Providing stream shade and woody debris, while also allowing for active management of riparian areas, is a nationwide challenge for meeting Clean Water Act requirements. This is a case study of developing simulation models to evaluate effectiveness of buffer strip prescriptions in meeting
multiple objectives. It was conducted in Idaho, where a state forest practices act requires buffer strips as a best management practice. This approach could be applied in other states where riparian management practices are required as a matter of regulation or as voluntary practices and where
forest inventory data are available for a range of forest stand conditions. Prescriptions were simulated on uncut stands and varied by the total width of the riparian buffer, widths of inner and outer zones within the riparian buffer, and residual stocking within each buffer zone. Simulation
models were shown to account for fine-scale differences in riparian function produced by a series of prescriptions that were examined. Alternative riparian buffer prescriptions were evaluated, comparing their ability to meet four objectives: protection of aquatic resources, economic viability,
silvicultural sufficiency, and the ability to operate throughout the riparian buffer. Potential impacts on stream shade were most constraining. We found that thinning throughout the buffer (i.e., up to the stream bank) and very narrow buffers (e.g., 50 ft or less) led to unacceptable decreases
in shade. However, we also found that the portion of the stand immediately adjacent to the stream was very important to stream shade. Harvest restrictions in a stream-adjacent buffer could permit greater overall management flexibility. However, there still was the desire to operate throughout
the buffer. We found that by thinning lightly in the inner 25-ft buffer zone, with heavier thinning in an outer 50-ft zone, these multiple objectives could be achieved. Similar principles underlie riparian forest practice regulations in other states (e.g., Washington and Oregon). However,
use of our framework could permit development of fine-scale site-specific prescriptions or be used for rule revision, including consideration of near-stream harvest. Overall, simulation modeling allowed evaluation of a range of riparian prescriptions that would be impractical in a field experiment.
In addition, simulation results form the basis for hypotheses to be tested through effectiveness monitoring.
The Journal of Forestry is the most widely circulated scholarly forestry journal in the world. In print since 1902, the Journal has received several national awards for excellence. The mission of the Journal of Forestry is to advance the profession of forestry by keeping forest management professionals informed about significant developments and ideas in the many facets of forestry: economics, education and communication, entomology and pathology, fire, forest ecology, geospatial technologies, history, international forestry, measurements, policy, recreation, silviculture, social sciences, soils and hydrology, urban and community forestry, utilization and engineering, and wildlife management. The Journal is published bimonthly: January, March, May, July, September, and November.