Hardwood Plantations Research Articles

Ecophysiological drivers of hardwood plantation diameter growth under non-limiting light conditions

While light is a primary driver of tree growth and development, other environmental variables are also essential, including water, nutrients, and temperature. Ecophysiological studies have helped to uncover mechanisms underlying these interactive processes, but such trials have been mainly conducted on seedlings, with relatively few dealing with trees past the sapling stage. We used environmental and ecophysiological data collected on 28 trees (age 14–20 years) across three study sites in Indiana, USA for several growing seasons to identify variables that drive diameter growth of plantation-grown hardwoods past the sapling stage under non-limiting light conditions. Results showed that water stress (as reflected in leaf water potential) had the greatest influence on growth; relative diameter growth of black walnut (Juglans nigra L.), northern red oak (Quercus rubra L.), and white oak (Quercus alba L.) was reduced with increasing water stress. Compared to previous studies carried out with seedlings, results provide some evidence to suggest that ecophysiological responses to water stress may differ between seedlings, juveniles, and mature trees of the same species. Relative diameter growth of black walnut and northern red oak increased with increasing soil or leaf nitrogen. We did not find relationships between relative diameter growth of white oak and nutrient variables. Overall, these results have important implications for reforestation and forest management efforts in light of climate change.

Structuring the Environment of Landslide-Prone Disaster and Its Mitigation in The District of Banyumanik

This research is conducted in the district of Banyumanik Semarang. The objectives of this study are; (a) recognising the distribution of landslide-prone residencies in the district of Banyumanik; (b) recognising the community efforts in dealing with their landslide-prone residency environment. The sample is taken by Purposive Sampling Technique, i.e. by considering the possibility of an area to landslide. The researched variables are (1) Physical parameter of landslide-prone field in residency environment, (2) The efforts accomplished by the community to overcome landslide-prone environment. The result of this research has varied in five categories. They are residencies with very high, high, medium, low and very low of landslide-prone. Two countermeasures from the community to prevent landslide are; (1) physical prevention, covering: constructing embankments and drainage channels, sealing/covering cracks on the ground, building blocks, planting hardwood plantations, and (2) partnership prevention, a cooperation between the community with the related institution, such as disaster socialization and land use planning.

Track-Monitoring and Analyzing Machine Clearances during Wood Forwarding

This article reports on track-monitoring and analyzing machine clearances during wood forwarding across seasons and weather, using ultrasonic distance sensors in combination with time-stamped GPS xy locations, at 10 sec intervals. The resulting data, obtained from 54 harvesting blocks, were analyzed by machine type (two wood forwarders and one grapple skidder), stand type (softwood plantation versus natural hardwood stands), month, slope, cartographic depth-to-water (DTW) classes, number of passes along track, and machine speed. For the most part, clearances were highly variable, due to passing over stumps, rocks, harvest slash, brushmats, ruts, and snow cover when present. This variability was on average greater for the lighter-weight wood forwarders than for the heavier-weight skidder, with the former mostly moving along equally spaced lines on brushmats, while the paths of the latter spread away from central wood-landing sites. In terms of trends, machines moved 1) more slowly on wet ground, 2) faster during returning than forwarding, and 3) fastest along wood-landing roads, as to be expected. Low clearances were most notable during winter on snow-covered ground, and on non-frozen shallow DTW and wet multiple-pass ground. During dry weather conditions, clearances also increased from low-pass tracks to multi-pass tracks due to repeat soil compaction of broadened tracks. These results are presented block-by-block and by machine type. Each block-based clearance frequency pattern was quantified through regression analysis and using a gamma probability distribution function.

A comparative life cycle study of alternative materials for Australian multi-storey apartment building frame constructions: Environmental and economic perspective

The building construction sector contributes to a quarter of the total Australian Greenhouse gas emissions. These emissions are mainly attributed to the use of energy intensive materials. To achieve better environmental benefits and cost saving, the utilisation of wood-based construction materials is currently attracting attention. However, the manufacturing of engineered wood products consumes large quantities of chemicals and energy, which may have adverse environmental impacts. Therefore, a life cycle study was conducted to compare various materials for constructing the structural frame of a 4-storey apartment building compliant with the Australian building codes. Five alternatives were assessed: Laminated Veneer Lumber (LVL) manufactured from early to mid-rotation hardwood plantation logs (LVLm), LVL manufactured from mature hardwood plantations (LVLh), LVL manufactured from mature softwood plantations (LVLs), concrete and steel. The functional unit was defined as the whole building structural frame. Global Warming Potential (GWP), Acidification, Eutrophication, Fossil Depletion, Human-toxicity Potential (HTP) and Life Cycle Cost (LCC) were evaluated. The LVL generally performed better than concrete and steel structural products. Particularly, LVLm had the lowest GWP (2.84E4±233 kg-CO2-eq) and LCC ($128,855 ± 2797), which were less than a quarter of the concrete option. However, the usage of chemical preservatives and phenol-formaldehyde adhesive during the LVL production and treatment caused the HTP impact to be higher than the steel option. Monte Carlo Analysis showed that while the LVL options presented a higher sensitivity to the combined uncertainties, the overall ranking of the five options remained the same. Therefore, the inclusion of wood-based material in structural elements may significantly contribute to reduce the environmental impacts and the LCC of the construction sector.

Mechanical Properties of Rotary Veneers Recovered from Early to Midrotation Subtropical-Hardwood Plantation Logs for Veneer-Based Composite Applications

AbstractThis paper experimentally investigates the mechanical properties of rotary veneers peeled from small-diameter hardwood plantation logs, recovered from early to midrotation subtropical hardw...

Assessment of bioenergy production from mid-rotation thinning of hardwood plantation: life cycle assessment and cost analysis

Forestry thinning logs, a low-value by-product of the forestry industry, present an opportunity for bioenergy production. It can be converted into solid, liquid, and gaseous fuels via different conversion techniques. Comparative life cycle assessment and life cycle costing (LCC) analysis were conducted to evaluate six options: woodchip gasification for power generation; wood pellets gasification in combined heat and power plant; wood pellet combustion for domestic water and space heating; pyrolysis for power generation; pyrolysis with bio-oil upgrading to transportation fuels; and ethanol production for transportation fuel mix. The functional unit used in this study was the treatment of 1 Mg of biomass. Global warming; acidification; eutrophication; fossil depletion, human toxicity; and land use impact categories were considered. The LCC also included greenhouse gas (GHG) emissions costs. The effects of uncertainties in the system on the overall performance of the scenarios were also evaluated. The results showed that all options except for ethanol production are GHG emission negative. Woodchips gasification performed best in all environmental impact categories and had the lowest LCC ($177.6/Mg). Biomass drying consumed more than 50% of the energy requirement for all options except for production of liquid transportation fuels via upgrading of pyrolytic oil, in which case the fuel upgrading process was the most energy intensive. In terms of energy return, all options, except electricity production through pyrolysis, offered positive return. The results highlight the importance of using biomass with least possible processing in order to maximise environmental and energy return and minimise LCC.

Integrated science informs forest and water allocation policies in the South East of Australia

Groundwater-dependent ecosystems are particularly vulnerable to groundwater decline. The South East of South Australia has experienced considerable hydrological change due to drainage, clearance of native vegetation, irrigated agriculture, and forestry. Recent hardwood plantings in the Limestone Coast Prescribed Wells Area (PWA) have increased considerably since 2000, coincident with groundwater decline; however, the introduction of hardwood plantations coincided with a period of lower than average rainfall. Given the economic implications of modifying water allocation policy based on apparent anthropogenic causes, establishing the contributions to the observed declines in groundwater level was necessary. The water balance shows a net gain in water across the entire Lower Limestone Coast Prescribed Wells Area, yet sites with forestry land use show the water table has been declining at a rate up to 0.7 m yr−1 since 2004, whereas no long-term change has occurred in the water table depth at adjacent pasture sites. Forested areas have 4050 wetlands at risk with groundwater decline >0.3 m yr−1, covering a total wetland area of of 212 km2. A series of 15 policy scenarios were simulated using a groundwater flow model to examine how climate, land use, and particularly forestry would impact groundwater, with an imperative to enact policy to protect remaining wetlands. Water allocation policy accounted for groundwater extraction for irrigated agriculture, but other activities, such as forestry, were not considered in water allocation even though they were found to be a major water user. Following this study, the South Australian Government amended its Natural Resources Management act to stipulate that forestry must have a water licence and a water allocation to account for water used by the forest.

Strength modelling of Laminated Veneer Lumber (LVL) beams

This paper develops a mechanical model to accurately predict the strength of Laminated Veneer Lumber (LVL) beams, and illustrates its applications to numerically predict the strength distribution of LVL beams manufactured from veneers rotary peeled from early to mid-rotation subtropical hardwood plantation logs. This resource is not traditionally used in the manufacturing of commercialised LVL beams. In the first part of the paper, the model is described, calibrated against experimental results performed on 8-ply LVL beams and then verified against experimental results performed on 13-ply LVL beams. Results show that the model is able to accurately reproduce the experimental results, both on flat and edge bending, with an average prediction-to-experiment ratio of 1.0 and a relatively low coefficient of variation of 0.10. A sound prediction of the non-linear behaviour of the beams before failure was also observed. In the second part of the paper illustrating the applications of the model, the mechanical properties of veneers analysed by the authors in a previous work are used as input values in the numerical model to predict the strength of six commercially available LVL beam sizes, manufactured from early to mid-rotation subtropical Gympie messmate (Eucalyptus cloeziana), spotted gum (Corymbia citriodora) and southern blue gum (Eucalyptus globulus) plantation veneers. The design strength (5th percentile) of the beams, obtained by Monte Carlo simulations, is reported and found to range from 32.3MPa to 97.2MPa, depending on the quality of the veneers used and the beam size. The LVL beams have design strengths comparable to, and in some cases up to 2.5 times higher than commercially available softwood LVL beams, making them attractive structural products. The strength variability is also reported in the paper for developing probability-based limit state design criteria in future studies.

Moisture-related adjustment factor to obtain a reference ultrasonic velocity in structural lumber of plantation hardwood

ABSTRACTWave propagation techniques based on ultrasound for timber grading are influenced by the moisture content (MC) of wood. The ultrasound velocities at an equilibrium MC (V12) and above saturation point (Vsat) were used to calculate moisture-related adjustment factors (kH). Tests were conducted using plantation hardwoods (Corymbia citriodora, Eucalyptus grandis and Eucalyptus pellita) grown in Brazil. Below the fiber saturation point (FSP), kH values were between 0.66% and 0.83%, which concurred with intervals proposed in existing literature for softwoods. However, the kH inferred from the velocities obtained at MCs above the FSP increased (from 10% to 30%) with increasing density. The sound velocity under saturated conditions (Vsat) obtained by adjustment equations was 2–9% lower than the actual Vsat obtained from the tests. The obtained adjustment factors may be useful for the standardization of nondestructive timber grading based on ultrasound propagation.

How do management techniques affect carbon stock in intensive hardwood plantations?

Recent studies in temperate regions have shown that agroforestry systems, especially silvopastoral systems, have greater carbon (C) sequestration potential than monocropping systems or pastures, or even forest plantations. In Europe, there is growing interest in establishing high quality wood plantations with intensive management comprising irrigation, fertilisation and chemical weed control to reduce rotation length. However, these operations can have major environmental impacts similar to the effects of intensive agriculture, such as impoverishment of soil C. The aim of this study is to identify optimum management practices for intensive systems of quality wood production to optimise soil C stock and plantation productivity. An experiment was conducted in Extremadura, mid-west Spain, from 2011 to 2014, in a 13-year-old hybrid walnut (Juglans major×regia mj 209xra) plantation with a density of 333 trees ha−1. Two essays were established: one with three techniques to control competition from herbaceous strata beneath trees – mowing, ploughing and sheep grazing (1 sheep ha−1) – and the other to test implementation of legumes (mixture of Trifolium michelanium and Ornithopus compressus complemented by the same quantities of phosphorous and potassium as mineral treatment) as an alternative to traditional mineral fertilisation (40kgNha−1, 40kg P2O5 ha−1 and 50kg K2O ha−1). The C stock estimate was based on soil organic carbon (SOC) and aboveground (tree trunks and branches) and belowground biomass (tree and pasture roots). Most of the C stock was contained in SOC, at 50% in the uppermost soil layer (0–25cm), followed by aboveground biomass. The response of SOC in each treatment was higher than the other parameters analysed, suggesting that SOC is a more sensitive pool to management techniques. Grazing as control of herbaceous vegetation and legume implementation as nitrogen supply are suitable techniques for optimising soil C stocks and also achieve adequate tree growth in the longer term.

Pathogens on the Move: A 100-Year Global Experiment with Planted Eucalypts

Co-evolved plant pathogens play an important role in shaping natural ecosystems. However, plants used in agriculture and forestry have been distributed globally, and their associated pathogens have moved with them. Eucalypts constitute the largest component of global hardwood plantations, and they are increasingly plagued by numerous pathogens, all of which are inconsequential in the native forests. Eucalypts provide a particularly interesting model to study tree diseases because plantations have been established in countries where these trees are exotic but also in Australia adjacent to native eucalypt forests. These situations present opportunities for pathogen movement between the two systems. We present seven different scenarios considering pathogen movement, important disease epidemics, and biosecurity risks, illustrated with examples of well-known eucalypt pathogens and research largely from our laboratories. The overview shows that vigilant biosecurity is required to protect the biodiversity of native forests and the sustainability of eucalypt plantations.

What to Do with Structurally Low-Grade Wood from Australia’s Plantation Eucalyptus; Building Application?

About one million hectares of plantation hardwoods, mostly eucalyptus trees of different sub-species (E. nitens and E. globulus), are annually being managed in Australia, which provides a promising resource of raw materials for fibre industries. However, the timber boards required by the Australian hardwood sector are still being either imported from other countries or harvested from the native forests. There is a need to find a practical way to use the plantation eucalyptus in the Australian timber industry. However, the fibre-managed plantation eucalyptus produces structurally low-grade timber which could not be used as individual boards for structural applications—such as building construction. Unsuitable for appearance applications, the structurally low-grade boards may be suitable for producing innovative high-mass engineered timber products. This editorial will briefly discuss drivers, opportunities, and challenges associated with conducting such a research project.

Environmental and economic assessment of utility poles using life cycle approach

Due to increasing demand for utility poles and the banning of native forests logging in Australia, it is necessary to find sustainable alternatives to roundwood utility poles. Currently, steel and concrete are the most common alternatives. Veneer-based composite (VBC) is a newly developed product made from hardwood plantation mid-thinning. To assess the viability of VBC, comparative life cycle assessment (LCA) and life cycle costing (LCC) analysis were conducted. Two end-of-life scenarios for VBC pole were assessed: incineration with energy recovery and landfilling. Five impact categories were considered: global warming (GWP); acidification (AP); eutrophication (EP); fossil depletion (FDP) and human toxicity (HTP). VBC pole with incineration showed the best environmental performance, particularly on GWP (63.22 kg-CO2-eq), AP (0.29 kg-SO2-eq), FDP (30.78 kg-Oil-eq) and HTP (2.27 kg-1,4-DB-eq), which are less than half of concrete and steel poles. However, VBC had higher EP than concrete and steel due to use of adhesives and preservatives. VBC pole also had the lowest LCC ($1529), due to use of low-value materials and lower manufacturing cost. The LCC showed that both VBC scenarios performed equally on economic grounds. Sensitivity analysis showed that service life was the most sensitive parameter affecting both environmental and economic results, especially the VBC. Transportation distances and fossil fuel consumption also had significant effects on LCA result. Monte Carlo analysis further revealed that despite the high levels of uncertainties in the input parameters, the overall ranking of the options remained the same with VBC being the best performer and concrete the least.

Histological analysis reveals the formation of shoots rather than embryos in regenerating cultures of Eucalyptus globulus

Eucalyptus globulus is an important species in international forestry in regions with Mediterranean climates and comprises 65 % of the plantation hardwood in Australia. Propagation by somatic embryogenesis would offer many advantages and its development has received much attention. Structures regenerating on explants from hypocotyls of mature zygotic embryos of E. globulus cultured on medium with NAA, reported previously to be effective for embryogenic regeneration, were analyzed morphologically and histologically to clarify their pathway of development. Analysis of series of sections revealed organogenic, rather than embryogenic, pathways of regeneration in this system. We show that protocols for propagation of E. globulus must be carefully evaluated by microscopic examination of adequate numbers of serial sections.

Using small hardwood logs to produce liquid fuels and electricity

ABSTRACTThe production of larger high-value sawlogs from native forests or plantations requires removal of smaller and defective stems by thinning. This provides space for residual stems to grow into larger high-value forest products. An acceptable return on investment from growing hardwoods in plantations requires that some value is returned from thinned wood. Thus new markets are needed for small-diameter hardwood forest products.The production of fuel and energy from woody biomass offers one such opportunity.The potential value added by converting wood to high-energy liquid fuels such as petroleum or aviation fuel and the prospect of diminishing mineral oil supplies justifies research in this field. The Fischer Tropsch (FT) synthesis appears to offer substantial advantages in the capacity to break down biomass by thermal decay and chemical reformation to form a range of high energy/value fuels. In addition, these processes are exothermic, and create opportunities to produce process heat, electricity and fuels concurrently.The returns on electricity production are optimised where fuel costs are low and where the electricity produced can be used to displace retail purchasing (self-supply). The costs of harvest and transport of biomass prevent profitable production of electricity and sale at wholesale prices.The primary research goal relating to the development of biomass to fuel and electricity production is the adaption of known processes to scales dictated by biomass supplies. However, to self-supply and disconnect from the national grid implies that power plants must incorporate redundancy so energy supply can be secured. This must be achieved within acceptable capital cost limits.

Responses of Castanopsis hystrix seedlings to macronutrient imbalances: Growth, photosynthetic pigments and foliar nutrient interactions

ABSTRACTImbalanced fertilization of nursery stock can lead to nutrient disorders which affect plant quality and productivity. Castanopsis hystrix Miq. is a plantation hardwood species that is being widely established in south China. Nutrient disorders are common in planting stock and difficult to manage, as the causes are unknown. Therefore, macronutrient deletion fertilizer treatments were applied to C. hystrix seedlings and foliar symptoms, growth performance, leaf area, photosynthetic pigments and foliar nutrient interactions were determined. The appearance of foliar symptoms including chlorosis, marginal scorching, necrotic spotting and leaf malformation will be useful for the initial diagnosis of fertilizer imbalances in this species in forest nurseries. Vector analysis revealed that foliar nutrient interactions tended to be enhanced under nutrient imbalance, and these findings may provide a preliminary guideline for confirming macronutrient disorders of this species in nursery production.

Relating upstream forest management to stream ecosystem condition in middle catchment reaches in Tasmania

We investigated the relationship between the extent of Clearfell, Burn and Sow (CBS) harvesting and conversion to plantation in catchments upstream of mid-catchment study reaches on instream biota and habitat. Study sites were situated in fourth order stream reaches with no adjacent forestry activity, so that impacts represented the accumulated effect of forestry activity in the upstream catchment. In-channel fine sediments increased and the proportion of aquatic insect taxa decreased with increasing percentage land area under CBS (PCBS), with substantive changes observed above 40% of catchment area under CBS. Two different diagnostic attributes for macroinvertebrate taxa (SIGNAL scoring and Flow Exposure Groups) showed different relationships with PCBS, indicating that reductions in flow may also partially drive the macroinvertebrate response to increasing PCBS. Relationships between % area under unsealed roads and PCBS on downstream macroinvertebrate fauna suggested that roading was a substantive co-contributor to the overall impact of upstream CBS operations. An increase of 1% of the upstream catchment area under unsealed roads was associated with a respective decrease of richness by 4–8 EPT species in study reach riffles. For study reaches with upstream catchments containing hardwood (Eucalyptus nitens) plantation operations only, there was also a significant increase in unsealed roading and instream fine sediment with increasing area of plantation, though the increases were considerably less pronounced than for CBS operations occupying similar relative catchment areas. There were no significant relationships between area of plantation and macroinvertebrate community variables, presumably reflecting the lower levels of sediment deposition we observed downstream in plantation-dominated catchments. Plantation dominated catchments, with lower roading density and lower erodibility basaltic soils, had smaller instream impacts relative to CBS-dominated catchments, which are generally characterised by a more prolonged and dispersed disturbance regime including intensive regeneration burns.

Use of genetic markers to build a new generation of Eucalyptus pilularis breeding population

Abstract Tree improvement generally proceeds by incremental gains obtained from recurrent selection in large diverse populations but is slow due to long generation times and delay till trees reach assessment age. This places a premium upon extracting data from historic introductions used to found landraces when reinstating modern breeding programs. The value of such resources, however, may be degraded due to a lack of records on germplasm origins, pedigrees and early performance, but DNA technology may help recoup some of this value. Eucalyptus pilularis (subgenus Eucalyptus) is regarded as a premier hardwood plantation species for saw log and poles in Australia, but has not been used extensively despite early introductions and testing in many countries overseas. Here we use DNA fingerprinting to assess genetic diversity and inbreeding in historic introductions of E. pilularis to evaluate this resource in advance of a reinvigorated breeding effort for this species in Brazil. As expected, based on the available documentation for the introductions, genetic diversity relative to Australian reference populations does not appear to be compromised, and there was unlikely to be excessive inbreeding. Also, favorable, was the likelihood that further selections should not unduly increase the relationship in the next generation. Interestingly, we note the importance of testing widely adapted sources of germplasm when making introductions, as provenances which performed poorly in tests on productive sites in Australia, may have value when matched with lower fertility sites overseas.

Analysis for the relationship of environmental factors and vegetation structure at natural streamside valley and riparian forest in South Korea

We classified the streamside plant community by phyto-sociological method and analyzed the relationship between en vironment factors and vegetation structure by using the classification and ordination method. We found that twenty one plant communities were classified according to dominant species at the natural streamside valley forest with surveying the 65 quadrats (10 m × 10 m). From the survey results, the hardwood plant communities were classified as streamside valley forest and the softwood plant communities as riparian forest according to the degree of flooding. The valley forest had a distribution of 17 plant communities which was 65% (42 quadrats) of 65 quadrats: Maackia amurensis community, Betula davurica community, Quercus variabilis community, Pinus densiflora community, Q. serrata community, Prunus sargentii community, and Meliosma oldhamii community etc. The riparian forest had a distribution of four plant communities which was 35% (23 quadrats) of 65 quadrats: Salix koreensis community, S. rorida community, S. purpurea var. japonica community, and S. glandulosa community, etc. From the two-way indicator species analysis (TWINSPAN) analysis, we found indicator species Oplismenus undulatifolius and Lindera obtusiloba for the streamside valley forest and Humulus japonicus, Phragmites japonica, and S. koreensis for the riparian forest. From the results of the canonical correspondence analysis (CCA), coordinates, altitude, and stream structure showed low correlation to the distribution of the plant community. Therefore, it seemed that valley forest and riparian forest were distinguished by the stream gradient and waterway width which determined by the stream water level.

Life cycle assessment of ACQ-treated Veneer Based Composite (VBC) hollow utility poles from hardwood plantation mid-thinning

Hardwood plantations are slow to mature with low financial returns in the early stage. Veneer Based Composite (VBC) products developed from mid-thinning may improve the industry’s profitability and win new markets. Due to the increasing demand for utility poles and the banning of native forests logging in Australia, VBC poles may become viable alternative to native hardwood poles. Alkaline copper quaternary (ACQ) preservative treated VBC pole was assessed using life cycle assessment (LCA) methodology. The manufacturing processes considered were based on the current technologies in Queensland. VBC pole life cycle stages assessed include mid-thinning, manufacturing, service-life, and disposal. Three end-of-life scenarios were considered: landfilling, incineration for energy recovery and recycling as particleboard. The functional unit used in this assessment is 1-metre-length pole with 115-mm internal-diameter and 15-mm wall-thickness. Global Warming Potential (GWP100), Fossil Depletion Potential (FDP), Acidification Potential (AP), Eutrophication Potential (EP), and Ecological Toxicity Potential (ETP) were quantified. Results indicated that landfilling and incineration outperform the recycling option. Incineration scenario performed slightly better under the GWP100 (0.3659kg-CO2-Eq), AP (2.12g-SO2-Eq), FDP (0.360kg-Oil-Eq) and EP (3.81g-PO4-Eq). Meanwhile, landfilling scenario had slightly less impact in ETP (12.32-CTUe). Despite generating valuable products, the burdens caused by secondary manufacturing and transportation overweighed credits earned from recycling. ACQ treatment, Phenol-formaldehyde (PF) resins production and transportation distances were identified as significant parameters affecting the final result. Sensitivity analysis indicated that EP was sensitive to change in ACQ consumption; ETP was affected by PF resin use while changing distances of transporting product affected GWP100, AP and FDP.