The effect of coppice management on stump volume recovery in mechanized operations

Abstract

Key message: Coppice stands result in slightly higher stump waste compared with planted stands, when felled mechanically by a harvester. Context: The large demand for wood fibre requires efficient production and cost-effective practices throughout the supply chain. Aims: The purpose of the study was to quantify the amount of volume lost to excessive stump height in coppiced and planted stands. Methods: Stump height was measured on similar eucalypt stands that differed only for their origin: coppiced or planted. The study sample comprised of 543 planted stems and 851 coppice stems; of which 365 grew as double stems and 486 as single. Results: Stump waste was highest for coppiced double stumps, smallest for coppiced single stumps and intermediate for planted tree stumps. All differences were statistically significant, but the difference between coppiced single stumps and planted tree stumps was much smaller (20%) than the difference between coppiced double stumps and the rest (220–260%). Regression analysis showed that stump waste volume increased with tree volume, and this effect was twice as large for coppiced double stumps compared with the other treatments. Stump waste seemed very small in both relative and absolute terms and is unlikely to offset the large benefits accrued through coppice management and mechanization. Conclusion: Comparison with previous stump height studies indicates that the results obtained in this experiment for planted eucalypt may have general value and could be extended to other coppice stands, although with caution.