EFFECTS OF BRANCHING ORDER ON FINE ROOT TRAITS AND DECOMPOSITION IN A MANAGED LOBLOLLY PINE (Pinus taeda) PLANTATION
Beidler, Katilyn Victoria
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The idea that the fine roots of woody plants can be separated into a short-lived ephemeral pool and a longer-lived structural pool is supported by order-based differences with respect to fine root form and function. This study aimed to characterize morphological and chemical traits of the first three branching orders and the rate at which these roots decompose in a managed <i>Pinus taeda </i>plantation and to characterize the influence of organic soil amendments on this process. A root window approach was used to track chemical and morphological changes in both intact and severed branching networks and litterbags were used to measure percent mass remaining and rate of decay over the course of a year. Rate of decay increased with branching order and although the root window method was unable to detect mass loss by order, changes in C:N values suggested that patterns of decomposition differ among root orders. A finer root pool, with smaller diameters and lower specific root mass, was detected in soil amended with logging residues. Determining the proportion of perennial and ephemeral roots within fine root branching networks and how this proportion varies with respect to soil conditions is key to improving our understanding of belowground carbon and nutrient cycling.