Long-Term Ecosystem Nutrient Pool Status for Aspen Forest Harvest Simulations on Glacial Till and Sandy Outwash Soils

Sandy outwash and glacial till soils compose large amounts of public forestland due to historically poor agricultural yields. The outwash soils have low fertility, poor nutrient retention and are restricted from whole-tree harvesting (WTH) in some states, whereas the glacial till has medium nutrient retention and fertility, and is unrestricted from WTH. To assess the long-term sustainability of harvesting, a nutrient budget was constructed from field measurements, the National Cooperative Soil Survey (NCSS) database, and literature values for stem-only harvesting (SOH) and WTH at a 45-year rotation length and 11 rotations were simulated. The budgets showed that SOH and WTH recovery years, or the time necessary for the inputs to match outputs through leaching and one harvest, exceeded common rotation lengths for both soil types under all weathering scenarios, and the average WTH reduced the total available rotations by one harvest. The large variation in soil nutrient pools and harvest removals complicated the ability to identify the difference between SOH and WTH early in the model, but differences became apparent with sequential harvests. The recovery years were 2–20 times the 45-year rotation length under all weathering rates. Taken together, models in this study bridge the gap between short- and long-term studies and bring into question the sustainability of WTH and SOH practices on nutrient-poor soils.

Working with dairy farmers to improve their pasture management skills through better understanding the principles of ryegrass growth

The relationships between leaf regrowth stage, pre- and post-grazing pasture covers, and grazing rotation length are complex. Despite the existence of well-documented grazing guidelines for managing these relationships, implementation on-farm is highly variable indicating that skill levels are often inadequate and/or farmers are not convinced of the benefits. Twenty dairy farm managers and assistant managers from the Hopkins Farming Group in the lower North Island engaged in structured observation and discussion with experts to test the potential of the 3-leaf grazing technique for increasing pasture production and reducing imported supplement use from mid-spring to mid-autumn. The farmer members of the study group initially had little knowledge of the principles of ryegrass growth at the plant level, and how their management influences pasture production and persistence. Grazing management skills developed by group members during the process included: identification of pasture species within the sward, including perennial ryegrass; identification of leaf morphology, tillers, tiller buds and daughter tillers; pasture health checks to understand when new tillers appeared and their grazing and nutrient needs; and the importance of grazing residuals for future pasture quality. Pasture productivity, as measured by the amount of silage conserved, increased by approximately 0.45 t DM/ha during the 6 months of study through the application of this grazing management technique. Managing grazing using the 3-leaf technique requires a greater depth of knowledge than previous, simple, rotation length-based systems. Many farmers are concerned about the lack of persistence of new ryegrass cultivars, whereas it may be their management practices that have a greater influence.

Effect of root and butt rot uncertainty on optimal harvest schedules and expected incomes at the stand level

• Key message Root and rot (RBR) caused byHeterobasidion parviporumNiemelä & Korhonen andHeterobasidion annosum(Fr.) Bref. damages Fennoscandian spruce stands. In case the rot infection and its severity are unknown, the mere risk of infection should seldom affect the harvest timing. When it does, the gains by harvesting earlier are minimal. • Context It has been suggested that stands infected by RBR should be harvested earlier than the healthy ones. Yet, we must decide on harvest timing decisions without reliable information on the infection. • Aims We studied if harvesting earlier pays off under RBR uncertainty. • Methods We structured the uncertainty with a decision tree and calculated the optimal rotations based on expected net present values. We compared rotation lengths to those of healthy stands and calculated gains from earlier harvesting. • Results The inclusion of RBR-related uncertainty in the model changed the rotation length of only 14–23% of the stands. The average reduction was 1.3–4.7 years. Yet, the gain from harvesting earlier was too low to be considered. • Conclusion In the absence of information on the extent and severity of RBR, it seldom pays off to advance harvests. The value growth in healthy trees tends to compensate for the value reduction due to rot.

Forest to Mill Timber Price Trends and Volatility for Mississippi Timber Products

We examined timber price trends along the Mississippi roundwood supply chain. Quarterly statewide data from Timber Mart-South for pine sawtimber, pine pulpwood, mixed hardwood sawtimber, and pulpwood were obtained covering 1992 to 2018. Prices for stumpage, delivered logs, and timber conversion—measured as the difference between delivered wood and stumpage—were analyzed across products for the 27-year series, as well as three equally spaced 9-year periods (Period 1, 1992 to 2000; Period 2, 2001 to 2009; Period 3, 2010 to 2018). Flat delivered wood prices, increased rates for timber conversion, and declining pine sawtimber and pulpwood stumpage prices were revealed over the long term. Hardwood product prices, however, increased across their supply chains. Prices have generally become less volatile, particularly from Period 2 to Period 3, indicating an increasing degree of price homogeneity within each product's market. The exception to this was pine sawtimber, suggesting resource, locational, and/or market differences may have emerged for this product. The hardwood price trends supported, as appropriate, considering silvicultural options to allow this resource's continued growth. Declining price expectations for pine products call into question any strictly financial rationale for extending rotation length.

Does Intramedullary Nailing for Distal Fibular Fractures Restore Anatomic Parameters and Syndesmotic Relationship?

Category: Trauma; Ankle Introduction/Purpose: Fibular nailing (FN) is a method of fixation that has proven to be useful for the treatment of distal fibular fractures (DF). FN minimizes soft tissue complications, provides similar stability compared to plating with less hardware related symptoms. Nevertheless, FN has been associated with syndesmotic malreduction and incapacity of restoring length and rotation of the fibula. We aimed to evaluate the fibular and syndesmotic reduction after fixation with FN compared to the uninjured ankle. Methods: Prospective cohort, cross-sectional study with a paired control group. Patients with DF fractures treated with FN between January 2017 and July 2019 were included. Immediate postoperative bilateral Ankle CT was obtained in all cases. Two independent radiologists performed all the measurements on both ankles (fibular rotation, length, translation, and syndesmotic diastasis. Statistical analysis was made using the Wilcoxon Test and Intraclass correlation coefficient (ICC). Considering a medium size sample effect, 95% confidence with .05 alpha error, a total sample of 26 subjects were needed to achieve a .80 of statistical power (G-Power 3.1). All analyses were performed using SPSS V20. Results: Twenty-six patients were included (14 Women). The mean age was 47 years (18-91). No statistically significant differences were identified considering fibular rotation (p:0,694), fibular length (p:0,585) and syndesmotic diastasis (p:0,078) between the injured and uninjured ankle. Fibular translation has statistical differences (p:0,043). The ICC shows an excellent concordance between radiologists except for Fibular translation (ICC 0,47) Conclusion: In this cohort, fixation of DF fractures with FN allows restoration of anatomical parameters of the ankle in terms of fibular rotation, length, and syndesmotic diastasis. However, Fibular translation had significant differences compared with the uninjured ankle.