I have used Simforest to create several simulations on two sets of date comming from two different terraces in Zoar Valley. I used all of the trees in the sampled quadrats to build a forest and then subjected it to all the different site treatments. Afterwards I exported them to Excel, determined what year each tree was born using a subtraction equation and then seperated out the trees that were still alive when the simulation stopped. My plan is to now run statistical tests on them data using SPSS.

~Erin K. Pfeil

SimForest Issues

I was attempting to run the SimForest simulation to find the number of tree species using the Zoar Valley Species Table, but I also encountered the same problems as Erin did, namely that this new species table is somehow incompatible with the equation list. Since the program does not run correctly when you modify the species table and the equation list at the same time, it will hamper our ability to track the number of trees of different species growing in Zoar Valley. 

I am also working to add the available light equation to my NetLogo program. This will use the leaf weight equation, which we have defined for the time being as being equal to 0.4 (the constant) * diameter of the tree.  

- Irena

I still cannot get Simforest to run all of our customizations at once. It will only cooperate with one or two at a time depending on what you want it to do. I emailed the creators of simforest and I was told that the project was no longer active and that they had no advice. This is very frustrating for me, I am not able to continue with my part of the project. I tried to add the number trees equation parameter to the original species table and then build the Zoar Valley species composition but it still won't work. I am going to have Irena try to run the new parameter with the zoar valley species table and see if it works for her. I am curious to see if it just my program or java not working correctly or if its an inherent problem with the program all together.

~Erin K. Pfeil

NetLogo Update

I've had some progress on the NetLogo model in that I finally have the trees growing to reflect their changing height and diameter. I am currently working on getting the user to insert their own tree species via a drop-down menu. This has been set up in the program, but a problem has been encountered in that the trees are currently only growing with the current values that the program was designed around. Now, the program must be able to work with a wide variety of species, so this is the last major issue that needs to be addressed. I think that this could be due to the fact that the available light equation is not reflecting the changing tree types, however, Erin is trying to address that by emailing a few of the people who worked on the SimForest project, and while some are no longer actively associated with it hopefully she can come across someone who will provide some info regarding the Botkin equations being used. 

After this (fairly major) issue has been addressed, all that remains will be to attempt to run the program with an eye to how it reflects the actual composition of Zoar Valley. 

Ok, I think I found a way to make it work. If you add the parameter and the equation to the original species table then change the species composition of the table it seems to work. I am going to print out the table that Dr. Lazar recently created and after adding the parameter "num trees" I will build the Zoar Valley species table. Cross your fingers everybody! I will post whether or not I am successfull later tonight.

~Erin K. Pfeil

Well Im still trying to get Simforest to work and produce usable data. After many hours over several days, I got it to accept the numbertrees equation into the Zoar Valley species composition table, but now the parameter won't actually do anything. Hey what a surprise. I will try to start all over again and see if it will work. It seems Simforest has serious issues allowing you to use more then one custom table at a time. If I use the new equation with the original tree list, it works fine and vise versa. When I try to use all of our custom stuff together it fails, several times its actually crashed the program. If anyone has any suggestions, let me know.

~Erin K. Pfeil

OK, I found some things that might be useful:

Ci = A constant of proportionallity relating leaf weight to tree diameter.

SLA = actually the leaf weight above tree n, the sum of the weight of the leaves on all trees taller then tree n.

soooo... when i get my simforest working again (which I optimistically am hoping is before our meeting today) i will see what equations they give in their equation list. I'm assuming that SLA depends on values provided from other equations, particularly one or ones that deal with leaf weight.

~Erin K. Pfeil