North Ryde, Australia
North Ryde, Australia

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Jurskis V.,Forest Science Center | Turner J.,Forsci Pty. Ltd. | Lambert M.,Forsci Pty. Ltd. | Bi H.,Forest Science Center
Applied Vegetation Science | Year: 2011

Studies of frequent burning in eucalypt ecosystems show that accumulation of N in the absence of fire drives changes in their composition, structure and function. © 2011 International Association for Vegetation Science.

Johnson D.W.,University of Nevada, Reno | Turner J.,Forsci Pty. Ltd.
Forest Ecology and Management | Year: 2014

A review of forest N cycling literature indicates that most forest ecosystems contain less N than would be expected from even modest inputs of N from atmospheric deposition and N fixation over millennial time scales. Periodic fire could account for this disparity, even in humid systems during drought periods. In contrast to the millennial time scale patterns noted above, several forest ecosystems appear to accumulate more N than can be accounted for by measured or estimated inputs over decadal time scales. There appears to be some disparity between results from short term process studies and those from longer term budget analyses. Unmeasured inputs by dry deposition, non-symbiotic N fixation, or (in ecosystems with sedimentary parent materials) weathering of N from rocks may account for this occult N when it occurs. Research over the last two decades has suggested that N retained within forest ecosystems is not leached away after inputs have slowed, but remains within the system unless it is harvested or burned. © 2013 Elsevier B.V.

Turner J.,Forsci Pty Ltd | Lambert M.J.,Forsci Pty Ltd
Australian Journal of Botany | Year: 2014

Alternative indices to use for nutrient use efficiency (NUE) were analysed for nitrogen, phosphorus, potassium, calcium, magnesium and sulfur, using 17 Eucalyptus pilularis forest sites to test the hypothesis that NUE increases with decreasing nutrient availability. Reported indices represent different measures of nutrient use, including (1) efficiency of acquisition from soil, (2) quantities required for organic matter production, (3) organic matter production related to uptake, (4) ability to internally retranslocate nutrients and (5) physiological requirement of nutrients. Some indices are highly correlated but the highest correlations were according to age. Phosphorus, the main growth-limiting nutrient, on average, produced 6.5 and 10.9 t of organic matter per kilogram of phosphorus required and taken up from soil, respectively. Comparable estimates were made for other nutrients. NUEs of mobile nutrients increased with decreases in nutrient availability and this supported the hypotheses when age was taken into account. The NUEs of one nutrient are not independent of other nutrients. The inverse of foliage nutrient concentration is a valuable low-cost index of nutrient utilisation and correlates with net primary production/nutrient requirement, and is related to age. Resorption of nutrients, comparing new and abscised tissue, was of low value, but abscised-tissue nutrient correlations are related to a lower benchmark and are of value. The use of selected NUE indices for species comparison was discussed.

Turner J.,Forsci Pty Ltd | Lambert M.,Forsci Pty Ltd
Australian Forestry | Year: 2016

Estimates of expenditure provide an index of overall forest industry commitment to research and development that underpins sustainable forestry. This article reports on research expenditure and capacity for 2013 and is an extension of a sequence of five-yearly assessments on research undertaken since 1985. Expenditure in 2013 on forestry research was estimated to be about $38 million (m) and on forest products research about $10.1 m, or $48 m in total, which is a reduction from about $122 m (Australian dollars in 2013) in the mid-1980s. These estimates do not include administrative costs and overhead charges. The number of staff (scientists, technicians, support and graduate students) involved in forestry and products research was about 276 in 2013 compared with 794 in the mid-1980s. The structure and type of research being undertaken has undergone major changes since the initial assessment. At the time of the initial assessment (1985) both forest resources and research were largely under the stewardship of state governments and further research was supported by the Commonwealth Government through CSIRO and universities, with strong links between the timber producers and the timber processors. Research was considered fundamental to supporting the development and improvement of all aspects of forest management and production. The loss of linkages between forest management and research organisations, the move away from state and Commonwealth support for forestry and the shift from science-based management, has reduced support for continued research. For research to develop there need to be well-defined, long-term industry objectives with an understanding that such objectives may be achieved with the support of research. It is concluded that commitment to maintain a strong scientific basis for forestry in Australia is greatly diminished and there is no evidence that contraction will not continue further. © 2016 Institute of Foresters of Australia (IFA).

Turner J.,Forsci Pty Ltd | Lambert M.,Forsci Pty Ltd
Australian Forestry | Year: 2011

Total expenditure on forestry research and forest products research in 2007-2008 in Australia was $87.8 million. This comprised $61.0 million on forestry research and $26.8 million on forest products research and was estimated using the same methods as in the several previous assessments (Quick and Booth 1987; Lambert and Turner 1992; Turner and Lambert 1997, 2005). When some peripheral expenditure such as support, administration and surveys were included, the total expenditure increased to about $ 105.8 million. The total expenditure represents an annual average increase of about 3% since 1982 but a slow decline (0.45% per annum) in adjusted terms (1982 dollars). About 50 organisations reported undertaking forestry and or forest products research, while other organisations provided funding for research. The expenditure was attributed to four broad sectors undertaking research-Commonwealth, state, university and private-and also to broad research areas (native forests, exotic species plantations, native species plantations and environment). Research on native forests and exotic species plantations generally declined, whereas that on surveys in native forests and native species in plantations increased from 2001-2002 to 2007-2008. Similarly, research capacity declined in traditionally strong research areas such as pests and diseases and fire behaviour, and increased in energy areas such as carbon and forest bio-energy. About 600 full-time-effective researchers and technicians were involved in research in 2007-2008, plus support and management staff. The staffing numbers of individual organisations ranged from single individuals to more than fifty. In 2007-2008, about 52% of the research funds were provided directly or indirectly by the Commonwealth Government, 28% by state governments and 20% by private companies. Total expenditure on forestry and forest products research ($87.8 million) averaged $5.78 ha -1 of managed forest. The forestry research expenditure according to forest type comprised $14.80 ha -1 on exotic species plantations, $36.90 ha -1 on native species plantations and $0.99 ha -1 on native forests (including ecological and environmental research, and hydrological studies and fauna-flora research). Additionally, there was expenditure of about $0.45 ha -1 on land-based surveys (mainly biodiversity), primarily in native forests. Total expenditure on forestry and forest products research equated to an average of $3.90 n -3 of harvested timber. This comprised $ 1.02 m -3 on timber removals from exotic species plantations, $7.38 m -3 from native species plantations and $ 1.90 m -3 from native forests.

Turner J.,Forsci Pty Ltd. | Lambert M.J.,Forsci Pty Ltd.
Forest Ecology and Management | Year: 2011

A trial in an 11-year-old stand of radiata pine (Pinus radiata D. Don) was used to analyse the effects of accelerated loss of nutrients from the site on forest productivity and nutrient status. Raking of litter was undertaken over 14. years prior to thinning, then for 2. years after thinning at which time the trial was destroyed in a wind storm. The experimental design was a factorial of three main treatments: (i) removal (raking) versus nil removal of the forest floor, (ii) replacement or non replacement of nutrients to adjust for imbalances between nutrients in litter and those in the tree stem, and (iii) complete replacement (or not) of all nutrients removed in the litter. Additionally, a small trial was incorporated to address components of physical aspects of litter removal by comparing raking with 'raking and a cover of woven plastic mesh'. Raking and nutrient additions were carried out approximately every 6. months.Over the study period, the raking treatment removed about 75Mgha-1 of organic material with contained nutrients (559kgha-1 of N, 68kgha-1 of P, 323kgha-1 of Ca, 91kgha-1 of Mg, 243kgha-1 of K, 0.9kgha-1 of B) and this related to about four normal sawlog harvests or one total tree harvest. Up to the time of thinning, raking reduced basal area increment by 25% while raking together with replacement of nutrients reduced this by about 12%. Nutrient additions to unraked plots led to increases of up to 14% in basal area increment. The raking treatment reduced foliage nitrogen and this was correlated with reduced growth while other nutrients such as boron and sulphur were reduced but not to a degree to affect growth or health. The results were used to assess the effects on soil nutrient status and growth of different harvesting regimes (wood only, wood plus bark, total tree). © 2011 Elsevier B.V.

Turner J.,Forsci Pty Ltd | Lambert M.,Forsci Pty Ltd
Forest Ecology and Management | Year: 2016

The distribution and cycling of carbon and nutrients of a small, calibrated research catchment vegetated with regrowth eucalypt forest was studied over a 30 year period. The vegetation is mixed species, dry Eucalyptus woodland with an average age of 64 years at the commencement. Study plots were established within land unit strata and used to estimate mean weighted averages for the catchment. Biomass equations for each aboveground component of each species were developed and each component was analyzed for N, P, K, Ca and Mg. In 1977 the mean weighted average carbon content of the catchment was 113.2 Mg C ha-1 of which 43.3% was in the vegetation and litter and in 2011 it was 149.6 Mg C ha-1 with 55.1% in the vegetation and litter, an accretion rate of 1.1 Mg C ha-1 yr-1. The nitrogen quantity was 3900 kg ha-1 of which 4.7% was in the vegetation increasing to 4188 kg N ha-1 in 2011 with 6.7% in vegetation, an apparent increase of 8.5 kg N ha-1 yr-1. The initial phosphorus quantity, using soil available P, was 25.6 kg P ha-1, with 45.8% in vegetation and in 2011 this changed to 33.0 kg P ha-1 of which 57.1% in litter and vegetation. When soil total P was estimated there was 1486 kg P ha-1 of which 0.8% was in the vegetation.The calcium quantity in 1977 was estimated at 1163 kg Ca ha-1 of which 51% was in vegetation and this had increased to 59% in 2011. There was 1066 kg K ha-1 of which 13.9% was in vegetation rising to 21% in 2011. Magnesium in 1977 was 624 kg Mg ha-1 with little change in 2011. Such quantities in the vegetation make the sites very vulnerable to nutrient loss when vegetation is removed in land use changes.Nutrient turnover was estimated including litterfall and throughfall and, using growth increments, annual uptake. The overall pattern shows long term transfers from the soil to vegetation and cycling is mainly in the soil A horizon. The net losses from the system are small and appear to be related to bedrock chemistry rather than the vegetation. Small catchments do not present an efficient method for studying biogeochemical cycling. © 2016 Elsevier B.V.

Turner J.,Forsci Pty Ltd | Lambert M.,Forsci Pty Ltd
New Forests | Year: 2013

Comparisons of plantation scale productive capacity and productivity were undertaken for first and second rotations of Pinus radiata plantation on clay soils in NSW, Australia where rotation length was about 30 years. Over a rotation, where there were no significant additions of nutrients, there were small declines in productivity from the first to the second rotation while productivity increased in the third rotation usually due to changes in management. On sites treated with significant quantities of phosphate fertilizer (50 kg P ha-1) in the second rotation, there were significant increases in the productivity of the second rotation with a residual effect into the third rotation. The early growth in the second rotation may be higher than the first rotation but the growth changes with age. Rotation length productivity appears to be related to the magnitude of soil nutrient pools. Nutrients such as calcium, potassium and boron appear to be affecting long term growth even though the foliage levels are much higher than normally considered limiting for growth. Most of the differences in productivity between rotations appear to be related to soil nutrients or management changes while potential genetic gains as estimated from experimental trials, are difficult to identify. © 2013 Springer Science+Business Media Dordrecht.

Turner J.,Forsci Pty Ltd | Lambert M.J.,Forsci Pty Ltd
Australian Forestry | Year: 2015

The effects of phosphatic fertiliser on growth and nutrients in trials at different stages of stand development have been studied in second-rotation Pinus radiata plantation sites of Lidsdale State Forest, New South Wales. The sites were on phosphorus-deficient clay soils. High, early growth responses to phosphatic fertiliser occurred when applied to individual trees at the time of planting compared with slower initial growth when fertiliser was broadcast applied. There were long-term responses to broadcast treatments of phosphorus or nitrogen/phosphorus at time of planting, but it took several growing seasons for the trees to access the applied phosphorus. Later-age applications of phosphorus also gave significant responses with and without nitrogen and the level of response was related to the prior nutritional status of the stand. There were additional responses to high levels of nitrogen when the initial phosphorus deficiency was overcome. Application of phosphorus or nitrogen/phosphorus after thinning resulted in significant increases in growth. Combining trial results and assuming treatments were additive, it was concluded that productivity could be increased from 8 m3 ha–1 y–1 to about 16 m3 ha–1 y–1 over 24 years. The trials show there could be a range of nutritional management strategies where fertilisers are applied at various times in the rotation process and the appropriate one would be selected in terms of management objective, the cost and outcomes. © 2015 Institute of Foresters of Australia (IFA)

Lambert M.,Forsci Pty Ltd | Turner J.,Forsci Pty Ltd
Australian Journal of Botany | Year: 2016

Subtropical rainforests in New South Wales (NSW) are distributed on the more fertile forest soils and are nutritionally distinct from the Eucalyptus forests in the same areas. The distribution, cycling of organic matter and nutrients and nutrient use efficiency in an Australian subtropical rainforest were studied and aspects were compared with reported Eucalyptus studies. The available nutrients were greatly in excess of the stand uptake or requirement. A single undisturbed plot within a research trial in mature forest was selected for the study. At the beginning of the study, the aboveground forest biomass was ∼334tha-1 of organic matter and, 22 years later, there was 357tha-1, giving a net accumulation rate of 1.03tha-1year-1, and net primary productivity of 13.0-14.6tha-1year-1. Litterfall and forest-floor analyses indicated a very rapid turnover of organic matter, with an estimated half-life of ∼0.5 years. The quantity of nutrients in the stand was high relative to other forest types in the area, with 1109.2kgNha-1, 62kgPha-1, 1999kgCaha-1, 591kgMgha-1 and 901kgKha-1. Nutrient requirement estimated as nutrient content of the current tissue was estimated to be 107, 5.3, 99, 26 and 61kgha-1year-1 for N, P, Ca, Mg and K, respectively, and uptake defined as removal from the soil was estimated to be 112, 4.7, 128, 37 and 49kgha-1year-1 for the same nutrients, the difference between these being net nutrient redistribution. Nutrient use efficiency (NUE), defined as net primary productivity (NPP) per requirement (tkg-1), was calculated to be 0.12, 2.43, 0.13, 0.50 and 0.21 for N, P, Ca, Mg and K, respectively; these values were low, for example, compared with mature E. pilularis, for which NPP was 0.20, 6.5, 0.43, 1.04 and 0.52tkg-1 for N, P, Ca, Mg and K, respectively. Using NUE defined as NPP per uptake provided comparable estimates. The rainforest represents a forest growing with basically no nutrient limitations, and, as such, is a benchmark for forest nutrient distribution, cycling and NUE. © CSIRO 2016.

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