Most studies of forest litter dynamics examine the biochemical characteristics and decomposition of leaf litter, but fine roots are also a large source of litter in forests. We quantified the concentrations of eight biochemical fractions and nitrogen (N) in leaf litter and fine roots at four sugar maple (Acer saccharum)-dominated hardwood forests in the north-central United States. We combined ...

This study investigated the effects of organic and inorganic nutrients on the microbial degradation of the common soil contaminant pyrene. The material used in this investigation was collected from potted trees that had been growing for over a year in a soil artificially contaminated with polycyclic aromatic hydrocarbons. Soil was removed from the nonroot (bulk) and root (rhizosphere) zones of ...

The interlayer soil identified in conventional French rail track corresponds to a mixture of fine and coarse grains. To investigate the role fines soil-water retention property such mixture, different grain contents f v dry densities ρ d–f were considered. filter paper method was applied measure matric suction. Mercury intrusion porosimetry tests performed observe microstructure soil. In terms ...

Attributes of fine roots (<LO mm diameter) were quantified in five southern Appalachian plant communities along an elevational gradient. These attributes include the seasonal dynamics of fine root mass and length, the depth distribution of fine roots, fine root width and, most importantly, the annual appearance and disappearance of fine roots. The principal objectives of this study were two-fol...

Investigating the responses of trees to the heterogeneous distribution of nutrients in soil and simultaneous presence of neighboring roots could strengthen the understanding of an influential mechanism on tree growth and provide a scientific basis for forest management. Here, we conducted two split-pot experiments to investigate the effects of nutrient heterogeneity and intraspecific competitio...

In this research, the effects of a sedimentary basin, environmental conditions, and the passage of time were investigated on consolidation processes and engineering characteristics of fine-grained soils in Kerman city. For this purpose, the natural consolidation curves of soil samples extracted from different locations of Kerman city were compared with the Kerman city intrinsic consolidation li...

The microbial community structure in various microaggregates in a loamy sand soil was investigated. The microaggregates were separated into outer and inner aggregates using a series of soil washes. Further physical fractionation of inner aggregates was achieved by separation into coarse and fine sand as macroaggregate fractions, coarse and fine silt as microaggregate fractions, and clay. Resear...

foam injection is becoming a standard conditioning agent when tunnelling with an earth-pressure balanced shield, resulting in an increasing interest in this technique. the technique is mostly based on empirical rules and experience. to be able to determine what foam and how may foam has to be injected for different soils, it is necessary to know the mechanical parameters of the foam-water-soil ...

Foam injection is becoming a standard conditioning agent when tunnelling with an earth-pressure balanced shield, resulting in an increasing interest in this technique. The technique is mostly based on empirical rules and experience. To be able to determine what foam and how may foam has to be injected for different soils, it is necessary to know the mechanical parameters of the foam-water-soil ...