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accounted for less than 1% of total sediment export for the settling basin treatment. ANOVA detected significant treat- ment effects on the sediment bag data collected from each of the treatments. The settling basin and sediment fence yielded significantly less sediment in die sediment bags than the rip-rap and vegetation (table 4). The rip-rap treatment yielded 20 times more sediment in sediment bags than the settling basin during the study period. DISCUSSION Exported sediment that then deposited on the forest floor consisted of the lazger soil particles carried in the surface runoff, which requires greater energy to remain suspended. The sediment collected in sediment bags was smaller soil particles easily transported by runoff for longer distances and therefore would more likely reach stream systems. Treat- ments with greater reductions in sediment deposited in sediment bags will likely reduce the water quality impacts of forest road sediment. The study soil in this investigation likely had an effect on the measured sediment delivery rates downslope. The loamy sand had a high infiltration rate of 30 cm/hr, which reduced the total runoff entering the treatment azea. The high infiltration rate reduced the erosive energy of the runoff, thereby reducing die sediment transport distances down- slope. Reduction of runoff volumes generally reduces the detachment and transport energy of the runoff waters. Table 2. Mean rmoH concentration reducnons for treatments during the study period. Mean Inflow Mean Runoff Runoff Concentration Concentration Reductronsr°l Treatment N (ppm) (ppm) Vegemtion 48 306.1 187.Oa Sediment fence 62 251.3 183.Sa Settling basin 74 142.0 129.2ab Rip-mp 49 228.7 115.76 r°l Means with the same letter indicate no significant difference using Dun- can's Multiple Range Tes; P> 0.05. Table 3. Sediment export during the study period. Average Average Sediment Total Pfow Drainage Expord°] RunoBt°] INsmnce Area Treatment N (kg) (m3) (m) (m2) Vegetation 3 43.4a 200a 60 240 Sediment fence 3 43.Oa 140a 50 170 Rip-rap 3 30.1a 170a 60 200 Settling basin 3 23.Oa 150a 50 180 r°l The same letters within a column indicate no significant diHemnce using Duncan's Multiple Range Tes; P> 0.05. Table 4. Mean mnectea sedlmeot bag welghes during the study period. Mean Sediment Bag Weightr°1 Tteatmem N (kg) Rip-rap 3 2.23a Vegemdon 3 1.66a Sediment fence 3 0.646 Settling basin 3 O.llb [°1 Means with the same letter indicate no significant diffetenceusing 1Tm- can's Multiple Range Tes; P> 0.05. Additional investigations to characterize the effect of erosion control treatments on different soil types aze being devel- oped. In the past 70 yeazs, reseazch has been carried out on sediment transport and erosion control on the traveled way, roadside slopes, and filter strips. The result of this work has spawned most states to recommend BMPs, which involve utilizing erosion control techniques on the road prism and adequate filter strip widths to remove sediment from runoff' before reaching waterways. Long-term monitoring of re- quired filter strip widths has no[ been accomplished by any of the previous work. The filtering capacity of the forest floor is not boundless and decreases as sediment is deposited from runoff. Ea time, as the filtering capacity of the forest floor is exhausted, sediment can be delivered to streams, complicating water quality issues. Effective filtering of sediment-laden runoff can be accomplished before runoff reaches die forest floor. Previous work has investigated filter strips used below erosion sources to control erosion losses but has not focused on the roadside ditch and control techniques that can be applied to reduce sediment transport. Research needs to be undertaken to investigate techniques that can be applied to reduce sediment transport onto the forest floor and eventually to streams. CONCLUSIONS All four treatments in the investigation resulted in mean runoff concentration reductions greater than 40rYo over die study period. ANOVA detected significant treatment effects (P > 0.001) on runoff concentration reductions. No signifi- cant differences were found between concentrations from vegetation, sediment fence, and settling basin treatments, or between settling basin and rip-rap. The vegetation and sediment fence treatments, however, yielded greater reduc- tions in runoff concentrations than [he rip-rap. Settling basins were very effective for stortas smaller than the design storm and appeaz to hold promise if they can be constmcted with enough capacity for most of the storm events. ANOVA detected no significant differences in total exported sediment below each treatment, but real differences may exist and might be detected if considerably lazger sample sizes could be obtained in future studies. The settling basin, which had the greatest retention time for runoff, had less sediment export below the treatment than all other treatments in the experiment. The rip-rap treatment also had a relatively low sediment export in comparison to the sediment fence and vegetation treatments. REFERENCES Alabama Forestry Commission. 1993. Alabama's best management practices for forestry. Montgomery, Ala.: Alabama Forestry Commission. Anderson, H. W, M. D. Hoover, and K G. Reinhart. 1976. Forest and water. Effects of forost management on floods, sedimenmdon, and water supply. General Technical Report PSW-18. San Francisco, Cal.: USDA Porest Service. Brinker, R. W. 1993. Best management practices for timber harvesters. Alabama Cooperative Extension Service, Agriculture Vol. 45(4): xxx-xxrz