The information required for constructing predictive models has been obtained from the establishment and (re) measurement of an extensive network of permanent plots and silvicultural trials. This network covers the geographical distribution of the plantations and growth zones defined for the species of interest.
The network of permanent plots provides information on the yields achieved by the plantations under operational conditions, allowing to calibrate the models under changes in genetic material, changes in management regimes, and climatic changes occurring between successive plantations.
In contrast, the trials have an experimental design with repetitions that can evaluate and model the effect of factors of interest such as establishment techniques, initial planting density, and spacing, as well as the intensity and periodicity of thinning and pruning on growth and quality of the trees. In this case, the trials consider management regimes that are not used in operations, thus allowing a greater response surface and flexibility for the developed models.
The data capture process is carried out following a strict measurement protocol defined and agreed upon by its members. Annual training is given to the contracting companies in charge of collecting the data. In addition, some of the permanent plots and trials measured are also controlled by the MNS. Data are recorded with the help of an electronic data capture device. Subsequently, all data is stored and managed in a database management system developed by the MNS. This system allows validation of the data entered, ensuring the integrity and consistency of the information on growth series at the tree level.