Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00030
S. Cosmulescu, Florentina Gavrila Calusaru
Phenology is the study of periodic biologic changes that plants are going through, under the influence of environmental factors, especially temperature. The present paper evaluates the behaviour of Prunus spinosa L. genotypes under the fluctuations of climatic factors by calculating the average time elapsed from bud-breaking to blooming, the average time elapsed between different phenophases, the heat demand and the chilling requirement. The data obtained show that the onset of spring season phenological phases is significantly speeded-up by temperatures increase and provides useful information on temperature influence on phenologic phased triggering and better understanding of temperature influence on phenology in Prunus spinosa L. genotypes in Oltenia region of Romania.
{"title":"Influence of temperature on blackthorn (Prunus spinosa L.) phenophases in spring season","authors":"S. Cosmulescu, Florentina Gavrila Calusaru","doi":"10.2480/agrmet.d-19-00030","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00030","url":null,"abstract":"Phenology is the study of periodic biologic changes that plants are going through, under the influence of environmental factors, especially temperature. The present paper evaluates the behaviour of Prunus spinosa L. genotypes under the fluctuations of climatic factors by calculating the average time elapsed from bud-breaking to blooming, the average time elapsed between different phenophases, the heat demand and the chilling requirement. The data obtained show that the onset of spring season phenological phases is significantly speeded-up by temperatures increase and provides useful information on temperature influence on phenologic phased triggering and better understanding of temperature influence on phenology in Prunus spinosa L. genotypes in Oltenia region of Romania.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2480/agrmet.d-19-00030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00043
S. Matsuda, H. Yoshikoshi, Tomoyo Suzuki, Yuuki Ohta, Ayaka Chiba, H. Arima, Hideaki Kumagai, D. Yasutake, M. Kitano
The irradiance of solar radiation in a greenhouse with a complex structure was calculated using a diagram for sky view factor (DSVF) and compared with observed values. Structural materials (such as side pillars and rafters) and non-structural materials (such as lock channels, door frames, and ventilation fans) were treated as sunshine obstacles, including lower rafters and equal leg angles in the inner spaces of the greenhouse. Radiation directions simulated using a DSVF were used for calculating the irradiance of diffuse solar radiation. With respect to the irradiance of total solar radiation on a sunny day, the calculated values were found to be higher than the observed values early in the morning. However, the overall fluctuation due to diurnal change of the solar elevation and in the sharp drops due to the sunshine obstacles were reproduced. Furthermore, the diurnal changes of the irradiance of non-direct solar radiation on a sunny day and the irradiance of total and non-direct solar radiations on a cloudy day could also be reproduced. The relative error of the calculated irradiance of daytime (from 04 :00 to 20 :00) total and non-direct solar radiations to the measured value was 4.3% for the total radiation on the sunny day, 5.5% for the non-direct radiation on the sunny day, -1.1% for the total radiation on the cloudy day, and 0.3% for the non-direct radiation on the cloudy day. The results of this study indicated that the DSVF can be useful for calculating diffuse solar radiation.
{"title":"Calculation of the irradiance of solar radiation in a greenhouse with a complex structure using a diagram for sky view factor","authors":"S. Matsuda, H. Yoshikoshi, Tomoyo Suzuki, Yuuki Ohta, Ayaka Chiba, H. Arima, Hideaki Kumagai, D. Yasutake, M. Kitano","doi":"10.2480/agrmet.d-19-00043","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00043","url":null,"abstract":"The irradiance of solar radiation in a greenhouse with a complex structure was calculated using a diagram for sky view factor (DSVF) and compared with observed values. Structural materials (such as side pillars and rafters) and non-structural materials (such as lock channels, door frames, and ventilation fans) were treated as sunshine obstacles, including lower rafters and equal leg angles in the inner spaces of the greenhouse. Radiation directions simulated using a DSVF were used for calculating the irradiance of diffuse solar radiation. With respect to the irradiance of total solar radiation on a sunny day, the calculated values were found to be higher than the observed values early in the morning. However, the overall fluctuation due to diurnal change of the solar elevation and in the sharp drops due to the sunshine obstacles were reproduced. Furthermore, the diurnal changes of the irradiance of non-direct solar radiation on a sunny day and the irradiance of total and non-direct solar radiations on a cloudy day could also be reproduced. The relative error of the calculated irradiance of daytime (from 04 :00 to 20 :00) total and non-direct solar radiations to the measured value was 4.3% for the total radiation on the sunny day, 5.5% for the non-direct radiation on the sunny day, -1.1% for the total radiation on the cloudy day, and 0.3% for the non-direct radiation on the cloudy day. The results of this study indicated that the DSVF can be useful for calculating diffuse solar radiation.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"76 1","pages":"44-52"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2480/agrmet.d-19-00043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00045
Yoshiyuki Kinose, Y. Masutomi, F. Shiotsu, Keiichi Hayashi, Daikichi Ogawada, Martin Gomez-Garcia, Akiko Matsumura, Kiyoshi Takahashi, K. Fukushi
{"title":"Impact assessment of climate change on the major rice cultivar Ciherang in Indonesia","authors":"Yoshiyuki Kinose, Y. Masutomi, F. Shiotsu, Keiichi Hayashi, Daikichi Ogawada, Martin Gomez-Garcia, Akiko Matsumura, Kiyoshi Takahashi, K. Fukushi","doi":"10.2480/agrmet.d-19-00045","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00045","url":null,"abstract":"","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2480/agrmet.d-19-00045","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-20-00001
Naru Takayama, H. Hori, Hidekazu Watanabe
We compared the difference of heatstroke risk of marathon runners in the Summer Olympics on the basis of the percentage of weight decrease due to sweating using potential effective sweating, between Tokyo and Sapporo For the women's marathon, the difference in the rate of decrease in body weight was 0 42 when the start time was 11 : 00, with 7 51 loss for Tokyo and 7 09 for Sapporo Nevertheless, when the start time was 7 : 00, as planned, the difference decreased to 0 28, with a 6 94 loss for Tokyo and 6 66 for Sapporo The estimated thermal load on runners when starting the race at 7 : 00 on August 8 in Sapporo was equivalent to starting at 5 : 30 or at 16 : 00 on August 2 in Tokyo For the men's marathon, the start time with the maximum rate of decrease in weight was 10 : 00, with a 6 91 loss for Sapporo and 7 42 for Tokyo If the race started at 7 : 00, the rate of decrease in body weight was 6 50 for Sapporo and 7 00 for Tokyo, a 0 50 difference However, as a result of the analysis based on the relation between wet bulb globe temperature and M-lE s (equivalent to the thermal load to the human body by net radiation and sensible heat exchange), severe weather conditions might place a large thermal load on runners, even if the race venue is changed to Sapporo
{"title":"Evaluation of heatstroke risk at Sapporo in the Tokyo 2020 Summer Olympic marathon event compared with Tokyo","authors":"Naru Takayama, H. Hori, Hidekazu Watanabe","doi":"10.2480/agrmet.d-20-00001","DOIUrl":"https://doi.org/10.2480/agrmet.d-20-00001","url":null,"abstract":"We compared the difference of heatstroke risk of marathon runners in the Summer Olympics on the basis of the percentage of weight decrease due to sweating using potential effective sweating, between Tokyo and Sapporo For the women's marathon, the difference in the rate of decrease in body weight was 0 42 when the start time was 11 : 00, with 7 51 loss for Tokyo and 7 09 for Sapporo Nevertheless, when the start time was 7 : 00, as planned, the difference decreased to 0 28, with a 6 94 loss for Tokyo and 6 66 for Sapporo The estimated thermal load on runners when starting the race at 7 : 00 on August 8 in Sapporo was equivalent to starting at 5 : 30 or at 16 : 00 on August 2 in Tokyo For the men's marathon, the start time with the maximum rate of decrease in weight was 10 : 00, with a 6 91 loss for Sapporo and 7 42 for Tokyo If the race started at 7 : 00, the rate of decrease in body weight was 6 50 for Sapporo and 7 00 for Tokyo, a 0 50 difference However, as a result of the analysis based on the relation between wet bulb globe temperature and M-lE s (equivalent to the thermal load to the human body by net radiation and sensible heat exchange), severe weather conditions might place a large thermal load on runners, even if the race venue is changed to Sapporo","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"76 1","pages":"174-179"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-20-00022
M. Ueyama, T. Ando
The mitigation of the urban heat island effect is an important environmental issue for sustainable urban development. We quantified the relative contributions to surface cooling associated with land use changes from an urban center to an urban park using the temperature decomposition method, with one-year paired eddy covariance measurements in Sakai, Japan. The enhanced heat transport efficiency achieved through park creation decreased daytime surface temperatures by 3.9-4.9 K, which was the greatest contribution to daytime surface cooling throughout the season. The disappearance of anthropogenic heat flux due to park creation reduced nighttime surface temperatures by 0.1-0.6 K, which was the greatest contribution at night in summer months. Enhancing heat transport efficiency through urban greening is thus a good mitigation strategy for cooling urban surfaces.
{"title":"Cooling effect of an urban park by enhanced heat transport efficiency","authors":"M. Ueyama, T. Ando","doi":"10.2480/agrmet.d-20-00022","DOIUrl":"https://doi.org/10.2480/agrmet.d-20-00022","url":null,"abstract":"The mitigation of the urban heat island effect is an important environmental issue for sustainable urban development. We quantified the relative contributions to surface cooling associated with land use changes from an urban center to an urban park using the temperature decomposition method, with one-year paired eddy covariance measurements in Sakai, Japan. The enhanced heat transport efficiency achieved through park creation decreased daytime surface temperatures by 3.9-4.9 K, which was the greatest contribution to daytime surface cooling throughout the season. The disappearance of anthropogenic heat flux due to park creation reduced nighttime surface temperatures by 0.1-0.6 K, which was the greatest contribution at night in summer months. Enhancing heat transport efficiency through urban greening is thus a good mitigation strategy for cooling urban surfaces.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00042
Satoshi Kawakita, N. Ishikawa, H. Takahashi, R. Okuno, Tadashi Takahashi
Wheat is one of the world’s most important crops, and its phenological model is useful for scheduling agricultural practices such as fungicide or fertilizer application. Although various wheat phenological models have been developed throughout the world, a conventional model-mostly used for Japanese cultivars-is one wherein temperature and daylength responses are expressed as sigmoidal and exponential functions that do not have a vernalization function. Since a gradual rise in daily development rate is expressed as an increase in mean temperature in the conventional model, the model may potentially miscalculate the wheat development when used to predict the phenology of a cultivar with a strong vernalization requirement. In this study, we proposed a modified model that combines the conventional model and a vernalization function that expressed the daily vernalization rate using an inverse sigmoid function. Cultivation data for five winter wheat cultivars with relatively strong vernalization requirement were collected for several years (more than 4 years), and the model for flowering date prediction was calibrated based on the sowing date for each cultivar. Six-fold cross-validation was conducted to calibrate and validate the models. We found that the proposed model predicted the flowering date of the wheat cultivars more accurately in the median of root mean square error (RMSE: 1-2 days) than the conventional model (RMSE: 2-5 days). Although the accuracy of the model varies with the cultivar, our results indicated the advantage of using the proposed model compared with that of using the conventional model for describing winter wheat phenology. These findings can contribute to further studies on the crop models of winter wheat and would be an example of combining the vernalization function expressed by an inverse sigmoidal function with the crop model.
{"title":"Winter wheat phenological development model with a vernalization function using sigmoidal and exponential functions","authors":"Satoshi Kawakita, N. Ishikawa, H. Takahashi, R. Okuno, Tadashi Takahashi","doi":"10.2480/agrmet.d-19-00042","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00042","url":null,"abstract":"Wheat is one of the world’s most important crops, and its phenological model is useful for scheduling agricultural practices such as fungicide or fertilizer application. Although various wheat phenological models have been developed throughout the world, a conventional model-mostly used for Japanese cultivars-is one wherein temperature and daylength responses are expressed as sigmoidal and exponential functions that do not have a vernalization function. Since a gradual rise in daily development rate is expressed as an increase in mean temperature in the conventional model, the model may potentially miscalculate the wheat development when used to predict the phenology of a cultivar with a strong vernalization requirement. In this study, we proposed a modified model that combines the conventional model and a vernalization function that expressed the daily vernalization rate using an inverse sigmoid function. Cultivation data for five winter wheat cultivars with relatively strong vernalization requirement were collected for several years (more than 4 years), and the model for flowering date prediction was calibrated based on the sowing date for each cultivar. Six-fold cross-validation was conducted to calibrate and validate the models. We found that the proposed model predicted the flowering date of the wheat cultivars more accurately in the median of root mean square error (RMSE: 1-2 days) than the conventional model (RMSE: 2-5 days). Although the accuracy of the model varies with the cultivar, our results indicated the advantage of using the proposed model compared with that of using the conventional model for describing winter wheat phenology. These findings can contribute to further studies on the crop models of winter wheat and would be an example of combining the vernalization function expressed by an inverse sigmoidal function with the crop model.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"76 1","pages":"81-88"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2480/agrmet.d-19-00042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-20-00026
Ji-Yoon Lee, A. Shimano, S. Hikosaka, Y. Ishigami, E. Goto
Ophiorrhiza pumila is a medicinal plant distributed on the floors of humid inland forests in subtropical areas and accumulates camptothecin (CPT) in whole plant organs. To elucidate the proper light and air temperature conditions for plant growth and CPT yield, we conducted two experiments under controlled environments. In experiment 1, we measured the net photosynthetic rate (Pn) and transpiration rate (E) of the whole plant O. pumila using an open-type assimilation chamber under different photosynthetic photon flux densities (PPFDs) and air temperatures. The result showed that the combination of an air temperature of 28 °C and a PPFD of 100 μmol m s was a good condition for photosynthesis and transpiration. In experiment 2, O. pumila was cultivated for 35 days under three PPFDs and three light periods at an air temperature of 28 °C. At a PPFD of 100 μmol m s and a light period of 16 h, growth was accelerated by the generating the lateral shoots and branches, and total CPT content per plant was the highest among these treatments. The present study revealed that the proper PPFD and light period conditions could enhance growth and CPT accumulation of O. pumila.
蛇根草(Ophiorrhiza pumila)是一种分布在亚热带湿润内陆森林地面的药用植物，在植物的整个器官中积累喜树碱(CPT)。为了阐明适宜的光照和空气温度条件对植物生长和CPT产量的影响，我们在受控环境下进行了两个实验。实验1在不同光合光子通量密度(ppfd)和不同气温条件下，利用开放式同化室测定了全株水草的净光合速率(Pn)和蒸腾速率(E)。结果表明，28℃的空气温度和100 μmol m s的PPFD是光合作用和蒸腾作用的良好条件。实验2在28℃的空气温度下，在3种ppfd和3个光照周期下培养35 d。在PPFD为100 μmol m s、光照16 h时，产生侧枝和侧枝有利于植株生长，且单株总CPT含量最高。本研究表明，适当的PPFD和光照条件可以促进稻壳的生长和CPT的积累。
{"title":"Effects of photosynthetic photon flux density and light period on growth and camptothecin accumulation of Ophiorrhiza pumila under controlled environments","authors":"Ji-Yoon Lee, A. Shimano, S. Hikosaka, Y. Ishigami, E. Goto","doi":"10.2480/agrmet.d-20-00026","DOIUrl":"https://doi.org/10.2480/agrmet.d-20-00026","url":null,"abstract":"Ophiorrhiza pumila is a medicinal plant distributed on the floors of humid inland forests in subtropical areas and accumulates camptothecin (CPT) in whole plant organs. To elucidate the proper light and air temperature conditions for plant growth and CPT yield, we conducted two experiments under controlled environments. In experiment 1, we measured the net photosynthetic rate (Pn) and transpiration rate (E) of the whole plant O. pumila using an open-type assimilation chamber under different photosynthetic photon flux densities (PPFDs) and air temperatures. The result showed that the combination of an air temperature of 28 °C and a PPFD of 100 μmol m s was a good condition for photosynthesis and transpiration. In experiment 2, O. pumila was cultivated for 35 days under three PPFDs and three light periods at an air temperature of 28 °C. At a PPFD of 100 μmol m s and a light period of 16 h, growth was accelerated by the generating the lateral shoots and branches, and total CPT content per plant was the highest among these treatments. The present study revealed that the proper PPFD and light period conditions could enhance growth and CPT accumulation of O. pumila.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"76 1","pages":"180-187"},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00026
Lifei Sun, K. Takagi, Munemasa Teramoto, Shintaro Hayakashi, N. Liang
To understand the magnitudes of temporal variation in soil respiration (Rs) and its spatial heterogeneity, and the effect of abiotic and biotic factors to cause the variation in a young plantation recovering after the clear-cutting of a mature forest, we analyzed 8 year Rs, microclimate, and vegetation data obtained in a young hybrid larch plantation with dense undergrowth of dwarf bamboo Sasa in northern Japan during snow-free periods from 2004 to 2014. Rs was measured by a multichannel automated chamber system and was resolved into two components, temperature sensitivity of respiration, Q10, and temperature-normalized basal respiration at 10°C, R10. Volumetric soil water content affects both seasonal and inter-annual variation of Rs by suppressing R10, whereas soil temperature affects only its seasonal variation. Vegetation recovery had significant effect on both temporal variation and spatial heterogeneity in Rs, although the tree and undergrowth Sasa had different contribution to these variations. Increase in the undergrowth Sasa PAI (plant area index) recovering after clear-cutting increased the Rs through the increase in Q10, whereas the spatial heterogeneity in Rs was increased by the increase in the tree PAI through the increase in R10. These results reveal that the soil water and vegetation has strong effect on the inter-annual variation of Rs and its spatial heterogeneity in the recovering young plantation, in spite of the strong exponential relationship of Rs with Ts in their seasonal variation. Although our results were obtained under the limited range in the inter-annual variation in seasonal mean Ts (< 2°C), this may not be the unique case only in our study site and gives us a caution when predicting Rs in future warmer environment.
{"title":"Inter-annual variation of soil respiration and its spatial heterogeneity in a cool-temperate young larch plantation in northern Japan","authors":"Lifei Sun, K. Takagi, Munemasa Teramoto, Shintaro Hayakashi, N. Liang","doi":"10.2480/agrmet.d-19-00026","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00026","url":null,"abstract":"To understand the magnitudes of temporal variation in soil respiration (Rs) and its spatial heterogeneity, and the effect of abiotic and biotic factors to cause the variation in a young plantation recovering after the clear-cutting of a mature forest, we analyzed 8 year Rs, microclimate, and vegetation data obtained in a young hybrid larch plantation with dense undergrowth of dwarf bamboo Sasa in northern Japan during snow-free periods from 2004 to 2014. Rs was measured by a multichannel automated chamber system and was resolved into two components, temperature sensitivity of respiration, Q10, and temperature-normalized basal respiration at 10°C, R10. Volumetric soil water content affects both seasonal and inter-annual variation of Rs by suppressing R10, whereas soil temperature affects only its seasonal variation. Vegetation recovery had significant effect on both temporal variation and spatial heterogeneity in Rs, although the tree and undergrowth Sasa had different contribution to these variations. Increase in the undergrowth Sasa PAI (plant area index) recovering after clear-cutting increased the Rs through the increase in Q10, whereas the spatial heterogeneity in Rs was increased by the increase in the tree PAI through the increase in R10. These results reveal that the soil water and vegetation has strong effect on the inter-annual variation of Rs and its spatial heterogeneity in the recovering young plantation, in spite of the strong exponential relationship of Rs with Ts in their seasonal variation. Although our results were obtained under the limited range in the inter-annual variation in seasonal mean Ts (< 2°C), this may not be the unique case only in our study site and gives us a caution when predicting Rs in future warmer environment.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00044
Xinli Zhang, Shun-Jiu Wang
In this paper, the spatiotemporal trend variability of precipitation days ( PDs ) in the southeast Tibetan Plateau ( STP ) from 1961 to 2012 is studied on annual and seasonal timescales for the first time. According to the results of the Mann-Kendall ( M-K ) test, the annual and seasonal area-averaged PDs shows a non-significant tendency except for spring PDs, and the spring PDs shows a significantly increased trend at 95 % confidence level during this period. The increase is 6.85 days per 100 years in annual PDs. The maximal increase occurs in spring, which is 7.13 days per 100 years. On the other hand, the PDs and their tendencies have notable spatial distribution variations over the STP. The PDs have some relationship with altitude, but their tendencies are unrelated to altitude in the STP. This study further finds that the Nujiang River is a dividing line for the PDs, and latitude 30 ° N is such a line for the PDs tendency. The results revealed the local differences of the PDs over the Tibetan Plateau ( TP ) , which is beneficial to understand the variations in precipitation patterns in the STP and gain insights into the change features of the TP under global changes.
{"title":"Long-term trend of precipitation days for southeast Tibetan Plateau, China","authors":"Xinli Zhang, Shun-Jiu Wang","doi":"10.2480/agrmet.d-19-00044","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00044","url":null,"abstract":"In this paper, the spatiotemporal trend variability of precipitation days ( PDs ) in the southeast Tibetan Plateau ( STP ) from 1961 to 2012 is studied on annual and seasonal timescales for the first time. According to the results of the Mann-Kendall ( M-K ) test, the annual and seasonal area-averaged PDs shows a non-significant tendency except for spring PDs, and the spring PDs shows a significantly increased trend at 95 % confidence level during this period. The increase is 6.85 days per 100 years in annual PDs. The maximal increase occurs in spring, which is 7.13 days per 100 years. On the other hand, the PDs and their tendencies have notable spatial distribution variations over the STP. The PDs have some relationship with altitude, but their tendencies are unrelated to altitude in the STP. This study further finds that the Nujiang River is a dividing line for the PDs, and latitude 30 ° N is such a line for the PDs tendency. The results revealed the local differences of the PDs over the Tibetan Plateau ( TP ) , which is beneficial to understand the variations in precipitation patterns in the STP and gain insights into the change features of the TP under global changes.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69169972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.2480/agrmet.d-19-00017
T. Ikeda, Y. Ishigami, E. Goto
We investigated the combined influence of cooling using electric heat pumps and CO 2 enrichment in a closed greenhouse equipped with a near infrared solar radiation ( NIR ) -reflecting film on the yield and quality of tomato fruits during the summer season. The air temperature of the ‘Control’ greenhouse were controlled through conventional natural ventilation windows, shading curtains and a fog cooling system. The air temperature of the ‘Closed’ greenhouse were controlled by cooling of electric heat pumps and a NIR-reflecting film curtain. The CO 2 concentration was maintained at around 1000 μ mol mol - 1 in the Closed greenhouse. During the experiment period when the outside temperature of the greenhouses was relatively high, the mean daytime air temperature was cooler by more than 3 ° C in the Closed greenhouse than that in the Control. The total dry weight of the tomato plants and fruit yield per plant at the end of the experiment was significantly higher in the Closed greenhouse compared to the Control. The result indicated that the improved yield and quality of the Closed greenhouse resulted from the air temperature being controlled within the optimal range for growth and the subsequent increased rates of fruit maturation and photosynthesis due to CO 2 enrichment.
{"title":"The effect of CO2 enrichment in a closed greenhouse equipped with NIR-reflecting film and EHP cooling on the yield and quality of tomato fruits during the summer season","authors":"T. Ikeda, Y. Ishigami, E. Goto","doi":"10.2480/agrmet.d-19-00017","DOIUrl":"https://doi.org/10.2480/agrmet.d-19-00017","url":null,"abstract":"We investigated the combined influence of cooling using electric heat pumps and CO 2 enrichment in a closed greenhouse equipped with a near infrared solar radiation ( NIR ) -reflecting film on the yield and quality of tomato fruits during the summer season. The air temperature of the ‘Control’ greenhouse were controlled through conventional natural ventilation windows, shading curtains and a fog cooling system. The air temperature of the ‘Closed’ greenhouse were controlled by cooling of electric heat pumps and a NIR-reflecting film curtain. The CO 2 concentration was maintained at around 1000 μ mol mol - 1 in the Closed greenhouse. During the experiment period when the outside temperature of the greenhouses was relatively high, the mean daytime air temperature was cooler by more than 3 ° C in the Closed greenhouse than that in the Control. The total dry weight of the tomato plants and fruit yield per plant at the end of the experiment was significantly higher in the Closed greenhouse compared to the Control. The result indicated that the improved yield and quality of the Closed greenhouse resulted from the air temperature being controlled within the optimal range for growth and the subsequent increased rates of fruit maturation and photosynthesis due to CO 2 enrichment.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2480/agrmet.d-19-00017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：