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Összefoglaló | Az erdők szénkörforgalmáról |
Letöltés és installálás |
A modell futtatása. Szenáriók |
Köszönet- nyilvánítás |
Hivatkozás a modellre |
CASMOFOR |
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A modellről általában |
Néhány példa a modell outputjára |
Részletes modell leírás |
Hasznos kapcsolók |
Felelősség- elhárítás |
Kapcsolat | ||
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CASMOFOR - segítség az input mezők kitöltéséhez Tartalomjegyzék A
scenáriók definiálása A
szcenáriók konkrét jellemzőinek megadása (második input ablak) A modell részletes leírását tartalmazó helpfile itt érhető el. In order to run the model, approppriate information must be provided. Three types of information are needed: the definition of the scenarios (e.g. duration of forestation program, is the rate of forestation constant etc.), the specifications of the scenarios (e.g. the annual rate of forestation), and the characteristics of the forest at the first year of the run. On input sheet 1, some very general parameters of the scenario(s) is (are) set. Based on some of these parameters, other, more detailed parameters can be set in input sheet 2. First calendar year of scenario This information is only needed to use it on graphs showing the results. The simulation can start at any calendar year past or future.Constant rate of afforestation? (Y/N) Increasing forest area can happen in two ways: either at a fix rate over the years and species, or in either a non-linear manner over time, or linearly over time, but not accross species, or at a varying rate accross both time and species. In the first case, the user must only set, in the second input sheet, the overall rate and, in this input sheet right below, the length of the afforestation program. Note that the rate must be constant not only over time, but also accross species. In all other cases, the user must type in the area of afforestations for each year of the scenario in the user.xls file. (If this has not been done, the user must quit from this program, load user.xls, type in the figures in Table 2, then rerun the program.) Length of afforestation program (yr) This is the length of period, in years, during which afforestations are made. This information is necessary to be set only if the afforestation rate is constant, otherwise this is inherently set when the user provides the afforestation rate for each year of the afforestation program. The length of this period is not necessariliy equal to the length of the scenarios, which is always 50 years. Baseline scenario: with natural revegetation? (Y/N) Baseline scenario is the one encompassing all the events that would occur on all the lands in the afforestation scenarios if the afforestation program did not take place. Quite naturally, it may happen that this land would be abandoned anyway, but also that land is used under, e.g., cropland management until it is actually afforested. Although any variation of the two cases can happen, one must not count considerable differences unless the land revegetates itself. This is because if land cannot revegetate itself, or if it is managed as a non-forest land, the land is supposed to be in equilibrium with respect to carbon, however, if trees occupy the land, they accumulate carbon in their biomass for several decades. If this cell is set to Y(es), revegetation will occur, and the carbon fixed in this path will be deducted from the carbon fixed in the afforestation program. See more detailes at the description of the baseline scenario. Forest present at start? (Y/N) The model can be run by using one of two assumptions: either there is forest already present or there is no forest at the beginning of the simulation. In the first case, the user must provide relevant data, i.e. the area of forest by species and yield class. These data must be in the file user.xls. The program cannot check if the data in the user.xls file are correct, and it will use them, so the users themselves must check and provide these data. If you encounter this when running the software, you must first quit the program, modify and save user.xls if necessary, then rerun the program.Is mortality randomly generated? (Y/N) As it is detailed at the description of the model, mortality, i.e. the senescence of trees due to various causes, is highly variable mainly due to the highly variable nature of the trees' environment. This year-to-year variability can only be modelled by using probability functions and random numbers. Whereas it is enough to use probability functions to model density-dependent mortality, density-independent mortality can only be approximated if the mortality rate randomly changed from year to year. This can be achieved by selecting a random number for each year, which is used to calculate the mortality rate. If random mortality is deselected, then it is supposed that only density dependent mortality occurs in the stands, which is independent of the variable environment. See more about mortality here.CASMOFOR can handle forest stands consisting of maximum three tree species. Here you must specify how many species will be used. You can not only specify three different species, but you can also select the same species maximum three times. This can be done if, e.g., you want to compare several afforestation programs where the distribution of forest area by yield class is different. Selecting the species themselves is done by using of the roll-down menus on the second input sheet.CASMOFOR can handle forest stands that are classified into one of the six yield classes that are used to assess the growth of the trees. The distribution of the forest, or the afforested area, by yield classes can either be done by typing in the overall ratios, in percent of the total area, on the second input sheet, if the rate is constant over the afforestation period, or in the user.xls file, if the rate changes from year to year. Note that it is not necessary to have forest in each yield class. If you have forest or forestation only in one, two, three, four or five yield classes, zero(s) must be typed in for the area of those classes. Note also that if only you select here one yield class, the program will use the data for the fourth yield class for each species. To provide forest area for one yield class only, select here any number greater than one, and, on input sheet 2, write zeros in all yield classes except for the one in which you have all your forest (and put there 100 for 100 percent).Second input window: Specifying scenario(s) On input sheet 2, some more detailed parameters of the scenario(s) must be provided. These parameters will be used during the calculations. Under this item, you can see so many roll-down menus that you specified on input sheet 1 under "Number of species?" Please select one species from each roll-down menu. If you do not want to select any species from a menu, select (none) at the end of the species list.If you selected, on input sheet 1, that the rate of afforestation is constant over the afforestation period, you must set this rate here. This rate is equal to the area, in ha, that is afforested each year, all species included in the scenario. If you selected the linear rate of afforestation, and typed it in, and also selected the number of species and yield classes, here you must set the distribution of the annual afforestation by species and yield class in percents. Note that you do not need to have forest in each species and yield class. You only have to make sure that the sum of the percents for all species and yield classes is 100.Yield class is one of (usually) six classes that reflects that site quality (e.g. availability of water and nutrient for the roots in the soil by time and space) considerably affects how much biomass can be produced by the trees of a species. Yield class one refers to the best site and the best performance of the species (in terms of yield), whereas yield class six refers to the poorest site and the poorest performance of the species. See details here. These are percent values of the afforested area for each species and yield class. See details here.If the afforestation rate is not constant over time, or if there is forest present at the beginning of the scenario, you must set the varying rates and/or the characteristics of the forest in the file user.xls. See here for details. | |||||||
