The Indian Council of Agricultural Research has set a target for increasing forest cover from the present level of 23% of land area to 33% and agroforestry contributes to this target. Methods: The effect of agroforestry on carbon sequestration and livelihood security of people in India was reviewed. Also, a survey was conducted in two regions of West Bengal, one drought-prone and the other in a mountainous district, to assess the contribution of agroforestry to human well-being and livelihood security. Results: The average carbon sequestration potential of agroforestry systems is estimated to be 25t.ha-1 over 96 million ha but there is substantial regional variability. The survey showed that village communities are dependent on agroforestry systems for income, employment opportunities and livelihood security. An account is also given of Government forestry and tree-planting programmes that encourage the practice of silvipasture, agrisilviculture, and agrihorticulture in rain-fed and irrigated areas. Conclusions: Agroforestry systems offer opportunities for the improvement of the livelihood of poor people through provision of economic and environmental security.

The areas of commercial wood plantations in Australia and New Zealand are 2.01 and 1.71 million hectares respectively, representing the predominant type of planted forest. Methods: This paper reviews the status of planted forests in Australia and New Zealand and discusses opportunities for further development taking into account economic, social and environmental factors. These factors include regional wood demand and supply conditions, emerging markets for ecosystem services, climate change impacts and social attitudes toward planted forests. Results: Both countries have followed a similar pattern of state intervention for the development of wood plantations, relying on government ownership and direct incentives such as taxation concessions that have gradually shifted to the use of more indirect policies. The main drivers for wood plantations were as an additional source of wood outside the natural forest, improved productivity and regional development. More recent policy has focused on the privatisation of forest assets and the promotion of ecosystem services such as carbon sequestration. To date, plantings for ecosystem services such as carbon sequestration has been limited. Conclusions: It is argued that better design of policy settings is needed to capture the carbon abatement benefits and other ecosystem services from planted forests, which may help overcome current investment hurdles. Careful attention will also need to be applied to managing future climate change risks as well as to realising the opportunities from forecast growth in wood and fibre product demand particularly in the Asian region.

Timber insurance is a form of risk management that can be used to protect forest owners from the effects of various types of disaster. Methods: A recent court ruling on a legal case in the United States is used to illustrate reasons for the lack of uptake of timber insurance and its effects on those dependent on forestry for their livelihood. Operational aspects of the timber insurance market are described and compared with markets for insurance of real estate and agricultural crops. The scope and implementation of timber insurance in several countries are reviewed, and some practical guidance is offered to those intending to develop a timber insurance programme to encourage investment in the growth of planted forests. Results: Salient features of the forest insurance market are described and the markets in a number of countries are reviewed. Conclusions: The development of timber insurance market requires some form of intervention by government or landowner associations.

The 27 countries in the European Union have a combined total of 177 million ha of forested and other wooded land. These are mainly characterised as semi-natural, multi-functional forests. Only about 13 million ha are characterised as plantationsi, although an additional 47 million ha are regarded as planted forests (Forest Europe 2011). European forests are highly diverse due to centuries of management in countries with different cultural objectives. Often the current management is nature oriented and so forests may not be used primarily for wood production. Wood provides only a small part of the income for many of the 16 million private owners according to the Confédération Européenne des Propriétaires Forestiers (CEPF 2013). These circumstances, plus sluggish demand for wood brought about by the current economic crisis, have generated challenges for the forestry sector. Demand for wood is expected to increase with expansion of the green economy and an increased emphasis on the use of bioenergy. Methods: Three forest management scenarios (analysed with the EFISCEN model) were used to project supply in response to demand for wood from EU forests over the next 50 years. Results: Shortening of broadleaved forest rotation length and planting 50% of the felled area with fast-growing coniferous species could increase coniferous wood supply from 473 to 561 million m3 y-1. Demand could reach more than 1200 million m3 y-1 by 2065. Conclusions: Conversion of 50% of broadleaved forest in EU27 countries to coniferous forest is not likely to satisfy the increased demand for wood expected by 2065.

Prior research in 2005 and 2008 estimated planted forest investment returns for a set of countries and included some natural forest species in a few countries. This research has extended those analyses to a larger set of countries and focused on plantation species, for seven years. This research serves as a “benchmarking” exercise that helps identify comparative advantages among countries for timber investment returns, as well as other institutional, forestry, and policy factors that affect investments. Furthermore, it extends the analyses to examine the effects of land prices, environmental regulations, and increased productivity on timber investment returns, as well as comparing timber returns with traditional stock market returns. Methods: We estimated financial returns in 2005, 2008, and 2011 for a range of global timber plantation species and countries, using net present value (NPV), internal rate of return (IRR), and Land Expectation Value (LEV)–or the Faustmann Formula–as criteria. Per the Faustmann approach, we excluded land costs initially, using a common real discount rate of 8% for all species in all countries to make equivalent comparisons. Results: Returns for exotic plantations in almost all of South America–Brazil, Argentina, Uruguay, Chile, Colombia, Venezuela, and Paraguay–were substantial, as well as in China. In 2011, returns for Eucalyptus species were generally greater than those for Pinus species in each country, with most having IRRs of 14% per year or more. The IRRs for Pinus species in South America were slightly less, ranging from 8% to 12%, except for Brazil, where they were 19% to 23%. Internal rates of return ranged from 5% to 12% for plantations of coniferous or deciduous species in China, South Africa, New Zealand, Australia, Mexico, and the United States. Although lower than returns from South America, these would still be attractive to forest investors. Land costs and environmental regulations reduced plantation investment returns for all the countries studied, but the largest reductions were observed in South America. However, net returns these remained greater than for plantations in temperate forests. Conclusions: Trend analyses indicated that Brazil had the greatest increase in timber investment returns during the period examined; returns in other southern hemisphere countries remained fairly stable; and the US South had substantial decreases in returns. New Zealand, Australia, the United States, Chile, and Mexico had the best rankings regarding risk from political, commercial, or government actions and for the ease of doing business. Conversely, Venezuela, Colombia, and Argentina had high risk ratings, and Brazil and Venezuela were ranked as more difficult countries for ease of business. Recent government actions in several countries in South America, except Colombia.

Soil fertility management and forest nutrition are key factors determining management and productivity of both natural and planted forests. Reference values for foliar and soil nutrient contents and assessment of nutrient balances to evaluate the sustainability of planted forest systems can guide forest managers in determining whether or not additional fertilisation is required. Methods: This review summarises the authors’ research into the nutritional requirements for planted teak (Tectona grandis L.f.) forests in Central and South America. Teak is an important species for commercial forest plantations, usually in carefully selected productive sites, with rotations of 20-25 years and commercial volume anticipated to be around 10 m3 ha-1 year-1. Results: Foliar nutrient concentration values can be used as a reference to evaluate the nutritional status of planted teak forests. In addition, there may be an association between the dynamics of the concentrations of K, Mg and N with tree age and the age-related declines in teak productivity. Timber extraction by felling constitutes a major nutrient output from the system and repeated nutrient exports during several rotations could be a cause of soil nutrients depletion, especially P and K which typically have low availability in these Central American systems. Multivariate analyses have been shown to be appropriate and helpful tools for grouping forest stands by fertility classes (i.e. soil management zones using the terminology of precision agriculture). Conclusions: The techniques developed can be used as tools for the design of efficient fertilisation programmes, taking into account the inherent heterogeneity of soil fertility across different stands. This is considered as a first step towards a precision forestry scheme. Whether age-related changes in nutrient concentrations are a cause or a consequence of age-related declines in productivity is an important issue for future research.

For economists, what matters is not how ecosystem services are classified, but what change in human well-being results from increasing, reducing or qualitatively varying their supply. Eight general approaches are available for valuing non-market effects: marketable benefits may be generated or lost elsewhere in the economy; costs may be imposed or alleviated elsewhere; costs willingly incurred by past decision-makers may be taken as indicating their valuation; sufficiently similar services may be traded elsewhere; consumers may voluntarily support “good causes”, including through price premia for environmentally friendly production; individuals may be asked their hypothetical willingness to pay for change in an environmental condition; experts may estimate what a reasonable willingness to pay might be; market products may exist which give access to ecosystem services or escape from disservices. All approaches have drawn criticism, which itself has drawn rebuttal and improvement from their proponents. All approaches have been applied to the regulating and supporting effects of forests on the qualities of land, watercourses, atmosphere and biological resources. Enormous valuations may be given when consumers attribute symbolic significance to or derive a “warm glow” from favouring a particular ecosystem. This may arise in response to questionnaires or by paying premia for certified goods. But directly elicited or implicitly accepted willingness to pay for ecosystem services requires consumers to have improbable understanding of processes: willingness to pay for final products, services or disservices delivered to the consumer is a more appropriate basis. Planted forests may have adverse as well as beneficial effects on watercourses, e.g. by reducing hydroelectricity output. With rapidly rising carbon prices, the carbon transactions of a single commercial forest cycle may have negative overall value. These examples illustrate that results may be surprising, but all of them are context dependent. Foresters should not regard economics as intrinsically hostile to ecosystem service provision, nor assume that forestry is always favoured by economic valuation of those services. © 2014 Price.

In common with many other countries, native forest in the Ireland is under pressure from a variety of sources. Although the area of forest has increased to 10.5% of the land area of Ireland, this is comprised mainly of exotic conifer species (6.8%). Native species woodland represents only 100,000 hectares (1.4%) of the land area. In addition, much of this area is fragmented and comprised of a narrow range of species. Just 20,000 hectares is represented by woodland resembling the ancient woodland that once covered much of Ireland. Methods: This paper examines the natural capital value of the existing area of woodland as represented by the value of the ecosystem services it provides. Results: The results demonstrate a significant economic value in excess of €67 million per year. We discuss the consequences of the erosion of this value that could result from continued mismanagement of native woodland. The results show that current government policy is failing to realise the economic value of native woodland and is deficient in terms of the continuity of support. Conclusions: The paper demonstrates the very significant values that could be supplied by a gradual expansion of woodland area up to 100% of the current forested area, especially if this expansion is targeted at areas with the highest potential for amenity and water resource protection.

Planted forests are expanding throughout the world, and now account for 7% of global forest cover and provide more than 60% of global industrial round wood. Negative ecological and social impacts of the establishment of planted forests and the challenges of their multi-purpose management have also given rise to concern. China has been playing an important role in global expansion of planted forests while reducing emission from deforestation and forest degradation. Methods: This article attempts to conduct an overall analysis and review of the current status, challenges and future perspectives of planted forests in China to obtain a better understanding on how to manage planted forests for multiple uses under a changing environment. Data from several national forest inventories and other sources, as well as new empirical data, were used for a statistical analysis on the dynamics of planted forests in China. Results: Planted forests in China have undergone a continuous expansion in the past 20 years, which has significantly contributed to an increase in total forest cover and timber supply as well as other ecosystem services like carbon sequestration. The three key driving forces for this expansion were government programmes, and market and technology development. However, the predominance of very few tree species in the plantations, uneven spatial distribution, skewed age-class distribution, and low volumes in growing stock, coupled with increasing complexity of multiple purpose forestry management under a changing environment, have generated several major challenges confronting planted forests in China. Conclusions: A strategic transition in the management of Chinese planted forests is needed, with a shifting emphasis from area expansion to stand productivity and quality enhancement, from traditional timber production to multi-purpose management for forest goods and services, and from monoculture plantations to biodiversity rich mixed forests. A landscape-design approach and adaptive management practices should be put in place to meet the diversified demands of stakeholders for different goods and ecosystem services while enhancing forest resilience under the changing climate.

Planted forests are increasingly important in world forestry, natural resources conservation, and climate change policies. There is great interest in their potential for carbon sequestration and conservation of natural forests while they remain an essential source of fuelwood and industrial roundwood. Methods: A method was developed for estimating the importance of planted forests in the global forestry sector. This was based on calculation of a global economic equilibrium with or without planted forests, using an adaptation of the Global Forest Products Model (GFPM) to simulate wood production in seven regions representing a total of 180 countries. The GFPM was then used to calculate production, consumption, trading balance, and price of forest products in 2009. Results: The utilisation of planted forests was estimated to reduce prices of forest products by 24 - 37%, and those of manufactured products by 4 - 14%, depending on the level of processing. World production of fuelwood was 4% greater due to the utilisation of planted forests, and industrial roundwood production was 14% higher. Conclusions: Although an increase in the level of consumption of end products was noted for all regions, production was sometimes lower if the effect of reduced prices was greater than the effect of the increase in wood supply. Nevertheless, the gain in global financial benefit to consumers far exceeded the loss of producer profits, leading to an estimated net gain of US$10,000 ha-1 in net present value at 2009 prices. Furthermore, planted forests reduced roundwood harvesting from natural forests by 26%, thereby contributing to ecological benefits such as carbon sequestration and biodiversity conservation.

To quantify the ability of genetics to provide a solution, RNC was assessed on a single clones-within-families genetics trial using two methods: the percentage needle cast that was attributable to red needle cast symptoms; and the percentage needle cast where the causal agent was not clearly identifiable. Both needle cast assessment methods were found to be heritable (ĥ2 0.21-0.31).Conclusions: Selecting for tolerance to RNC is likely to deliver healthier trees. More assessments across a number of sites and seasons are required to confirm this result.Background: Red needle cast (RNC) is a new needle disease of Pinus radiata D. Don (radiata pine) in New Zealand that is causing significant, but as-yet un-quantified, loss of growth and productivity. This foliar disease has recently been attributed to the infection of the needles by Phytophthora pluvialis Reeser, Sutton & E Hansen. Genetic improvement is seen as a possible solution to mitigate the effects of this needle disease on forest productivity.

Descriptions of five species of fungi recorded on trees and shrubs are given in this paper. Three species are recorded from New Zealand for the first time, a new combination is proposed for one species and the fifth species has been recorded only once before. The fungi are:Fungal species described: Corticolous Ascomycota: Rugonectria castaneicola (W.Yamamoto & Oyasu) Hirooka & P.Chaverri on Quercus robur Linnaeus × canariensis Willdenow.Foliicolous Ascomycota: Acrospermum gaubae Petrak on Banksia ericifolia Linné fil. × spinulosa J.E.Smith and on B. spinulosa J.E.Smith; Dictyothyrium hibisci (F.Stevens) comb. nov. on Hibiscus rosa-sinensis Linnaeus.Foliicolous coelomycetes: Pestalotiopsis adusta (Ellis & Everhart) Steyaert on Macadamia tetraphylla L.A.S.Johnson; Septoriella halensis B.Sutton & Melnik on Pachystegia insignis (Hooker fil.) Cheeseman.

Successful plantation efforts growing Robinia pseudoacacia L. (black locust) in the drier regions of Hungary and East Germany (Brandenburg), have demonstrated the potential of black locust as an alternative tree species for short-rotation biomass energy plantations.Methods: The response of black locust to water limitation was investigated in a lysimeter experiment. Plants were grown under three different soil moisture regimes, with values set at 35%, 70%, and 100% of the soil water availability, namely WA35, WA70, and WA100. Their morphological adaptation and productivity response to water constraint were assessed together with their water-use efficiency. Furthermore, the ecophysiological adaptation at the leaf level was assessed in terms of net photosynthesis and leaf transpiration.Results: During the growing season, plants in the WA35, WA70, and WA100 treatments transpired 239, 386, and 589 litres of water respectively. The plants subjected to the WA35 and WA70 treatments developed smaller leaves compared with the plants subjected to the WA100 treatment (66% and 36% respectively), which contributed to the total leaf area reduction from 8.03 m2 (WA100) to 3.25 m2 (WA35). The total above-ground biomass produced in the WA35 (646 g) and WA70 (675 g) treatments reached only 46% and 48% of the biomass yield obtained in the WA100 (1415 g). The water-use efficiency across all treatments was 2.31 g L−1. At vapour pressure deficit (VPD) values <1.4 kPa trees growing under the WA35 soil moisture regime showed a stomatal down-regulation of transpiration to 5.3 mmol m−2 s−1, whereas the trees growing under the WA100 regime did not regulate their stomatal conductance and transpiration was 11.7 mmol m−2 s−1, even at VPD values >2 kPa.Conclusions: Black locust plants can adapt to prolonged drought conditions by reducing water loss through both reduced transpiration and leaf size. However, under well-watered conditions it does not regulate its transpiration, and therefore it cannot be considered a water-saving tree species.

The establishment of even-aged planted stands of New Zealand kauri (Agathis australis (D.Don) Lindl.) for timber has been constrained by a lack of quantitative information on productivity and rotation length on which forest management and investment decisions could be made.Methods: Stand-level models of height and basal area against time were developed (as well as a stand-volume function to calculate volume from height and basal area) based on planted stands that were up to 83-years old and represented planting sites both within and outside the current natural range of the species.Results: Planted kauri was shown to be slow to establish with little height growth for the first five years after planting. Similar trends were observed for basal area and whole-tree volume development. A Schumacher equation with local slope parameter and asymptote bounded at 45 m gave the best fit for height, while a von Bertalanffy-Richards equation in difference form with local slope parameter gave the best fit for basal area. For plantations with an average site index (20.4), height was predicted to be 22.3 m in height at age 60, with a basal area of 78.1 m2 ha−1. Whole-tree volume was predicted to be 702 m3 ha−1. Predicted volume mean annual increment was 11.7 m3 ha−1 yr−1for all stands at age 60. From age 20–60 years, stands with a higher site index had a volume mean annual increment of 18.6 m3 ha−1 yr−1. The best stand exceeded 20 m3 ha−1 yr−1.Conclusions: This study indicates an opportunity to grow kauri in plantations on selected good-quality sites over rotations of 60–80 years or less.

To understand the underlying control of patterns of important wood properties is fundamental to silvicultural control of wood quality and genetic selection. This study examines the influences of site, silviculture and seedlot on diameter growth, wood density and estimated wood stiffness in mid-rotation radiata pine (Pinus radiata D Don) stands across New Zealand.Methods: Selected treatment combinations were assessed across five sites in a 17-year-old experiment comparing silvicultural treatments and improved breeds of radiata pine. Diameter at breast height (DBH), and stress-wave velocity (an indicator of wood stiffness) and outerwood (outermost five growth rings) basic density at breast-height were assessed for ten trees from each plot in the experiment.Results: There were large differences in DBH and wood properties between sites. Silviculture (stand density) had a stronger influence than seedlot on DBH and stress-wave velocity, while the converse applied to outerwood density. There was a positive relationship between stand density and both stress-wave velocity and outerwood density. Trees in the un-pruned 500 stems ha−1 treatment had larger DBH, lower outerwood density and lower stress-wave velocity than trees in the 400 stems ha−1 pruned treatment. This suggests that silvicultural manipulation (pruning) of green crown length is important for controlling both growth and wood properties.Conclusions: Results from this study support previous research which indicates that thinning, and to a lesser extent pruning, have a strong impact on DBH, stress-wave velocity and outerwood density. Increasing stand density is consistently associated with stiffer and denser outerwood.

Microfibril angle (MFA) is a property of wood cell walls that has a strong influence on end-product quality, particularly for solid timber. Forest managers, tree breeders and wood processors require more quantitative information on the inter- and intra-stem variation in MFA in order to understand the impacts of their decisions on wood quality. The aim of this study was to develop parametric models that can be used to predict the intra- and inter-stem variation in MFA in radiata pine (Pinus radiata D. Don) trees growing in New Zealand Methods: Empirical models were developed using a dataset that contained records from 347 trees in which radial profiles of MFA have been measured at different heights up the stem. Radial variation in MFA was modelled as a function of cambial age using both a modified logistic function and a modified Michaelis-Menten equation. Additional terms were added to these models to account for differences in MFA with relative height up the stem. Results: Values of MFA ranged from more than 40° near the pith to approximately 10-15° in the outerwood. Values greater than 30° were largely confined to the inner rings of the butt logs. A variance components analysis showed that most of the variation in MFA occurred within stems, with less than 15% of the variation due to differences between sites. The final models were able to account for 57-63% of the variation in MFA and inclusion of a relative height term significantly improved the model fit. Conclusions: Radiata pine has a region of high microfibril angle in the first 10-15 growth rings from the pith, particularly at the base of the tree. Growth rate had a small positive influence on average MFA (wider rings resulting in higher MFA values). Site differences were small, indicating that regional variation in wood stiffness is due more to the known trends in wood density. The models developed here can be coupled to growth models to examine how the combination of site productivity and silvicultural regime affect the size of the central zone containing high MFA wood.

The effect of soil erosion on New Zealand production forestry is not well known and there has been no research prior to our study into the relationship between soil nutrient status and planted forests growing in eroded soils in steeplands. Methods: The impact of soil erosion by mass movement on forest productivity was investigated in a paired plot trial in a planted forest in a mainly hilly to steepland catchment (Pakuratahi) near Napier, eastern North Island, New Zealand. Tree growth and form were measured and soil properties analysed to compare productivity and productivity drivers in adjacent non-eroded and eroded plots. Results: Regression analysis showed that the decreased soil total nitrogen, total carbon, total phosphorus, and soil organic matter content in eroded plots had a negative impact on tree volume, resulting in a 10% decrease in measured tree volume. Based on an assessment of log quality, trees in the eroded plots were forecast to produce 16% less volume from high-quality pruned logs (with associated reduction in revenue of around $4000 per hectare), than trees in non-eroded plots. The total recoverable volume (TRV), estimated (for a 25-year rotation) from the measured Pinus radiata D. Don trees growing on the eroded sites, was valued at $68,500, about 9% less than the estimated TRV from trees measured on non-eroded plots ($76,000). Tree form and mean tree height in eroded and non-eroded plots were not significantly different. Conclusions: Soil erosion impacts production in planted forests. Afforestation of erodible land provides a valuable ecosystem service through land and soil stabilisation but this service is currently not reflected in the market prices for timber in New Zealand. Maintaining the productive capacity of erodible soils through practices such as fertilisation or continuous-cover forestry can add further costs to production forestry. To ensure that sustainable forest practices are carried out to protect the productivity of soils, financial incentives may be justified.

Invasive wilding conifer species are a major threat to biological conservation in New Zealand. Scattered individual plants are particularly problematic as these are very costly to treat and once they reach reproductive maturity can act as point sources for further invasion. A novel method is described in this paper that delivers a precise dose of oil-based herbicide mixtures into the tree crown via a hand held lance using a helicopter as a platform. Using this method the objective of this research was to test the efficacy of six triclopyr based herbicides in an oil carrier, on isolated naturally occurring Pinus contorta (Dougl.) and P. nigra subsp. laricio (Poir.) Maire. Methods: For each species and treatment combination treated trees covered a wide range of heights, ranging from ca. 0.5 to 16 m. Measurements of mortality taken 24 months post herbicide application were used to examine variation in efficacy of these herbicides, where successful treatment was defined by a mortality rate of 85% or higher. Logistic regression models were fitted for each species and from these models we determined the threshold tree height at which 85% mortality occurred, H85. Results: For both species treatment efficacy significantly (P ≤ 0.05) declined as tree height increased. The two most effective treatments for both species were a 500 mL dose that included 60 g triclopyr in oil with addition of 1% alkylsilicone surfactant (20 G OM 500 mL) and a 1 litre dose that included 120 g triclopyr and 20 g picloram in oil (10G T20). Values of H85 for 10G 20T and 20 G OM 500 mL were, respectively, 7.7 m and 8.0 m for P. contorta and 7.1 m and 6.8 m for P. nigra. Conclusion: Spot application of triclopyr based herbicides, in an oil carrier, onto the tree crown was found to be an effective means of controlling two of the most vigorous New Zealand wilding conifer species.

This review summarises two key aspects of in vitro plant tracheary element (TE) culture systems: establishment of in vitro TE systems and methods for analysing TEs, based on examples of in vitro TE systems in angiosperms and gymnosperms. A comparison between different TE systems suitable for various species and recent research studies are also presented along with a presentation of the issues and future challenges underlying in vitro TE systems.

The design, construction and application of a Pinus microarray platform are described. The oligonucleotide microarray was developed using publicly available Pinus cDNA sequences mostly derived from Pinus taeda to test whether heterologous hybridisation of microarray probes will generate useful data when hybridised with cRNA constructed from the dominant New Zealand forestry species Pinus radiata. Methods: A comprehensive consensus sequence collection of Pinus cDNA sequences was collated into a non-redundant database used for automated design of 60-mer oligonucleotide microarray probes. The microarray slides, manufactured by Agilent Technologies (Palo Alto, California), were used to monitor gene expression in an induction experiment using 2-chloroethylphosphonic acid, common name ethephon and the active ingredient of the plant growth regulator Ethrel® (Bayer Crop Science). The transcriptomes from tissues of 2-year old Pinus radiata saplings +/− ethephon treatment were compared by hybridisation onto the Pinus microarray slides. Results: Statistically significant differentially expressed genes identified by heterologous hybridisation to the Pinus microarray following ethephon induction included the up-regulation of genes in the xylem that were related to the metabolism of phenylpropanoids and flavonoids, and also defence responses, specifically against fungal/insect attack and oxidative stress. Bark, mucilaginous xylem and xylem generated largely mutually exclusive cohorts of genes and Gene Ontology (GO) classes. The results are also interpreted in reference to gross and microscopic morphological changes. Samples of gene responses were validated by quantitative RT-PCR. Conclusion: These results confirm the successful development of a Pinus microarray and demonstrate the utility of the microarray for transcriptomic research in Pinus radiata through heterologous hybridisation.

Tawa (Beilschmiedia tawa (A. Cunn.) Kirk) remains a minor but significant hardwood timber in New Zealand, currently sourced from tawa-dominant forest on freehold and Maori land where selective harvesting under sustainable management plans is permitted. Sustainable management plans require reliable tree growth estimates, which are used to calculate annual volume increment and harvest levels. The aims of this study were to model the relationship between diameter growth rate and tree size using existing data, and to determine the influences of within-stand competition, local climate and soil parent material on growth rates.Methods: A dataset was compiled on the diameter growth rates of nearly 1800 trees from a wide range of published and unpublished sources for the middle North Island. Non-linear quantile regressions were used to model average growth and growth of the fastest 25% of stems, termed rapid growth.Results: Across the middle North Island, average growth of a 400 mm DBH (diameter at breast height) tree was 1.8 mm year−1 and rapid growth was 2.8 mm year−1. Overall, the model accounted for 12% of the total variation in growth rate. The effect of size on diameter growth rate was modest but positive. Within-stand competition reduced tawa diameter growth rates, particularly when basal area exceeded 100 m2 ha−1. Also, climate (winter minimum temperature and annual vapour pressure deficit) had little influence on growth rates and explained <2% of total variation in stem growth. Soil parent material strongly influenced tawa growth rates and explained >10% of variation in stem growth. The fastest growth rates were on soils derived from Tertiary mudstone in inland Taranaki.Conclusions: Most of the existing data on growth rates of tawa are for trees growing on volcanic substrates. This means that the markedly faster growth on some sedimentary rather than volcanic substrates suggests that growth rates and volume increment may be underestimated for many sites in the middle North Island beyond the Volcanic Plateau. A growth dataset more representative of the range of substrates occupied by tawa is needed for management plans elsewhere in the North Island.

Effective use of the high capital cost equipment in a central processing yard requires a good understanding of the human component of the system. Poorly designed work schedules have been linked with mental and physical fatigue of the machine operators, low productivity and low value recovery for some operations. The aim of this study was to determine if time of day impacts machine productivity and value recovery in an off-forest central processing yard.Methods: A database, containing over 120,000 records on Pinus radiata D.Don (radiata pine) stems processed during 214 work shifts, was analysed in order to determine the impact of time of day on value recovery and productivity of log-handling equipment that consisted of a scanning optimiser and two mechanised processors operating in an off-forest central processing yard in New Zealand.Results: Analyses indicate time of day negatively impacted volume productivity and value recovery for the scanning optimizer between the first shift operating mainly in daylight hours and the second shift operating mainly during night hours. There were no clear trends in productivity for the mechanised processors.Conclusions: These findings are in agreement with an earlier study carried out in on-forest mechanised harvesting operations in Chile but differ from findings of another off-forest central processing yard in New Zealand.

LiDAR is an established technology that is increasingly being used to characterise spatial variation in stand metrics used in forest inventory. As the cost of LiDAR acquisition markedly declines with LiDAR pulse density, it is useful to identify how far pulse density can be reduced without compromising the precision of relationships between LiDAR and stand metrics. Using plot measurements and LiDAR data obtained from highly stocked and unthinned Douglas-fir plantations (Pseudotsuga menziesii [Mirb.] Franco), the objective of this research was to characterise the precision of regressions between LiDAR metrics and stand metrics (mean top height, Hm, volume, V and mean diameter, D) under a range of pulse densities using Digital Terrain Models (DTMs) representing two common scenarios. Under the first scenario, which represents an initial acquisition, the point cloud was sequentially culled and used for creation of a DTM and corresponding LiDAR cloud metrics. In the second scenario, which represents a subsequent acquisition, a DTM generated at high pulse density (10 pulses m−2) was used for the creation of the corresponding LIDAR cloud metrics. Methods: Models describing the precision of regressions between LiDAR metrics and stand metrics were developed at 10 pulses m−2. LiDAR data were culled to pulse densities ranging from 10 to 0.01 pulses m−2 and the impact of culling on the precision of these regressions was examined under the two scenarios. Results: For the scenario with the culled DTM, precision of the three models remained stable until densities of 2 – 3 pulses m−2 were reached. Below this threshold, there was a gradual decline in precision to pulse densities of 0.7 – 1 pulses m−2 at which point the R2 was 95% of the maximum values. Further culling of the data resulted in a sharp decline in model precision for all three regressions. For the scenario where the DTM was held at a high pulse density, little change in the precision of the regressions was found until pulse densities of 0.04 to 0.2 pulses m−2 were reached. There was a sharp decline in precision below pulse densities of 0.04 pulses m−2 for all three models. Conclusion: This study was undertaken in highly stocked unthinned Douglas-fir stands located in areas with complex topography. Consequently, the pulse density thresholds described here are likely to be conservative and could be used to guide acquisition of high-quality LiDAR datasets for this species.

Sequoia sempervirens (D. Don) Endl.) (redwood) has the potential to be grown in New Zealand in commercial forestry operations and is valued for its naturally durable heartwood. A viable redwood industry based on planted forests can only be achieved if the timber produced meets quality expectations, in particular durability. Natural durability is highly variable among trees. Also, a within-tree pattern of low durability close to the pith has been observed. Natural durability is preliminarily caused by secondary metabolites deposited into the cell walls during heartwood formation. The exact nature of the compounds responsible for natural durability in redwood is unknown.Methods: Samples of heartwood from 22 different trees were obtained, ground and extracted using a range of solvents. The ability of some of these extracts to reduce the growth of two fungi (Gloeophyllum trabeum and Trametes versicolor) was tested in vitro. Information on the composition of the extracts was obtained using infrared spectroscopy and gas chromatography.Results: Fungicidal properties were found in solvent extracts of ground S. sempervirens heartwood samples at concentrations comparable to those known to be present in intact wood. The entire acetone-soluble extracts and ethyl-acetate-soluble fraction of the ethanol extracts caused the greatest reduction in the growth of both fungi tested. Large variations in acetone-soluble or ethanol-soluble extract content and fungicidal activity among trees were found. Agatharesinol and sequerin-C appear to be trace compounds in the dried extracts of S. sempervirens.Conclusions: Further work is needed to identify the key compounds contributing to the natural durability of S. sempervirens.

Instruments based on resonance are widely used in the forest industry to predict modulus of elasticity (MOE) and segregate logs of varying quality for different end uses for fast growing softwoods such as Pinus radiata D. Don. Predictions of MOE, made using resonance instruments, often assume a constant green density, ρg, of 1,000 kg m−3. However, little research has been done to test the robustness of this assumption. The objective of this research was to describe changes in predictive precision of MOE as ρg is increasingly well characterised.Methods: Longitudinal measurements of velocity, V, and ρg taken from eighty 17-year old unthinned P. radiata trees growing at two sites in Chile were used to calculate MOE. Predictions of MOE were then made by substituting measurements of ρg for values predicted by the following models (i) Model 1 - assuming a constant ρg of 1,000 kg m−3, (ii) Model 2 - using the mean tree ρg of 914 kg m−3, (iii) Model 3 - using a model with fixed effects to account for the mean longitudinal variation in ρg, (iv) Model 4 – inclusion of previous terms and random effects to account for tree level variation and (v) Model 5 – inclusion of previous effects (in model 4) and a random quadratic term. Differences in MOE determined from measurements of ρg and the five predictions of ρg were expressed as both a percentage difference, (D) and an absolute percentage difference (Da) to assess precision and bias.Results: At the tree level, values for mean D and Da (in brackets) were −9.9 (10.4)%, −0.459 (5.49)%, −0.262 (4.15)%, −0.045 (0.232)% and −0.0406 (0.189)%, for Models 1, 2, 3, 4 and 5, respectively. At the log level, considerable longitudinal bias in D was evident for Model 1 where over-prediction of MOE was greatest between relative heights of >0.1 − 0.4, with D reaching maximum values of −33.8% between relative heights of > 0.1 − 0.2.Conclusion: Assuming constant ρg can result in substantial error in estimates of MOE using acoustic instruments particularly when predictions are made at the log level. The mixed effects modelling approach described here demonstrates a useful method for characterising variation in ρg allowing more accurate estimates of MOE to be made using acoustic methods.

Poplars and willows are used widely in soil conservation in New Zealand to prevent shallow landslides on hill country. Determining when plants become effective at soil stabilisation is important for developing guidelines and policy for land management. The aim of this study was to determine if the size of plant material (0.5-m stakes, 1-m wands, 3-m poles) influences the early below-ground plant growth of poplars and willows used in conservation plantings.Methods: In a small field trial, the above- and below-ground growth of three forms of vegetative planting material (poles, wands, stakes) of two clones of poplar (Populus spp.) and willow (Salix spp.) were determined 9 months after planting. Whole trees were excavated and destructively sampled.Results: Plant growth was rapid and exceeded previously reported New Zealand rates. Willows performed better than poplars in above-ground growth metrics (net tree height, above-ground biomass) and 3-m poles performed the best of the planting types tested (net tree height, above-ground biomass, below-ground biomass, total root length). Lateral roots grew more than 2.5 m and up to 5.5 m from the stem in 9 months.Conclusion: While poles significantly out-performed smaller plant materials in most growth metrics and will continue to be the material of choice in most soil conservation applications, the growth of lesser-grade materials was still rapid and suggests that “lesser” grade materials could be used for erosion control especially where stock are excluded from planted areas. Root observations such as those from this trial, contribute to improving the understanding of how and when, and at what planting density, plants used in soil conservation become effective for controlling shallow landslide erosion in New Zealand.

Kauri (Agathis australis (D.Don) Lindl.) is endemic to New Zealand and is the southernmost species of the tropical genus Agathis.Methods: The growth history of the second southern-most known stand of New Zealand kauri is documented. This stand is located at Wairongoa Springs near Dunedin, approximately 8° of latitude south of the modern natural range of the species. This stand was established in the 1950s and now approximates a natural ‘ricker’ stand of juvenile kauri. Sample plot measurements of height and diameter growth taken in 2009 were compared to published 1986 data from the same stand, and were used for modelling self-thinning dynamics. An investigation was also undertaken using ring-widths from cores obtained by increment boring to generate a 52-year dendrochronological record that shows a strong common pattern of long-term and inter-annual changes in growth. Carbon isotope analysis of annual rings from 1983–2009 revealed corresponding multi-decadal chemical trends. Segmented linear regression was used to compare the ring-width record with existing kauri growth and self-thinning models.Results: Growth of kauri at Wairongoa Springs was fast, was comparable to other plantations of kauri without silvicultural tending, and was generally faster than that of natural stands. The growth of the stand can be considered as occurring in two apparent phases. The first was a 26-year period of relatively constant rapid growth with ring-widths averaging 3.5 mm while the second phase showed a steady decline in annual growth thought to be indicative of self-thinning due to increasing competition. This ring-width decline was matched by a gradual decline in the ratio of carbon isotope 13C to 12C.Conclusions: Ring-width measurements and carbon isotope determinations compared with forestry-based modelling of self-thinning in kauri suggest that this stand is undergoing self-thinning much sooner than other kauri stands. This result highlights other possible influences beyond simple biomass accumulation triggering the onset of self-thinning. The growth rate of the plantation is comparable to others from the North Island, demonstrating that kauri can be grown, albeit in sheltered sites, throughout the length of New Zealand.

There is increasing interest in establishing indigenous forests on marginal pastoral hill country in New Zealand to improve soil conservation, water quality and indigenous biodiversity. Large-scale reforestation using native seedlings is extremely costly. However, given suitable seed sources, it is possible to encourage natural regeneration of grassland into native plants.Methods: A grazed, sloping pasture site in Northland where totara (Podocarpus totara D.Don) regeneration had been allowed to develop over a 10-year period was assessed using a grid of 2-metre diameter plots. Counts of regenerating woody species and cover of herbaceous species were obtained in each plot. Plots were classified on the basis of herbaceous species cover using the TWINSPAN classification procedure. Regression analyses were used to identify site factors and characteristics of the herbaceous vegetation associated with totara regeneration.Results: More than 7,000 stems ha−1 of woody species, mostly totara and gorse (Ulex europaeus L.), had accumulated over the 10-year period despite the presence of cattle grazing. Regeneration of totara was associated with steeper slopes and sites with the greatest diversity of herbaceous species but with lower overall levels of herbaceous cover. The regeneration pattern of the other main woody species was similar although gorse colonised a wider range of sites. Regeneration of woody species was absent on flatter sites, which were dominated by a few high-fertility tolerant herbaceous species and had high levels of herbaceous cover.Conclusion: This study has shown that regeneration of totara on a pastoral hill-country site was most prevalent on steeper slopes of lower fertility with typically sparse vegetation cover comprising low fertility tolerant herbaceous species. Conversely, totara regeneration was absent on flatter areas of higher fertility. It seems likely that grazing assists totara regeneration by keeping pasture cover short, thus increasing light levels near ground level for newly germinated seedlings. The propensity for totara to regenerate on pastoral hill country in the presence of grazing and where there is a nearby seed source could provide a practical option for re-establishing indigenous woody vegetation on erosion-prone marginal land.

Three of the traits considered of most economic importance in the genetic improvement of Pinus radiata D. Don, termed as ‘key’ traits, are tree diameter (a proxy for stem volume), wood density and wood stiffness. A number of other traits (non-key traits) may be of equal importance to growers depending on where and for what purpose the trees are being grown. Two such non-key traits are: resistance to the needle blight caused by Dothistroma septosporum (Dorog.) M. Morelet, and reduced heartwood content. Methods: Data from two trial series (each planted at two sites, from a total of some 330 families (189 were half-sib and 142 were full-sib) with 10 to 30 individuals assessed per family) were analysed to determine the effect forwards selection of key traits had upon genetic gains of these two non-key traits. Results: Multivariate analysis for each trial provided estimates of trait narrow-sense heritabilities (h2) and genetic correlations between traits. Density was the most heritable trait assessed (ĥ2 0.50 to 0.72) with heartwood ring number (0.21 to 0.35), acoustic velocity (0.40), resistance to Dothistroma septosporum (0.20 to 0.34) and stem diameter (0.11 to 0.25) being less heritable. Wood properties were adversely correlated with growth rate to varying degrees. To estimate the impact of differing technical weights on multiple traits a selection index model was used. Strong positive genetic correlations (rg 0.69 to 0.87) between resistance to Dothistroma septosporum and stem diameter means that strong selection for stem diameter after severe Dothistroma attack assures genetic gain in resistance to Dothistroma septosporum. Strong selection for stem diameter compromised wood properties due to adverse correlations between the two. Heartwood ring number was almost uncorrelated with the other key traits, density and stiffness, meaning that zero or slight negative gain would be expected via indirect selection. Conclusions: In such instances, it is advocated that key traits be selected for in the breeding population using a selection index and that non-key traits such as heartwood be selected using independent culling in the production population.

There is wide variation in the wood properties of plantation-grown coast redwood (Sequoia sempervirens (D.Don) Endl.) in New Zealand. Contributing factors are the seed source, silviculture, growth rate and age of the trees in the plantation forests. Little is known about how these factors affect the variation of wood properties among and within the trees of New Zealand's coast redwood forests.METHODS:The wood of plantation-grown coast redwood trees from three forests in the North Island, New Zealand, was evaluated using butt log and breast height discs and cores, and in vitro decay tests with brown- and white-rot fungal cultures, to determine the variation in the heartwood content, basic density, and red colour and natural durability of the heartwood.RESULTS:The heartwood content of the coast redwood trees was strongly influenced by the age and size of the trees. The basic density of the wood varied widely among the trees in the forests. There were strong radial trends of heartwood colour and natural durability within the stems of trees, with differences among trees at the same growth rings. The heartwood showed a wide range of natural durability, with trees from the older forest stands having a higher proportion of durable heartwood.CONCLUSIONS:The diameter growth and age of the coast redwood trees, and the variation among and within the stems of trees will affect the wood properties. Faster diameter growth is likely to increase the heartwood content, and longer rotations will increase the quantity of durable heartwood. The variation among trees suggests there is potential for genetic improvement.

Plant community assemblage is influenced by many factors, including soil characteristics and the arrival of diaspores from surrounding areas. These factors may be especially important in transition areas, leading to spatial gradients in the plant community.Methods: This study was performed in the understorey of an abandoned Eucalyptus grandis W. Hill ex Maiden plantation between a savanna and a forest, 490 m apart, in south-eastern Brazil. This study assessed whether the spatial variation in several variables related to the understorey’s structure and composition is best described by linear or non-linear (quadratic) models. The linear model would indicate a gradient between the two vegetation types, whereas the quadratic model would indicate a stronger effect of the plantation’s edges.Results: There was a gradient in species composition between the two edges of the plantation. Mean vegetation height was greatest at the savanna edge and lowest in the centre of the plantation. The total number of individuals per plot and the phylogenetic diversity decreased with distance from the savanna edge. Different patterns were observed for different dispersal syndromes, with animal dispersal being more common at the savanna edge, wind dispersal in the centre of the plantation and self dispersal at the forest edge.Conclusions: The greater number of individuals at the savanna edge may indicate that dispersal and arrival of diaspores are the most important factors influencing community structure and composition of the understorey of this abandoned E. grandis plantation, with most propagules coming from the savanna area. The smaller vegetation height in the centre of the fragment may also indicate older colonisation at the edges. Therefore, in addition to highlighting the recovery potential of undergrowth beneath abandoned Eucalyptus spp. plantations, these results show that this recovery is spatially heterogeneous and that dispersal plays a large role in it. This should be taken into account in restoration projects. The authors recommend careful consideration before removing regenerating Eucalyptus spp. trees as part of the site restoration. Instead the focus should be on the recovery potential of the undergrowth, with gradual removal of Eucalyptus trees, if necessary.

Development of a relatively simple growth modelling approach for plantation species that allows derivation of cardinal (base, optimum and ceiling) air temperatures for growth, whilst accounting for changes in organism size, would represent a considerable advance over existing models. Such an approach would provide insight into species phenology and, in an agronomic setting, allow growers to closely match species to sites. Here, a model is described that can be used to predict seasonal variation in growth and cardinal air temperatures from simple seasonal measurements at a single site.METHODS:The model was applied to data from an irrigated trial comprising two Eucalyptus species and three Eucalyptus crosses. Using measurements of mean daily air temperature data and stem volume, taken over a two year period, the model was fitted to the data and used to estimate cardinal air temperatures for the five species/crosses.RESULTS:The model predictions corresponded well to the actual data for all five species/crosses, with R2 ranging from 0.993 to 0.999. The optimum air temperature, To, for E. camaldulensis x E. globulus of 26.9degreesC significantly exceeded To for the other four species/crosses, where To ranged from 15.4 to 18.7degreesC. As To for E. camaldulensis x E. globulus was close to the highest mean daily air temperature recorded at the study site, the air temperature modifier for this species was almost always sub-optimal and consequently this cross was not well matched to the site. In contrast, To for the other four species/crosses were considerably closer to the mean air temperature of the site with To for E. nitens most closely approximating the mean air temperature (15.4 vs. 13.0degreesC).CONCLUSION:The described approach can be used to account for complex variation in seasonal growth patterns and provides insight into how well a species may be matched to a particular site. As climatic information is available at a range of scales (from local to global), this type of model is likely to be useful for producing maps that describe species growth and areas of optimal suitability.

Phosphorous acid is being investigated as a fungicide for the management of a needle disease caused by Phytophthora pluvialis in Pinus radiata in New Zealand. However, little is known about the penetration characteristics of this fungicide into Pinus radiata foliage. This study was undertaken to determine: i) the penetration characteristics of a commercial phosphorous acid formulation, applied at 3 kg ha-1and 12 kg ha-1in 100 L water, into Pinus radiata foliage and, ii) the effect of four commercially available adjuvants on phosphorous acid uptake into Pinus radiata foliage. Efficacy of the best treatment was tested in vitro with two Phytophthora species, Phytophthora kernoviae and P. pluvialis.Methods: Foliar uptake of orthophosphoric acid radio-labelled with [32P] was used to determine penetration characteristics of phosphorous acid as affected by the adjuvants tested. Needles collected from potted Pinus radiata plants sprayed with the best performing treatment were used in a detached needle assay, where treated needles were exposed to the zoospores of the Phytophthora species being tested.Results: Uptake of the phosphorous acid formulation into Pinus radiata needles applied without adjuvants was low (3.9-6.6%) at both concentrations tested. An alcohol ethoxylate adjuvant (applied at 0.2%) and two organosilicone adjuvants (applied at 0.2%) were found to significantly increase uptake of the fungicide over that applied alone or in combination with pinolene (applied at 0.35%). Highest uptake of phosphorous acid into Pinus radiata foliage (51.6%) occurred over a period of 72 hours when the phosphorous acid was applied at the equivalent of 12 kg ha-1with an organosilicone blend adjuvant at 0.2%. A significant reduction in lesion length on infected needles was found relative to the control when the two phosphorous acid treatments were applied with 0.2% organosilicone blend adjuvant. However, there were no significant differences in lesion length between the two treatments.Conclusions: These results show that an organosilicone adjuvant significantly enhances uptake of phosphorous acid into Pinus radiata needles and may increase its efficacy against Phytophthora species.

Phytophthora pluvialis Reeser, W.L. Sutton & E.M. Hansen is the cause of a newly described disease, red needle cast, in certain stands of Pinus radiata D. Don in New Zealand that experience periodic foliage browning, while Phytophthora kernoviae Brasier, Beales & Kirk is also infrequently isolated from symptomatic needles.Methods: Studies were undertaken to test the possibility that these species may be transported on pine logs either as superficial contaminants or as colonists of bark or wood.Results: Pine-needle baiting found no evidence of Phytophthora species in bark samples or aqueous bark washes from stems of 603 symptomatic trees in 17 affected stands implying that survival after natural deposition of sporangia or zoospores is low or absent. The persistence of zoospores or oospores was evaluated at intervals after applying them at artificially high surface densities to the bark on log segments and incubating at five temperatures between 15°C and 35°C in the laboratory. The ability to re-isolate Phytophthora kernoviae decreased with time and increasing temperature, but this species was still obtained at low frequencies after 4 weeks at 15°C and 20°C following treatment with oospores of Phytophthora kernoviae. Phytophthora pluvialis could not be isolated under any conditions of time or temperature tested. Percentage vitality of oospores of both species as determined using tetrazolium bromide vital staining also decreased with time, although some oospores of both species remained alive after 4 weeks at all temperatures tested. In a further study to test potential log colonisation, Phytophthora spp. were not isolated from bark or xylem at or near points where zoospores, oospores or mycelium of either species were applied to the bark or sapwood of pine segments and incubated for 6 weeks under ambient or humid conditions at 17°C.Conclusion: The results of these studies suggest that occurrence of Phytophthora kernoviae or Phytophthora pluvialis on export logs from affected stands is negligible. In addition, although some remained alive, the substantial decline in vitality among artificially applied oospores implies that the survival of any few that may be naturally present on logs is likely to be slight. Based on the evidence from this work there appears to be little risk of transporting these Phytophthora species on New Zealand radiata pine logs.

Red needle cast, a new foliage disease of Pinus radiata in New Zealand is described. The disease has been variable in incidence and severity both regionally and in different years. The early symptoms of discrete olive coloured lesions, often with a narrow dark resinous mark or band, were first recognised in winter of 2008 in plantation forests on the eastern coast of the North Island. These lesions develop further to result in rapid needle senescence and premature defoliation. The disease has been termed red needle cast in New Zealand as affected trees have a reddish appearance prior to the casting of the needles. The subsequent four years of monitoring have confirmed that, depending on location, symptoms are first observed in late autumn through late winter. Newly developing spring and summer foliage is seldom affected. Isolation from needles using a Phytophthora-selective medium frequently yielded an unknown species of Phytophthora which was subsequently found to be identical to Phytophthora pluvialis, a species described from Oregon, USA in 2013 where it is not associated with disease. Infection appears to be limited to the needles with no recoveries of Phytophthora pluvialis having been made from the roots, stems or branches. Occasionally a second species of Phytophthora, P. kernoviae, was also recovered from needles with the same symptoms.Methods: Needle symptoms were described in the field from 2008-2012 with isolation onto Phytophthora selective media. Koch’s postulates was completed on potted plants and detached needles.Results: Symptoms were reproduced on both detached needles and potted plants of Pinus radiata when inoculated with zoospore suspensions of Phytophthora pluvialis.Conclusions: This paper presents evidence that Phytophthora pluvialis is the primary cause of red needle cast in New Zealand.

Wilding conifers are a major threat to biological conservation within New Zealand and currently cover at least 500,000 ha throughout the South Island. A range of herbicide treatments was applied to field trials established within wilding Pinus contorta (height range 1 – 15 m) and P. mugo (height range 0.5 – 5 m) infestations. Measurements of mortality taken two years post herbicide application were used to determine the efficacy of (i) the traditionally used contact herbicide diquat, applied in an application volume of 300 L ha-1, and (ii) a range of systemic herbicides applied in an application volume of 150 L ha-1. Methods: All herbicides were applied by helicopter using a coarse droplet spectra (VMD = 720 μm) to minimise spray drift. Damage assessments were made two years following application and trees were considered to have died if they had 100% dead foliage. The influence of height class and treatment on tree mortality was assessed using analysis of variance. Results: For a treatment to be considered effective, a mortality rate of over 85% should be achieved on all trees up to 8 m in height. Under this criterion, none of the treatments used in this study provided satisfactory control of the two wilding species. Application of 7200 g ha-1 glyphosate and 120 g ha-1 metsulfuron was significantly better than any other treatment, for both species, causing 64% mortality for P. contorta and 36% for P. mugo. The traditionally used herbicide diquat was the poorest performing herbicide for P. contorta and the second poorest performing for P. mugo, inducing respective mortality rates of 2.7% and 2.4%. For all herbicides used there was a significant decline in efficacy with increases in tree height. Conclusion: These results suggest that control of dense wilding pine stands using low spray volumes and coarse droplet size is unlikely to be successful as foliage coverage is poor.

The effect of storage duration and technique on the moisture content of radiata pine (Pinus radiata D. Don) biomass logs in New Zealand was studied. Methods: Two trials were established in the South Island to represent favourable and unfavourable storage conditions, namely: summer storage in a warm and dry location and winter storage in a cold and relatively wet location. In total twenty stacks were installed, each consisting of approximately 600 kg of radiata pine logs (wet initial weight), with treatments intended to compare small diameter logs, large diameter logs, large diameter logs split, as well as the effect of cover. Moisture content was gravimetrically determined at the beginning and the end of the trials. All stacks were weighed at 1 to 4 week intervals to follow the weight loss trend over time. Results: After 24 weeks in summer storage, the moisture content (wet basis) of radiata pine logs decreased from an initial value of 53% to between 33 and 21%. The decrease was greatest for uncovered small logs and decreased was smallest for covered large logs. Due to wet and cold weather conditions, logs stored in winter- dried very little over a 17-week period. Moisture content decreased from an initial value of 58% to between 51 and 49%, with no significant treatment differences observed in the winter trial. Conclusions: The best summer storage technique was the simplest and consisted of stacking small logs without any cover. The larger logs dried the slowest, but splitting accelerated drying significantly. Covering did not help and results indicated that, while covering is useful for preventing rewetting of dry logs, it does not improve drying of wet logs.

Regional governing organisations in New Zealand are developing new policies to assess and manage the effects of land use intensification on water quality. Such policies require an assessment to be made of potential nitrogen leaching losses from different land uses, particularly where land use may be becoming more intensive. This review compiles the information on nitrogen concentrations and fluxes in stream and soil water drainage from indigenous and planted forests in New Zealand. Nitrogen concentrations and losses in streams from undisturbed indigenous forests and from planted forests established on land that has not been developed for agriculture are low. Nitrogen concentrations and losses in streams draining forests established on pasture land are commonly higher than in streams from indigenous forests and from forests planted on non-agricultural land, however most of the values for planted forests on pasture land were influenced by high volcanic nitrogen inputs. The impact of afforestation of pasture land on nitrogen leaching is described, as are the effects of planted forest management practices including fertilisation, harvesting and herbicide use. Nitrogen leaching is generally not greatly affected by forest management practices, however fertilisation can cause large leaching losses in coastal sand forests. While nitrogen leaching from planted forests is normally less than from other major land uses, there are key times during the forest rotation when nitrogen leaching may occur, particularly in forests planted on coastal sands or pasture land. It is advantageous to minimise leaching at these key stages to limit adverse effects on the environment and maintain nitrogen in the soil for the benefit of crop nutrition. Measures to reduce nitrogen leaching losses in forests are discussed, as are practices to minimise nitrogen leaching of forest plantings in catchments with high nitrogen soils, where forests may be planted specifically to reduce nitrogen loss to sensitive waterways.

To understand the effects of silvicultural treatments on tree and product modulus of elasticity (MOE), an intensive study along the stand-tree-product value chain was conducted. Acoustic tests were performed on 460 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from two sites in the US Pacific Northwest. Methods: Trees on a site in Washington were 51 years old, while those situated in Oregon were 45 years old. Both sites comprised five plots: Plot A was the control, while Plots B, C, D, and E were prescribed with differing thinning treatments. Acoustic readings were stratified, and a sample of six trees per plot randomly selected from the stratified samples. Trees were harvested, cross-cut, and peeled into veneer. Veneer was acoustically tested, and density and MOE calculated for each sheet. Veneer sheets were grouped by parent bolt and tree, and MOE of the butt veneer bolt and the parent tree determined from the mean. Plot means were compared using one-way analysis of variance (ANOVA), and regression models developed with mean tree MOE as the response variable and non-destructive tree measures as explanatory variables. Further models were developed to demonstrate the relationship between tree diameter and the number of veneer sheets peeled, and between MOE of the parent tree and butt bolt. Results: MOE was negatively correlated with diameter and taper, and positively correlated with acoustic velocity, V. The relationship with V2, following the wave equation (MOE = ρV2) under the assumption of constant density, ρ, was no better than that with V. While the correlations suggest that thinning regimes that cause rapid diameter growth and increased taper may be susceptible to a reduction in overall stiffness, there was no evidence, as determined by ANOVA, to suggest that thinning reduces stiffness. On the contrary, mean MOE at plot E (light thinning) was 12.6 GPa and the control was 10.2 GPa, with the difference significant at the 10% level (p-value = 0.074). Conclusions: In general, trees with MOE exceeding the recommended tree breeding value of 11 GPa were of low taper and small diameter, suggesting that regimes with a lesser impact on taper and diameter, as demonstrated by Plot E, are worthy of further investigation.