【Title】【Author】This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district （10,876 ha）, a mountainous region of northern Iran. For t...【Title】【Author】This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district （10,876 ha）, a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM＋ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon （SOC） density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland （0.45×104 Mg C in 0-40 cm depth layer）; and the conversion of rangeland to cultivated land （0.37×104 Mg C in 0-40 cm）, which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran.展开更多
By the use of the software of ARCGIS, dynamic changes of the landscape elements, landscape structure, conversion processes of the landscape gradients and the responses of wetland eco-security to land use/cover changes...By the use of the software of ARCGIS, dynamic changes of the landscape elements, landscape structure, conversion processes of the landscape gradients and the responses of wetland eco-security to land use/cover changes (LUCC) in the western Jilin Province were studied from 1930 to 2000. The results show that the landscape elements of grassland, wetland, forestland and water area shrank rapidly, and wetlands underwent huge losses in the study period due to the conversion from wetland into arable land and grassland in large quantities. The responses of wetland eco-security to LUCC were inverse evolvement of wetland vegetation, loss of biodiversity, water deficiency in wetland ecosystem, the changes of the heterogeneity of wetlands and the fragmentation of the wetland habitats. Suggestions were given for protection of wetlands and the regional sustainable development.展开更多
文摘【Title】【Author】This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district （10,876 ha）, a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM＋ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon （SOC） density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland （0.45×104 Mg C in 0-40 cm depth layer）; and the conversion of rangeland to cultivated land （0.37×104 Mg C in 0-40 cm）, which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran.
基金U nderthe auspices ofK now ledge Innovation Program ofC hinese A cadem y ofSciences (N o.K ZC X 2-308-3-5)
文摘By the use of the software of ARCGIS, dynamic changes of the landscape elements, landscape structure, conversion processes of the landscape gradients and the responses of wetland eco-security to land use/cover changes (LUCC) in the western Jilin Province were studied from 1930 to 2000. The results show that the landscape elements of grassland, wetland, forestland and water area shrank rapidly, and wetlands underwent huge losses in the study period due to the conversion from wetland into arable land and grassland in large quantities. The responses of wetland eco-security to LUCC were inverse evolvement of wetland vegetation, loss of biodiversity, water deficiency in wetland ecosystem, the changes of the heterogeneity of wetlands and the fragmentation of the wetland habitats. Suggestions were given for protection of wetlands and the regional sustainable development.
