Understanding Plant Competition and Resource Allocation in SWAT+ Plant Communities

[Ilef Abid]

Dear SWAT + Community, 

I am currently conducting research on how SWAT+ considers multiple plants within the same plant community. My objective is to understand and justify, from a mechanistic point of view, how SWAT+ represents multiple plants in a community, particularly how competition for resources is modeled, how resources are distributed among the plants, and how stress affects each plant.

I would specifically like to understand how SWAT+ internally allocates each resource among the different plants within a plant community. In particular, I would like to know the mechanism used to determine how water, radiation, nutrients, and other resources are allocated between competing plants, rather than assuming a fixed percentage-based or spatial distribution. I am interested in the actual internal logic and equations used by the model to determine the share of each resource received by each plant.

I have found the relevant Fortran source code, but I am having difficulty understanding the entire mechanism and how the different parts of the code are connected.

Is there any documentation, technical report, paper, or other reference that could help me better understand the underlying mechanism of plant competition and resource allocation between multiple plants in a SWAT+ plant community?

Thank you so much