Integrated Modeling of Long-Term Vegetation and Hydrologic Dynamics in Rocky Mountain Watersheds

Changes in forest structure resulting from natural disturbances, or managed treatments, can have negative and long lasting impacts on water resources. To facilitate integrated management of forest and water resources, a System for Long-Term Integrated Management Modeling (SLIMM) was developed. By combining two spatially explicit, continuous time models, vegetation patterns can be simulated forward in time based on management criteria. Output from the SIMPPLLE vegetation simulator are converted into landcover maps at every time-step and used to predict hydrologic watershed responses to time-series landcover change with the SWAT model. Long-term watershed responses to vegetation management scenarios can therefore be evaluated from both terrestrial and hydrologic perspectives. Watersheds are common landscape analysis units, but vegetation dynamics within them do not function in isolation. Repeated century spanning SIMPPLLE simulations produced succession patterns that were significantly different in 84% of analysis watersheds when each was considered in isolation and within their landscape context. Watersheds with \u3e30% internal forest cover, and \u3c10% barren ground along their perimeters were more connected to landscape processes than those with more barren boundaries, and less forest cover within them. Calibration of SWAT was based on four years of streamflow and climate data recorded within the Tenderfoot Creek Experimental Forest research watershed. Validation with an additional four years used both traditional and objective regression-based hypothesis testing procedures. Adjustment of snow process, surface runoff lag, and groundwater recession parameters contributed most significantly to model calibration. Results confirm that when calibrated in a forested mountain watershed having snow-dominated hydrology, SWAT can predict annual, monthly and daily streamflow with high levels of accuracy and efficiency. For demonstration, SLIMM was used to evaluate natural and fire-suppressed forest management alternatives over a 300-year period. Compared to natural development, fire suppression created larger stand sizes, greater levels of aggregation, and increased the likelihood of process propagation across the landscape. Averaged over all simulations, fire suppression reduced annual water yield by up to 3%, streamflow variability by a factor of four, and the magnitude of annual peak flows by 15%. Literature supported results highlight the applicability of SLIMM as a management tool

Weight-bearing in ankle fractures: An audit of UK practice.

INTRODUCTION: The purpose of this national study was to audit the weight-bearing practice of orthopaedic services in the National Health Service (NHS) in the treatment of operatively and non-operatively treated ankle fractures. METHODS: A multicentre prospective two-week audit of all adult ankle fractures was conducted between July 3rd 2017 and July 17th 2017. Fractures were classified using the AO/OTA classification. Fractures fixed with syndesmosis screws or unstable fractures (>1 malleolus fractured or talar shift present) treated conservatively were excluded. No outcome data were collected. In line with NICE (The National Institute for Health and Care Excellence) criteria, "early" weight-bearing was defined as unrestricted weight-bearing on the affected leg within 3 weeks of injury or surgery and "delayed" weight-bearing as unrestricted weight-bearing permitted after 3 weeks. RESULTS: 251 collaborators from 81 NHS hospitals collected data: 531 patients were managed non-operatively and 276 operatively. The mean age was 52.6 years and 50.5 respectively. 81% of non-operatively managed patients were instructed for early weight-bearing as recommended by NICE. In contrast, only 21% of operatively managed patients were instructed for early weight-bearing. DISCUSSION: The majority of patients with uni-malleolar ankle fractures which are managed non-operatively are treated in accordance with NICE guidance. There is notable variability amongst and within NHS hospitals in the weight-bearing instructions given to patients with operatively managed ankle fractures. CONCLUSION: This study demonstrates community equipoise and suggests that the randomized study to determine the most effective strategy for postoperative weight-bearing in ankle fractures described in the NICE research recommendation is feasible