As a consumed and influential natural plant beverage,tea is widely planted in subtropical and tropical areas all over the world.Affected by(sub)tropical climate characteristics,the underlying surface of the tea distri...As a consumed and influential natural plant beverage,tea is widely planted in subtropical and tropical areas all over the world.Affected by(sub)tropical climate characteristics,the underlying surface of the tea distribution area is extremely complex,with a variety of vegetation types.In addition,tea distribution is scattered and fragmentized in most of China.Therefore,it is difficult to obtain accurate tea information based on coarse resolution remote sensing data and existing feature extraction methods.This study proposed a boundary-enhanced,object-oriented random forest method on the basis of high-resolution GF-2 and multi-temporal Sentinel-2 data.This method uses multispectral indexes,textures,vegetable indices,and variation characteristics of time-series NDVI from the multi-temporal Sentinel-2 imageries to obtain abundant features related to the growth of tea plantations.To reduce feature redundancy and computation time,the feature elimination algorithm based on Mean Decrease Accuracy(MDA)was used to generate the optimal feature set.Considering the serious boundary inconsistency problem caused by the complex and fragmented land cover types,high resolution GF-2 image was segmented based on the MultiResolution Segmentation(MRS)algorithm to assist the segmentation of Sentinel-2,which contributes to delineating meaningful objects and enhancing the reliability of the boundary for tea plantations.Finally,the object-oriented random forest method was utilized to extract the tea information based on the optimal feature combination in the Jingmai Mountain,Yunnan Province.The resulting tea plantation map had high accuracy,with a 95.38%overall accuracy and 0.91 kappa coefficient.We conclude that the proposed method is effective for mapping tea plantations in high heterogeneity mountainous areas and has the potential for mapping tea plantations in large areas.展开更多
Studies on the spatial variability of the soil cation exchange capacity （CEC） were made to provide a theoretical basis for an ecological tea plantation and management of soil fertilizer in the tea plantation. Geosta...Studies on the spatial variability of the soil cation exchange capacity （CEC） were made to provide a theoretical basis for an ecological tea plantation and management of soil fertilizer in the tea plantation. Geostatistics were used to analyze the spatial variability of soil CEC in the tea plantation site on Mengding Mountain in Sichuan Province of China on two sampling scales. It was found that, （1） on the small scale, the soil CEC was intensively spatially correlative, the rate of nugget to sill was 18.84% and the spatially dependent range was 1 818 m, and structural factors were the main factors that affected the spatial variability of the soil CEC; （2） on the microscale, the soil CEC was also consumingly spatially dependent, and the rate of nugget to sill was 16.52%, the spatially dependent range was 311 m, and the main factors affecting the spatial variability were just the same as mentioned earlier. On the small scale, soil CEC had a stronger anisotropic structure on the slope aspect, and a weaker one on the lateral side. According to the ordinary Kriging method, the equivalence of soil CEC distributed along the lateral aspect of the slope from northeast to southwest, and the soil CEC reduced as the elevation went down. On the microscale, the anisotropic structure was different from that measured on the small scale. It had a stronger anisotropic structure on the aspect that was near the aspect of the slope, and a weaker one near the lateral aspect of the slope. The soil CEC distributed along the lateral aspect of the slope and some distributed in the form of plots. From the top to the bottom of the slope, the soil CEC increased initially, and then reduced, and finally increased.展开更多
As the source and main producing area of tea in the world, China has formed unique tea culture, and achievedremarkable economic benefits. However, frequent meteorological disasters, particularly low temperature frostd...As the source and main producing area of tea in the world, China has formed unique tea culture, and achievedremarkable economic benefits. However, frequent meteorological disasters, particularly low temperature frostdamage in late spring has seriously threatened the growth status of tea trees and caused quality and yield reduction of tea industry. Thus, timely and accurate early warning of frost damage occurrence in specific tea garden isvery important for tea plantation management and economic values. Aiming at the problems existing in currentmeteorological disaster forecasting methods, such as difficulty in obtaining massive meteorological data, largeamount of calculation for predicted models and incomplete information on frost damage occurrence, this paperproposed a two-fold algorithm for short-term and real-time prediction of temperature using field environmentaldata, and temperature trend results from a nearest local weather station for accurate frost damage occurrence leveldetermination, so as to achieve a specific tea garden frost damage occurrence prediction in a microclimate. Timeseries meteorological data collected from a small weather station was used for testing and parameterization of atwo-fold method, and another dataset acquired from Tea Experimental Base of Zhejiang University was furtherused to validate the capability of a two-fold model for frost damage forecasting. Results showed that comparedwith the results of autoregressive integrated moving average (ARIMA) and multiple linear regression (MLR),the proposed two-fold method using a second order Furrier fitting model and a K-Nearest Neighbor model(K = 3) with three days historical temperature data exhibited excellent accuracy for frost damage occurrence prediction on consideration of both model accuracy and computation (98.46% forecasted duration of frost damage,and 95.38% for forecasted temperature at the onset time). For field test in a tea garden, the proposed methodaccurately predicted three times frost damage occurrences, including onset time, duration and occurrence level.These results suggested the newly-proposed two-fold method was suitable for tea plantation frost damage occurrence forecasting.展开更多
The spider resources in tea plantations in Enshi region have been investigated and 51 species of spiders belonging to 22 families have been identified in the paper. The dominant species are clarified and their directo...The spider resources in tea plantations in Enshi region have been investigated and 51 species of spiders belonging to 22 families have been identified in the paper. The dominant species are clarified and their directory and distribution status are also listed in the paper.展开更多
By analyzing the present situation and advantages of tea plantations in Helong Township,Ya'an City,the construction modes of rural landscape and ecological tea plantation were studied from the perspective of lands...By analyzing the present situation and advantages of tea plantations in Helong Township,Ya'an City,the construction modes of rural landscape and ecological tea plantation were studied from the perspective of landscape ecology.展开更多
To survey the tea resource advantages in Guizhou's mountainous areas and complete rational layout of pollution-free tea planting areas, we take the case of Guiding County in Guizhou Province to establish the compr...To survey the tea resource advantages in Guizhou's mountainous areas and complete rational layout of pollution-free tea planting areas, we take the case of Guiding County in Guizhou Province to establish the comprehensive evaluation indicator system of pollution-free land for tea plantation and comprehensive evaluation model of soil suitability of land for tea plantation according to the Environmental Conditions Standard for Pollution-free Food-Tea Producing Areas by the Ministry of Agriculture (NY 5020-2001), using land use data, remote sensing data, soil data, temperature, precipitation, light, DEM and other critical basic data, combined with the spatial analysis statistical method. The results show that the area of land suitable for planting tea is 1265 km2, accounting for 77.57% of the entire study area; the area of land with soil quality, climatic conditions and terrain conditions to meet the planting standard of pollution-free tea is 1232.51 km2, accounting for 75.57% of the total land area; the area of land most suitable for the planting of pollution-free tea is 128.71 km2, accounting for 7.89% of the total land area. The above studies can provide scientific basis and decision support for the implementation of tea planting industry standards in the specific areas, and provide reference for the comprehensive assessment of tea planting in other areas.展开更多
The present study introduced the concept and characteristics of preserved tea plantation,and analyzed application and benefit of stereoscopic trimming and pruning technology in the cultivation of tea tree canopy in pr...The present study introduced the concept and characteristics of preserved tea plantation,and analyzed application and benefit of stereoscopic trimming and pruning technology in the cultivation of tea tree canopy in preserved tea plantations.The results show that the stereoscopic trimming and pruning technology of tea trees has more advantages in production efficiency than other trimming and pruning techniques in terms of yield and output value,and can better exert the regeneration ability of tea branches.The grade of branching is increased from grade 3-4 before unpruning to grade 9-13(3-4 times higher),the length of internode is increased from 1-2 cm to 3-7 cm(increased 3-4 times),the picking area is increased from 0.9 m×1.1 m to 2.8 m×4.2 m(an increase of nearly 10 times),accordingly achieving the best production and economic benefits required in tea production.展开更多
The changing patterns of land cover and land use in the tropical river basin over time are critical. The hydrological phenomena at basin and sub basin scale are affected positively or negatively by dynamics of the lan...The changing patterns of land cover and land use in the tropical river basin over time are critical. The hydrological phenomena at basin and sub basin scale are affected positively or negatively by dynamics of the land cover and land use patterns. Hence identifying causes and driving factors aid in taking appropriate measures to avert the impacts. This study determined the influences of sub basins dominated by tea plantations, forests and agricultural land uses in terms of streamflow and sediment flux variability in Sondu Miriu River Basin in Kenya, East Africa. Field-based investigations were conducted through sampling of flow velocities, turbidity and TSSC obtained from existing River Gauging Stations established within the three sub basins. The sub basin dominated by mixed farming land cover exhibits high turbidity approximately 620 NTU and high levels of total suspended sediment concentration (TSSC) of the order of 630 mg/l in wet seasons. The turbidity levels and TSSC were low in sub basins dominated by forest and tea plantations with approximately mean value of 17 - 29 NTU and 0.019 g/l. The sediment loads in sub basin dominated by mixed farming in the pre planting season in January to February were about 900 tonnes/day higher than that in crop growing season. In sub basins dominated by forest cover and tea plantations, sediment loads were low ranging between 2 - 7 tonnes/day. The relationship between stream flows and area under tea plantations, forests and mixed farming ranged between R<sup>2</sup> of 0.025 and 0.16. Tea plantations and forests influence the stream flows and sediment yields in long term duration while in mixed farming variations were observed seasonally. The strong relationships between rainfall and stream flows at the sub basins ranging between R<sup>2</sup> of 0.84 and 0.97 revealed the significance of rainfall in hydrologic response of the Sondu Miriu River Basin.展开更多
基金National Natural Science Foundation of China(No.41830110)National Key Research Development Program of China(No.2018YFC1503603)+2 种基金Key Laboratory of Land Satellite Remote Sensing Application,Ministry of Natural Resources of the People’s Republic of China(No.KLSMNR-202106)Water Conservancy Science and Technology Project of Jiangsu Province,China(No.2020061)Natural Science Foundation of Jiangsu Province,China(No.20180779)。
文摘As a consumed and influential natural plant beverage,tea is widely planted in subtropical and tropical areas all over the world.Affected by(sub)tropical climate characteristics,the underlying surface of the tea distribution area is extremely complex,with a variety of vegetation types.In addition,tea distribution is scattered and fragmentized in most of China.Therefore,it is difficult to obtain accurate tea information based on coarse resolution remote sensing data and existing feature extraction methods.This study proposed a boundary-enhanced,object-oriented random forest method on the basis of high-resolution GF-2 and multi-temporal Sentinel-2 data.This method uses multispectral indexes,textures,vegetable indices,and variation characteristics of time-series NDVI from the multi-temporal Sentinel-2 imageries to obtain abundant features related to the growth of tea plantations.To reduce feature redundancy and computation time,the feature elimination algorithm based on Mean Decrease Accuracy(MDA)was used to generate the optimal feature set.Considering the serious boundary inconsistency problem caused by the complex and fragmented land cover types,high resolution GF-2 image was segmented based on the MultiResolution Segmentation(MRS)algorithm to assist the segmentation of Sentinel-2,which contributes to delineating meaningful objects and enhancing the reliability of the boundary for tea plantations.Finally,the object-oriented random forest method was utilized to extract the tea information based on the optimal feature combination in the Jingmai Mountain,Yunnan Province.The resulting tea plantation map had high accuracy,with a 95.38%overall accuracy and 0.91 kappa coefficient.We conclude that the proposed method is effective for mapping tea plantations in high heterogeneity mountainous areas and has the potential for mapping tea plantations in large areas.
文摘Studies on the spatial variability of the soil cation exchange capacity （CEC） were made to provide a theoretical basis for an ecological tea plantation and management of soil fertilizer in the tea plantation. Geostatistics were used to analyze the spatial variability of soil CEC in the tea plantation site on Mengding Mountain in Sichuan Province of China on two sampling scales. It was found that, （1） on the small scale, the soil CEC was intensively spatially correlative, the rate of nugget to sill was 18.84% and the spatially dependent range was 1 818 m, and structural factors were the main factors that affected the spatial variability of the soil CEC; （2） on the microscale, the soil CEC was also consumingly spatially dependent, and the rate of nugget to sill was 16.52%, the spatially dependent range was 311 m, and the main factors affecting the spatial variability were just the same as mentioned earlier. On the small scale, soil CEC had a stronger anisotropic structure on the slope aspect, and a weaker one on the lateral side. According to the ordinary Kriging method, the equivalence of soil CEC distributed along the lateral aspect of the slope from northeast to southwest, and the soil CEC reduced as the elevation went down. On the microscale, the anisotropic structure was different from that measured on the small scale. It had a stronger anisotropic structure on the aspect that was near the aspect of the slope, and a weaker one near the lateral aspect of the slope. The soil CEC distributed along the lateral aspect of the slope and some distributed in the form of plots. From the top to the bottom of the slope, the soil CEC increased initially, and then reduced, and finally increased.
基金Zhejiang Public Welfare Program of Applied Research(LGN19D010001)the National Key R&D Program of China(2019YFE0125300)+1 种基金Zhejiang Provincial Natural Science Foundation of China under Grant No.LGN19F030001Zhejiang Agricultural Cooperative and Extensive Project of Key Technology(2020XTTGCY04-02).
文摘As the source and main producing area of tea in the world, China has formed unique tea culture, and achievedremarkable economic benefits. However, frequent meteorological disasters, particularly low temperature frostdamage in late spring has seriously threatened the growth status of tea trees and caused quality and yield reduction of tea industry. Thus, timely and accurate early warning of frost damage occurrence in specific tea garden isvery important for tea plantation management and economic values. Aiming at the problems existing in currentmeteorological disaster forecasting methods, such as difficulty in obtaining massive meteorological data, largeamount of calculation for predicted models and incomplete information on frost damage occurrence, this paperproposed a two-fold algorithm for short-term and real-time prediction of temperature using field environmentaldata, and temperature trend results from a nearest local weather station for accurate frost damage occurrence leveldetermination, so as to achieve a specific tea garden frost damage occurrence prediction in a microclimate. Timeseries meteorological data collected from a small weather station was used for testing and parameterization of atwo-fold method, and another dataset acquired from Tea Experimental Base of Zhejiang University was furtherused to validate the capability of a two-fold model for frost damage forecasting. Results showed that comparedwith the results of autoregressive integrated moving average (ARIMA) and multiple linear regression (MLR),the proposed two-fold method using a second order Furrier fitting model and a K-Nearest Neighbor model(K = 3) with three days historical temperature data exhibited excellent accuracy for frost damage occurrence prediction on consideration of both model accuracy and computation (98.46% forecasted duration of frost damage,and 95.38% for forecasted temperature at the onset time). For field test in a tea garden, the proposed methodaccurately predicted three times frost damage occurrences, including onset time, duration and occurrence level.These results suggested the newly-proposed two-fold method was suitable for tea plantation frost damage occurrence forecasting.
基金Supported by National Science and Technology Foundation Program(2008FY210500)
文摘The spider resources in tea plantations in Enshi region have been investigated and 51 species of spiders belonging to 22 families have been identified in the paper. The dominant species are clarified and their directory and distribution status are also listed in the paper.
文摘By analyzing the present situation and advantages of tea plantations in Helong Township,Ya'an City,the construction modes of rural landscape and ecological tea plantation were studied from the perspective of landscape ecology.
基金Supported by Guizhou Provincial Science and Technology Support Program(20093021)Guizhou Provincial Science and Technology Plan Project(20123058)
文摘To survey the tea resource advantages in Guizhou's mountainous areas and complete rational layout of pollution-free tea planting areas, we take the case of Guiding County in Guizhou Province to establish the comprehensive evaluation indicator system of pollution-free land for tea plantation and comprehensive evaluation model of soil suitability of land for tea plantation according to the Environmental Conditions Standard for Pollution-free Food-Tea Producing Areas by the Ministry of Agriculture (NY 5020-2001), using land use data, remote sensing data, soil data, temperature, precipitation, light, DEM and other critical basic data, combined with the spatial analysis statistical method. The results show that the area of land suitable for planting tea is 1265 km2, accounting for 77.57% of the entire study area; the area of land with soil quality, climatic conditions and terrain conditions to meet the planting standard of pollution-free tea is 1232.51 km2, accounting for 75.57% of the total land area; the area of land most suitable for the planting of pollution-free tea is 128.71 km2, accounting for 7.89% of the total land area. The above studies can provide scientific basis and decision support for the implementation of tea planting industry standards in the specific areas, and provide reference for the comprehensive assessment of tea planting in other areas.
文摘The present study introduced the concept and characteristics of preserved tea plantation,and analyzed application and benefit of stereoscopic trimming and pruning technology in the cultivation of tea tree canopy in preserved tea plantations.The results show that the stereoscopic trimming and pruning technology of tea trees has more advantages in production efficiency than other trimming and pruning techniques in terms of yield and output value,and can better exert the regeneration ability of tea branches.The grade of branching is increased from grade 3-4 before unpruning to grade 9-13(3-4 times higher),the length of internode is increased from 1-2 cm to 3-7 cm(increased 3-4 times),the picking area is increased from 0.9 m×1.1 m to 2.8 m×4.2 m(an increase of nearly 10 times),accordingly achieving the best production and economic benefits required in tea production.
文摘The changing patterns of land cover and land use in the tropical river basin over time are critical. The hydrological phenomena at basin and sub basin scale are affected positively or negatively by dynamics of the land cover and land use patterns. Hence identifying causes and driving factors aid in taking appropriate measures to avert the impacts. This study determined the influences of sub basins dominated by tea plantations, forests and agricultural land uses in terms of streamflow and sediment flux variability in Sondu Miriu River Basin in Kenya, East Africa. Field-based investigations were conducted through sampling of flow velocities, turbidity and TSSC obtained from existing River Gauging Stations established within the three sub basins. The sub basin dominated by mixed farming land cover exhibits high turbidity approximately 620 NTU and high levels of total suspended sediment concentration (TSSC) of the order of 630 mg/l in wet seasons. The turbidity levels and TSSC were low in sub basins dominated by forest and tea plantations with approximately mean value of 17 - 29 NTU and 0.019 g/l. The sediment loads in sub basin dominated by mixed farming in the pre planting season in January to February were about 900 tonnes/day higher than that in crop growing season. In sub basins dominated by forest cover and tea plantations, sediment loads were low ranging between 2 - 7 tonnes/day. The relationship between stream flows and area under tea plantations, forests and mixed farming ranged between R<sup>2</sup> of 0.025 and 0.16. Tea plantations and forests influence the stream flows and sediment yields in long term duration while in mixed farming variations were observed seasonally. The strong relationships between rainfall and stream flows at the sub basins ranging between R<sup>2</sup> of 0.84 and 0.97 revealed the significance of rainfall in hydrologic response of the Sondu Miriu River Basin.
