Coordination between leaf biomechanical resistance and hydraulic safety across 30 subtropical woody species

2021 ◽  
Author(s):  
Yong-Qiang Wang ◽  
Ming-Yuan Ni ◽  
Wen-Hao Zeng ◽  
Dong-Liu Huang ◽  
Wei Xiang ◽  
...  

Abstract Background and Aims Leaf biomechanical resistance protects leaves from biotic and abiotic damage. Previous studies have revealed that enhancing leaf biomechanical resistance is costly for plant species and leads to an increase in leaf drought tolerance. We thus predicted that there is a functional correlation between leaf hydraulic safety and biomechanical characteristics. Methods We measured leaf morphological and anatomical traits, pressure–volume parameters, maximum leaf hydraulic conductance (Kleaf-max), leaf water potential at 50% loss of hydraulic conductance (P50leaf), leaf hydraulic safety margin (SMleaf), and leaf force to tear (Ft) and punch (Fp) of 30 co-occurring woody species in a subtropical evergreen broadleaved forest. Linear regression analysis was performed to examine the relationships between biomechanical resistance and other leaf hydraulic traits. Key Results We found that higher Ft and Fp values were significantly associated with a lower (more negative) P50leaf and a larger SMleaf, thereby confirming the correlation between leaf biomechanical resistance and hydraulic safety. However, leaf biomechanical resistance showed no correlation with Kleaf-max, although it was significantly and negatively correlated with leaf outside-xylem hydraulic conductance. In addition, we also found that there was a significant correlation between biomechanical resistance and the modulus of elasticity by excluding an outlier. Conclusions The findings of this study reveal leaf biomechanical-hydraulic safety correlation in subtropical woody species.

2020 ◽  
Vol 16 (11) ◽  
pp. 20200456
Author(s):  
Chao-Long Yan ◽  
Ming-Yuan Ni ◽  
Kun-Fang Cao ◽  
Shi-Dan Zhu

Leaf hydraulic conductance and the vulnerability to water deficits have profound effects on plant distribution and mortality. In this study, we compiled a leaf hydraulic trait dataset with 311 species-at-site combinations from biomes worldwide. These traits included maximum leaf hydraulic conductance ( K leaf ), water potential at 50% loss of K leaf (P50 leaf ), and minimum leaf water potential ( Ψ min ). Leaf hydraulic safety margin (HSM leaf ) was calculated as the difference between Ψ min and P50 leaf . Our results indicated that 70% of the studied species had a narrow HSM leaf (less than 1 MPa), which was consistent with the global pattern of stem hydraulic safety margin. There was a positive relationship between HSM leaf and aridity index (the ratio of mean annual precipitation to potential evapotranspiration), as species from humid sites tended to have larger HSM leaf . We found a significant relationship between K leaf and P50 leaf across global angiosperm woody species and within each of the different plant groups. This global analysis of leaf hydraulic traits improves our understanding of plant hydraulic response to environmental change.


Author(s):  
Muhammad Rois Rois ◽  
Manarotul Fatati Fatati ◽  
Winda Ihda Magfiroh

This study aims to determine the effect of Inflation, Exchange Rate and Composite Stock Price Index (IHSG) to Return of PT Nikko Securities Indonesia Stock Fund period 2014-2017. The study used secondary data obtained through documentation in the form of PT Nikko Securities Indonesia Monthly Net Asset (NAB) report. Data analysis is used with quantitative analysis, multiple linear regression analysis using eviews 9. Population and sample in this research are PT Nikko Securities Indonesia. The result of multiple linear regression analysis was the coefficient of determination (R2) showed the result of 0.123819 or 12%. This means that the Inflation, Exchange Rate and Composite Stock Price Index (IHSG) variables can influence the return of PT Nikko Securities Indonesia's equity fund of 12% and 88% is influenced by other variables. Based on the result of the research, the variables of inflation and exchange rate have a negative and significant effect toward the return of PT Nikko Securities Indonesia's equity fund. While the variable of Composite Stock Price Index (IHSG) has a negative but not significant effect toward Return of Equity Fund of PT Nikko Securities Indonesia


Liquidity ◽  
2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Yanti Budiasih

The objectives of this study are to analyze changes in organizational structure, job design, organizational culture and its influence on employee productivity at PT. XX in Jakarta and to identify variables that have a dominant influence on the productivity of employees. The research method used is using multiple linear regression analysis. The results show that the all variables simultaneously and partially change the organizational structure, job design, and organizational culture has a significant impact on employee productivity at PT. XXin Jakarta.


10.32698/0642 ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 120
Author(s):  
Wiwi Delfita ◽  
Neviyarni S. ◽  
Riska Ahmad

Some students perceive lesbian, gay, bisexual, and transgender (LGBT) positively, even though LGBT is a sexual deviation that is not appropriate with values and norms. There are several factors that influence an individual's perception of LGBT, including sexual identity. This study aims at looking at the contribution of sexual identity to student perceptions about LGBT. This research used a quantitative approach with a descriptive method and a simple linear regression analysis. The sample of this research was 385 taken from 15.752 undergraduate students of Universitas Negeri Padang which the sample was drawn by using the Slovin formula and continued with a Proportional Random Sampling technique. The instrument used was the Guttman model's sexual identity scale and the scale of students' perceptions of the LGBT Likert model. After analyzing the data with the descriptive technique and the simple linear regression analysis, the results showed that sexual identity significantly contributed to the students' perceptions of LGBT. This research has implications as a basis for counselors to help students avoid sexual identity mismatches and prevent the emergence of positive perceptions of LGBT.


MBIA ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 76-84
Author(s):  
Muhammad Idris ◽  
Dian Novita Sari

The problem in this study is whether there is an influence of leadership and work discipline on the employees’ performance of PT.Sucofindo Palembang City. This research includes associative research. The sample in this study were 88 respondents, with propotionate random sampling analysis technique. The data used were primary data and secondary data. Data collection method through questionnare. Analysis techniques using multiple linear regression analysis, F test (Simultaneoys) and t test (partial) and determination coeffiecient. The results show that there is influence of leadership and work discipline on the performance of PT.Sucofindo Palembang City.


2019 ◽  
Vol 13 (2) ◽  
pp. 199
Author(s):  
Asrye Tutur Sinaga ◽  
Nurul Wardani

AbstrakPenelitian ini bertujuan untuk mengetahui dan dapat menjelaskan pengaruh Kualitas Pelayanan dan Word Of Mouth terhadap Keputusan pembelian di Kafe Potret Medan. Populasi dalam penelitian ini adalah 700 orang ditentukan dari jumlah pengunjung Kafe Potret Medan dalam kurun waktu satu minggu, dan sampel yang digunakan berjumlah 88 pengunjung. Sedangkan tehnik pengumpulan data menggunakan angket (kuesioner) dan pengujiannya yaitu uji kualitas data dan uji asumsi klasik.Pengujian hipotesis menggunakan analisis regresi linier berganda, uji F, uji t, dan uji R2. Hipotesis penelitian dimensi Kualitas Pelayanan dan Word Of Mouth secara parsial terhadap Keputusan Pembelian diterima jika t hitung > t tabel dengan tingkat signifikan 0.05.Nilai t tabel dalam penelitian ini 1,662. Nilai t hitung variabel X1 sebesar 1,990 t hitung  > t tabel maka hipotesis diterima, nilai t hitung variabel X2 sebesar 2,628 t hitung > t tabel maka hipotesis diterima. Dari 2 variabel, variabel Word Of Mouth yang paling dominan mempengaruhi Keputusan Pembelian  sebesar 2,628. Kata Kunci : Kualitas Pelayanan, Word Of Mouth, Keputusan Pembelian AbstractThe purpose of this study is to identify and able to explain the influence of Service Quality and Word Of Mouth to Purchasing Decisions of Kafe Potret Medan. The population in this study were 700 people from visitors Kafe Potret Medan in one week, and the samples used were 88 visitors. While the techniques of data collection using the questionnaire and use the test of quality data and classical assumption. The hypothesis test uses multiple linear regression analysis, F test, R square and t test. The study hypothesis was partially of Service Quality and Word Of Mouth dimension to  Purchasing Decisions is acceptable if t hitung > t tabel with a significant level 0.05. The t tabel value in this study 1.662. The t hitung X1 is 1.990 that mean t hitung > t tabel then the hypothesis is accepted, t hitung X2 is 2.628 that mean t hitung > t tabel then the hypothesis is accepted. From 2 variables fascination that the most dominant variable for Purchasing Decisions is Word Of Mouth of 2.628. Keywords : Service Quality, Word Of Mouth, Purchasing Decisions


2019 ◽  
Vol 3 (2) ◽  
pp. 26
Author(s):  
Niken Ayu Wulandari ◽  
Tegoeh Hari Abrianto ◽  
Edi Santoso

This research to analyze and evaluate intellectual capital on financial performance obtained by return on equity, asset turnover and growth in revenue. The population in this study are consumer goods companies listed on the Stock Exchange in 2015-2017. The research sample was received by 21 companies obtained by using purposive sampling technique. The analytical method used is simple linear regression analysis with the SPSS version 20 application and uses the VAICTM method to measure intellectual capital. The results of this study indicate that intellectual capital has a significant effect on financial performance generated by return on equity, but intellectual capital does not have a significant effect on financial performance required by asset turnover and growth in revenue.


2013 ◽  
Vol 27 (4) ◽  
pp. 359-367 ◽  
Author(s):  
T. Adak ◽  
N.V.K. Chakravarty

Abstract Temporal changes in surface soil temperature were studied in winter crop. Significant changes in bare and cropped soil temperature were revealed. Air temperature showed a statistically positive and strong relationship (R2 = 0.79** to 0.92**) with the soil temperature both at morning and afternoon hours. Linear regression analysis indicated that each unit increase in ambient temperature would lead to increase in minimum and maximum soil temperatures by 1.04 and 1.02 degree, respectively. Statistically positive correlation was revealed among biophysical variables with the cumulative surface soil temperature. Linear and non-linear regression analysis indicated 62-69, 72-86 and 72-80% variation in Leaf area index, dry matter production and heat use efficiency in Indian mustard crop as a function of soil degree days. Below 60% variation in yield in Indian mustard was revealed as a function of soil temperature. In contrast, non-significant relationship between oil content and soil temperature was found, which suggests that oil accumulation in oilseed crops was not affected significantly by the soil temperature as an independent variable.


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