Long term recovery from experimental and old trail off-road vehicle impacts in the Big Cypress National Preserve

Duever, Michael; Riopelle, Lawrence; Mccollom, Jean

The current study details recovery seven years after the experimental lanes had been created or the old trails abandoned. Parameters evaluated included visual, soil, and vegetation characteristics. Our original study was designed to evaluate the ability of the major types of off-road vehicles used in the Big Cypress National Preserve to impact the preserve's major habitat types. We subsequently measured one annual cycle of recovery in these experimentally created lanes. We also measured one annual cycle of recovery in old trails which had been heavily used for many years, but were closed to vehicle use at the beginning of our study. The current study details recovery seven years after the experimental lanes had been created or the old trails abandoned. Parameters evaluated included visual, soil, and vegetation characteristics. Among the wheeled vehicles, the ATC was the least impacting. There were only minor differences in the impacting ability of the various types of swamp buggy. The airboat produced the least severe impacts, primarily because it was not normally in contact with the ground surface and did not significantly disturb the soil. The track vehicle produced impacts in marl marshes comparable to those of swamp buggies in the small cypress, where the latter created their most severe impacts. The most sensitive habitats were the small cypress and marl marsh. These habitats typically have relatively sparse vegetation and soils which are extremely soft when wet, so that a passing vehicle can readily reach and displace the soil. The sand and rock substrates of the sand marsh and pine habitats are more stable and densely vegetated, and thus less susceptible to displacement. The dense vegetation of the peat marshes tends to protect them from impacts, but once a vehicle breaks through to the peat substrate, it becomes very susceptible to displacement. After seven years recovery, few of the one pass and medium impact experimental lanes were still significantly different from adjacent controls. However, very few of the heavy impact lanes had recovered. Only one of the old trails had recovered completely during the seven year period of our study, although some parameters in some trails had recovered to the point where they were not significantly different from the adjacent controls. It appears that once soils are displaced, there are few natural mechanisms capable of restoring the ground contour, and the ruts remain indefinitely. Also when soil disturbance occurs, the recovery rate of visual and vegetation impacts is appreciably slowed.