Biochar for Forest Restoration in Western States

This factsheet introduces biochar, bio-oil, synthesis gas, pyrolysis, and torrified wood products to the reader. We describe biochar production methods and applications for forest restoration projects in the Intermountain West

Protect Your Home from Wildfire: Ember Awareness Checklist

Many communities in the western U.S. are fire-prone, as are many other areas in the world. These areas will always face wildfire, and will likely experience an increased number of extreme wildfire events in the future, resulting in substantial economic, social, and environmental impacts. Over the last 10 years, 3.4 to 10.1 million acres have burned annually in the U.S. In terms of area burned, 2017 has been one of the largest fire years in the last decade, with over 8.5 million acres burned across the U.S. (NIFC). Figure 1 shows the distribution of wildfires in the western U.S. in 2017. Unprecedented amounts of live and dead fuel, combined with warmer University of Arizona Cooperative Extension has also produced fire mitigation education materials to help communities understand how to coexist with wildfire. Please visit https:// extension.arizona.edu/pubs and type “wildfire” in the search box for specific Firewise® defensible space materials. This fact sheet was developed to help you and members of your community understand the danger of embers during a wildfire and take proactive steps to reduce the risk

Beyond the black box: promoting mathematical collaborations for elucidating interactions in soil ecology

This work is licensed under a Creative Commons Attribution 4.0 International License.Understanding soil systems is critical because they form the structural and nutritional foundation for plants and thus every terrestrial habitat and agricultural system. In this paper, we encourage increased use of mathematical models to drive forward understanding of interactions in soil ecological systems. We discuss several distinctive features of soil ecosystems and empirical studies of them. We explore some perceptions that have previously deterred more extensive use of models in soil ecology and some advances that have already been made using models to elucidate soil ecological interactions. We provide examples where mathematical models have been used to test the plausibility of hypothesized mechanisms, to explore systems where experimental manipulations are currently impossible, or to determine the most important variables to measure in experimental and natural systems. To aid in the development of theory in this field, we present a table describing major soil ecology topics, the theory previously used, and providing key terms for theoretical approaches that could potentially address them. We then provide examples from the table that may either contribute to important incremental developments in soil science or potentially revolutionize our understanding of plant–soil systems. We challenge scientists and mathematicians to push theoretical explorations in soil systems further and highlight three major areas for the development of mathematical models in soil ecology: theory spanning scales and ecological hierarchies, processes, and evolution

Beyond the black box: Promoting mathematical collaborations for elucidating interactions in soil ecology

© 2019 The Authors. Understanding soil systems is critical because they form the structural and nutritional foundation for plants and thus every terrestrial habitat and agricultural system. In this paper, we encourage increased use of mathematical models to drive forward understanding of interactions in soil ecological systems. We discuss several distinctive features of soil ecosystems and empirical studies of them. We explore some perceptions that have previously deterred more extensive use of models in soil ecology and some advances that have already been made using models to elucidate soil ecological interactions. We provide examples where mathematical models have been used to test the plausibility of hypothesized mechanisms, to explore systems where experimental manipulations are currently impossible, or to determine the most important variables to measure in experimental and natural systems. To aid in the development of theory in this field, we present a table describing major soil ecology topics, the theory previously used, and providing key terms for theoretical approaches that could potentially address them. We then provide examples from the table that may either contribute to important incremental developments in soil science or potentially revolutionize our understanding of plant-soil systems. We challenge scientists and mathematicians to push theoretical explorations in soil systems further and highlight three major areas for the development of mathematical models in soil ecology: Theory spanning scales and ecological hierarchies, processes, and evolution

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Transient physiological responses of planting frozen root plugs of Douglas-fir seedlings

Short-term physiological responses of planting frozen (FR) and rapidly thawed (TR) root plugs of Douglas-fir (Pseudotsuga rnenziesii (Mirb.) Franco) seedlings were examined through time series (0 h, 6 h, 12 h, 1 day, 3 days, and 7 days) measurements in two separate experiments: 10 °C day : 6 °C night, RH 75% and 30 °C day : 20 °C night, RH 50%, respectively. Net photosynthesis, transpiration, shoot water potential, and root hydraulic conductance were lower in FR compared with TR seedlings under both growing conditions. Magnitude of difference in root hydraulic conductance was higher under warm-dry conditions. Chlorophyll fluorescence (Fv/Fm) values were higher for TR than FR seedlings at 0 h, but similar thereafter for both growing conditions. Needle electrolyte leakage and chlorophyll content did not differ between FR and TR seedlings under both environmental regimes. Higher root 0 2 uptake was observed in FR seedlings in warm-dry conditions and in TR seedlings under cool-moist conditions. TR seedlings planted under warm-dry conditions had more flushed buds and new roots than FR seedlings, while no buds flushed for both FR and TR seedlings under cool-moist conditions. Comparatively higher photosynthesic rates in TR seedlings planted under warm-dry conditions likely contributed toward more new roots, which could be advantageous for survival and early growth

Fall fertilization of Pinus resinosa seedlings: nutrient uptake, cold hardiness, and morphological development

•  Fall fertilization may increase plant nutrient reserves, yet associated impacts on seedling cold hardiness are relatively unexplored. •  Bareroot red pine (Pinus resinosa Ait.) seedlings in north-central Minnesota, USA were fall fertilized at the end of the first growing season with ammonium nitrate (NH$_{4}$NO$_{3})$ at 0, 11, 22, 44, or 89 kg N ha$^{-1}$. Seedling morphology and cold hardiness [assessed by freeze induced electrolyte leakage (FIEL)] were evaluated six weeks after fertilization and following the second growing season. •  Seedling height and number of needle primordia increased with fertilizer rate for both sampling years. Seedlings fertilized with 44 and 89 kg N ha$^{-1}$ attained target height (15 cm) after the second growing season. Shoot and root N concentration increased after the first growing season in fall fertilized seedlings compared to controls. Fall fertilized seedlings had lower FIEL (i.e., increased cold hardiness) compared to controls when tested at –40 °C after the first growing season, but no significant differences in FIEL of control and fertilized seedlings were observed after the second growing season. •  Results suggest that fall fertilization of red pine seedlings can help render desired target height in the nursery, while maintaining or increasing cold hardiness levels.Fertilisation automnale des plants de Pinus resinosa : absorption des éléments nutritifs, rusticité au froid, et développement morphologique. • La fertilisation automnale peut augmenter les réserves en éléments nutritifs des plants, mais les répercussions sur la rusticité au froid des semis sont encore relativement inexplorées. •  Des plants à racines nues de Pinus resinosa Ait.dans le centre-nord du Minnesota (USA) ont été fertilisés à l'automne à la fin de la première saison de croissance avec du nitrate d'ammonium (NH$_{4}$NO$_{3})$ à 0, 11, 22, 44, ou 89 kg N ha$^{-1}$. La morphologie des plants et la rusticité au froid [estimée par la fuite d'électrolyte (FIEL) induite par le gel] ont été évaluées six semaines après la fertilisation et à la suite dans la deuxième saison de croissance. •  La hauteur des plants et le nombre de primordiums d'aiguilles ont augmenté avec le taux de fertilisation pour les deux années d'échantillonnage. Les plants fertilisés avec 44 et 89 kg N ha$^{-1}$ ont atteint l'objectif de hauteur (15 cm) après la deuxième saison de croissance. La concentration en N des tiges et des racines a augmenté après la première saison de croissance chez les plants fertilisés à l'automne par rapport aux témoins. Les plants fertilisés à l'automne ont eu un plus faible FIEL (c'est-à-dire, une augmentation de rusticité), comparativement aux témoins lors du test à –40 °C après la première saison de croissance, mais aucune différence significative de FIEL entre plants fertilisés et témoins n'a été observée après la deuxième saison de croissance. • Les résultats suggèrent que la fertilisation d'automne des plants de Pinus resinosa Ait. peut aider à obtenir l'objectif de hauteur souhaité dans la pépinière, tout en maintenant ou en augmentant les niveaux de rusticité au froid

Growth, physiology, and nutrient retranslocation in nitrogen-15 fertilized Quercus rubra seedlings

We evaluated gas exchange, chlorophyll index (CI) using SPAD-502 chlorophyll meter, and leaf nutritional responses in one-year-old northern red oak (Quercus rubra L.) container seedlings transplanted into control (unfertilized) or fertilized (0.86 g N plant$^{-1})$ sand culture and grown in a greenhouse for 90 days. We labeled current nitrogen (N) uptake with ($^{15}$NH$_{4})_{2}$SO$_{4}$ and directly quantified proportional contributions of N derived from fertilizer (NF) compared with retranslocation or N derived from plant (NP) in leaf growth of red oak seedlings. NF met a greater N demand in leaf growth of fertilized plants while unfertilized seedlings relied entirely on NP for their leaf growth. Fertilization increased leaf dry mass by 67% and new stem dry mass by 253% 90 days after transplanting compared to control seedlings. Specific leaf area (SLA) was not significantly altered but CI increased 90 days after transplanting. Higher leaf N concentration and content in fertilized compared with control seedlings was linked to greater chlorophyll concentrations in the former plants. The higher coefficient of determination ($r$$^{2}$ = 0.72) noted between leaf N concentrations and CI suggests that the SPAD meter could be a useful tool for assessing leaf N status in northern red oak seedlings. Fertilized seedlings exhibited higher net assimilation, stomatal conductance, and transpiration rates compared with controls. Increased seedling growth in response to fertilization was related to maintenance of higher gas exchange and greater nutrient uptake, which could improve outplanting success.Croissance, échanges gazeux et réponses nutritionnelles de jeunes semis de Quercus rubra soumis à une fertilisation par ($^{15}$NH$_{4})_{2}$SO$_{4}$. Nous avons estimé les échanges gazeux foliaires, un index de teneurs en chlorophylles (IC) avec un chlorophylle-mètre SPAD-502 et les teneurs en nutriments dans les feuilles de jeunes plants de chêne rouge d'Amérique (Quercus rubra L.) âgés d'un an. Les plants ont été transplantés dans du substrat sableux non fertilisé (témoins) ou fertilisé avec 0.86 g N par plante, et cultivés pendant 90 jours sous serre. L'azote apporté par la fertilisation était marqué avec ($^{15}$NH$_{4})_{2}$SO$_{4}$ et nous avons directement quantifié les contributions à la croissance foliaire de N apporté par la fertilisation (NF) par rapport à celle de N remobilisé depuis les pools de réserve de la plante (NP). NF constituait la fraction la plus importante d'azote foliaire de plants fertilisés, alors que l'azote foliaire des plants non fertilisés était exclusivement constitué de NP. La fertilisation s'est traduite par une augmentation, par rapport aux plantes témoins, de 67 % de la biomasse foliaire et de 253 % de la biomasse de tiges nouvellement formées 90 jours après la transplantation. La surface spécifique des feuilles n'était pas affectée par la fertilisation alors que CI avait significativement augmenté. Des teneurs plus élevées en N foliaire en comparaison des témoins, étaient donc liées à des concentrations plus fortes en chlorophylles. Le coefficient de détermination élevé ($r$$^{2}$ = 0.72) des relations entre concentration de N et CI montrent que le SPAD-502 pourrait être un instrument utile pour l'évaluation des teneurs en N dans des semis de chêne rouge. Les semis fertilisés présentaient également des niveaux d'assimilation nette de CO$_{2}$, de conductance stomatique et de transpiration plus élevés que les plants témoins. La croissance plus forte des semis en réponse à la fertilisation était liée à des échanges gazeux plus actifs et une plus forte assimilation de nutriments, ce qui peut augmenter les chances de succès à la transplantation en forêt

Spectral Indices Accurately Quantify Changes in Seedling Physiology Following Fire: Towards Mechanistic Assessments of Post-Fire Carbon Cycling

Fire activity, in terms of intensity, frequency, and total area burned, is expected to increase with a changing climate. A challenge for landscape-level assessment of fire effects, often termed burn severity, is that current remote sensing assessments provide very little information regarding tree/vegetation physiological performance and recovery, limiting our understanding of fire effects on ecosystem services such as carbon storage/cycling. In this paper, we evaluated whether spectral indices common in vegetation stress and burn severity assessments could accurately quantify post-fire physiological performance (indicated by net photosynthesis and crown scorch) of two seedling species, Larix occidentalis and Pinus contorta. Seedlings were subjected to increasing fire radiative energy density (FRED) doses through a series of controlled laboratory surface fires. Mortality, physiology, and spectral reflectance were assessed for a month following the fires, and then again at one year post-fire. The differenced Normalized Difference Vegetation Index (dNDVI) spectral index outperformed other spectral indices used for vegetation stress and burn severity characterization in regard to leaf net photosynthesis quantification, indicating that landscape-level quantification of tree physiology may be possible. Additionally, the survival of the majority of seedlings in the low and moderate FRED doses indicates that fire-induced mortality is more complex than the currently accepted binary scenario, where trees survive with no impacts below a certain temperature and duration threshold, and mortality occurs above the threshold.National Aeronautics and Space Administration (NASA) [NNX11AO24G]; National Science Foundation [IOS-1146751, DEB-1251441, IIA-1301792]; National Science Foundation under Hazards SEES award [DMS-1520873]; Idaho Space Grant ConsortiumThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]