This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite ima...This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite images;Landsat Thematic Mapper (TM) (1980), Landsat Enhanced Thematic Mapper (ETM) (2001), and Landsat 8 Operational Land Imager (OLI) (2016) scenes were employed to investigate the changes in LULC. The use of satellite images was supplemented with individual interviews, discussions with focus groups and key informants, and direct field observations. Five categories of LULC classes were identified namely: thick woody vegetation (natural forest and oil palms), light vegetation (croplands), savannah (grasslands), buildings (settlements), and bare grounds. The results showed that between 1980 and 2016, croplands, buildings and bare lands increased by 4%, 0.43% and 5.7% respectively while savannah/grassland and natural forest decreased by 4.4% and 5.8% respectively. Household survey revealed soil fertility decline and lack of credit schemes to be major constraints to crop production. Many religious holidays contribute to seasonal food shortages and the community faces a host of socio-economic and institutional challenges. Consequently, majority of house-holds are destitute, live in abject poverty;which is an indication of the need for interventions by government and other development stakeholders to tackle the problems of soil fertility, land use change and food insecurity.展开更多
The inhibitory allelopathic activity of </span><i><span style="font-family:Verdana;">Pueraria montana </span></i></span><span style="font-family:Verdana;">...The inhibitory allelopathic activity of </span><i><span style="font-family:Verdana;">Pueraria montana </span></i></span><span style="font-family:Verdana;">(Kudzu), and activities of two putative allelochemical isoflavones, puerarin and daidzein, were evaluated using the protoplast co-culture method with digital image analysis using lettuce as a recipient (DIA-PP</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">method). Cotyledon protoplasts of Kudzu were isolated using Cellulase R10 and Driselase 20 in 0.6 M mannitol solution. Optimal hormonal condition and density for growth of Kudzu protoplasts were surveyed. Medium for co-culture of Kudzu or isoflavones with lettuce protoplasts was 50 μl liquid MS basal medium containing 1 μM 2,4-dichlorophenoxyacetic acid, 0.1 μM benzyladenine, 3% sucrose, and 0.4 M or 0.6 M mannitol. Protoplast division of lettuce was strongly inhibited by Kudzu at a low density (10</span><sup><span style="font-family:Verdana;">4</span></sup><span style="font-family:Verdana;">/ml). Slightly less inhibition by Kudzu on cell wall formation and yellow pigment accumulation stages of lettuce growth was also observed. Puerarin did not inhibit the growth of lettuce protoplasts at three growth stages but slightly stimulated growth at high concentrations. By contrast, daidzein, aglycon of puerarin, inhibited growth at three stages of lettuce protoplast growth and strongly inhibited cell division at 100 μM. Daidzein might be one cause of the strong inhibitory allelopathic activity of Kudzu. Grade of inhibitory activities w</span></span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> compared with th</span><span style="font-family:Verdana;">at</span><span style="font-family:Verdana;"> of other allelopathic plants including an invader plant and their allelochemicals studied using the DIA-PP method.展开更多
This study measures regional impacts of adaptation to climate change for the Paris Agreement under the Shared Socio-Economic Pathways and Representative Concentration Pathways scenarios. We develop a global economic m...This study measures regional impacts of adaptation to climate change for the Paris Agreement under the Shared Socio-Economic Pathways and Representative Concentration Pathways scenarios. We develop a global economic model with adaptation to climate change. Simulated results indicate that: 1) Asian and African adaptation costs exceed more than one percent of GDP in the year 2100 under the business as usual scenario;2) adaptation costs under the 2.0°C target are higher in Asia and Africa than other regions;and 3) adaptation costs amount to one percent of GDP in Japan, EU and Latin America under the 1.5°C target scenario by adaptation.展开更多
Single-tree detection is one of the main research topics in quantifying the structural properties of forests. Drone Li DAR systems and terrestrial laser scanning systems produce high-density point clouds that offer gr...Single-tree detection is one of the main research topics in quantifying the structural properties of forests. Drone Li DAR systems and terrestrial laser scanning systems produce high-density point clouds that offer great promise for forest inventories in limited areas. However, most studies have focused on the upper canopy layer and neglected the lower forest structure. This paper describes an innovative tree detection method using drone Li DAR data from a new perspective of the under-canopy structure. This method relies on trunk point clouds, with undercanopy sections split into heights ranging from 1 to 7 m, which were processed and compared, to determine a suitable height threshold to detect trees. The method was tested in a dense cedar plantation forest in the Aichi Prefecture, Japan, which has a stem density of 1140 stems·ha^(-1) and an average tree age of 42 years. Dense point cloud data were generated from the drone Li DAR system and terrestrial laser scanning with an average point density of 5000 and 6500 points·m^(-2), respectively. Tree detection was achieved by drawing point-cloud section projections of tree trunks at different heights and calculating the center coordinates. The results show that this trunk-section-based method significantly reduces the difficulty of tree detection in dense plantation forests with high accuracy(F1-Score=0.9395). This method can be extended to different forest scenarios or conditions by changing section parameters.展开更多
The Soil and Water Assessment Tool(SWAT)is an ecohydrological watershed-scale model which was initially developed in the early 1990s to simulate the impacts of land use,management systems,and climate on hydrology and/...The Soil and Water Assessment Tool(SWAT)is an ecohydrological watershed-scale model which was initially developed in the early 1990s to simulate the impacts of land use,management systems,and climate on hydrology and/or water quality.First adopted in the U.S.,the use of the model then spread to Europe and then later to Asia and other regions.The range of applications that SWAT has been applied to have also expanded dramatically,which influenced ongoing model development which has been virtually continuous over the past two decades.A key component of many SWAT applications in Asia is accounting for rice paddy production that is common in some subregions within the continent.However,most of these studies do not provide explicit details of how rice production was simulated in SWAT.Other research has revealed that significant problems occur when trying to represent rice paddy systems in standard versions of SWAT,due to limitations in algorithms based on the runoff curve number approach or the pothole option.In response,key modifications have been made to SWAT in recent studies that have resulted in more accurate representation of rice paddy systems.These developments point to the need for the incorporation of an enhanced rice paddy module within SWAT to better capture rice paddy hydrological and pollutant dynamics,which would support improved use of the model in Asia and other rice production regions.Subtopics related to simulating rice production in SWAT are discussed as follows:1)an overview of global rice production;2)history of SWAT development;3)typical approaches for simulating rice production;4)problems associated with the typical approaches;5)recent code modifications to address deficiencies in replicating rice paddy systems;6)recommendations for developing a standard rice paddy module for future SWAT codes.展开更多
文摘This work assessed the impact of land use and land cover (LULC) change on the socio-economic conditions of the inhabitants in the Mount Bambouto Caldera from 1980-2016. To achieve this, three time series satellite images;Landsat Thematic Mapper (TM) (1980), Landsat Enhanced Thematic Mapper (ETM) (2001), and Landsat 8 Operational Land Imager (OLI) (2016) scenes were employed to investigate the changes in LULC. The use of satellite images was supplemented with individual interviews, discussions with focus groups and key informants, and direct field observations. Five categories of LULC classes were identified namely: thick woody vegetation (natural forest and oil palms), light vegetation (croplands), savannah (grasslands), buildings (settlements), and bare grounds. The results showed that between 1980 and 2016, croplands, buildings and bare lands increased by 4%, 0.43% and 5.7% respectively while savannah/grassland and natural forest decreased by 4.4% and 5.8% respectively. Household survey revealed soil fertility decline and lack of credit schemes to be major constraints to crop production. Many religious holidays contribute to seasonal food shortages and the community faces a host of socio-economic and institutional challenges. Consequently, majority of house-holds are destitute, live in abject poverty;which is an indication of the need for interventions by government and other development stakeholders to tackle the problems of soil fertility, land use change and food insecurity.
文摘The inhibitory allelopathic activity of </span><i><span style="font-family:Verdana;">Pueraria montana </span></i></span><span style="font-family:Verdana;">(Kudzu), and activities of two putative allelochemical isoflavones, puerarin and daidzein, were evaluated using the protoplast co-culture method with digital image analysis using lettuce as a recipient (DIA-PP</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">method). Cotyledon protoplasts of Kudzu were isolated using Cellulase R10 and Driselase 20 in 0.6 M mannitol solution. Optimal hormonal condition and density for growth of Kudzu protoplasts were surveyed. Medium for co-culture of Kudzu or isoflavones with lettuce protoplasts was 50 μl liquid MS basal medium containing 1 μM 2,4-dichlorophenoxyacetic acid, 0.1 μM benzyladenine, 3% sucrose, and 0.4 M or 0.6 M mannitol. Protoplast division of lettuce was strongly inhibited by Kudzu at a low density (10</span><sup><span style="font-family:Verdana;">4</span></sup><span style="font-family:Verdana;">/ml). Slightly less inhibition by Kudzu on cell wall formation and yellow pigment accumulation stages of lettuce growth was also observed. Puerarin did not inhibit the growth of lettuce protoplasts at three growth stages but slightly stimulated growth at high concentrations. By contrast, daidzein, aglycon of puerarin, inhibited growth at three stages of lettuce protoplast growth and strongly inhibited cell division at 100 μM. Daidzein might be one cause of the strong inhibitory allelopathic activity of Kudzu. Grade of inhibitory activities w</span></span><span style="font-family:Verdana;">as</span><span style="font-family:Verdana;"> compared with th</span><span style="font-family:Verdana;">at</span><span style="font-family:Verdana;"> of other allelopathic plants including an invader plant and their allelochemicals studied using the DIA-PP method.
文摘This study measures regional impacts of adaptation to climate change for the Paris Agreement under the Shared Socio-Economic Pathways and Representative Concentration Pathways scenarios. We develop a global economic model with adaptation to climate change. Simulated results indicate that: 1) Asian and African adaptation costs exceed more than one percent of GDP in the year 2100 under the business as usual scenario;2) adaptation costs under the 2.0°C target are higher in Asia and Africa than other regions;and 3) adaptation costs amount to one percent of GDP in Japan, EU and Latin America under the 1.5°C target scenario by adaptation.
基金funded by KAKENHI Number 16H02556 of the Cabinet Office,Government of Japan,the Cross-ministerial Strategic Innovation Promotion Program(SIP),“Enhancement of Societal Resiliency Against Natural Disasters”Funding was provided by the Japan Science and Technology Agency(JST)as part of the Belmont ForumThis work was supported by JST SPRING,Grant Number JPMJSP2124。
文摘Single-tree detection is one of the main research topics in quantifying the structural properties of forests. Drone Li DAR systems and terrestrial laser scanning systems produce high-density point clouds that offer great promise for forest inventories in limited areas. However, most studies have focused on the upper canopy layer and neglected the lower forest structure. This paper describes an innovative tree detection method using drone Li DAR data from a new perspective of the under-canopy structure. This method relies on trunk point clouds, with undercanopy sections split into heights ranging from 1 to 7 m, which were processed and compared, to determine a suitable height threshold to detect trees. The method was tested in a dense cedar plantation forest in the Aichi Prefecture, Japan, which has a stem density of 1140 stems·ha^(-1) and an average tree age of 42 years. Dense point cloud data were generated from the drone Li DAR system and terrestrial laser scanning with an average point density of 5000 and 6500 points·m^(-2), respectively. Tree detection was achieved by drawing point-cloud section projections of tree trunks at different heights and calculating the center coordinates. The results show that this trunk-section-based method significantly reduces the difficulty of tree detection in dense plantation forests with high accuracy(F1-Score=0.9395). This method can be extended to different forest scenarios or conditions by changing section parameters.
基金The work was partially supported by the Rural Development Administration of the Republic of Korea(Grant No.M2100296).
文摘The Soil and Water Assessment Tool(SWAT)is an ecohydrological watershed-scale model which was initially developed in the early 1990s to simulate the impacts of land use,management systems,and climate on hydrology and/or water quality.First adopted in the U.S.,the use of the model then spread to Europe and then later to Asia and other regions.The range of applications that SWAT has been applied to have also expanded dramatically,which influenced ongoing model development which has been virtually continuous over the past two decades.A key component of many SWAT applications in Asia is accounting for rice paddy production that is common in some subregions within the continent.However,most of these studies do not provide explicit details of how rice production was simulated in SWAT.Other research has revealed that significant problems occur when trying to represent rice paddy systems in standard versions of SWAT,due to limitations in algorithms based on the runoff curve number approach or the pothole option.In response,key modifications have been made to SWAT in recent studies that have resulted in more accurate representation of rice paddy systems.These developments point to the need for the incorporation of an enhanced rice paddy module within SWAT to better capture rice paddy hydrological and pollutant dynamics,which would support improved use of the model in Asia and other rice production regions.Subtopics related to simulating rice production in SWAT are discussed as follows:1)an overview of global rice production;2)history of SWAT development;3)typical approaches for simulating rice production;4)problems associated with the typical approaches;5)recent code modifications to address deficiencies in replicating rice paddy systems;6)recommendations for developing a standard rice paddy module for future SWAT codes.
