Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The...Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of L0C and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands （pine forest （PF） on slope land, barren hill （BH） on slope land, citrus orchard （C0） on terrace land and Cinnarnornum Camphora （CC） on terrace land） at a sampling depth of 20 cm. Soil nutrients, soil organic carbon （SOC）, L0C and CMI were measured. Results showed that the L0C and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC 〉 PF 〉 CO 〉 BH at the upper- slope, while CO 〉 CC 〉 BH 〉 PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order： upper-slope 〉 down-slope 〉 mid- slope. As whole, the mean values of LOC and CMI in different lands followed the order CC 〉 CO 〉 PF 〉 BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high~ quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.展开更多
In mountain regions such as Lake Sevan basin, landscape-ecological problems are manifested sharply. Lake Sevan basin lies in the east of the RA （Republic of Armenia） and is characterized by unique natural and econom...In mountain regions such as Lake Sevan basin, landscape-ecological problems are manifested sharply. Lake Sevan basin lies in the east of the RA （Republic of Armenia） and is characterized by unique natural and economic peculiarities. It covers an area of 4,891 km^2, or 16% of the entire territory of the country. The article considers the dynamics of the ecosystems of Lake Sevan basin through remote sensing data. To achieve the stated goal, multi-zonal satellite images Landsat ETM （Enhanced Thematic Mapper Plus）, Landsat TM （Thematic Mapper） and Landsat MSS （Multispectral Scanner） were applied. All satellite imagery data was geometrically and atmospherically corrected. Temporal changes were determined using both a supervised classification approach and NDVI （normalized difference vegetation index） in that time series. Supervised procedure, a hierarchical land cover classification system was used to detect the different land cover classes in the Lake Sevan basin, Armenia. According to this system, four land cover categories exist in this area： （1） water; （2） vegetation-bare; （3） man-altered land; （4） vegetated land, which indicate that for the last 40 years the study area has displayed expansion of man-made landscapes and vegetation-bare sites, ecosystems having lower biomass and reduction of woodlands. NDVI values and the area they covered indicate that between 1973 and 2011, the area of almost non-vegetated lands increased approximately by three times. The main cause of such changes is activation of erosion processes as a result of a climate warming.展开更多
A study on community soil fertility management concepts and practices was conducted through rapid and participatory method of research in 15 villages of the Gourma region in Eastern part of Burkina Faso. These investi...A study on community soil fertility management concepts and practices was conducted through rapid and participatory method of research in 15 villages of the Gourma region in Eastern part of Burkina Faso. These investigations aimed at determining farmers＇ knowledge on soil resources： local soil taxonomy and indicators of soil degradation, soil fertility management practices, and capacity for adoption of new technologies in soil fertility management. The results of the study showed that the main parameter for soil classification for all the investigated villages was soil texture composition; soil degradation was evaluated according to crops yield decrease and the development Striga sp. in 100% of the investigated villages; the use of organic manure and long term fellow were the main practices for soil fertility management; concerning the villages where modem technologies of soil fertility management were introduced, the lack of tools and capacity building were the main limiting factors of the adoption of these improved practices at small scale farmers＇ level. Even if discordance between scientific and local soil taxonomy were revealed by our investigations; significant similarities between indigenous and scientific indices of soil degradation were noticed. With regard to the actual magnitude of soil degradation; the local techniques of soil fertility management need to be improved and accessible to a big number of farmers.展开更多
基金financially supported by the National Natural Science Foundation of China (41271294)the Program for New Century Excellent Talents in University (NCET-09-330)the Natural Science Foundation of Hunan Province of China (11JJ3041)
文摘Labile organic carbon （LOC） and carbon management index （CMI）, which are sensitive factors to the changes of environment, can improve evaluating the effect of land management practices changes on soil quality. The objective of this study was to investigate the effects of land use types and landscape positions on soil quality as a function of L0C and CMI. A field study in a small watershed in the red soil hilly region of southern China was conducted, and soil samples were collected from four typical lands （pine forest （PF） on slope land, barren hill （BH） on slope land, citrus orchard （C0） on terrace land and Cinnarnornum Camphora （CC） on terrace land） at a sampling depth of 20 cm. Soil nutrients, soil organic carbon （SOC）, L0C and CMI were measured. Results showed that the L0C and CMI correlated to not only soil carbon but also soil nutrients, and the values of LOC and CMI in different land use types followed the order CC 〉 PF 〉 CO 〉 BH at the upper- slope, while CO 〉 CC 〉 BH 〉 PF at mid-slope and down-slope. With respect to slope positions, the values of LOC and CMI in all the lands were followed the order： upper-slope 〉 down-slope 〉 mid- slope. As whole, the mean values of LOC and CMI in different lands followed the order CC 〉 CO 〉 PF 〉 BH. High CMI and LOC content were found in the terrace lands with broadleaf vegetations. These results indicated that the terracing and appropriate vegetations can increase the carbon input and lability and decrease soil erosion. However, the carbon pools and CMI in these lands were significantly lower than that in reference site. This suggested that it may require a long time for the soil to return to a high~ quality. Consequently, it is an efficient way to adopt the measures of terracing and appropriate vegetations planting in improving the content of LOC and CMI and controlling water and soil loss in fragile ecosystems.
文摘In mountain regions such as Lake Sevan basin, landscape-ecological problems are manifested sharply. Lake Sevan basin lies in the east of the RA （Republic of Armenia） and is characterized by unique natural and economic peculiarities. It covers an area of 4,891 km^2, or 16% of the entire territory of the country. The article considers the dynamics of the ecosystems of Lake Sevan basin through remote sensing data. To achieve the stated goal, multi-zonal satellite images Landsat ETM （Enhanced Thematic Mapper Plus）, Landsat TM （Thematic Mapper） and Landsat MSS （Multispectral Scanner） were applied. All satellite imagery data was geometrically and atmospherically corrected. Temporal changes were determined using both a supervised classification approach and NDVI （normalized difference vegetation index） in that time series. Supervised procedure, a hierarchical land cover classification system was used to detect the different land cover classes in the Lake Sevan basin, Armenia. According to this system, four land cover categories exist in this area： （1） water; （2） vegetation-bare; （3） man-altered land; （4） vegetated land, which indicate that for the last 40 years the study area has displayed expansion of man-made landscapes and vegetation-bare sites, ecosystems having lower biomass and reduction of woodlands. NDVI values and the area they covered indicate that between 1973 and 2011, the area of almost non-vegetated lands increased approximately by three times. The main cause of such changes is activation of erosion processes as a result of a climate warming.
文摘A study on community soil fertility management concepts and practices was conducted through rapid and participatory method of research in 15 villages of the Gourma region in Eastern part of Burkina Faso. These investigations aimed at determining farmers＇ knowledge on soil resources： local soil taxonomy and indicators of soil degradation, soil fertility management practices, and capacity for adoption of new technologies in soil fertility management. The results of the study showed that the main parameter for soil classification for all the investigated villages was soil texture composition; soil degradation was evaluated according to crops yield decrease and the development Striga sp. in 100% of the investigated villages; the use of organic manure and long term fellow were the main practices for soil fertility management; concerning the villages where modem technologies of soil fertility management were introduced, the lack of tools and capacity building were the main limiting factors of the adoption of these improved practices at small scale farmers＇ level. Even if discordance between scientific and local soil taxonomy were revealed by our investigations; significant similarities between indigenous and scientific indices of soil degradation were noticed. With regard to the actual magnitude of soil degradation; the local techniques of soil fertility management need to be improved and accessible to a big number of farmers.
