Influence of humidity and temperature during exposure on SO2-induced leaf necrosis of Virginia pine and river birch

1987 ◽  
Vol 17 (10) ◽  
pp. 1213-1218 ◽  
Author(s):  
D. M. Umbach ◽  
D. D. Davis
Keyword(s):  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Leaf Conductance ◽  
Negative Slope ◽  
Pine Seedlings ◽  
Temperature And Humidity ◽  
Leaf Necrosis ◽  
Effects Of Temperature ◽  
Increasing Temperature ◽  
The Relationship

River birch and Virginia pine seedlings were exposed to 0.8 or 1.0 ppm SO2 (approximately 2100 and 2600 μg m−3, respectively) for 4 h at temperatures of 16, 24, and 32 °C and at relative humidities of 60, 75, and 90%, in all combinations. Virginia pine seedlings exhibited increased SO2-induced leaf necrosis with increasing temperature and with increasing humidity. For greenhouse-grown Virginia pine seedlings, the relationship between leaf necrosis and vapor pressure deficit was linear with a common negative slope but with different intercepts for each temperature. For Virginia pine seedlings grown outdoors, the relationship between leaf necrosis and vapor pressure deficit was also linear, but both slope and intercept changed with temperature. For river birch, temperature did not greatly affect the overall level of injury; instead, the response to humidity was negligible, linear, or quadratic, depending on temperature and on the conditions under which seedlings were grown. The effects of temperature and humidity on injury to Virginia pine are consistent with an explanation based on changes in leaf conductance; however, such an explanation cannot easily account for the observed response of river birch.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

scholarly journals Modeling Infection of Strawberry Flowers by Botrytis cinerea Using Field Data

2000 ◽  
Vol 90 (12) ◽  
pp. 1367-1374 ◽  
Author(s):  
Xiangming Xu ◽  
David C. Harris ◽  
Angela M. Berrie
Keyword(s):  
Vapor Pressure ◽  
Botrytis Cinerea ◽  
Vapor Pressure Deficit ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Gray Mold ◽  
Weather Variables ◽  
Infection Models ◽  
The Relationship ◽  
Field Plots

The incidence of strawberry flower infection by Botrytis cinerea was monitored in unsprayed field plots in three successive years together with meteorological data and numbers of conidia in the air. There were large differences in conidia numbers and weather conditions in the 3 years. Three sets of models were derived to relate inoculum and weather conditions to the incidence of flower infection; by inoculum only, by weather variables only, and by both inoculum and weather variables. All the models fitted the observed incidence satisfactorily. High inoculum led to more infection. Models using weather variables only gave more accurate predictions than models using inoculum only. Models using both weather variables and inoculum gave the best predictions, but the improvement over the models based on weather variables only was small. The relationship between incidence of flower infection and inoculum and weather variables was generally consistent between years. Of the weather variables examined, daytime vapor pressure deficit and nighttime temperature had the greatest effect in determining daily incidence of flower infection. Infection was favored by low day vapor pressure deficit and high night temperature. The accuracy and consistency of the weather-based models suggest they could be explored to assist in management of gray mold.

Effects of Temperature and Humidity on the Germination of Two Pioneer Species in Ecological Restoration

2012 ◽  
Vol 209-211 ◽  
pp. 1265-1268 ◽  
Author(s):  
Di Zhang ◽  
Xi Liu ◽  
Fang Qing Chen
Keyword(s):  
Seed Germination ◽  
Ecological Restoration ◽  
Ecological Engineering ◽  
Treatment Level ◽  
Pioneer Species ◽  
Important Species ◽  
Germination Temperature ◽  
Temperature And Humidity ◽  
Effects Of Temperature ◽  
Increasing Temperature

Seed germination and seedling establishment is a critical stage in the life cycle. Cynodon dactylon and Medicago sativa are two important species using in ecological restoration. Control experiments were employed to test the effects of temperature and humidity on the germination of the two pioneer species. The experiment included three temperature treatment level (15, 20, 25 °C) and four humidity treatment (5, 10, 15, 20 %) with three repeats. Results showed that temperature and humidity had significant effects on the germination of both species seeds. Seed germination of C. dactylon fluctuated with the increasing temperature, but increased with the increasing humidity. The optimal germination temperature and humidity for C. dactylon seeds was 20 °C and 20 % respectively. Seed germination of M. sativa increased with the increasing temperature meanwhile fluctuated with the increasing humidity. The optimal germination temperature and humidity for M. sativa seeds was 25 °C and 10 % respectively. It is critical to provide suitable soil humidity for seed germination in the ecological engineering.

HUMIDITY AND SOIL WATER INFLUENCE THE TRANSPIRATION RESPONSE OF MAIZE TO CO2 ENRICHMENT

1990 ◽  
Vol 70 (4) ◽  
pp. 941-948 ◽  
Author(s):  
ALAN G. BARR ◽  
K. M. KING ◽  
G. W. THURTELL ◽  
M. E. D. GRAHAM
Keyword(s):  
Vapor Pressure ◽  
Soil Water ◽  
Vapor Pressure Deficit ◽  
Water Vapor Pressure ◽  
Period Doubling ◽  
Co2 Enrichment ◽  
Leaf Conductance ◽  
High Vapor ◽  
Water Vapor Pressure Deficit ◽  
The Impact

The impact of increasing atmospheric CO2 on the productivity of C4 crops may vary with soil water availability. This study investigates the hypothesis that elevating CO2 in Zea mays L. reduces the degree to which transpiration is limited by soil water at high vapor pressure deficits or low soil water contents. Plants growing in controlled environments at 300 and 600 μmol mol−1 CO2 were exposed daily to five levels of vapor pressure deficit as water was withheld and the soil dried over an 8-d period. Doubling CO2 caused an overall reduction of 23% in the transpiration rate and 34% in the leaf conductance, but the effect of CO2 on transpiration and leaf conductance was greatest at high soil water content and low vapor pressure deficit, when soil water least limited transpiration. Implications for the productivity of C4 crops in the field are discussed.Key words: Maize, transpiration, carbon dioxide, soil water, vapor pressure deficit, controlled environment

scholarly journals The longevity response to warm temperature is neurally controlled via regulation of collagen genes

2021 ◽  
Author(s):  
Sankara Naynar Palani ◽  
Durai Sellegounder ◽  
Yiyong Liu
Keyword(s):  
Reaction Rates ◽  
Warm Temperature ◽  
Extended Lifespan ◽  
Effects Of Temperature ◽  
Negative Impacts ◽  
Response To Temperature ◽  
Increasing Temperature ◽  
Collagen Genes ◽  
The Relationship ◽  
Living Theory

ABSTRACTLower temperatures have been associated with longer lifespan, while higher temperatures with shorter lifespan. These inverse effects of temperature on longevity were traditionally explained by the “rate of living theory”, which posits that higher temperatures increase chemical reaction rates, thus speeding up the aging process. Recent studies have identified specific molecules and cells that mediate the longevity response to temperature, suggesting that the temperature effects on aging are not simply thermodynamic but regulated processes. However, the mechanisms underlying such regulation are not well understood. In the current study, we found that Caenorhabditis elegans lacking NPR-8, a neuronal GPCR related to the mammalian neuropeptide Y receptors, exhibited extended lifespan at warm temperature. Such lifespan extension can be suppressed by re-expression of NPR-8 in the amphid sensory neurons AWB and AWC or by inactivation of NPR-8-regulated collagen genes. These results suggest that the warm temperature effect on longevity is regulated by the nervous system through controlling collagen gene expression. Our study potentially provides mechanistic insights into understanding the relationship between temperature and longevity, which could prove useful in mitigating negative impacts of increasing temperature due to global warming.

scholarly journals Effects of temperature on the metabolic stoichiometry of Arctic zooplankton

2013 ◽  
Vol 10 (2) ◽  
pp. 689-697 ◽  
Author(s):  
M. Alcaraz ◽  
R. Almeda ◽  
E. Saiz ◽  
A. Calbet ◽  
C. M. Duarte ◽  
...  
Keyword(s):  
Nutrient Pool ◽  
Marine Food Web ◽  
Carbon Biomass ◽  
Metabolic Products ◽  
Natural Temperature ◽  
Effects Of Temperature ◽  
Excretion Rates ◽  
Increasing Temperature ◽  
The Relationship

Abstract. We assessed the relationship between zooplankton metabolism (respiration and inorganic N and P excretion) and "in situ" temperature through a grid of stations representing a range of natural temperature variation during the ATOS-Arctic cruise (July 2007). The objective was to explore not only the direct effects of temperature on zooplankton carbon respiratory losses (hereafter CR) and NH4-N and PO4-P excretion rates (hereafter NE and PE, respectively), but also to investigate whether these metabolic pathways responded similarly to temperature, and so how temperature could affect the stoichiometry of the metabolic products. Metabolic rates, normalised to per unit of zooplankton carbon biomass, increased with increasing temperature following the Arrhenius equation. However, the activation energy differed for the various metabolic processes considered. Respiration, CR, was the metabolic activity least affected by temperature, followed by NE and PE, and as a consequence the values of the CR : NE, CR : PE and NE : PE atomic quotients were inversely related to temperature. The effects of temperature on the stoichiometry of the excreted N and P products would contribute to modifying the nutrient pool available for phytoplankton and induce qualitative and quantitative shifts in the size, community structure and chemical composition of primary producers that could possibly translate to the whole Arctic marine food web.

scholarly journals Effects of Temperature, Solar Radiation, and Vapor-Pressure Deficit on Flower Opening Time in Rice

2010 ◽  
Vol 13 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Kazuhiro Kobayasi ◽  
Tsutomu Matsui ◽  
Mayumi Yoshimoto ◽  
Toshihiro Hasegawa
Keyword(s):  
Solar Radiation ◽  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Flower Opening ◽  
Effects Of Temperature
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