scholarly journals Wood and bark water content and monthly stem growth in Amazonian tree species

2021 ◽  
Vol 51 (4) ◽  
pp. 363-369
Author(s):  
Daniela Pereira DIAS ◽  
Ricardo Antonio MARENCO

ABSTRACT The knowledge of how trees respond to microclimate variability is important in the face of climate changes. The objectives of this study were to examine the variation in wood water content (WWC) and bark water content (BWC) in Amazonian trees, as well as to assess the effect of microclimatic variability on monthly diameter growth rates (DGR). We extracted a core sample from each of 120 trees (28 species) and determined WWC and BWC on a fresh matter basis. DGR was measured monthly during the 12 months of 2007. The effect of microclimatic variability on DGR was analyzed by redundancy analysis. Average BWC and WWC were 53.4% and 34.7%, respectively, with a large variation in stem water content among species (BWC = 36.2−67.1%; WWC = 26.4−50.8%). There was no significant relationship between stem diameter and WWC or BWC, nor between DGR and wood density (p > 0.05). However, wood density was negatively correlated with WWC (r s = −0.69, p < 0.001). The high BWC emphasizes the importance of the bark tissue in Amazonian trees. Contrary to expectations, variability of monthly irradiance, rainfall and temperature had no effect on DGR (p > 0.20). The unresponsiveness of DGR to microclimatic variability, even in an above-average rainy year such as 2007, indicates that other parts of the tree may have greater priority than the stem for carbon allocation during the dry season.

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Yunjeong Yang ◽  
Ji Eun Kim ◽  
Hak Jin Song ◽  
Eun Bin Lee ◽  
Yong-Keun Choi ◽  
...  

Abstract Background Water content variation during plant growth is one of the most important monitoring parameters in plant studies. Conventional parameters (such as dry weight) are unreliable; thus, the development of rapid, accurate methods that will allow the monitoring of water content variation in live plants is necessary. In this study, we aimed to develop a non-invasive, radiofrequency-based monitoring system to rapidly and accurately detect water content variation in live plants. The changes in standing wave ratio (SWR) caused by the presence of stem water and magnetic particles in the stem water flow were used as the basis of plant monitoring systems. Results The SWR of a coil probe was used to develop a non-invasive monitoring system to detect water content variation in live plants. When water was added to the live experimental plants with or without illumination under drought conditions, noticeable SWR changes at various frequencies were observed. When a fixed frequency (1.611 GHz) was applied to a single experimental plant (Radermachera sinica), a more comprehensive monitoring, such as water content variation within the plant and the effect of illumination on water content, was achieved. Conclusions Our study demonstrated that the SWR of a coil probe could be used as a real-time, non-invasive, non-destructive parameter for detecting water content variation and practical vital activity in live plants. Our non-invasive monitoring method based on SWR may also be applied to various plant studies.


2015 ◽  
Vol 51 (4) ◽  
pp. 901-909 ◽  
Author(s):  
Kassandra Azevedo Tadini ◽  
Daiane Garcia Mercurio ◽  
Patrícia Maria Berardo Gonçalves Maia Campos

abstract Acetyl hexapeptide-3 has been used in anti-aging topical formulations aimed at improving skin appearance. However, few basic studies address its effects on epidermis and dermis, when vehiculated in topical formulations. Thus, the objective of this study was to determine the clinical efficacy of acetyl hexapeptide-3 using biophysical techniques. For this purpose, formulations with and without acetyl hexapeptide-3 were applied to the ventral forearm and the face area of forty female volunteers. Skin conditions were evaluated after 2 and 4-week long daily applications, by analyzing the stratum corneum water content and the skin mechanical properties, using three instruments, the Corneometer(r) CM 825, CutometerSEM 575 and ReviscometerRV600. All formulations tested increased the stratum corneum water content in the face region, which remained constant until the end of the study. In contrast, only formulations containing acetyl hexapeptide-3 exhibit a significant effect on mechanical properties, by decreasing the anisotropy of the face skin. No significant effects were observed in viscoelasticity parameters. In conclusion, the effects of acetyl hexapeptide-3 on the anisotropy of face skin characterize the compound as an effective ingredient for improving conditions of the cutaneous tissue, when used in anti-aging cosmetic formulations.


2019 ◽  
Author(s):  
Hao Liang ◽  
Meng Zhang ◽  
Yandong Zhao ◽  
Chao Gao ◽  
Hailan Wang

To achieve a rational allocation of limited water resources, and formulation of an appropriate irrigation system, this research studied the change characteristics of stem water content (StWC) in plant and its response to micro-environmental factors. In this study, the StWC and micro-environmental factors of Lagerstroemia indica in Beijing were continuously observed by BD-IV plant stem water content sensor and a forest microclimate monitoring station from 2017 to 2018. The variation of StWC and its correlation with environmental factors were analyzed. The results showed the StWC of Lagerstroemia indica varies regularly day and night during the growth cycle. Meanwhile, the rising time, valley time, and falling time of StWC were various at the different growth stages of Lagerstroemia indica. The results of correlation analysis between StWC and micro-environmental factors indicated that the StWC of Lagerstroemia indica was positively correlated with air relative humidity, while it was negatively correlated with total radiation and air temperature. The multiple regression equation of StWC and micro-environmental factors of Lagerstroemia indica was StWC = 11.789-1.402Rn-0.931T-1.132Ws+0.933RH-3.368ST+2.168SMC, and the coefficient of determination of the equation was of 0.87. Furthermore, the results illustrated that the irrigation should pay attention to supplementing irrigation in time during the peak growing season of fruit.


2021 ◽  
Author(s):  
Yulong Zhu ◽  
Tatsuya Ishikawa ◽  
Tomohito J. Yamada ◽  
Srikrishnan Siva Subramanian

Abstract This paper proposes an effective approach for evaluating the influences of climate change on slope stability in seasonally cold regions. Firstly, to semi-quantitatively assess the effects of climate changes on the uncertainty of climate factors, this study analyzes the trend of the two main climate factors (precipitation and air temperature) by the regression analysis using the meteorological monitoring data of the past 120 years in different scales (e.g., world, country (Japan), and city (Sapporo)), and the meteorological simulation data obtained by downscaling the outputs of three different regional atmospheric models (RAMs) with lateral boundary conditions from three different general circulation models (GCMs). Next, to discuss the effects of different climate factors (air temperature, precipitation, etc.) and to determine the key climate factors on the slope instability, an assessment approach for evaluating the effects of climate changes on slope instability is proposed through the water content simulation and slope stability analysis using a 2-dimensional (2D) finite element method (FEM) homogeneous conceptual slope model with considering freeze-thaw action. Finally, to check the effectiveness of the above assessment approach, assessment of instability of an actual highway embankment slope with the local layer geometry is done by applying the past and predicted future climate data. The results indicate that affected by global warming, the air temperature rise in some cold cities is more serious. The predicted future weather will affect the shape of the normal density curve (NDC) of the distribution of slope failures in one year. The climate changes (especially the increase in precipitation) in the future will increase the infiltration during the Spring season. It will lengthen the time that the highway slope is in an unstable state due to high volumetric water content, thereby enhancing the instability of the slopes and threatening more slopes in the future.


Author(s):  
А.В. Лебедев ◽  
В.В. Кузьмичев

Сосна обыкновенная является одной из основных лесообразующих пород Европы, а ее древесина находит широкое применение в лесопромышленном комплексе. При оценке углерододепонирующих функций считается, что конверсионные коэффициенты являются константными по времени. Последние исследования показывают, что происходящие климатические изменения оказывают существенное влияние на прирост древесины и ее свойства. Цель данного исследования – выявление долговременных тенденций в изменении биомассы фракций деревьев сосны обыкновенной в Европе, происходящих с 1940 г. Для проверки гипотезы о влиянии календарного года на биомассу фракций деревьев проводился регрессионный анализ с применением линейных моделей смешанных эффектов. Проведенный статистический анализ позволил выявить достоверное влияние (при p < 0,05) календарного года только на биомассу стволов в коре. Наиболее сильно изменения проявляются для деревьев в молодняках и средневозрастных насаждениях, где происходит формирование наибольшего радиального прироста. Для крупномерных стволов, согласно результатам моделирования, снижение биомассы стволов в коре не прослеживается. В ближайшие десятилетия в результате продолжающихся климатических изменений процесс снижения биомассы и плотности древесины крупномерных стволов должен усилиться. Выявленные изменения биомассы сопровождаются снижением плотности древесины, что происходит в результате увеличения в структуре годичного прироста более рыхлой и менее плотной ранней древесины. Таким образом, в условиях ускоряющихся темпов роста древесных растений объемы стволов и запасы древесины не должны напрямую пересчитываться в депонированный углерод с учетом исторических значений конверсионных коэффициентов. Это также следует учитывать при мониторинге, моделировании и использовании углерода и биомассы в лесах в условиях глобальных изменений. Scots pine is one of the main forest-forming species in Europe, and its wood is widely used in the timber industry. When evaluating carbon-depositing functions, the conversion rations are assumed to be constant over time. Recent studies show that the ongoing climatic changes have a significant impact on the growth of trees and wood properties. Therefore, the purpose of this study is to identify long-term trends in the change in the biomass of Scots pine tree fractions in Europe since 1940. To test the hypothesis about the influence of the calendar year on the biomass of tree fractions, regression analysis was performed using linear mixed-effect models. The performed statistically analysis made it possible to reveal a significant effect (p < 0.05) of the calendar year only on the biomass of the trunks in the bark. The changes are most pronounced for trees in young and middle-aged stands, where the formation of the greatest radial growth occurs. For large-sized trunks, according to the simulation results, the biomass of the stems in the bark is not traced. In the coming decades, as a result of ongoing climate change, the decline in biomass and wood density of largesized stems should intensify. The revealed changes in biomass are accompanied by a decrease in wood density, which occurs as a result of an increase in the structure of the annual growth of looser and less dense early wood. Thus, in the context of accelerating growth rates of woody plants, the volume of trunks and wood stock should not be directly converted into deposited carbon, considering the historical values of conversion rations. This should also be considered when monitoring, modeling and using carbon and biomass in forests in the face of global change.


1996 ◽  
Vol 16 (10) ◽  
pp. 809-815 ◽  
Author(s):  
S. D. Wullschleger ◽  
P. J. Hanson ◽  
D. E. Todd

2016 ◽  
Vol 73 (3) ◽  
pp. 601-614 ◽  
Author(s):  
Fleur Longuetaud ◽  
Frédéric Mothe ◽  
Meriem Fournier ◽  
Jana Dlouha ◽  
Philippe Santenoise ◽  
...  

Trees ◽  
2014 ◽  
Vol 28 (6) ◽  
pp. 1867-1868
Author(s):  
Lidewei L. Vergeynst ◽  
Maurits W. Vandegehuchte ◽  
Mary Anne McGuire ◽  
Robert O. Teskey ◽  
Kathy Steppe

Sign in / Sign up

Export Citation Format

Share Document