Treesearch

Foliar nutrient concentrations are often useful in inferring soil fertility and plant-soil interactions. This study examined pre- and post-senescent foliar macronutrients and Mn of Rubus allegheniensis to assess potential effects of two nutrient amendments on mineral soil nutrient availability in aggrading hardwood stands: additions of (NH4)2SO4 (simulating increases in acid deposition) and additions of (NH4)2SO4 with dolomitic limestone (simulating mitigation of effects of acidification). Foliar Mn analysis further addressed a prediction of the nutrient redistribution hypothesis, i.e.,...

Thermo-chemical pretreatments of biomass typically result in environmental impacts from water use and emission. The degradation byproducts in the resulting sugars can be inhibitory to the activities of enzymes and yeasts. The results of this study showed that combining existing commercial comminution technology can reduce total energy consumption with improved saccharification yield while eliminating chemical use. Impact mill was found to be the most efficient milling for size reduction of forest residual chips from ca. 2mm to a specific value below 100 μm. The further micronization...

Fine wood powders have advantages over traditional coarse wood particles for various emerging applications. However, an efcient system to produce fne wood powders has not been well established. We investigated the comminution capability and efciency of a two-stage grinding system consisting of a hammer mill circuit and an rotor impact mill circuit to convert wood feedstocks into fne powders. Air-dried forest harvest residuals were comminuted by the hammer mill circuit to three intermediate product sizes with geometric mean particle sizes of 1618, 669, and 316 μm. These intermediate...

A three-stage wood milling process was investigated leading to coarse, fine and amorphization of milled wood (MW) as a pretreatment for enzymatic wood hydrolysis. An eccentric vibratory tube mill (EVTM) and a spring suspended vibratory tube mill (SSVTM) were found to be suitable for wood cellulose amorphization. Both methods gave rise to highly digestible and amorphous wood powders amenable to enzymatic hydrolysis. The SSVTM had superior energy efficiency. The resulting MW afforded a 70% sugar yield via enzymatic hydrolysis and the total energy consumption was around 1.5 kWh kg−1 oven-dried...

Forest inventories are constrained by resource-intensive fieldwork, while unmanned aerial systems (UASs) offer rapid, reliable, and replicable data collection and processing. This research leverages advancements in photogrammetry and market sensors and platforms to incorporate a UAS-based approach into existing forestry monitoring schemes. Digital imagery from a UAS was collected, photogrammetrically processed, and compared to in situ and aerial laser scanning (ALS)-derived plot tree counts and heights on a subsample of national forest plots in Oregon. UAS- and ALS-estimated tree counts...

Photogrammetry-based three-dimensional reconstruction of objects is becoming increasingly appealing in research areas unrelated to computer vision. It has the potential to facilitate the assessment of forest inventory-related parameters by enabling or expediting resource measurements in the field. We hereby compare several implementations of photogrammetric algorithms (CMVS/PMVS, CMPMVS, MVE, OpenMVS, SURE and Agisoft PhotoScan) with respect to their performance in vegetation assessment. The evaluation is based on (i) a virtual scene where the precise location and dimensionality of objects...

Microbial necromass is now recognized as an important input into stable soil organic matter pools in terrestrial ecosystems. While melanin and nitrogen content have been identified as factors that influence the decomposition rate of fungal necromass, the effects of mycelial morphology on necromass decomposition remain largely unknown. Using the fungus Armillaria mellea, which produces both diffuse and rhizomorphic biomass in pure culture, we assessed the effects of necromass morphology on decomposition in a 12 week field experiment in Pinus and Quercus dominated forests in Minnesota, USA....

Lindera melissifolia (Pondberry) is a federally endangered shrub that reproduces primarily by ramets from rhizomes and occurs in scattered clonal populations in bottomland forests of the southeastern US. Like other members of the Lauraceae indigenous to the US, Pondberry is susceptible to laurel wilt, a lethal disease caused by the fungal pathogen, Raffaelea lauricola. We conducted studies to determine the impact of laurel wilt on Pondberry colonies. We grew Pondberry in pots and in raised beds for 2-5 y; during this time, multiple ramets developed around the original plants. We subsequentl...

This chapter of the IPBES Land Degradation and Restoration Assessment evaluates the effectiveness of current response strategies both for avoiding or mitigating land degradation and for restoring previously degraded lands. More specifically: it develops a framework to assess the effectiveness of existing interventions designed to avoid and reduce land degradation processes and to rehabilitate or restore various types of degraded lands (e.g., croplands, rangelands, forest lands, urban lands and wetlands) through the recovery of biodiversity, ecosystem structure and services; assesses how...