A process-oriented methodology to conduct precise evaluation temporally and spatially on temperature suitability for potato growth was applied in China. Arable lands in China were gridded with 1 km×1 km geographi...A process-oriented methodology to conduct precise evaluation temporally and spatially on temperature suitability for potato growth was applied in China. Arable lands in China were gridded with 1 km×1 km geographic units, and potential potato phenology in each unit was automatically identified in terms of the potato planting initial temperature and effective accu- mulated temperature. A temperature thermal response coefficient model was used to compute a temperature suitability value for each day of potato phenology in each geographic unit. In addition, five temperature suitability ranking methods were applied to define suitable areas： （1） upper fourth quantile, （2） median, （3） expected value＋1/4 standard deviation, （4） expected value＋1/2 standard deviation, （5） expected value＋1 standard deviation. A validation indicator was innovated to test the effectiveness of the five ranking methods. The results showed that from a strict degree point of view, the five methods sequence was as follows： 1=3〉4〉2〉5, with a and c determined as the two best ranking methods. For methods 1 and 3, the suitable potato growing area was 1 of 57.76× 10^4 km2. In addition, the suitable, areas were spatially coincident with the main potato producing counties. The study output technically supports the proposal from China＇s government that there is a large potential area to grow winter-ploughed potato in South China because the potential suitable area for growing potato is approximately 2×10^7 ha. In southeast Heilongjiang and east Jilin, where it is hilly and mountainous, there are still some potentially suitable areas for potato growing accounting for nearly 2.32×10^6 ha. The authors suggest to optimize the agricultural regionalization and layout in China and to adjust the cropping pattern structure.展开更多
The rooting law of modem Chinese rose variety -Betty prior at different conditions was studied dwhg 1995-96. The suhable temperaure for initiating healing organization which is a prempuisite for rooting was aboot 21...The rooting law of modem Chinese rose variety -Betty prior at different conditions was studied dwhg 1995-96. The suhable temperaure for initiating healing organization which is a prempuisite for rooting was aboot 21℃. The experimedl result showed the percent root was not di odly related to healing organtheion, bul related to the cnding' diamde. The coding diamoter should be 4-5 mm in order to keep a higher rooting tate in water cnding Percat root of water cutting haddired relations with temperature . The most suitable temperatur for Chinese rose rooting was in rangeof 20 ~ 25℃.展开更多
Temporal and spatial scales play important roles in fishery ecology,and an inappropriate spatio-temporal scale may result in large errors in modeling fish distribution.The objective of this study is to evaluate the ro...Temporal and spatial scales play important roles in fishery ecology,and an inappropriate spatio-temporal scale may result in large errors in modeling fish distribution.The objective of this study is to evaluate the roles of spatio-temporal scales in habitat suitability modeling,with the western stock of winter-spring cohort of neon flying squid （Ornmastrephes bartramii） in the northwest Pacific Ocean as an example.In this study,the fishery-dependent data from the Chinese Mainland Squid Jigging Technical Group and sea surface temperature （SST） from remote sensing during August to October of 2003-2008 were used.We evaluated the differences in a habitat suitability index model resulting from aggregating data with 36 different spatial scales with a combination of three latitude scales （0.5°,1 ° and 2°）,four longitude scales （0.5°,1°,2° and 4°）,and three temporal scales （week,fortnight,and month）.The coefficients of variation （CV） of the weekly,biweekly and monthly suitability index （SI） were compared to determine which temporal and spatial scales of SI model are more precise.This study shows that the optimal temporal and spatial scales with the lowest CV are month,and 0.5° latitude and 0.5° longitude for O.bartramii in the northwest Pacific Ocean.This suitability index model developed with an optimal scale can be cost-effective in improving forecasting fishing ground and requires no excessive sampling efforts.We suggest that the uncertainty associated with spatial and temporal scales used in data aggregations needs to be considered in habitat suitability modeling.展开更多
Extreme nutrient solution temperature significantly affects photosynthetic characteristics of hydroponic vegetables and gives rise to slow plant growth.In this study,a method was proposed to obtain the suitable nutrie...Extreme nutrient solution temperature significantly affects photosynthetic characteristics of hydroponic vegetables and gives rise to slow plant growth.In this study,a method was proposed to obtain the suitable nutrient solution temperature range of hydroponic crops.Nested experiments of net photosynthetic rates were designed.The experiments considered the impact of nutrient solution temperatures,air temperatures,photon flux densities,and CO_(2) concentrations.Then we established a prediction model of photosynthetic rate based on a regression support vector machine.The results have shown that the coefficient of determination between the measured values and the predicted values of photosynthetic rate is 0.982,and the root mean square error is 0.990μmol/m2·s.Taking the net photosynthetic rate prediction model as the objective function,the maximum photosynthetic rate could be found using multiple population genetic algorithms,and then the nutrient solution temperature response curve could be created.According to the U-chord curvature theory,the suitable nutrient solution temperature range was calculated.After optimization by the multi-population genetic algorithm,the coefficient of determination between measured values and optimized values of maximum photosynthetic rate was 0.989 and the mean square error was 0.003.An analysis of the calculation based on the theory of U-chord curvature indicated that the suitable nutrient solution temperature range to grow hydroponic lettuce is 20.04°C-26.32°C.The proposed method provides a solid foundation to accurately acquire the suitable nutrient solution temperature range for a crop grown in hydroponics.展开更多
基金funded by the Innovation Project Special Funding of the Chinese Academy of Agricultural Sciences(CAAS-IARRP,2017-727-1)the National Natural Science Foundation of China(41001049)
文摘A process-oriented methodology to conduct precise evaluation temporally and spatially on temperature suitability for potato growth was applied in China. Arable lands in China were gridded with 1 km×1 km geographic units, and potential potato phenology in each unit was automatically identified in terms of the potato planting initial temperature and effective accu- mulated temperature. A temperature thermal response coefficient model was used to compute a temperature suitability value for each day of potato phenology in each geographic unit. In addition, five temperature suitability ranking methods were applied to define suitable areas： （1） upper fourth quantile, （2） median, （3） expected value＋1/4 standard deviation, （4） expected value＋1/2 standard deviation, （5） expected value＋1 standard deviation. A validation indicator was innovated to test the effectiveness of the five ranking methods. The results showed that from a strict degree point of view, the five methods sequence was as follows： 1=3〉4〉2〉5, with a and c determined as the two best ranking methods. For methods 1 and 3, the suitable potato growing area was 1 of 57.76× 10^4 km2. In addition, the suitable, areas were spatially coincident with the main potato producing counties. The study output technically supports the proposal from China＇s government that there is a large potential area to grow winter-ploughed potato in South China because the potential suitable area for growing potato is approximately 2×10^7 ha. In southeast Heilongjiang and east Jilin, where it is hilly and mountainous, there are still some potentially suitable areas for potato growing accounting for nearly 2.32×10^6 ha. The authors suggest to optimize the agricultural regionalization and layout in China and to adjust the cropping pattern structure.
文摘The rooting law of modem Chinese rose variety -Betty prior at different conditions was studied dwhg 1995-96. The suhable temperaure for initiating healing organization which is a prempuisite for rooting was aboot 21℃. The experimedl result showed the percent root was not di odly related to healing organtheion, bul related to the cnding' diamde. The coding diamoter should be 4-5 mm in order to keep a higher rooting tate in water cnding Percat root of water cutting haddired relations with temperature . The most suitable temperatur for Chinese rose rooting was in rangeof 20 ~ 25℃.
基金funded by National High Technology Research and Development Program of China (863 Program,2012AA092303)Project of Shanghai Science and Technology Innovation (12231203900)+2 种基金Industrialization Program of National Development and Reform Commission (2159999)National Science and Technology Support Program (2013BAD13B01)Shanghai Leading Academic Discipline Project
文摘Temporal and spatial scales play important roles in fishery ecology,and an inappropriate spatio-temporal scale may result in large errors in modeling fish distribution.The objective of this study is to evaluate the roles of spatio-temporal scales in habitat suitability modeling,with the western stock of winter-spring cohort of neon flying squid （Ornmastrephes bartramii） in the northwest Pacific Ocean as an example.In this study,the fishery-dependent data from the Chinese Mainland Squid Jigging Technical Group and sea surface temperature （SST） from remote sensing during August to October of 2003-2008 were used.We evaluated the differences in a habitat suitability index model resulting from aggregating data with 36 different spatial scales with a combination of three latitude scales （0.5°,1 ° and 2°）,four longitude scales （0.5°,1°,2° and 4°）,and three temporal scales （week,fortnight,and month）.The coefficients of variation （CV） of the weekly,biweekly and monthly suitability index （SI） were compared to determine which temporal and spatial scales of SI model are more precise.This study shows that the optimal temporal and spatial scales with the lowest CV are month,and 0.5° latitude and 0.5° longitude for O.bartramii in the northwest Pacific Ocean.This suitability index model developed with an optimal scale can be cost-effective in improving forecasting fishing ground and requires no excessive sampling efforts.We suggest that the uncertainty associated with spatial and temporal scales used in data aggregations needs to be considered in habitat suitability modeling.
基金supported by the National Key Research and Development Program of China(Grant No.2020YFD1100602)the Shaanxi Key Research and Development Program(Grant No.2023-ZDLNY-66)the Shaanxi Provincial Science and Technology Program(Grant No.Z2024-ZYFS-0043).
文摘Extreme nutrient solution temperature significantly affects photosynthetic characteristics of hydroponic vegetables and gives rise to slow plant growth.In this study,a method was proposed to obtain the suitable nutrient solution temperature range of hydroponic crops.Nested experiments of net photosynthetic rates were designed.The experiments considered the impact of nutrient solution temperatures,air temperatures,photon flux densities,and CO_(2) concentrations.Then we established a prediction model of photosynthetic rate based on a regression support vector machine.The results have shown that the coefficient of determination between the measured values and the predicted values of photosynthetic rate is 0.982,and the root mean square error is 0.990μmol/m2·s.Taking the net photosynthetic rate prediction model as the objective function,the maximum photosynthetic rate could be found using multiple population genetic algorithms,and then the nutrient solution temperature response curve could be created.According to the U-chord curvature theory,the suitable nutrient solution temperature range was calculated.After optimization by the multi-population genetic algorithm,the coefficient of determination between measured values and optimized values of maximum photosynthetic rate was 0.989 and the mean square error was 0.003.An analysis of the calculation based on the theory of U-chord curvature indicated that the suitable nutrient solution temperature range to grow hydroponic lettuce is 20.04°C-26.32°C.The proposed method provides a solid foundation to accurately acquire the suitable nutrient solution temperature range for a crop grown in hydroponics.
