Soil quality assessments are essential for determining impacts on belowground microbial community structure and function. We evaluated the suitability of active carbon (C), a rapid field test, as an indicator of soil ...Soil quality assessments are essential for determining impacts on belowground microbial community structure and function. We evaluated the suitability of active carbon (C), a rapid field test, as an indicator of soil biological quality in five paired forest stands (clear cut harvested 40 years prior and unharvested) growing on volcanic ash-cap soils in northern Idaho. Active C was compared with several traditional measures of soil microbial properties (microbial biomass, respiration, fungal hyphal biomass, bacterial number and biomass and PLFA community structure). Despite the significant differences in forest vegetation between paired stands, no differences in active C and only a few significant differences in microbial properties were detected. Total bacteria (microscope counts) and PLFA signatures (gram positive bacteria, gram negative bacteria, actinomycetes) were significantly higher in the managed stands. Our results indicate that either mineral soil biological properties in managed stands were relatively unaffected at the time of harvest or some biological recovery occurred 40 years later. Additionally, volcanic ash-cap soils in moist ecosystems could be highly resilient to the impacts of harvest operations and therefore few significant biological changes could be detected.展开更多
Paleosol identification is simplified by considering soil as a natural body withinternal organization and a history of formation. This definition assumes that we accept paleosolsas soils. In a paleosol classification,...Paleosol identification is simplified by considering soil as a natural body withinternal organization and a history of formation. This definition assumes that we accept paleosolsas soils. In a paleosol classification, inclusion of the cold region paleosols at the suborder levelplaces temperature (climate) in balance with the other soil forming factors. Because ancienttemperatures were not recorded, we use soil and parent material properties as proxies to identifyancient soils from Arctic and Subarctic regions. The properties include permafrost andcryoturbation features as well as those resulting from glacial processes. These features generallypersist through later cycles of soil formation as climate has changed. Examples both within andbeyond the glacial borders in Wyoming, Illinois, and Indiana, USA are presented and classifiedusing an arctic paleosol suborder modifier, the formative element.展开更多
文摘Soil quality assessments are essential for determining impacts on belowground microbial community structure and function. We evaluated the suitability of active carbon (C), a rapid field test, as an indicator of soil biological quality in five paired forest stands (clear cut harvested 40 years prior and unharvested) growing on volcanic ash-cap soils in northern Idaho. Active C was compared with several traditional measures of soil microbial properties (microbial biomass, respiration, fungal hyphal biomass, bacterial number and biomass and PLFA community structure). Despite the significant differences in forest vegetation between paired stands, no differences in active C and only a few significant differences in microbial properties were detected. Total bacteria (microscope counts) and PLFA signatures (gram positive bacteria, gram negative bacteria, actinomycetes) were significantly higher in the managed stands. Our results indicate that either mineral soil biological properties in managed stands were relatively unaffected at the time of harvest or some biological recovery occurred 40 years later. Additionally, volcanic ash-cap soils in moist ecosystems could be highly resilient to the impacts of harvest operations and therefore few significant biological changes could be detected.
文摘Paleosol identification is simplified by considering soil as a natural body withinternal organization and a history of formation. This definition assumes that we accept paleosolsas soils. In a paleosol classification, inclusion of the cold region paleosols at the suborder levelplaces temperature (climate) in balance with the other soil forming factors. Because ancienttemperatures were not recorded, we use soil and parent material properties as proxies to identifyancient soils from Arctic and Subarctic regions. The properties include permafrost andcryoturbation features as well as those resulting from glacial processes. These features generallypersist through later cycles of soil formation as climate has changed. Examples both within andbeyond the glacial borders in Wyoming, Illinois, and Indiana, USA are presented and classifiedusing an arctic paleosol suborder modifier, the formative element.
