Use 3pg model in order to simulate growth for stands where trees don’t have the same age ( uneven aged )

[issamyax]

Hi,

I would like to know if is it possible to use R3pg package in order to make simulation of biomass growth, knowing that trees in forest ( even those located in the same plot ) don’t have the same age ( uneven aged forest ). Thus, it is impossible for me to set plantation date as recquired in species data frame.

Any help would be appreciated.

Issamyax

[trotsiuk]

Hi @issamyax ,

Thank you for the interest on using the r3PG R package.

For such a purpose, consider specifying each age class as a separate cohort for the simulation. An example of such simulation was shortly presented in the issue #42. Basically, instead of simulating different species you can use different age classes.

[issamyax]

Thank you for your quick response dear @trotsiuk .

In fact this alternative also cannot be possible due to the mixture of ages.

To be more forward, In the present forest, even trees that are separeted by 3m for example do not have the same age. The regime of cut is called jardinatory means that it is based on the size of tree not on the age. So, the forest's managers do not have any idea on the age of this forest and the regeneration seems to be ''natural''.

Many thanks.

[trotsiuk]

Unfortunately without knowing the age it is not possible to run the simulation. Age is one of the main requirements for the initiation of the model. You might consider estimating it based on the cutting system.

[issamyax]

I will try to overcome this missing data using biomass increment. Knowing the current biomass of each tree, I could estimate the current age of each tree.

Many thanks @trotsiuk