Soil C 0 2 efflux resulting from rnicrobinl and root respiration is a major cornponent of the forest C cycle. In this investigation, we examined in detail how soil C 0 2 efflux differs both spatially and temporally with rcspeit to stand age for loblolly pine (Pinus rrrecio LA.) plantations on the Virginia Pied~rront. Througlrout a 12-month period, efflux rates were rncasured both near the base ...

Studying on the spatial distribution and variation characteristics of soil fertility by Application of geographical information systems (GIS) and data mining(DM), with the quantitative analysis of spatial variability of soil fertility in complexity, and provide the effective way for simulations which can be closer to the farmland soil fertility variability. At the same time, interpolation metho...

A novel experimentation and analysis technique has been developed to enable detailed investigation of robot interactions with granular regolith. This technique, the Shear Interface Imaging Analysis Tool, provides visualization and analysis capability of soil shearing and flow as it is influenced by a wheel or excavation tool. The method places an implement (wheel, excavation bucket, etc.) in gr...

A frequency domain dynamic analysis is needed to obtain the response of structures constructed on a system of base isolators on flexible soil when subjected to earthquake ground motion. In such systems, the lateral stiffness of the base isolators is so small, compared to the structural stiffness, that in an earthquake attack the fundamental vibration mode dominates the response. With this in mi...

This study presents a new approach for physical and material modeling of space frame-raft-soil system. The physical modeling consists of a modified Thimoshenko beam bending element with six degrees of freedom per node to model the beams and columns of the superstructure, a modified Mindlin's plate bending element with five degrees of freedom per node to represent the structural slabs and raft, ...

Decomposition of plant residues is largely mediated by soil-dwelling microorganisms whose activities are influenced by both climate conditions and properties of the soil. However, a comprehensive understanding of their relative importance remains elusive, mainly because traditional methods, such as soil incubation and environmental surveys, have a limited ability to differentiate between the co...

Principal components analysis (PCA) and correlation analysis were used to estimate the contribution of four components related to pollutant sources on the total variation in concentrations of Cu, Zn, Pb, Cd, As, Se, Hg, Fe and Mn in surface soil samples from a valley in east China with numerous copper and zinc smelters. Results indicate that when carrying out source identification of inorganic ...

In structural analysis, the base of structures is usually assumed to be completely rigid. However, the combination of foundation and the subsurface soil, makes in fact a flexible-base for the soil-structure system. It is well-known that the structural responses can be significantly affected by incorporating the Soil-structure Interaction (SSI) effects. The aim of the present study is to provide...

Termites are an important component of tropical soil communities and have a significant effect on the structure and nutrient content of soil. Digestion in termites is related to gut structure, gut physicochemical conditions, and gut symbiotic microbiota. Here we describe the use of 16S rRNA gene sequencing and terminal-restriction fragment length polymorphism (T-RFLP) analysis to examine methan...

The objective of this study was to evaluate the effect of soil moisture condition and irrigation regime on the bioelectric potential of crops with different growth stages. The bioelectric potential of broccoli (Brassica oleracea var. italica) plants at the initial and mid-growth stages was measured under different soil moisture conditions and irrigation regimes using pot experiments. The result...