Experimental design : 2 replicates X 2 sides of a railroad bed (North and South) X 3 vegetation types (spatter dock, cattail, scrub shrub).

Description of stations

station n.	code	vegetation type	side of railroad bed
1	NA-SS	scrub shrub	north
2	NB-SS	scrub shrub	north
3	SA-SD	scrub spatter dock	south
4	SB-SD	scrub spatter dock	south
5	SA-CT	cattail	south
6	SB-CT	cattail	south
7	NA-SD	spatter dock	north
8	NB-SD	spatter dock	north
9	SA-SS	scrub shrub	south
10	SB-SS	scrub shrub	south
11	NA-CT	cattail	north
12	NB-CT	cattail	north

Measurement technique

Elevation is measured from the top of the SET plate, using a metal ruler placed at the base of the bolt. Pins are not dropped on the surface but gently touch it.

SET model

The SET used for this study was built by Haupt Machine and Manufactoring Corp., Baton Rouge, LA in 1999