Soil Aeration and Tree Health: Correlating Soil Oxygen Measurements With the Decline of Established Oaks
AbstractField measurements of oxygen concentration and oxygen diffusion rate (ODR) indicate that ODR is a more reliable indicator of problem sites. In a landscaped area where oak trees are declining, ODR in the upper part of the soil profile ranged between 0.1-0.2 µg O2cm2/minute (where µg = micrograms, and O2 = oxygen) for weeks at a time. In laboratory experiments, we have found low oxygen levels to inhibit oak root growth, and to predispose cork oak roots to extensive colonization by Phytophthora cinnamomi. Work is continuing to better define stress thresholds, and the effectiveness of aeration management practices in alleviating root stress.
Alternate TitleUSDA Forest Service Gen. Tech. Rep. PSW-126. 1991