In this study, the quadrat method was used to study the effects of tsaoko （Fructus tsaoko） plantation on tree diversity and canopy structure of two natural habitats of eastern hoolock gibbon （Hoolock leuconedys）：...In this study, the quadrat method was used to study the effects of tsaoko （Fructus tsaoko） plantation on tree diversity and canopy structure of two natural habitats of eastern hoolock gibbon （Hoolock leuconedys）： Nankang （characterized by extensive tsaoko plantation） and Banchang （relatively well reserved and without tsaoko plantation）. Totally, 102 tree species from 25 families and 16 woody liana species from 10 families were recorded in Nankang, whereas 108 tree species from 30 families and 17 woody liana species from 12 families were recorded in Banchang. Although the tree species between two habitats is different, both habitats are characterized by enriched food resources for eastern hoolock gibbons, sharing similar dominant plant families. Due to tsaoko plantation, tree density proportion and diversity of forest layer I （〉20 m） in Nankang were both significantly decreased, but the tree density of layerH （10-20 m） increased. Likewise, in conjunction with these behavioral observations, we also address potential impacts of tsaoko plantation on the behavior of eastern hoolock gibbon.展开更多
Increasing foreign exchange problems and deteriorating prices of traditional exports have led policy makers and donor agencies to seek diversification in export crop production. In Ghana, crops such as pineapples and ...Increasing foreign exchange problems and deteriorating prices of traditional exports have led policy makers and donor agencies to seek diversification in export crop production. In Ghana, crops such as pineapples and mangoes appear promising because of their high labour intensity and expanding demand for fruits in Europe. Notwithstanding, there is a possible trade-off between export and food crop production because of the possibility of resource re-allocation. So far the major concern of government has been the growth in export earnings while the micro-level distributional effects remain under-investigated. The study focused on a household survey undertaken in the forest and coastal-savannah transition zones, where the farming system has undergone transition from an established food-crop farming for urban markets to an intensive production of horticultural products for export. Logistic regression and Gini coefficient approaches were used to estimate the determinants of household food availability and income distribution respectively. Though, households engaged in export horticulture appear better-off than those that do not, the sole adoption of either staple or export crop is not sufficient for improving food availability. Consequently, linkages which allow simultaneous and reliably access to equitable distribution of resources and services are critical for household survival in competitive global food markets展开更多
Extensive bleaching of Montastrea annularis spp. group and several other scleractinian taxa occurred on the reefs within the Arrecifes de Cozumel National Park of Cozumel, Mexico, after the passage of Hurricane/Tropic...Extensive bleaching of Montastrea annularis spp. group and several other scleractinian taxa occurred on the reefs within the Arrecifes de Cozumel National Park of Cozumel, Mexico, after the passage of Hurricane/Tropical Storm Rina. We conducted six drift dives at five different dive sites （-13 h of scuba diving） and photographed a variety of reefs scenes at depths of 10-28 m. Bleaching was noted at depths of 10-40 m in a variety of scleractinian species, including M. annularis species group, especially M. faveolata and Siderastrea siderea. Considering that local dive guides had not observed bleaching prior to the storm and the sea surface temperature did not exceed the local bleaching threshold, it is probable that the extensive rainfall associated with Hurricane/Tropical Storm Rina lowered salinity sufficiently via subsurface freshwater springs to cause bleaching in susceptible species. This suggests the need to monitor not only subsurface sea temperature but also subsurface salinity in localities where freshwater springs occur adjacent to or within coral reefs.展开更多
In this paper, I carried on the research under the guidance of the theory of hierarchy of needs, and preventing a detailed work plan. During the research, we cleared for measures, which were ＂adhere to the people-ori...In this paper, I carried on the research under the guidance of the theory of hierarchy of needs, and preventing a detailed work plan. During the research, we cleared for measures, which were ＂adhere to the people-oriented, mining the potential of students, make up the insufficient to properly resolve the crisis, to create a learning atmosphere＂. So it provides a new idea for promoting the construction and development of college student cadres, and maintains the stability of the campus and the construction of harmonious campus.展开更多
Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth...Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. Key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.展开更多
基金supported by the National Natural Science Foundation of China(31160424)Natural Science Foundation of Yunnan Province(20110426)Science Foundation Project of Mt.Gaoligong National Natural Reserve(201215)
文摘In this study, the quadrat method was used to study the effects of tsaoko （Fructus tsaoko） plantation on tree diversity and canopy structure of two natural habitats of eastern hoolock gibbon （Hoolock leuconedys）： Nankang （characterized by extensive tsaoko plantation） and Banchang （relatively well reserved and without tsaoko plantation）. Totally, 102 tree species from 25 families and 16 woody liana species from 10 families were recorded in Nankang, whereas 108 tree species from 30 families and 17 woody liana species from 12 families were recorded in Banchang. Although the tree species between two habitats is different, both habitats are characterized by enriched food resources for eastern hoolock gibbons, sharing similar dominant plant families. Due to tsaoko plantation, tree density proportion and diversity of forest layer I （〉20 m） in Nankang were both significantly decreased, but the tree density of layerH （10-20 m） increased. Likewise, in conjunction with these behavioral observations, we also address potential impacts of tsaoko plantation on the behavior of eastern hoolock gibbon.
文摘Increasing foreign exchange problems and deteriorating prices of traditional exports have led policy makers and donor agencies to seek diversification in export crop production. In Ghana, crops such as pineapples and mangoes appear promising because of their high labour intensity and expanding demand for fruits in Europe. Notwithstanding, there is a possible trade-off between export and food crop production because of the possibility of resource re-allocation. So far the major concern of government has been the growth in export earnings while the micro-level distributional effects remain under-investigated. The study focused on a household survey undertaken in the forest and coastal-savannah transition zones, where the farming system has undergone transition from an established food-crop farming for urban markets to an intensive production of horticultural products for export. Logistic regression and Gini coefficient approaches were used to estimate the determinants of household food availability and income distribution respectively. Though, households engaged in export horticulture appear better-off than those that do not, the sole adoption of either staple or export crop is not sufficient for improving food availability. Consequently, linkages which allow simultaneous and reliably access to equitable distribution of resources and services are critical for household survival in competitive global food markets
文摘Extensive bleaching of Montastrea annularis spp. group and several other scleractinian taxa occurred on the reefs within the Arrecifes de Cozumel National Park of Cozumel, Mexico, after the passage of Hurricane/Tropical Storm Rina. We conducted six drift dives at five different dive sites （-13 h of scuba diving） and photographed a variety of reefs scenes at depths of 10-28 m. Bleaching was noted at depths of 10-40 m in a variety of scleractinian species, including M. annularis species group, especially M. faveolata and Siderastrea siderea. Considering that local dive guides had not observed bleaching prior to the storm and the sea surface temperature did not exceed the local bleaching threshold, it is probable that the extensive rainfall associated with Hurricane/Tropical Storm Rina lowered salinity sufficiently via subsurface freshwater springs to cause bleaching in susceptible species. This suggests the need to monitor not only subsurface sea temperature but also subsurface salinity in localities where freshwater springs occur adjacent to or within coral reefs.
文摘In this paper, I carried on the research under the guidance of the theory of hierarchy of needs, and preventing a detailed work plan. During the research, we cleared for measures, which were ＂adhere to the people-oriented, mining the potential of students, make up the insufficient to properly resolve the crisis, to create a learning atmosphere＂. So it provides a new idea for promoting the construction and development of college student cadres, and maintains the stability of the campus and the construction of harmonious campus.
基金supported by the National Natural Science Foundation of China (No. 41471189)the Youth Science and Technology New Star Foundation of Shaanxi Province, China (No. 2013KJXX-09)+1 种基金the CAS "Light of West China" Programthe Youth Innovation Promotion Association CAS
文摘Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. Key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.
