Accelerator trial series in Pinus radiata stands in New Zealand: Trial establishment, site description and initial soil, forest floor and tree data.

Interest in establishing biological-based economies has created increasing and rapidly moving demand for wood and fibre from production forests. Meeting the global demand for timber supply will require investment and development across all components of the supply chain but will ultimately rely on the ability of the forestry sector to increase productivity without compromising the sustainability of plantation management. To address this issue in the context of New Zealand forestry, a trial series was established from 2015 to 2018 to accelerate plantation forest growth by exploring current and future limitations to timber productivity, then altering management practices to overcome these limits. The six sites in this Accelerator trial series were planted with a mix of 12 different types of D. Don stock expressing various traits related to tree growth, health and wood quality. The planting stock included ten clones, a hybrid and a seed lot representing a widely planted tree stock used throughout New Zealand. At each trial site a range of treatments were applied, including a control. The treatments were designed to address the specific current and predicted limitations to productivity at each location, with consideration for environmental sustainability and impacts on wood quality. Additional site-specific treatments will be implemented across the approximately 30-year life span of each trial. Here we present data describing both the pre-harvest and time zero state of at each trial site. These data provide a baseline that will enable treatment responses to be holistically understood as the trial series matures. This comparison will determine if current tree productivity has been enhanced, and if improvements in site characteristics may also benefit future rotations. The Accelerator trials represent an ambitious research goal that will take planted forest productivity to a new level of enhanced long-term forest productivity without compromising the sustainable management of future forests.