Abstract
AbstractThe influence of tree roots on physical properties and spatial arrangement of adjacent soil materials were studied. Soil fabric in the vicinity of tree root‐soil interface was observed microscopically using specially prepared soil thin sections from samples obtained from forest soils by a freezing in situ technique. Micromorphological observations showed that within the 0‐ to 0.4‐mm radial interval from the root‐soil interface there was a relative decrease in grains and pores > 20µ. An increase in oriented clay, and percentage elongate grains oriented within 30° tangent to the root surface was observed. These features imply that the matrix adjacent to tree roots (within 1 to 2 mm) contain more fine‐grained materials, with a consequent pore‐size distribution shift toward smaller pore diameters (20–50µ or less). Microscopic measurement of pore size distribution compared closely to aeration porosity values calculated from bulk density, particle density, and moisture content at 60‐cm tension data. Percent pores determined microscopically on soil thin sections without reference to distances from soil‐root interfaces agreed closely with values measured at a distance interval of 2.0 to 4.0 mm from root‐soil interface. Aeration porosity, measured microscopically in the area of close proximity to actively growing roots at time of sampling, was very low.These data and inferences suggest that physical properties of the soil contiguous to a tree root may differ appreciably from such factors farther away from the root.
Highlights
Root channels and large pores or voids appear to be an important factor affecting the movement of water in soils, especially in forested soils
Numerous techniques and equipment have been developed in recent years, none seem to be satisfactory for making accurate measure ments of soil porosity and pore size distribution of forested soils
The objectives of this study were directed to an evaluation of what influences tree roots have on the physical properties and spatial arrangement of adjacent soil materials
Summary
Root channels and large pores or voids appear to be an important factor affecting the movement of water in soils, especially in forested soils. The interconnected channels formed by earthworms, burrowing animals and tree roots apparently provide effective routes for rapid downward flow of water This water often appears as free water at some lower depth and changes to a lateral flow due to contact with a much less permeable soil layer Q-OD . Numerous techniques and equipment have been developed in recent years, none seem to be satisfactory for making accurate measure ments of soil porosity and pore size distribution of forested soils. These soils present special problems due to presence of numerous roots and channels, and because often they are incoherent and have stony surface layers. Because of the very important effect of pore space distribution and continuity upon water movement and storage within soils, it is essential to obtain such measurements of these parameters with some degree of accuracy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
