Further investigation of younger cedar trees, approximately 300 years old, revealed a lesser amount of canopy soil deposition and a lower number of invertebrate families and orders detected.

These radionuclides are strongly fixed to fine soil particles and are not taken up by plants. During erosion and deposition processes they move with the soil particles and can be used to trace soil ...

of the University of Arizona at a cross-section of a hill near Xi'an, China. The layers of loess soil shown in the photo represent thousands of years of soil deposition.