RESUMO
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.
RESUMO
BACKGROUND: Reducing net greenhouse gas emissions through conserving existing forest carbon stocks and encouraging additional uptake of carbon in existing and new forests have become important climate change mitigation tools. The contribution of harvested wood products (HWPs) to increasing carbon uptake has been recognised and approaches to quantifying this pool developed. In New Zealand, harvesting has more than doubled since 1990 while log exports have increased by a factor of 11 due to past afforestation and comparatively little expansion in domestic processing. This paper documents New Zealand's application of the IPCC approaches for reporting contributions of the HWP pool to net emissions, in order to meet international greenhouse gas inventory reporting requirements. We examine the implications of the different approaches and assumptions used in calculating the HWP contribution and highlight model limitations. RESULTS: Choice of system boundary has a large impact for a country with a small domestic market and significant HWP exports. Under the Production approach used for New Zealand's greenhouse gas inventory reporting, stock changes in planted forests and in HWPs both rank highly as key categories. The contribution from HWPs is even greater under the Atmospheric Flow approach, because emissions from exported HWPs are not included. Conversely the Stock Change approach minimises the contribution of HWPs because the domestic market is small. The use of country-specific data to backfill the time series from 1900 to 1960 has little impact but using country-specific parameters in place of IPCC defaults results in a smaller HWP sink for New Zealand. This is because of the dominance of plantation forestry based on a softwood mainly used in relatively short-lived products. CONCLUSIONS: The NZ HWP Model currently meets international inventory reporting requirements. Further disaggregation of the semi-finished HWP end uses both within New Zealand and in export markets is required to improve accuracy. Product end-uses and lifespans need to be continually assessed to capture changes. More extensive analyses that include the benefits of avoided emissions through product substitution and life cycle emissions from the forestry sector are required to fully assess the contribution of forests and forest products to climate change mitigation and a low emissions future.
RESUMO
Stakeholders in plantation forestry are increasingly aware of the importance of the ecosystem services and non-market values associated with forests. In New Zealand, there is significant interest in establishing species other than Pinus radiata D. Don (the dominant plantation species) in the belief that alternative species are better suited to deliver these services. Significant risk is associated with this position as there is little objective data to support these views. To identify which species were likely to be planted to deliver ecosystem services, a survey was distributed to examine stakeholder perceptions. Stakeholders were asked which of 15 tree attributes contributed to the provision of five ecosystem services (amenity value, bioenergy production, carbon capture, the diversity of native habitat, and erosion control/water quality) and to identify which of 22 candidate tree species possessed those attributes. These data were combined to identify the species perceived most suitable for the delivery of each ecosystem service. Sequoia sempervirens (D.Don) Endl. closely matched the stakeholder derived ideotypes associated with all five ecosystem services. Comparisons to data from growth, physiological and ecological studies demonstrated that many of the opinions held by stakeholders were inaccurate, leading to erroneous assumptions regarding the suitability of most candidate species. Stakeholder perceptions substantially influence tree species selection, and plantations established on the basis of inaccurate opinions are unlikely to deliver the desired outcomes. Attitudinal surveys associated with engagement campaigns are essential to improve stakeholder knowledge, advancing the development of fit-for-purpose forest management that provides the required ecosystem services.