27 research outputs found
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 (NHNO at 0, 11, 22, 44, or 89 kg N ha. 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 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
(NHNO à 0, 11, 22, 44, ou 89 kg N ha. 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 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 sand culture and grown in a greenhouse
for 90 days. We labeled current nitrogen (N) uptake with (NHSO 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
( = 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 (NHSO. 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 (NHSO 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
( = 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,
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]