averaged one by one and multiplied on a monthly basis |
44 | // double response = mResponse->absorbedRadiation()[month] * |
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45 | // mResponse->vpdResponse()[month] * |
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46 | // mResponse->soilWaterResponse()[month] * |
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47 | // mResponse->tempResponse()[month]; |
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48 | // minimum approach: for each day the minimum aof vpd, temp, soilwater is calculated, then averaged for each month |
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327 | werner | 49 | //double response = mResponse->absorbedRadiation()[month] * |
50 | // mResponse->minimumResponses()[month]; |
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51 | double response = mResponse->utilizableRadiation()[month]; |
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273 | werner | 52 | |
226 | werner | 53 | return response; |
54 | } |
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55 | /** calculate the alphac (=photosynthetic efficiency) for the given month. |
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56 | this is based on a global efficiency, and modified per species. |
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227 | werner | 57 | epsilon is in gC/MJ Radiation |
226 | werner | 58 | */ |
227 | werner | 59 | inline double Production3PG::calculateEpsilon(const int month) const |
226 | werner | 60 | { |
61 | double epsilon = Model::settings().epsilon; // maximum radiation use efficiency |
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62 | epsilon *= mResponse->nitrogenResponse() * |
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300 | werner | 63 | mResponse->co2Response()[month]; |
226 | werner | 64 | return epsilon; |
65 | } |
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66 | |||
227 | werner | 67 | inline double Production3PG::abovegroundFraction() const |
68 | { |
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536 | werner | 69 | double utilized_frac = 1.; |
70 | if (Model::settings().usePARFractionBelowGroundAllocation) { |
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71 | utilized_frac = mResponse->totalUtilizedRadiation() / mResponse->yearlyRadiation(); |
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72 | } |
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73 | double harsh = 1 - 0.8/(1 + 2.5 * mResponse->nitrogenResponse() * utilized_frac); |
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227 | werner | 74 | return harsh; |
75 | } |
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76 | |||
369 | werner | 77 | void Production3PG::clear() |
78 | { |
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79 | for (int i=0;i<12;i++) { |
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80 | mGPP[i] = 0.; mUPAR[i]=0.; |
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81 | } |
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440 | werner | 82 | mEnvYear = 0.; |
369 | werner | 83 | } |
84 | |||
697 | werner | 85 | /** calculate the stand-level NPP |
86 | @ingroup core |
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698 | werner | 87 | Standlevel (i.e ResourceUnit-level) production (NPP) following the 3PG approach from Landsberg and Waring. |
226 | werner | 88 | @sa http://iland.boku.ac.at/primary+production */ |
115 | Werner | 89 | double Production3PG::calculate() |
113 | Werner | 90 | { |
226 | werner | 91 | Q_ASSERT(mResponse!=0); |
92 | // Radiation: sum over all days of each month with foliage |
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230 | werner | 93 | double year_raw_gpp = 0.; |
369 | werner | 94 | clear(); |
226 | werner | 95 | double utilizable_rad, epsilon; |
230 | werner | 96 | // conversion from gC to kg Biomass: C/Biomass=0.5 |
485 | werner | 97 | const double gC_to_kg_biomass = 1. / (biomassCFraction * 1000.); |
226 | werner | 98 | for (int i=0;i<12;i++) { |
513 | werner | 99 | utilizable_rad = calculateUtilizablePAR(i); // utilizable radiation of the month times ... (MJ/m2) |
100 | epsilon = calculateEpsilon(i); // ... photosynthetic efficiency ... (gC/MJ) |
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230 | werner | 101 | mUPAR[i] = utilizable_rad ; |
102 | mGPP[i] =utilizable_rad * epsilon * gC_to_kg_biomass; // ... results in GPP of the month kg Biomass/m2 (converted from gC/m2) |
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251 | werner | 103 | year_raw_gpp += mGPP[i]; // kg Biomass/m2 |
113 | Werner | 104 | } |
436 | werner | 105 | |
106 | // calculate f_env,yr: see http://iland.boku.ac.at/sapling+growth+and+competition |
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107 | double f_sum = 0.; |
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108 | for (int i=0;i<12;i++) |
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437 | werner | 109 | f_sum += mGPP[i] / gC_to_kg_biomass; // == uAPar * epsilon_eff |
436 | werner | 110 | |
467 | werner | 111 | // the factor f_ref: parameter that scales response values to the range 0..1 (1 for best growth conditions) (species parameter) |
112 | const double perf_factor = mResponse->species()->saplingGrowthParameters().referenceRatio; |
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485 | werner | 113 | // f_env,yr=(uapar*epsilon_eff) / (APAR * epsilon_0 * fref) |
436 | werner | 114 | mEnvYear = f_sum / (Model::settings().epsilon * mResponse->yearlyRadiation() * perf_factor); |
480 | werner | 115 | if (mEnvYear > 1.) { |
483 | werner | 116 | qDebug() << "ERROR: fEnvYear > 1 for " << mResponse->species()->id() << mEnvYear << "f_sum, epsilon, yearlyRad, perf_factor" << f_sum << Model::settings().epsilon << mResponse->yearlyRadiation() << perf_factor; |
485 | werner | 117 | mEnvYear = 1.; |
480 | werner | 118 | } |
436 | werner | 119 | |
120 | // calculate fraction for belowground biomass |
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227 | werner | 121 | mRootFraction = 1. - abovegroundFraction(); |
137 | Werner | 122 | |
123 | // global value set? |
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215 | werner | 124 | double dbg = GlobalSettings::instance()->settings().paramValue("gpp_per_year",0); |
227 | werner | 125 | if (dbg) { |
280 | werner | 126 | year_raw_gpp = dbg; |
227 | werner | 127 | mRootFraction = 0.4; |
128 | } |
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137 | Werner | 129 | |
230 | werner | 130 | // year GPP/rad: kg Biomass/m2 |
131 | mGPPperArea = year_raw_gpp; |
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132 | return mGPPperArea; // yearly GPP in kg Biomass/m2 |
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113 | Werner | 133 | } |