Will Whole-Tree Harvest of Jack Pine (Pinus banksiana) deplete soil nutrients in low-productivity sand soils?

In 2009 and 2010 a study was conducted on the Hiawatha National Forest (HNF) to determine if whole-tree harvest (WTH) of jack pine would deplete the soil nutrients in the very coarse-textured Rubicon soil. WTH is restricted on Rubicon sand in order to preserve the soil fertility, but the increasing construction of biomass-fueled power plants is expected to increase the demand for forest biomass. The specific objectives of this study were to estimate biomass and nutrient content of above- and below-ground tree components in mature jack pine (Pinus banksiana) stands growing on a coarse-textured, low-productivity soil, determine pools of total C and N and exchangeable soil cations in Rubicon sand, and to compare the possible impacts of conventional stem-only harvest (CH) and WTH on soil nutrient pools and the implications for productivity of subsequent rotations. Four even-aged jack pine stands on Rubicon soil were studied. Allometric equations were used to estimate above-ground biomass and nutrients, and soil samples from each stand were taken for physical and chemical analysis. Results indicate that WTH will result in cation deficits in all stands, with exceptionally large Ca deficits occurring in two stands. Where a deficit does not occur, the cation surplus is small and, chemical weathering and atmospheric deposition is not anticipated to replace the removed cations. CH will result in a surplus of cations, and will likely not result in productivity declines during the first rotation. However even under CH, the surplus is small, and chemical weathering and atmospheric deposition will not supply enough cations for the second rotation.

THE HOLOGRAPHIC DETECTOR FOR CLOUDS FROM TRL 5 TO TRL 8

Clouds are one of the most influential elements of weather on the earth system, yet they are also one of the least understood. Understanding their composition and behavior at small scales is critical to understanding and predicting larger scale feedbacks. Currently, the best method to study clouds on the microscale is through airborne in situ measurements using optical instruments capable of resolving clouds on the individual particle level. However, current instruments are unable to sufficiently resolve the scales important to cloud evolution and behavior. The Holodec is a new generation of optical cloud instrument which uses digital inline holography to overcome many of the limitations of conventional instruments. However, its performance and reliability was limited due to several deficiencies in its original design. These deficiencies were addressed and corrected to advance the instrument from the prototype stage to an operational instrument. In addition, the processing software used to reconstruct and analyze digitally recorded holograms was improved upon to increase robustness and ease of use.