Skip to main content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

FVS Models & Event Monitor Files

The Oak Decline Event Monitor Addfiles

What is it?

The Oak Decline Event Monitor is a program that simulates the effects of oak decline within the confines of the Forest Vegetation Simulator (FVS). Individual stands are evaluated with a probability/risk rating system to determine the susceptibility of the stand to the effects of oak decline. An oak decline event is scheduled in the FVS multi-year cycle if a drawn random number is less than or equal to the estimated probability in that multi-year cycle. If an event is scheduled, oak decline mortality is leveled against red oak, white oak and hickory species at the end of that FVS cycle. Oak decline induced mortality is determined by the stand risk rating, with greater mortality scheduled for stands with elevated risk.

This is a strategic model that demonstrates the potential loss of oak/hickory timber and habitat (Oak et al. 1988, Starkey et al. 2000) due to oak decline. The user can proactively reduce oak decline risk of forest stands and probability of oak decline events by scheduling appropriate management actions within FVS such as thinning to alter species composition. Once an event is scheduled by the Oak Decline Event Monitor there are no reactive measures the user can take to prevent the loss due to oak decline.

Who should use it?

The Oak Decline Event Monitor is intended for use by those familiar with the proper use and execution of the Forest Vegetation Simulator. It is recommended that the user be well versed in interpretation of standard FVS output. Specific Event Monitor variables can be exported to spread sheet programs for further user analysis.

How do I use it?

The Oak Decline Event Monitor is an FVS Addfile, which typically have a "*.kcp" file extension. The geographically appropriate Event Monitor must be added to the simulation, after one or more stands have been selected for use within FVS. The Oak Decline Event Monitor Users Guide included with the event monitor files describes how to use the addfile, evaluate its results, and who to contact with questions.

Which Oak Decline Event Monitor Files do I use?

There are six types of oak decline keyword component (.kcp) addfiles appropriate for use with the Central States (CS), North East (NE), or Southern (SN) variants of FVS. Users who wish to simulate the effects of oak decline should use OD_CS.kcp, OD_NE.kcp or OD_SN.kcp dependent upon stand location and their preferred FVS variant. These addfiles utilize custom variables not available with the base FVS model. Users who wish to ignore simulated oak decline effects and still view these custom variables for comparison purposes should use x_OD_CS.kcp, x_OD_NE.kcp or x_OD_SN.kcp.

The Oak Decline Event Monitor is most meaningfully applied in forest types with a significant oak component. The user is strongly urged to apply the correct Event Monitor file to the appropriate stands. This is best achieved by creating geographically homogenous FVS simulations through creative use of FVS grouping codes.


Oak Decline Event Monitor (OD_em.exe, 108 KB)

Branch dieback in oak trees

Branch dieback in pin oak. Photo by Joseph OBrien, USDA Forest Service.