Insitu needle and fine root respiration in mature slash pine (Pinuselliottii) trees

Abstract

Respiration of needles and surface fine roots was measured in a north central Florida slash pine (Pinuselliottii Engelm. var. elliottii) plantation. A controlled temperature chamber system was used to estimate respiration rates and Q10 values of insitu tissues over a range of 10 to 35 °C. Respiration rates did not differ significantly among seasons, fertilized versus unfertilized plots, or time of day in a diurnal time series (needles). Needle respiration from the lower canopy was less than that from the upper canopy. Fine root respiration measurements were consistent with previously made estimates based on soil CO2 partitioning and trenched plots.