In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through...In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through comparisons with soils from a natural forest using a polyphasic approach (chemical and molecular microbial assays). Changes in the ammonium, nitrate and phosphate concentration were observed in soils converted to agricultural use. Soil enzyme activities in plantation soils showed reduced β-glucosidase, cellobiohydrolase and acid phosphatase activities (50% - 55% decrease). PCR-DGGE based analysis showed that the soil bacterial community from agricultural soils exhibited the lowest similarity amongst the different microbial groups (fungi and Archaea) evaluated (34% similarity to the natural forest soil). Shannon Diversity index values showed that generally the conversion of tropical peatland natural forest to rubber plantation resulted in a greater impact on microbial diversity (ANOVA p < 0.05). Overall, this study indicated substantial shifts in the soil microbial activity and diversity upon conversion of natural peatland forest to agriculture, with a greater change being observed under rubber plantation compared to oil palm plantation. These findings provided important data for future peatland management by relating changes in the soil microbial community and activities associated to agricultural practices carried out on peatland.展开更多
We explored the potential use of combining wavelength-dispersive X-ray spectroscopy(WDX) and micromorphology of thin sections to identify minerals in peat soils. Peat soil minerals from three peats and swamps across G...We explored the potential use of combining wavelength-dispersive X-ray spectroscopy(WDX) and micromorphology of thin sections to identify minerals in peat soils. Peat soil minerals from three peats and swamps across Golestan Province in northern Iran were first characterized by micromorphological studies. Soils were composed mainly of quartz, muscovite, biotite, pyroxene,sericitized Fe-nodules, and iron-rich garnet. In addition,micromorphological results indicated that Galougah Coastal Swamp sections contained some inorganic residue with biological origin including oyster and limpet, which may be related to the swamp's location near Gorgan Gulf.In order to determine mineralogical properties of samples,twelve unknown grains were chosen for elemental concentration map studies. Quartz, garnet, ilmenite, calcite,and pyroxene in Suteh samples; epidote and Fe-nodule in Ghaleh-Ghafeh Peat Swamp; and barite, phyllosilicates,and calcite in Galougah were identified by WDX mapping of Si, Al, Fe, Ca, Mg, C, Ba, S, and Ti. Composition of the oysters' body was also analyzed by WDX for Si, Ca, Fe,and C. The results indicated that most of the minerals in all sections likely formed through weathering, inheriting their composition from the parent rock. This research suggests that merging micromorphology and SEM/WDX image techniques can be useful in confirming the presence of mineral particles in soil science.展开更多
Climate change is now evident in the Qinghai-Tibet Plateau(QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic ch...Climate change is now evident in the Qinghai-Tibet Plateau(QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers(OTC) and the control manipulations were collected over a complete year. The results show that annual(2008) air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.展开更多
文摘In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through comparisons with soils from a natural forest using a polyphasic approach (chemical and molecular microbial assays). Changes in the ammonium, nitrate and phosphate concentration were observed in soils converted to agricultural use. Soil enzyme activities in plantation soils showed reduced β-glucosidase, cellobiohydrolase and acid phosphatase activities (50% - 55% decrease). PCR-DGGE based analysis showed that the soil bacterial community from agricultural soils exhibited the lowest similarity amongst the different microbial groups (fungi and Archaea) evaluated (34% similarity to the natural forest soil). Shannon Diversity index values showed that generally the conversion of tropical peatland natural forest to rubber plantation resulted in a greater impact on microbial diversity (ANOVA p < 0.05). Overall, this study indicated substantial shifts in the soil microbial activity and diversity upon conversion of natural peatland forest to agriculture, with a greater change being observed under rubber plantation compared to oil palm plantation. These findings provided important data for future peatland management by relating changes in the soil microbial community and activities associated to agricultural practices carried out on peatland.
文摘We explored the potential use of combining wavelength-dispersive X-ray spectroscopy(WDX) and micromorphology of thin sections to identify minerals in peat soils. Peat soil minerals from three peats and swamps across Golestan Province in northern Iran were first characterized by micromorphological studies. Soils were composed mainly of quartz, muscovite, biotite, pyroxene,sericitized Fe-nodules, and iron-rich garnet. In addition,micromorphological results indicated that Galougah Coastal Swamp sections contained some inorganic residue with biological origin including oyster and limpet, which may be related to the swamp's location near Gorgan Gulf.In order to determine mineralogical properties of samples,twelve unknown grains were chosen for elemental concentration map studies. Quartz, garnet, ilmenite, calcite,and pyroxene in Suteh samples; epidote and Fe-nodule in Ghaleh-Ghafeh Peat Swamp; and barite, phyllosilicates,and calcite in Galougah were identified by WDX mapping of Si, Al, Fe, Ca, Mg, C, Ba, S, and Ti. Composition of the oysters' body was also analyzed by WDX for Si, Ca, Fe,and C. The results indicated that most of the minerals in all sections likely formed through weathering, inheriting their composition from the parent rock. This research suggests that merging micromorphology and SEM/WDX image techniques can be useful in confirming the presence of mineral particles in soil science.
基金funded by The Natural Science foundation of China (No. 40925002)The Natural Science foundation of Fujian Province (No. 2015J05114)
文摘Climate change is now evident in the Qinghai-Tibet Plateau(QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers(OTC) and the control manipulations were collected over a complete year. The results show that annual(2008) air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.
