Rhizotrophism
Definition
The directional growth of roots toward zones of higher nutrient concentration, including the nitrogen- and phosphorus-rich environment created by decomposing organic matter in soil.
- Response type
- Positive chemotropism toward nutrient gradients
- Trigger
- Nitrogen- and phosphorus-rich decomposition zones
- Forensic use
- Estimating time since burial from root growth patterns
- Compared against
- Undisturbed control soil near the grave
Common questions
How is rhizotrophism used to estimate time since burial?+
Investigators compare root density and orientation around a grave to undisturbed control soil nearby. Denser, inward-oriented root growth toward the burial suggests a longer period since disturbance, since roots take time to detect and grow toward the nutrient plume from decomposition.
Does rhizotrophism give a precise burial date?+
No. Root response speed depends heavily on plant species, soil moisture, temperature and season, so estimates are comparative and site-specific rather than a fixed timeline, and are normally paired with other burial-dating methods.
Related terms
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- Burial Interval
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- Root Encasement
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- Root-Tip Injury Dating
- Technique in which growth rings distal to a root-tip scar or redirection point are counted to estimate the number of growing seasons...