An experimental assessment of the impact of drought and fire on western larch injury, mortality and recovery

2018 ◽  
Vol 27 (7) ◽  
pp. 490 ◽  
Author(s):  
Aaron M. Sparks ◽  
Alan F. Talhelm ◽  
Raquel Partelli Feltrin ◽  
Alistair M. S. Smith ◽  
Daniel M. Johnson ◽  
...  
Keyword(s):  
Water Stress ◽  
Prescribed Fires ◽  
Larix Occidentalis ◽  
Western Larch ◽  
Lower Growth ◽  
Plant Ecophysiology ◽  
Low Intensity ◽  
Injury Mortality ◽  
Foliar Senescence ◽  
The Impact

Climate change is increasing drought and fire activity in many fire-prone regions including the western USA and circumpolar boreal forest. These changes highlight the need for improved understanding of how multiple disturbances impact trees in these regions. Recent studies linking fire behaviour to plant ecophysiology have improved understanding of how fire affects tree function and mortality but have not investigated interactions between drought stress and fire. In this study, Larix occidentalis saplings were subjected to different levels of water stress followed by low-intensity surface fires in a controlled laboratory setting. Post-fire mortality, recovery and growth were monitored for up to 1 year post fire. Generally, increased pre-fire water stress resulted in decreased post-fire stem diameter (up to 5% lower) and height (up to 19% lower) growth. However, severely water-stressed saplings whose foliage had senesced before the fires had lower 1-year mortality (14%) and significantly greater post-fire bud densities than moderately stressed saplings that did not senesce (86% mortality). The mortality patterns suggest that water-stressed western larch saplings exposed to low-intensity wildfires, or prescribed fires conducted as part of forest management activities, may exhibit lower mortality rates if stress-induced foliar senescence has occurred.

scholarly journals Photosynthetic decline and pigment loss during autumn foliar senescence in western larch (Larix occidentalis)

1997 ◽  
Vol 17 (12) ◽  
pp. 767-775 ◽  
Author(s):  
S. I. Rosenthal ◽  
E. L. Camm
Keyword(s):  
Larix Occidentalis ◽  
Western Larch ◽  
Foliar Senescence

scholarly journals Therapist Characteristics and their Effect on Training Outcomes: What Counts?

2015 ◽  
Vol 43 (3) ◽  
pp. 374-380 ◽  
Author(s):  
Amanda Branson ◽  
Roz Shafran
Keyword(s):  
High Intensity ◽  
Clinical Performance ◽  
Clinical Skill ◽  
Individual Characteristics ◽  
Therapist Characteristics ◽  
Training Outcomes ◽  
Low Intensity ◽  
Cognitive Behavioural ◽  
The Impact ◽  
And Training

Background:Evidence exists for a relationship between individual characteristics and both job and training performance; however relationships may not be generalizable. Little is known about the impact of therapist characteristics on performance in postgraduate therapist training programmes.Aims:The aim of this study was to investigate associations between the grades of trainee Low-Intensity and High-Intensity cognitive behavioural therapists and individual characteristics.Method:Trainee Low-Intensity (n= 81) and High-Intensity (n= 59) therapists completed measures of personality and cognitive ability; demographic and course grade data for participants were collected.Results:Degree classification emerged as the only variable to be significantly associated with performance across assessments and courses. Higher undergraduate degree classifications were associated with superior academic and clinical performance. Agreeableness was the only dimension of personality to be associated (positively) with clinical skill. Age was weakly and negatively associated with performance.Conclusions:Relationships between individual characteristics and training outcomes are complex and may be context specific. These results could have important implications for the selection and development of therapists for Low or High-Intensity cognitive behavioural therapy (CBT) training.

Effect of water stress and NaCl triggered changes on yield, physiology, biochemistry of broad bean (Vicia faba) plants and on quality of harvested pods

Biologia ◽  
2014 ◽  
Vol 69 (8) ◽  
Author(s):  
Georgia Ouzounidou ◽  
Ilias Ilias ◽  
Anastasia Giannakoula ◽  
Ioanna Theoharidou
Keyword(s):  
Water Stress ◽  
Field Experiments ◽  
Broad Bean ◽  
Foliar Application ◽  
Water Control ◽  
Simultaneous Exposure ◽  
Ameliorative Effect ◽  
Normal Water ◽  
The Impact

AbstractSalinity and drought are the most important abiotic stresses affecting crop yield. Broad bean was chosen as model plant for assessing the impact of salt stress and its interaction with drought in the field experiments. The factors examined in the experiments were the two irrigation rates (normal watering — NW with 3 L plant−1 and drought — D) and three salinity rates imposed by foliar application (0, 50, 100 mg L−1 NaCl). Highest NaCl level with normal water irrigation caused maximum reduction in plant height and production, which it was due to photosynthetic disturbances. Salt injuries were alleviated by increasing water stress. The control plants exposed to NaCl lost their ability over water control. The increased malondialdehyde (MDA) and H2O2 indicate the prevalence of oxidative stress due to salinity. The levels of proline and carbohydrates were higher under salinity alone than under simultaneous exposure to drought and NaCl. The protein concentration of immature and mature broad bean pods was more inhibited more by NaCl supply than by drought alone. The combination of drought and NaCl resulted in a significant increase in proteins, glucose, fructose and sucrose content. Overall, the ameliorative effect of drought under NaCl supply was quantified.

The impact of acute cold water stress on blood parameters, mortality rate and stress-related genes in Oreochromis niloticus, Oreochromis mossambicus and their hybrids

2021 ◽  
pp. 103049
Author(s):  
Sevdan Yilmaz ◽  
Sebahattin Ergün ◽  
Ekrem Şanver Çelik ◽  
Mohamed Banni ◽  
Ehsan Ahmadifar ◽  
...  
Keyword(s):  
Water Stress ◽  
Mortality Rate ◽  
Oreochromis Niloticus ◽  
Cold Water ◽  
Oreochromis Mossambicus ◽  
Blood Parameters ◽  
Stress Related Genes ◽  
The Impact

scholarly journals Root Growth Potential and Microsite Effects on Conifer Seedling Establishment in Northern Idaho

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 597
Author(s):  
Jacob A. Reely ◽  
Andrew S. Nelson
Keyword(s):  
Root Growth ◽  
Douglas Fir ◽  
Seedling Quality ◽  
Growth Potential ◽  
Larix Occidentalis ◽  
Root Growth Potential ◽  
Western Larch ◽  
Neighborhood Conditions ◽  
Seedling Performance ◽  
Survival And Growth

Environmental conditions and seedling quality interact to produce complex patterns of seedling survival and growth. Root growth potential (RGP) is one metric of seedling quality that can be rapidly measured prior to planting, but the correlation of RGP and seedling performance is not consistent across studies. Site factors including microsite objects that cast shade and competing vegetation can also influence seedling performance. We examined the effects of RGP, presence/absence of a microsite object, and competition cover on the survival and growth of three native conifers to the Inland Northwest, USA, over 5 years. We found that RGP had no effect on the survival or growth of western larch (Larix occidentalis), Douglas fir (Pseudotsuga menziesii var. glauca), and grand fir (Abies grandis) at a mesic north aspect site and a xeric south aspect site. Comparatively, the presence of a microsite increased the odds of survival by 37% for western larch and 158% for grand fir, while the absence of forb cover increased the odds of survival of western larch by 72% and of grand fir by 26%. Douglas fir was less sensitive to microsites and competition. The strong effects of neighborhood conditions around seedlings help inform silvicultural practices to enhance the establishment of western larch and grand fir, including planting seedlings near shading objects and competition control, while these practices may not be as important for Douglas fir.

Longleaf Pine (Pinus palustris Mill.) Branch Pruning by Prescribed Fire

2021 ◽  
Author(s):  
John P McGuire ◽  
John S Kush ◽  
J Morgan Varner ◽  
Dwight K Lauer ◽  
J Ryan Mitchell
Keyword(s):  
Prescribed Fire ◽  
Longleaf Pine ◽  
Wood Quality ◽  
Pinus Palustris ◽  
Planting Density ◽  
Prescribed Fires ◽  
Pine Tree ◽  
Southeastern Us ◽  
Tree Survival ◽  
The Impact

Abstract Efforts to restore longleaf pine (Pinus palustris Mill.) in the southeastern US require substantial artificial regeneration. Once established, important questions remain about when to introduce fire. We investigated the impact of initial planting density on tree branching and how prescribed fire might interact with tree architecture and survival. A particular focus was on how prescribed fires could “prune” lower branches. Lower density plantings (897 trees ha−1) had more and larger live lower branches than higher density plantings (2,243 trees ha−1). Fire was effective in pruning lower branches regardless of season burned, but fire in the growing season was more effective at pruning. Branches up to a height of 1.5 to 2 m were killed by fire. Fire applied in August caused greater damage with more needles scorched and/or consumed and more stem char. Prescribed fire did not impact longleaf pine tree survival. In general, fire applied to longleaf pine facilitated pruning lower branches that affect long-term wood quality, an additional argument for its utility in restoration and management of these ecosystems.

scholarly journals Elevated CO2 Concentrations and Water Stress Affect the Ability of Italian Ryegrass to Remediate Herbicides and Enhance its Allelopathic Effect

2019 ◽  
Vol 37 ◽  
Author(s):  
L.P. SILVEIRA ◽  
A.R. FEIJÓ ◽  
C. BENETTI ◽  
J.P. REFATTI ◽  
M.V. FIPKE ◽  
...  
Keyword(s):  
Water Stress ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Italian Ryegrass ◽  
Allelopathic Effect ◽  
Irrigated Rice ◽  
Allelopathic Potential ◽  
Co2 Concentrations ◽  
Temporal Persistence ◽  
The Impact

ABSTRACT: The long temporal persistence of select herbicides negatively impacts crops sown in succession to irrigated rice. One way to reduce these compounds in the soil over time is through phytoremediation. However, elevated CO2 concentrations may interfere with the phytoremediation process. Another consequence of climate change is the production of allelopathic compounds by forage species used as remedial agents. This study aimed to evaluate the impact of elevated CO2 concentration and drought stress on the remediation of soil samples contaminated with imazapyr + imazapic herbicides by Italian ryegrass and any subsequential affect on the allelopathic effect of this species. We report that the increasing CO2 decreased the phytoremediation potential of ryegrass. Water stress combined with a CO2 concentration of 700 µmol mol-1 caused increased allelopathy. Overall, these are the first data to indicate a significant effect of higher CO2 levels with respect to both phytoremediation efficacy and allelopathic potential of the plant species used in phytoremediation.

scholarly journals A threat to life and livelihoods: examining the effects of the first wave of COVID-19 on health and wellbeing in Bengaluru and Patna slums

2021 ◽  
pp. 095624782110487
Author(s):  
Harlan Downs-Tepper ◽  
Anirudh Krishna ◽  
Emily Rains
Keyword(s):  
Health And Wellbeing ◽  
Low Intensity ◽  
Slum Dwellers ◽  
Seeking Help ◽  
Neighbourhood Characteristics ◽  
The Impact ◽  
Indian Cities ◽  
Threat To Life

Taking advantage of our existing dataset of 6,721 slum households in two Indian cities, we undertook six rounds of follow-up phone interviews on the impact of COVID-19 between July and November 2020 with three key informants in each of 40 diverse slums. These cities showed contrasting health effects resulting from the first major wave of the COVID-19 pandemic – no deaths and nearly no illnesses were reported in Patna, while there was widespread low-intensity sickness and a cluster of deaths in Bengaluru. We found no clear pattern in the links between outbreaks and city or neighbourhood characteristics. Livelihood effects, however, were devastating across both cities. All but a few slum dwellers lost their jobs for several months and survived by cutting back on essentials, incurring loans, liquidating assets, and seeking help from neighbours. Government assistance, generous in the early part of the lockdown, dwindled rapidly. Many will likely become chronically poor.

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