This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitor...This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented.展开更多
Background and Objectives: The species to the Lannea genus are trees, shrubs with compound leaves. Thus, individuals called atypical Lannea with single leaves and of socio-economic interests have been identified in th...Background and Objectives: The species to the Lannea genus are trees, shrubs with compound leaves. Thus, individuals called atypical Lannea with single leaves and of socio-economic interests have been identified in the central plateau region (Burkina Faso). This study aimed to contribute to the identification of atypical species. Material and Methods: The Polymerase Chain Reaction (PCR) method using specific primers was performed and consisted of extracting DNA from young leaves of Lannea individuals, amplifying and then sequencing portions of discriminating DNA (matK, rbcL and rps16). Results: It was shown that individuals belong to the Lannea genus, but are subdivided into three subgroups: a first subgroup containing Lannea microcarpa and two subgroups with no previously identified Lannea species. Conclusion: These atypical individuals are ecotypes or mutants of Lannea microcarpa.展开更多
Metallic ore mining causes heavy metal pollution worldwide.However,the fate of heavy metals in agrosystems with long-term contamination has been poorly studied.Dongchuan District(Yunnan,southwest China),located at the...Metallic ore mining causes heavy metal pollution worldwide.However,the fate of heavy metals in agrosystems with long-term contamination has been poorly studied.Dongchuan District(Yunnan,southwest China),located at the middle reaches of the Xiaojiang River,is a well-known 2000-year-old copper mining site.In this work,a survey on soil heavy metal contents was conducted using a handheld X-ray fluorescence instrument to understand the general contamination of heavy metals in the Xiaojiang River Basin.Furthermore,river water,soil,and rice samples at six sites along the fluvial/alluvial fans of the river were collected and analyzed to implement an environmental assessment and an evaluation of irrigated agrosystem.V,Zn,and Cu soil levels(1724,1047,and 696mg·kg-1,respectively)far exceeded background levels.The geo-accumulation indexes(Igeo)showed that cultivated soils near the mining sites were polluted by Cd and Cu,followed by Zn,V,Pb,Cr,Ni,and U.The pollution index(Pi)indicated that rice in the area was heavily polluted with Pb,Cr,Cd,Ni,Zn,and Cu.The difference in orders of metal concentrations between the soil and rice heavy metal contamination was related to the proportion of bioavailable heavy metals in the soil.The crop consumption risk assessment showed that the hazard quotient exceeded the safe threshold,indicating a potential carcinogenic risk to consumers.The Nemerow integrated pollution index and health index indicated that the middle of the river(near the mining area)was the heaviest polluted site.展开更多
Countries in the Middle Eastern and North African (MENA) region are among the most water-scarce regions in the world, and their dryland soils are usually poor in organic carbon content (<0.5%). In this study, we su...Countries in the Middle Eastern and North African (MENA) region are among the most water-scarce regions in the world, and their dryland soils are usually poor in organic carbon content (<0.5%). In this study, we summarize examples of how people in the few oases of the MENA region overcome environmental challenges by sustainably managing economically important date production. On the basis of the limited studies found in the existing literature, this mini-review focuses on the role of traditional soil organic matter amendments beneath the soil surface as a key tool in land restoration. We conclude that soil organic matter amendments can be very successful in restoring soil water and preventing the soil from salinization.展开更多
Many researches deal with practices which could adduce reliable answers to insure an ecological development which meets the nowadays global issue ＂feed the world＂ in a sustainable way. But scientific research is muc...Many researches deal with practices which could adduce reliable answers to insure an ecological development which meets the nowadays global issue ＂feed the world＂ in a sustainable way. But scientific research is much less prolific about social adhesion to those practices. How could we be certain that peasants will integrate them and transform their agriculture？ It is at that particular point that we settled our contribution. Our goal is to determine what are the levers which could be activated to promote agroecological practices, and, on the contrary, what are the obstacles which could prevent social adhesion to agroecology. The meticulous fieldwork carried in Barani, a landlocked small village in the North-West of the Burkina Faso, shows that all the ingredients for the development and the dissemination of agroecology already exist. Indeed, traditional agriculture is not so far from agroecology. But we noticed among peasants ofBarani a rejection of the local farming system synonymous, according to them, with backwardness, and an attraction for industrial agriculture, sign of modernity. Dissemination of agroecology will have to go through a major confidence-building work of the peasants with their own practices, as opposed to multiple trainings where they are always being taught what they already know.展开更多
This study was to assess the effect of bush fires and human actions on the settlement status of the shea tree in cropping systems. It was carried out using </span><span style="font-family:Verdana;"&...This study was to assess the effect of bush fires and human actions on the settlement status of the shea tree in cropping systems. It was carried out using </span><span style="font-family:Verdana;">three farming systems as treatments in which randomized plots were set.</span> <span style="font-family:Verdana;">Thus, dendrometric data were collected from the shea trees. The sampling</span><span style="font-family:Verdana;"> concerned twelve plots of 0.5 ha (100 m × 50 m) each and the number of adults of shea trees and that of the regeneration per plot was recorded. Forty-five (45) species divided into 20 families and 36 genera have been identi</span><span style="font-family:Verdana;">fied, with a decreasing number ranging from unburned fallow to fields</span><span style="font-family:Verdana;"> through burnt fallow. From these results, it emerges that the young shea plants are predominant in the unburned fallow. The mapping using geographic coordinates showed that the shea tree gradually aggregated in the fallows with a higher density. Actions must then be taken to support farmers in the domestication and protection of the shea tree for its effective conservation in cropping systems.展开更多
This study evaluates the productivity of cotton and sorghum in a shea-based agroforestry system in northernBenin. Tomboutou and Gounarou villages were respectively selected in the shea parklands of Bembèrèk&...This study evaluates the productivity of cotton and sorghum in a shea-based agroforestry system in northernBenin. Tomboutou and Gounarou villages were respectively selected in the shea parklands of Bembèrèkè and Kandi. Within each parkland and village, three classes of tree crown diameter for shea trees (4 -8 m, 8 -10 mand <10 m), were defined after the inventory phase. In each class of crown diameter, three trees intercropped with cotton and sorghum were randomly selected among the 18 to 21 farms in each of the two village territories. The crops were planted in accordance with the technical procedures recommended by the national agricultural extension service. The following data was collected for sorghum and cotton on1 m2area under the crown and outside the crown, in the four cardinal directions of each sample tree: crop height, fresh biomass per crop and buds per cotton plant. Data analysis revealed a very significant difference in the variables (height of sorghum and cotton, biomass of cotton and sorghum, number cotton buds) between the areas under the crown and those outside the crown (P < 0.01). The productivity variables for sorghum, i.e., average plant height and average biomass, dropped by 9.75% and 29.31%, respectively, when planted under the crown. Cotton under the crown was 6.58% shorter compared to plants outside the crown. Average bud production and average fresh biomass for cotton plants was 13.06% and 36.06% less, respectively, when planted under the crown of shea trees.展开更多
Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based o...Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based on a literature review and ifeld investigations, we analyzed the history and development, structure and characteristics, functions and values of the Xinghua Duotian Agrosystem in this research. The system has a long history, rich biodiversity, important ecosystem services, traditional adapted agricultural technologies and a folk culture. Altogether, these features form an attractive landscape created by its special water-land utilization. It also has great importance for the livelihood maintenance of the local people. However, the inheritance and conservation effort of Xinghua Duotian Agrosystem is facing great threats from modern agriculture, urbanization and labor loss. This paper wil provide insight into the Xinghua Duotian Agrosystem, and provide scientiifc support for the conservation and development of this special system. It will also provide a good example for similar areas in China and worldwide.展开更多
Chemical defenses are frequently accompanied by salient color patterns actively avoided by predators,a phe-nomenon referred to as aposematism.However,the production of both chemical defenses and pigments is costly,and...Chemical defenses are frequently accompanied by salient color patterns actively avoided by predators,a phe-nomenon referred to as aposematism.However,the production of both chemical defenses and pigments is costly,and is thus expected to be reduced under mild predator pressure.In this work,I compared the size and coloration of parotoid glands(2 dorsal,external swollen structures that secrete toxins in toads)of male and female Epidalea calamita toads from agrosystems and from pine groves.I also quantified the predator attacks received by plas-ticine toad models,whose“parotoid glands”differed in size and color conspicuousness,exposed in each habitat.Predators avoided models with large and conspicuous parotoid glands,but models in agrosystems were more of-ten attacked.Concerning actual toads,agrosystem and male individuals had larger parotoid glands,presumably implying greater production of chemical defenses than in pine grove and female conspecifics.Thesefindings are aligned with previous research suggesting that both agrosystem toads and males in this system are subjected to a more intense predator pressure.Difference between parotoid gland and dorsum coloration was greater in agrosys-tem toads.A marked internal pattern could function as an aposematic signal,which could counteract increased predator pressure.展开更多
文摘This article presents a review of the analytical relevance of trace metal speciation analysis, which must be considered in environmental and biophysicochemical systems for reliable and efficient assessment and monitoring of trace metals. Examples are given of methodological approaches used for speciation analysis. An overview of speciation analysis in sediments, aquatic ecosystems and agrosystems is also presented.
文摘Background and Objectives: The species to the Lannea genus are trees, shrubs with compound leaves. Thus, individuals called atypical Lannea with single leaves and of socio-economic interests have been identified in the central plateau region (Burkina Faso). This study aimed to contribute to the identification of atypical species. Material and Methods: The Polymerase Chain Reaction (PCR) method using specific primers was performed and consisted of extracting DNA from young leaves of Lannea individuals, amplifying and then sequencing portions of discriminating DNA (matK, rbcL and rps16). Results: It was shown that individuals belong to the Lannea genus, but are subdivided into three subgroups: a first subgroup containing Lannea microcarpa and two subgroups with no previously identified Lannea species. Conclusion: These atypical individuals are ecotypes or mutants of Lannea microcarpa.
基金funded by National Key Research and Development Program of China (Grant No. 2017YFC0504902)National Key Technology R&D Program of China (Grant No. 2012BAC06B02)
文摘Metallic ore mining causes heavy metal pollution worldwide.However,the fate of heavy metals in agrosystems with long-term contamination has been poorly studied.Dongchuan District(Yunnan,southwest China),located at the middle reaches of the Xiaojiang River,is a well-known 2000-year-old copper mining site.In this work,a survey on soil heavy metal contents was conducted using a handheld X-ray fluorescence instrument to understand the general contamination of heavy metals in the Xiaojiang River Basin.Furthermore,river water,soil,and rice samples at six sites along the fluvial/alluvial fans of the river were collected and analyzed to implement an environmental assessment and an evaluation of irrigated agrosystem.V,Zn,and Cu soil levels(1724,1047,and 696mg·kg-1,respectively)far exceeded background levels.The geo-accumulation indexes(Igeo)showed that cultivated soils near the mining sites were polluted by Cd and Cu,followed by Zn,V,Pb,Cr,Ni,and U.The pollution index(Pi)indicated that rice in the area was heavily polluted with Pb,Cr,Cd,Ni,Zn,and Cu.The difference in orders of metal concentrations between the soil and rice heavy metal contamination was related to the proportion of bioavailable heavy metals in the soil.The crop consumption risk assessment showed that the hazard quotient exceeded the safe threshold,indicating a potential carcinogenic risk to consumers.The Nemerow integrated pollution index and health index indicated that the middle of the river(near the mining area)was the heaviest polluted site.
基金supported by the Exploratory Grant(STC_TUNGER-006/INTOASES)as part of the Bilateral Scientific and Technological Cooperation between the Republic of Tunisia and the Federal Republic of Germany
文摘Countries in the Middle Eastern and North African (MENA) region are among the most water-scarce regions in the world, and their dryland soils are usually poor in organic carbon content (<0.5%). In this study, we summarize examples of how people in the few oases of the MENA region overcome environmental challenges by sustainably managing economically important date production. On the basis of the limited studies found in the existing literature, this mini-review focuses on the role of traditional soil organic matter amendments beneath the soil surface as a key tool in land restoration. We conclude that soil organic matter amendments can be very successful in restoring soil water and preventing the soil from salinization.
文摘Many researches deal with practices which could adduce reliable answers to insure an ecological development which meets the nowadays global issue ＂feed the world＂ in a sustainable way. But scientific research is much less prolific about social adhesion to those practices. How could we be certain that peasants will integrate them and transform their agriculture？ It is at that particular point that we settled our contribution. Our goal is to determine what are the levers which could be activated to promote agroecological practices, and, on the contrary, what are the obstacles which could prevent social adhesion to agroecology. The meticulous fieldwork carried in Barani, a landlocked small village in the North-West of the Burkina Faso, shows that all the ingredients for the development and the dissemination of agroecology already exist. Indeed, traditional agriculture is not so far from agroecology. But we noticed among peasants ofBarani a rejection of the local farming system synonymous, according to them, with backwardness, and an attraction for industrial agriculture, sign of modernity. Dissemination of agroecology will have to go through a major confidence-building work of the peasants with their own practices, as opposed to multiple trainings where they are always being taught what they already know.
文摘This study was to assess the effect of bush fires and human actions on the settlement status of the shea tree in cropping systems. It was carried out using </span><span style="font-family:Verdana;">three farming systems as treatments in which randomized plots were set.</span> <span style="font-family:Verdana;">Thus, dendrometric data were collected from the shea trees. The sampling</span><span style="font-family:Verdana;"> concerned twelve plots of 0.5 ha (100 m × 50 m) each and the number of adults of shea trees and that of the regeneration per plot was recorded. Forty-five (45) species divided into 20 families and 36 genera have been identi</span><span style="font-family:Verdana;">fied, with a decreasing number ranging from unburned fallow to fields</span><span style="font-family:Verdana;"> through burnt fallow. From these results, it emerges that the young shea plants are predominant in the unburned fallow. The mapping using geographic coordinates showed that the shea tree gradually aggregated in the fallows with a higher density. Actions must then be taken to support farmers in the domestication and protection of the shea tree for its effective conservation in cropping systems.
基金the Program RIPIECSA,made possible by the French Ministry of Foreign Affairs,for funding this study.
文摘This study evaluates the productivity of cotton and sorghum in a shea-based agroforestry system in northernBenin. Tomboutou and Gounarou villages were respectively selected in the shea parklands of Bembèrèkè and Kandi. Within each parkland and village, three classes of tree crown diameter for shea trees (4 -8 m, 8 -10 mand <10 m), were defined after the inventory phase. In each class of crown diameter, three trees intercropped with cotton and sorghum were randomly selected among the 18 to 21 farms in each of the two village territories. The crops were planted in accordance with the technical procedures recommended by the national agricultural extension service. The following data was collected for sorghum and cotton on1 m2area under the crown and outside the crown, in the four cardinal directions of each sample tree: crop height, fresh biomass per crop and buds per cotton plant. Data analysis revealed a very significant difference in the variables (height of sorghum and cotton, biomass of cotton and sorghum, number cotton buds) between the areas under the crown and those outside the crown (P < 0.01). The productivity variables for sorghum, i.e., average plant height and average biomass, dropped by 9.75% and 29.31%, respectively, when planted under the crown. Cotton under the crown was 6.58% shorter compared to plants outside the crown. Average bud production and average fresh biomass for cotton plants was 13.06% and 36.06% less, respectively, when planted under the crown of shea trees.
基金National Natural Science Fund of China (31200376)Chinese Academy of Sciences Visiting Professorship for Senior International Scientists (2013T2Z0011)
文摘Xinghua Duotian Agrosystem is a raised ifeld agriculture system with typical water-land utilization. It was identiifed as a Globally Important Agricultural Heritage Systems （GIAHS） site by FAO in April 2014. Based on a literature review and ifeld investigations, we analyzed the history and development, structure and characteristics, functions and values of the Xinghua Duotian Agrosystem in this research. The system has a long history, rich biodiversity, important ecosystem services, traditional adapted agricultural technologies and a folk culture. Altogether, these features form an attractive landscape created by its special water-land utilization. It also has great importance for the livelihood maintenance of the local people. However, the inheritance and conservation effort of Xinghua Duotian Agrosystem is facing great threats from modern agriculture, urbanization and labor loss. This paper wil provide insight into the Xinghua Duotian Agrosystem, and provide scientiifc support for the conservation and development of this special system. It will also provide a good example for similar areas in China and worldwide.
文摘Chemical defenses are frequently accompanied by salient color patterns actively avoided by predators,a phe-nomenon referred to as aposematism.However,the production of both chemical defenses and pigments is costly,and is thus expected to be reduced under mild predator pressure.In this work,I compared the size and coloration of parotoid glands(2 dorsal,external swollen structures that secrete toxins in toads)of male and female Epidalea calamita toads from agrosystems and from pine groves.I also quantified the predator attacks received by plas-ticine toad models,whose“parotoid glands”differed in size and color conspicuousness,exposed in each habitat.Predators avoided models with large and conspicuous parotoid glands,but models in agrosystems were more of-ten attacked.Concerning actual toads,agrosystem and male individuals had larger parotoid glands,presumably implying greater production of chemical defenses than in pine grove and female conspecifics.Thesefindings are aligned with previous research suggesting that both agrosystem toads and males in this system are subjected to a more intense predator pressure.Difference between parotoid gland and dorsum coloration was greater in agrosys-tem toads.A marked internal pattern could function as an aposematic signal,which could counteract increased predator pressure.
