ABSTRACT
Global climate change and shift towards a bio-economy has heightened the need to design sustainable forestry systems that balance economic, environmental and social benefits. In New Zealand, production forests are dominated by planted Pinus radiata, which makes up 90 % of the planted forest area. There is very little data driven evidence in New Zealand to support diversifying across a range of tree species and what timber and non-timber benefits may be gained by diversifying tree species in New Zealand's production forests. The New Zealand New Forest Trial Series (NFTS) was designed and established in 2013 on marginal pastoral land to address the knowledge gap for how afforesting land with different trees species, both exotic and indigenous to New Zealand, across a climate range can deliver to both timber and non-timber benefits. These trials were planted with Cupressocyparis ovensii, Eucalyptus fastigata, Fraxinus excelsior, Nothofagus fusca (plus Leptospermum scoparium), Pinus radiata, Podocarpus totara and Sequoia sempervirens plus a control with no planting to monitor natural succession. The Before-After-Control-Impact (BACI) experiment design has collected pre-planting data describing the present vegetation and a range of soil properties, presented in this paper. This will allow the comparative monitoring of the changes that will occur through planting the various tree species on marginal land in different environments through time. With time the long-term trials will deliver data evidence on tree species survival when planted into marginal pastoral land, tree productivity and the flow of economic, environmental and social benefits from the new plantings. This knowledge will strengthen New Zealand's forestry sector confidence to make informed decisions to diversify tree species with changing climatic and social challenges.
ABSTRACT
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 Pinus radiata 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.
ABSTRACT
Future human well-being under climate change depends on the ongoing delivery of food, fibre and wood from the land-based primary sector. The ability to deliver these provisioning services depends on soil-based ecosystem services (e.g. carbon, nutrient and water cycling and storage), yet we lack an in-depth understanding of the likely response of soil-based ecosystem services to climate change. We review the current knowledge on this topic for temperate ecosystems, focusing on mechanisms that are likely to underpin differences in climate change responses between four primary sector systems: cropping, intensive grazing, extensive grazing and plantation forestry. We then illustrate how our findings can be applied to assess service delivery under climate change in a specific region, using New Zealand as an example system. Differences in the climate change responses of carbon and nutrient-related services between systems will largely be driven by whether they are reliant on externally added or internally cycled nutrients, the extent to which plant communities could influence responses, and variation in vulnerability to erosion. The ability of soils to regulate water under climate change will mostly be driven by changes in rainfall, but can be influenced by different primary sector systems' vulnerability to soil water repellency and differences in evapotranspiration rates. These changes in regulating services resulted in different potentials for increased biomass production across systems, with intensively managed systems being the most likely to benefit from climate change. Quantitative prediction of net effects of climate change on soil ecosystem services remains a challenge, in part due to knowledge gaps, but also due to the complex interactions between different aspects of climate change. Despite this challenge, it is critical to gain the information required to make such predictions as robust as possible given the fundamental role of soils in supporting human well-being.
