Temperature effect on growth rates of Eriophorum vaginatum roots

Root growth rates of the sedge Eriophorum vaginatum L. were studied under controlled environmental conditions. The air temperature was maintained constant at 15°C while the root temperatures varied in 5°C intervals between 2° and 37° C (12° C excluded). Root growth rates of 1.2 mm d^-1 at 2°, 20.4 mm d^-1 at 32° C and 10.1 mm d^-1 at 37° C were recorded. A Q₁₀ of 3.2 was calculated for the temperature range from 7° to 27° C. Root growth rates at temperatures above 17° C declined after one week of growth. The degree of decline was proportional to the applied root temperature. Depletion of available nonstructural carbohydrate was the probable cause for this decline.