Poplar Growth Modal Updates.

[qjhart]

We have a number of opportunities for the poplar growth model right now. In October, we are going to Vancouver WA, to present the model to a large number of poplar growers. Their interest is primarily in water use however, so we need to consider the following questions:

What modifications can we make to the poplar growth model to be more useful for water growers
Root depth ?
Depth to Ground water ?
More advanced soil horizons?
Affects from salinity ?
Irrigation nutrients ?
In addition, in October, Greenwood wants to do a better job of validation of our model. This is the perfect opportunity to complete our first paper. Some of the things we need to look at are:

We MUST allow for different increments of the time scale.
We need to determine how to model each species if possible
We need to discuss with greenwood their guesses at mortality rates
We REALLY need to get a better handle on how we partition stem growth
This includes the ability to better predict the quality of the woods (bark vs. wood)

[jrmerz]

Should we break this up in to several issues? Perhaps some are better suited for the 3PG model repo? I have added the ability to specify specific coppice dates here: CSTARS/poplar-3pg-model@c552912