Changes in the fungal and bacterial biomass and community structure in litter after the volcanic eruptions of Mount Usu, northern Japan were investigated using a chronosequence approach, which is widely used for analy...Changes in the fungal and bacterial biomass and community structure in litter after the volcanic eruptions of Mount Usu, northern Japan were investigated using a chronosequence approach, which is widely used for analyzing vegetation succession. The vegetation changed from bare ground （10 years after the eruptions） with little plant cover and poor soil to monotonic grassland dominated by Polygonum sachalinense with undeveloped soil （33 years） and then to deciduous broad-leaved forest dominated by Populus maximowiczii with diverse species composition and well-developed soil （100 years）. At three chronosequential sites, we evaluated the compositions of phospholipid fatty acids （PLFAs）, carbon （C） and nitrogen （N） contents and the isotope ratios of C （δ13C） and N （δ15N） in the litter of two dominant species, Polygonum sachalinense and Populus maximowiezii. The C/N ratio, δ13C and δ15N in the litter of these two species were higher in the forest than that in the bare ground and grassland. The PLFAs gradually increased from the bare ground to the forest, showing that microbial biomass increased with the development of the soil and/or vegetation. The fungi-to-bacteria ratio of PLFA was constant at 5.3 ± 1.4 in all three sites, suggesting that fungi were predominant. A canonical correspondence analysis suggested that the PLFA comoosition was related to the successional ages and the developing soil properties （P 〈 0.05, ANOSIM）. The chrono- sequential analysis effectively detected the successional changes in both microbial and plant communities.展开更多
Understanding the effects of elevation and related factors(climate,vegetation) on the physical and chemical soil properties can help to predict changes in response to future climate or afforestation forcings.This work...Understanding the effects of elevation and related factors(climate,vegetation) on the physical and chemical soil properties can help to predict changes in response to future climate or afforestation forcings.This work aims to contribute to the knowledge of soil evolution and the classification of forest soils in relation to elevation in the montane stage,with special attention to podzolization and humus forms.The northern flank of the Moncayo Massif(Iberian Range,SW Europe) provides a unique opportunity to study a forest soils catena within a consistent quartzitic parent material over a relatively steep elevation gradient.With increasing elevation,pH,base saturation,exchangeable potassium,and fine silt-sized particles decrease significantly,while organic matter,the C/N ratio,soil aggregate stability,water repellency and coarse sand-sized particles increase significantly.The soil profiles shared a set of properties in all horizons:loamy-skeletal particle-size,extreme acidity(pH-H_2O<5.6) and low base saturation(<50%).The most prevalent soil forming processes in the catena include topsoil organic matter accumulation and even podzolization,which increases with elevation.From the upper to lower landscape positions of wooded montane stage of the Moncayo Massif,mull-moder-mor humus and an UmbrisolCambisol-Podzol soil unit sequences were found.展开更多
文摘Changes in the fungal and bacterial biomass and community structure in litter after the volcanic eruptions of Mount Usu, northern Japan were investigated using a chronosequence approach, which is widely used for analyzing vegetation succession. The vegetation changed from bare ground （10 years after the eruptions） with little plant cover and poor soil to monotonic grassland dominated by Polygonum sachalinense with undeveloped soil （33 years） and then to deciduous broad-leaved forest dominated by Populus maximowiczii with diverse species composition and well-developed soil （100 years）. At three chronosequential sites, we evaluated the compositions of phospholipid fatty acids （PLFAs）, carbon （C） and nitrogen （N） contents and the isotope ratios of C （δ13C） and N （δ15N） in the litter of two dominant species, Polygonum sachalinense and Populus maximowiezii. The C/N ratio, δ13C and δ15N in the litter of these two species were higher in the forest than that in the bare ground and grassland. The PLFAs gradually increased from the bare ground to the forest, showing that microbial biomass increased with the development of the soil and/or vegetation. The fungi-to-bacteria ratio of PLFA was constant at 5.3 ± 1.4 in all three sites, suggesting that fungi were predominant. A canonical correspondence analysis suggested that the PLFA comoosition was related to the successional ages and the developing soil properties （P 〈 0.05, ANOSIM）. The chrono- sequential analysis effectively detected the successional changes in both microbial and plant communities.
基金supported by project CGL2013-43440-R,funded by the Ministerio de Economiay Competitividad of Spain
文摘Understanding the effects of elevation and related factors(climate,vegetation) on the physical and chemical soil properties can help to predict changes in response to future climate or afforestation forcings.This work aims to contribute to the knowledge of soil evolution and the classification of forest soils in relation to elevation in the montane stage,with special attention to podzolization and humus forms.The northern flank of the Moncayo Massif(Iberian Range,SW Europe) provides a unique opportunity to study a forest soils catena within a consistent quartzitic parent material over a relatively steep elevation gradient.With increasing elevation,pH,base saturation,exchangeable potassium,and fine silt-sized particles decrease significantly,while organic matter,the C/N ratio,soil aggregate stability,water repellency and coarse sand-sized particles increase significantly.The soil profiles shared a set of properties in all horizons:loamy-skeletal particle-size,extreme acidity(pH-H_2O<5.6) and low base saturation(<50%).The most prevalent soil forming processes in the catena include topsoil organic matter accumulation and even podzolization,which increases with elevation.From the upper to lower landscape positions of wooded montane stage of the Moncayo Massif,mull-moder-mor humus and an UmbrisolCambisol-Podzol soil unit sequences were found.
