Difference between revisions of "Simulation models"
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(Created page with 'Author: Björn Elfving. ==Introduction== Heureka replaces the former planning systems Hugin and Forest Planning Package, and the growth models from those systems are available in�?�') |
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Author: Björn Elfving. | Author: Björn Elfving. | ||
==Introduction== | ==Introduction== | ||
| − | + | The default options for growth modelling in Heureka are based functions which will be presented here. All growth functions are common for the three applications StandWise, PlanWise and RegWise, and predictions can be based on single plot data or data from several plots representing a stand. | |
Two stages are distinguished at the growth modelling: the stand establishment period (h<7 m) and the development of established stands (h>7 m). Predictions of stand establishment and development of young stands are based on data from the Hugin young stand survey. For un-stocked areas (in initial inventory data or on areas that are clear-cut during the growth predictions) the expected stocking 12 years after clear-cut in natural regenerations or 12 years after sowing or planting is calculated as a function of site conditions and prescribed regeneration measures. With stocking, regeneration type and site conditions as indicators, data on height- and species distribution in the new stand is either imported from a data-base with measured plots or estimated with functions based on data from this data-base. Probabilities for all trees to become a future crop tree are calculated, and from this the mean height of different species in this population. Those probabilities are also used for stem selection at pre-commercial thinning. | Two stages are distinguished at the growth modelling: the stand establishment period (h<7 m) and the development of established stands (h>7 m). Predictions of stand establishment and development of young stands are based on data from the Hugin young stand survey. For un-stocked areas (in initial inventory data or on areas that are clear-cut during the growth predictions) the expected stocking 12 years after clear-cut in natural regenerations or 12 years after sowing or planting is calculated as a function of site conditions and prescribed regeneration measures. With stocking, regeneration type and site conditions as indicators, data on height- and species distribution in the new stand is either imported from a data-base with measured plots or estimated with functions based on data from this data-base. Probabilities for all trees to become a future crop tree are calculated, and from this the mean height of different species in this population. Those probabilities are also used for stem selection at pre-commercial thinning. | ||