plant community #95
Description
We are currently working on the simulation of forest systems using the SWAT+ model (version 61.0.1), with a focus on land-use change and forest regrowth. During this work, we have come across a few inconsistencies in the interaction between plant_comm, LAI, and growth control that we’d like to share:
There appears to be no check for whether a plant in the plant_comm is actively growing (grow = y/n). As a result, after harvesting evergreen forests, the LAI returns to LAImin during the dormancy phase, even when no vegetation is actively growing. This leads to continued simulation of interception, despite the absence of active vegetation.
When we include a second plant (e.g., for reforestation) in a plant_comm, LAI values (both LAIpot and LAImin) seem to be summed across species, regardless of their individual growth status. To address the LAI issue, we added the condition if (pcom(j)%plcur(ipl)%gro == "y") then in the calc total lai for plant community section of pl_community.f90. This resolved the LAI summation problem when plants are not growing.
However, we still observe interaction effects between plants within the same community, even if one is inactive. We suspect that this interaction is related to the pnt_pop parameter, as we have tested other parameters without observing similar effects. It seems that an additional status check might be missing elsewhere in the model code to properly isolate inactive plants within a plant_comm.
We would really appreciate any feedback on whether this behaviour is intentional or if there’s a recommended way to handle this type of plant community setup.