Combined effects of elevated air temperature and CO2 on growth, yield, and yield components of japonica rice (Oryza sativa L.)

Masahiro Yamaguchi,Nobuyuki Tazoe,Tomoki Nakayama,Tetsushi Yonekura,Takeshi Izuta,Yoshihisa Kohno 한국대기환경학회 2023 Asian Journal of Atmospheric Environment (AJAE) Vol.17 No.1

In the region where heat stress has become evident, the elevation of air temperature could reduce yield of heat stress-susceptible crops, such as rice (Oryza sativa L.), which is a major food staple in Asia. In addition to air temperature, atmospheric CO2 is projected to be elevated in the future. To project rice yield in the future, it is necessary to clarify the responses of rice to concurrent elevations of air temperature and atmospheric CO2. In the present study, two japonica rice cultivars with different heat tolerance, Hinohikari (sensitive) and Nikomaru (tolerant), were grown in pots inside open-top chambers and exposed to elevated air temperature and/or CO2. The degrees of increase in the air temperature and CO2 concentration by the treatments were approximately 1 °C and 120 μmol mol− 1 (ppm). The study was conducted in Nagasaki, Japan, where heat stress on rice has become evident. Elevated air temperature significantly decreased both whole-plant growth and grain yield. Elevated CO2 significantly increased the growth but significantly decreased the yield. The effects of elevated air temperature and elevated CO2 on growth and yield did not significantly differ between two cultivars. In both cultivars, the main cause of yield reduction by both treatments was reduction in spikelet fertility, which is typical heat stress on rice. The elevated CO2- induced reduction in spikelet fertility could be explained partially by high-temperature regime during flowering due to acceleration of heading and by increase in canopy temperature via stomatal closure in flag leaves. Because elevated air temperature and elevated CO2 treatments additively reduced spikelet fertility in both cultivars, concurrent elevations of air temperature and CO2 caused considerable reduction in grain yield.

A Case Study of Risk Assessment of Ozone Impact on Forest Tree Species in Japan

Watanabe, Makoto,Yamaguchi, Masahiro,Matsumura, Hideyuki,Kohno, Yoshihisa,Koike, Takayoshi,Izuta, Takeshi Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.4

Ozone ($O_3$) is a main component of photochemical oxidants and a phytotoxic air pollutant. Although the current levels of tropospheric $O_3$ in East Asia could adversely affect productivity of forest tree species, risk assessments of $O_3$ impact were limited. In this paper, we summarize the methodology of risk assessment of $O_3$ on forest tree species based on our two previous studies, risk assessments of $O_3$ impact on the growth of Fagus crenata by Watanabe et al. (2012) and on the annual carbon absorption of three representative conifers, Cryptomeria japonica, Pinus densiflora and Larix kaempferi by Watanabe et al. (2010). $O_3$ sensitivity of each tree species obtained from an experimental study, $O_3$ exposure and atmospheric N deposition based on field monitoring and vegetation survey were integrated by geographic information system method. Based on the results, we conclude that the area with high risk of $O_3$ impact does not necessarily correspond to the area with high $O_3$ exposure. The varieties of tree habitat, tree sensitivity to $O_3$ and annual carbon absorption among the tree species, and N deposition-induced change in the $O_3$ sensitivity of F. crenata are raised as the factors of discordance between areas with high risk and those with high $O_3$ exposure. In the last part of this paper, we discuss the present uncertainty and perspectives of risk assessment for the future studies on the impact of $O_3$ on forest tree species in East Asia.

알루미늄 농도에 따른 소나무 묘목의 생장 , 영양상태 및 광합성속도에 미치는 영향

이충화(Choong Hwa Lee),진현오(Hyun O Jin),이두전맹(Takeshi Izuta) 한국산림과학회 1999 한국산림과학회지 Vol.88 No.2

The effects of various levels of Al concentration on growth, nutrient status and net photosynthetic rate of 2-year-old Pinus densiflora Sieb. et Zucc. seedlings grown in a nutrient culture solution were investigated. Al concentrations were added as aluminum chloride(AlCl₃) at 0(control), 10, 30 and 60ppm to the nutrient culture solution. The nutrient culture solution was maintained at pH 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution and grown in a greenhouse for 90 days from May 8 to August 6, 1996. The treatment above 10ppm of Al concentrations induced a significant reduction on the dry weight growth of the seedlings. The relative growth rate(RGR), net assimilation rate(NAR) and net photosynthetic rate of the seedlings were reduced with increasing of Al concentrations in the nutrient culture solutions. This result suggests that reductions in the RGR and NAR of the seedlings were mainly due to the inhibition of net photosynthesis. In addition, the increase of Al concentrations in a nutrient culture solution decreased the concentration of essential mineral elements such as Ca and Mg in the needle of the seedlings. However, the concentrations of Al of each plant organ increased in the treatment above 10ppm of Al concentrations in the nutrient culture solutions. This result suggests that the increased Al concentration in the belowground part resulted from the decreased concentration of essential mineral elements in the aboveground part of the seedlings.

Experimental Studies on the Effects of Ozone on Growth and Photosynthetic Activity of Japanese Forest Tree Species

Masahiro Yamaguchi,Makoto Watanabe,Hideyuki Matsumura,Yoshihisa Kohno,Takeshi Izuta 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.2

Ozone (O_3) is a main component of photochemical oxidants, and a phytotoxic anthropogenic air pollutant. In North America and Europe, the current concentration of O_3 has been shown to have significant adverse effects on vegetation. In this review, we summarize the experimental studies on the effects of O-3 on the growth and photosynthetic activity of Japanese forest tree species to understand the present knowledge and provide sound basis for future research toward the assessment of O_3 impacts on Japanese forest ecosystem. Since the 1990s, several Japanese researchers have conducted the experimental studies on the effects of ambient levels of O_3on growth and physiological functions such as net photosynthesis of Japanese forest tree species. Although the sensitivity to O_3 of whole-plant growth is quite different among the species, it was suggested that the current ambient levels of O_3 in Japan are high enough to adversely affect growth and photosynthetic activity of Japanese forest tree species classified into high O_3 sensitivity group such as Japanese beech. The N load to soil has been shown to reduce the sensitivity to O_3 of Japanese larch and increase that of Japanese beech. To establish the critical level of O_3 for protecting Japanese forest tree species, therefore, it is necessary to take into account the N deposition from the atmosphere. There is little information on the combined effects of O_3 and other environmental factors such as elevated CO_2and drought on growth and physiological functions of Japanese forest tree species. Therefore, it is necessary to promote the experimental study and accumulate the information on the combined effects of O_3and any other abiotic environmental factors on Japanese forest tree species.

A Case Study of Risk Assessment of Ozone Impact on Forest Tree Species in Japan

Makoto Watanabe,Masahiro Yamaguchi,Hideyuki Matsumura,Yoshihisa Kohno,Takayoshi Koike,Takeshi Izuta 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.4

Ozone (O_3) is a main component of photochemical oxidants and a phytotoxic air pollutant. Although the current levels of tropospheric O_3 in East Asia could adversely affect productivity of forest tree species,risk assessments of O_3 impact were limited. In this paper, we summarize the methodology of risk assessment of O_3 on forest tree species based on our two previous studies, risk assessments of O_3 impact on the growth of Fagus crenata by Watanabe et al. (2012) and on the annual carbon absorption of three representative conifers, Cryptomeria japonica, Pinus densiflora and Larix kaempferi by Watanabe et al. (2010). O_3 sensitivity of each tree species obtained from an experimental study, O_3 exposure and atmospheric N deposition based on field monitoring and vegetation survey were integrated by geographic information system method. Based on the results, we conclude that the area with high risk of O_3 impact does not necessarily correspond to the area with high O_3 exposure. The varieties of tree habitat, tree sensitivity to O_3 and annual carbon absorption among the tree species, and N deposition-induced change in the O_3 sensitivity of F. crenata are raised as the factors of discordance between areas with high risk and those with high O_3 exposure. In the last part of this paper, we discuss the present uncertainty and perspectives of risk assessment for the future studies on the impact of O_3 on forest tree species in East Asia.

Visualization of Artificially Deposited Submicron-sized Aerosol Particles on the Surfaces of Leaves and Needles in Trees

Kenichi Yamane,Satoshi Nakaba,Masahiro Yamaguchi,Katsushi Kuroda,Yuzou Sano,I. Wuled Lenggoro,Takeshi Izuta,Ryo Funada 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

To understand the effect of aerosols on the growth and physiological conditions of trees in forests, it is important to know the state of aerosols that are deposited on the surface of the leaves or needles. In this study, we developed methods of visualization of submicron-sized aerosols that were artificially deposited from the gas-phase or liquid phase onto tree leaves or needles in trees. Firstly, we used field-emission scanning electron microscopy (FE-SEM) to observe black carbon (BC) particles that were artificially sprayed onto the leaves or needles. The distribution of BC particles deposited on the leaves and needles were distinguished based on the size and morphological features of the particles. The distribution and agglomerates size of BC particles differed between two spraying methods of BC particles employed. Secondly,we tried to visualize gold (Au) particles that were artificially sprayed onto the leaves using energy dispersive X-ray spectrometry (EDX) coupled to FE-SEM. We detected the Au particles based on the characteristic X-ray spectrum, which was secondarily generated from the Au particles. In contrast to the case of BC particles, the Au particles did not form agglomerates and were uniformly distributed on the leaf surfaces. The present results show that our methods provide useful information of adsorption and/or behavior of fine particles at the submicron level on the surface of the leaves. To understand the effect of aerosols on the growth and physiological conditions of trees in forests, it is important to know the state of aerosols that are deposited on the surface of the leaves or needles. In this study, we developed methods of visualization of submicron-sized aerosols that were artificially deposited from the gas-phase or liquid phase onto tree leaves or needles in trees. Firstly, we used field-emission scanning electron microscopy (FE-SEM) to observe black carbon (BC) particles that were artificially sprayed onto the leaves or needles. The distribution of BC particles deposited on the leaves and needles were distinguished based on the size and morphological features of the particles. The distribution and agglomerates size of BC particles differed between two spraying methods of BC particles employed. Secondly,we tried to visualize gold (Au) particles that were artificially sprayed onto the leaves using energy dispersive X-ray spectrometry (EDX) coupled to FE-SEM. We detected the Au particles based on the characteristic X-ray spectrum, which was secondarily generated from the Au particles. In contrast to the case of BC particles, the Au particles did not form agglomerates and were uniformly distributed on the leaf surfaces. The present results show that our methods provide useful information of adsorption and/or behavior of fine particles at the submicron level on the surface of the leaves.

Effects of Ozone and Soil Salinity, Singly and in Combination, on Growth, Yield and Leaf Gas Exchange Rates of Two Bangladeshi Wheat Cultivars

Kamal, Mohammed Zia Uddin,Yamaguchi, Masahiro,Azuchi, Fumika,Kinose, Yoshiyuki,Wada, Yoshiharu,Funada, Ryo,Izuta, Takeshi Korean Society for Atmospheric Environment 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.2

In Bangladesh, increases in the tropospheric ozone ($O_3$) concentration and in soil salinization may lead to crop damage. To clarify the effects of $O_3$ and/or soil salinity on Bangladeshi wheat cultivars, BAW1059 (salt-tolerant) and Shatabdi (salt-sensitive) were exposed to 70-day treatments with $O_3$ (charcoal-filtered air (CF), $1.0{\times}O_3$, and $1.5{\times}O_3$) and different levels of soil salinity (0, 4, and $8dS\;m^{-1}$). In both cultivars, the whole-plant dry mass and grain yield were significantly reduced by exposure to $O_3$. Increased soil salinity caused significant reductions in whole-plant growth and yield in Shatabdi, but the reductions were negligible in BAW1059. No significant interactions between $O_3$ and salinity were detected for growth, yield, and leaf gas exchange parameters in both cultivars. We concluded that the effects of $O_3$ are not ameliorated by soil salinity in two Bangladeshi wheat cultivars, regardless of their salinity tolerance.

Effects of Ozone and Soil Salinity, Singly and in Combination, on Growth, Yield and Leaf Gas Exchange Rates of Two Bangladeshi Wheat Cultivars

Mohammed Zia Uddin Kamal,Masahiro Yamaguchi,Fumika Azuchi,Yoshiyuki Kinose,Yoshiharu Wada,Ryo Funada,Takeshi Izuta 한국대기환경학회 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.2

In Bangladesh, increases in the tropospheric ozone (O3) concentration and in soil salinization may lead to crop damage. To clarify the effects of O3 and/or soil salinity on Bangladeshi wheat cultivars, BAW1059 (salt-tolerant) and Shatabdi (salt-sensitive) were exposed to 70-day treatments with O3 (charcoal-filtered air (CF), 1.0×O3, and 1.5×O3) and different levels of soil salinity (0, 4, and 8 dS m-1). In both cultivars, the whole-plant dry mass and grain yield were significantly reduced by exposure to O3. Increased soil salinity caused significant reductions in whole-plant growth and yield in Shatabdi, but the reductions were negligible in BAW1059. No significant interactions between O3 and salinity were detected for growth, yield, and leaf gas exchange parameters in both cultivars. We concluded that the effects of O3 are not ameliorated by soil salinity in two Bangladeshi wheat cultivars, regardless of their salinity tolerance.

Optical Method for Measuring Deposition Amount of Black Carbon Particles on Foliar Surface

Yamaguchi, Masahiro,Takeda, Kenta,Otani, Yoko,Murao, Naoto,Sase, Hiroyuki,Lenggoro, I. Wuled,Yazaki, Kenichi,Noguchi, Kyotaro,Ishida, Atsushi,Izuta, Takeshi Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

To perform quick measurements of black carbon (BC) particles deposited on foliar surfaces of forest tree species, we investigated an optical method for measuring the amount of BC extracted from foliar surfaces and collected on quartz fiber filters. The seedlings of Fagus crenata, Castanopsis sieboldii, Larix kaempferi and Cryptomeria japonica were exposed to submicron BC particles for one growing season (1 June to 7 December 2009). At the end of the growing season, the leaves or needles of the seedlings were harvested and washed with deionized water followed by washing with chloroform to extract the BC particles deposited on the foliar surfaces. The extracted BC particles were collected on a quartz fiber filter. The absorption spectrum of the filters was measured by spectrophotometer with an integrating sphere. To obtain the relationship between the absorbance of the filter and the amount of BC particles on the filter, the amount of BC particles on the filter was determined as that of elemental carbon (EC) measured by a thermal optical method. At wavelengths below 450 nm, the absorption spectrum of the filter showed absorption by biological substances, such as epicuticular wax, resulting in the low coefficient of determination ($R^2$) in the relationship between the amount of EC on the filter ($M_{EC}$, ${\mu}g\;C\;cm^{-2}$ filter area) and the absorbance of the filter. The intercept of the regression line between $M_{EC}$ and the absorbance of the filter at 580 nm ($A_{580}$) was closest to 0. There was a significant linear relationship between the $A_{580}$ and $M_{EC}$ ($R^2$=0.917, p<0.001), suggesting that the amount of BC particles collected on the filter can be predicted from the absorbance. This optical method might serve as a simple, fast and cost-effective technique for measuring the amount of BC on foliar surfaces.

Visualization of Artificially Deposited Submicron-sized Aerosol Particles on the Surfaces of Leaves and Needles in Trees

Yamane, Kenichi,Nakaba, Satoshi,Yamaguchi, Masahiro,Kuroda, Katsushi,Sano, Yuzou,Lenggoro, I. Wuled,Izuta, Takeshi,Funada, Ryo Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

To understand the effect of aerosols on the growth and physiological conditions of trees in forests, it is important to know the state of aerosols that are deposited on the surface of the leaves or needles. In this study, we developed methods of visualization of submicron-sized aerosols that were artificially deposited from the gas-phase or liquid phase onto tree leaves or needles in trees. Firstly, we used field-emission scanning electron microscopy (FE-SEM) to observe black carbon (BC) particles that were artificially sprayed onto the leaves or needles. The distribution of BC particles deposited on the leaves and needles were distinguished based on the size and morphological features of the particles. The distribution and agglomerates size of BC particles differed between two spraying methods of BC particles employed. Secondly, we tried to visualize gold (Au) particles that were artificially sprayed onto the leaves using energy dispersive X-ray spectrometry (EDX) coupled to FE-SEM. We detected the Au particles based on the characteristic X-ray spectrum, which was secondarily generated from the Au particles. In contrast to the case of BC particles, the Au particles did not form agglomerates and were uniformly distributed on the leaf surfaces. The present results show that our methods provide useful information of adsorption and/or behavior of fine particles at the submicron level on the surface of the leaves.