Jerome Vanclay

• 46Impact points

• 166Publications

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Publications

• The balance between facilitation and competition in mixtures of Eucalyptus and Acacia changes as stands develop.

  Authors: David I Forrester, Jerome K Vanclay, Robert I Forrester

  Oecologia.

  The balance between facilitation and competition is likely to change with age due to the dynamic nature of nutrient, water and carbon cycles, and light availability during stand development. TheseThe balance between facilitation and competition is likely to change with age due to the dynamic nature of nutrient, water and carbon cycles, and light availability during stand development. These processes have received attention in harsh, arid, semiarid and alpine ecosystems but are rarely examined in more productive communities, in mixed-species forest ecosystems or in long-term experiments spanning more than a decade. The aim of this study was to examine how inter- and intraspecific interactions between Eucalyptus globulus Labill. mixed with Acacia mearnsii de Wildeman trees changed with age and productivity in a field experiment in temperate south-eastern Australia. Spatially explicit neighbourhood indices were calculated to quantify tree interactions and used to develop growth models to examine how the tree interactions changed with time and stand productivity. Interspecific influences were usually less negative than intraspecific influences, and their difference increased with time for E. globulus and decreased with time for A. mearnsii. As a result, the growth advantages of being in a mixture increased with time for E. globulus and decreased with time for A. mearnsii. The growth advantage of being in a mixture also decreased for E. globulus with increasing stand productivity, showing that spatial as well as temporal dynamics in resource availability influenced the magnitude and direction of plant interactions.

• An evaluation of the Australian Research Council's journal ranking

  Authors: Jerome K. Vanclay

  As part of its program of 'Excellence in Research for Australia' (ERA), the Australian Research Council ranked journals into four categories (A*, A, B, C) in preparation for their performanceAs part of its program of 'Excellence in Research for Australia' (ERA), the Australian Research Council ranked journals into four categories (A*, A, B, C) in preparation for their performance evaluation of Australian universities. The ranking is important because it likely to have a major impact on publication choices and research dissemination in Australia. The ranking is problematic because it is evident that some disciplines have been treated very differently than others. This paper reveals weaknesses in the ERA journal ranking and highlights the poor correlation between ERA rankings and other acknowledged metrics of journal standing. It highlights the need for a reasonable representation of journals ranked as A* in each scientific discipline.

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• Calibrating the self-thinning frontier

  Authors: Jerome K. Vanclay, Peter J. Sands

  Calibration of the self-thinning frontier in even-aged monocultures is hampered by scarce data and by subjective decisions about the proximity of data to the frontier. We present a simple model thatCalibration of the self-thinning frontier in even-aged monocultures is hampered by scarce data and by subjective decisions about the proximity of data to the frontier. We present a simple model that applies to observations of the full trajectory of stand mean diameter across a range of densities not close to the frontier. Development of the model is based on a consideration of the slope s=ln(Nt/Nt 1)/ln(Dt/Dt 1) of a log-transformed plot of stocking Nt and mean stem diameter Dt at time t. This avoids the need for subjective decisions about limiting density and allows the use of abundant data further from the self-thinning frontier. The model can be solved analytically and yields equations for the stocking and the stand basal area as an explicit function of stem diameter. It predicts that self-thinning may be regulated by the maximum basal area with a slope of -2. The significance of other predictor variables offers an effective test of competing self-thinning theories such Yoda's -3/2 power rule and Reineke's stand density index. Comment: Typos corrected, missing reference added

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• Tree diameter, height and stocking in even-aged forests

  Authors: Jerome K Vanclay

  Empirical observations suggest that in pure even-aged forests, the mean diameter of forest trees (D, diameter at breast height, 1.3 m above ground) tends to remain a constant proportion of standEmpirical observations suggest that in pure even-aged forests, the mean diameter of forest trees (D, diameter at breast height, 1.3 m above ground) tends to remain a constant proportion of stand height (H, average height of the largest trees in a stand) divided by the logarithm of stand density (N, number of trees per hectare): D = beta (H-1.3)/Ln(N). Thinning causes a relatively small and temporary change in the slope beta, the magnitude and duration of which depends on the nature of the thinning. This relationship may provide a robust predictor of growth in situations where scarce data and resources preclude more sophisticated modelling approaches. Comment: 15 pages, 8 figures. Annals of Forest Science, in press

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• Improved tropical forest management for carbon retention.

  Authors: Francis E Putz, Pieter A Zuidema, Michelle A Pinard, Rene G. A Boot, Jeffrey A Sayer, Douglas Sheil, Plinio Sist, Jerome K Vanclay

  PLoS biology. 6(7):e166.

• Ranking forestry journals using the h-index

  Authors: Jerome K. Vanclay

  An expert ranking of forestry journals was compared with journal impact factors and h-indices computed from the ISI Web of Science and internet-based data. Citations reported by Google Scholar appearAn expert ranking of forestry journals was compared with journal impact factors and h-indices computed from the ISI Web of Science and internet-based data. Citations reported by Google Scholar appear to offer the most efficient way to rank all journals objectively, in a manner consistent with other indicators. This h-index exhibited a high correlation with the journal impact factor (r=0.92), but is not confined to journals selected by any particular commercial provider. A ranking of 180 forestry journals is presented, on the basis of this index.

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• On the robustness of the h-index

  Authors: Jerome K Vanclay

  The h-index (Hirsch, 2005) is robust, remaining relatively unaffected by errors in the long tails of the citations-rank distribution, such as typographic errors that short-change frequently-citedThe h-index (Hirsch, 2005) is robust, remaining relatively unaffected by errors in the long tails of the citations-rank distribution, such as typographic errors that short-change frequently-cited papers and create bogus additional records. This robustness, and the ease with which h-indices can be verified, support the use of a Hirsch-type index over alternatives such as the journal impact factor. These merits of the h-index apply to both individuals and to journals.

• Effects of Selection Logging on Rainforest Productivity

  Authors: Jerome K Vanclay

  An analysis of data from 212 permanent sample plots provided no evidence of any decline in rainforest productivity after three cycles of selection logging in the tropical rainforests of northAn analysis of data from 212 permanent sample plots provided no evidence of any decline in rainforest productivity after three cycles of selection logging in the tropical rainforests of north Queensland. Relative productivity was determined as the difference between observed diameter increments and increments predicted from a diameter increment function which incorporated tree size, stand density and site quality. Analyses of variance and regression analyses revealed no significant decline in productivity after repeated harvesting. There is evidence to support the assertion that if any permanent productivity decline exists, it does not exceed six per cent per harvest.

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• The effectiveness of parks.

  Authors: J K Vanclay

  Science (New York, N.Y.). 293(5532):1007.

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• Proceedings of the Tropical Silviculture Workshop IUFRO centennial conference Berlin, 1-3 September 1992 / edited by Peter J. Wood, JeromeK. Vanclay, Wan Razali Wan Mohd

  Authors: Germany Berlin, Jeroma K Vanclay, Wan Razali Wan Mohd, IUFRO

  SERBIULA (sistema Librum 2.0).

  Incluye bibliografía

• Sustainable Harvesting of Tropical Rainforests: Reply to Keto, Scott and Olsen

  Authors: Jerome K Vanclay, E. John Rudder, Glen Dale, Geoff A. Blake

  This paper refutes the Keto et al. proposition that the Queensland selection logging system is neither ecologically nor economically sustainable. The key requirements of this system are: (1) thatThis paper refutes the Keto et al. proposition that the Queensland selection logging system is neither ecologically nor economically sustainable. The key requirements of this system are: (1) that logging guidelines are sympathetic to the silvicultural characteristics of the forest, ensuring adequate regeneration of commercial species and discouraging invasion by weeds; (2) tree-marking by trained staff specifies trees to be retained, trees to be removed and the direction of felling to ensure minimal damage to the residual stand; (3) logging equipment is appropriate and driven by trained operators to ensure minimal damage and soil disturbance, compaction and erosion; (4) prescriptions ensure that adequate stream buffers and steep slopes are excluded from logging; (5) sufficient areas for scientific reference, feature protection and recreation are identified and excluded from logging; and (6) that deficiencies in an evolving system are recognized and remedied, leading to an improved system. Many studies of the effects of logging in these forests have been published and collectively provide a unique demonstration of one possible approach to sustainable timber harvesting.

• Planning for World Heritage: Experiences and Future Directions for Use of Geographical Information Systems

  Authors: Robert A Preston, Jerome K Vanclay, Geoff Gibson, Glen Dale

  Events leading to the World Heritage listing of north Queensland rainforests and subsequent ban on timber harvesting result from a number of factors including insufficient education of anEvents leading to the World Heritage listing of north Queensland rainforests and subsequent ban on timber harvesting result from a number of factors including insufficient education of an increasingly articulate and environmentally aware public. Foresters should meet this challenge by renewing efforts to collect reliable information on the multi-resource values of forest areas. GIS has the potential to contribute to this process, particularly when applied as part of a multi-resource decision support system. Source data for multi-resource management could be collected in conjunction with timber inventory, provided additional funding is made available. Use of a GIS as a map overlaying tool can be prone to error unless its users are fully aware of limitations that can arise with this approach. Any multi-resource strategy should be phased into existing timber inventory programmes. Full scale adoption of a multi-resource decision support system in forest services is not likely to occur until the full cost of land use conflicts is included in the cost benefit equation.

• Calculation of timber yields from North Queensland rainforests

  Authors: Robert A Preston, Jerome K Vanclay

  Jerome K Vanclay.

  Calculation of timber yields from north Queensland rainforests indicate that the long term average yield is in the vicinity of 63 000 cubic metres per year, and that an allowable cut of 60 000 cubicCalculation of timber yields from north Queensland rainforests indicate that the long term average yield is in the vicinity of 63 000 cubic metres per year, and that an allowable cut of 60 000 cubic metres per year should apply for the period 1986-1991. These calculations apply to the 158 000 hectares of Crown land managed for timber production between Townsville and the Daintree River. Estimates were prepared using cutting cycle analysis, and incorporated a number of innovations made possible by advances in computing technology. These included simulating the growth of individual plots rather than of stratum averages, and the use of a dynamic growth model which accommodated stand density, composition and site quality.

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• Utility of Landsat Thematic Mapper data for mapping site productivity in tropical moist forests

  Authors: Jerome K Vanclay, Robert A Preston

  Jerome K Vanclay.

  Regression analysis was used to develop a relationship between Landsat 5 Thematic Mapper data and site quality of permanent sample plots. The thermal band (6) produced misleading results, but theRegression analysis was used to develop a relationship between Landsat 5 Thematic Mapper data and site quality of permanent sample plots. The thermal band (6) produced misleading results, but the ratio of band 4 on 5 showed promise when combined with geological information. Best results were obtained when regression analysis was restricted to ensure that at least one each of the visible (1 to 3), mid-infrared (5 and 7) and near-infrared (4) bands were included. Results suggest that Landsat TM may be useful for mapping site quality in tropical moist forest in north Queensland. Interpolation of site productivity within a single pass seems feasible, but attempts to extrapolate results to other passes or to imagery obtained on different dates may be unreliable.

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• Technologies for Sustainable Forest Management: Challenges for the 21st Century.

  Authors: J.A. Sayer, Jerome K. Vanclay, N. Byron

  Technology will help to address the challenges for sustainable forestry in the 21st century. Some of the challenges will include the shift of production from native forest to plantations in areas ofTechnology will help to address the challenges for sustainable forestry in the 21st century. Some of the challenges will include the shift of production from native forest to plantations in areas of comparative advantage, more efficient processing delinking end-use products from raw wood characteristics, increased demand, better information technologies to support decision makers, and more options for conserving biodiversity. Definitions of sustainability will vary in time and space as society's expectations and aspirations change, so there can be no 'silver bullet' to ensure sustainability. However, progress may be facilitated with a systematic approach to forest management embracing the usual planning cycle: formulation of objectives, preparation of a strategy, planning, implementing, monitoring, and reappraisal. This requires a good understanding of each particular situation. Managers need good resource assessment and decision support systems; they must foster stakeholder participation in decisions, costs and benefits; and ensure effective procedures to resolve conflicts. Within an appropriate system, technical advances such as better machines and new implements may help to make a difference, but will not in themselves ensure sustainability. The important technologies for sustainable forestry are those that foster better communication between stakeholders and allow informed decisions spanning scales from the gene to the ecosystem. This remains an important challenge for forest managers in their search for sustainability.

• Spatially Explicit Model of Deforestation in Bolivia

  Authors: Jerome K. Vanclay, David Kaimowitz, Atie Puntodewo, P. Mendez

  A GIS compiled by the Departmental Government of Santa Cruz, Bolivia offers data that may help to resolve some competing theories of tropical deforestation. The GIS contains many attributes relatingA GIS compiled by the Departmental Government of Santa Cruz, Bolivia offers data that may help to resolve some competing theories of tropical deforestation. The GIS contains many attributes relating to land use at two points in time, 1989 and 1994, and allow us to address questions like: 1. What has been the impact of past road construction on deforestation and land use? 2. What impacts might be expected from future road construction? 3. What impact do zoning policies such as forest concessions and protected areas have? 4. What influence do cultural factors have on forest clearing and fragmentation? We discuss our methodology and report interim results. We seek to provoke discussion on appropriate statistical procedures for such analyses.

• Modeling Deforestation at Distinct Geographic Scales and Time Periods in Santa Cruz, Bolivia

  Authors: Benoit Mertens, David Kaimowitz, Atie Puntodewo, Jerome K. Vanclay, Patricia Mendez

  This article analyzes geo-referenced data to elucidate the relations between deforestation and access to roads and markets, attributes of the physical environment, land tenure, and zoning policies inThis article analyzes geo-referenced data to elucidate the relations between deforestation and access to roads and markets, attributes of the physical environment, land tenure, and zoning policies in Santa Cruz, Bolivia. It presents separate models for Santa Cruz as a whole and for seven different zones within Santa Cruz, as well as for two different time periods (pre-1989 and 1989 to 1994). The relation between deforestation and the explanatory variables varies depending on geographic scale and the zone and time period analyzed. At the department scale, locations closer to roads and the city and places that have more fertile soils and wetter climates have a greater probability of being deforested. The same applies to colonization areas. Protected areas and forest concessions are less likely to be deforested. Nevertheless, in many specific zones, these variables had no significant impact or actually had the opposite impact than in the entire department. Most of these relations were weaker between 1989 and 1994 than in the previous period.

• Priorities for International Forest Research

  Authors: J.A. Sayer, N. Byron, Dennis D. Dykstra, Jerome K. Vanclay

  The world is moving towards knowledge-based societies. Economies are globalizing. The global public goods value of forests is being recognised at the same time that the traditional role of stateThe world is moving towards knowledge-based societies. Economies are globalizing. The global public goods value of forests is being recognised at the same time that the traditional role of state forest agencies in production forestry is being taken over by multi-national corporations. At the same time emerging technologies are greatly enhancing our ability to assess and monitor forest attributes, process and disseminate information, and enhance forest production. All of these changes will have an impact on how forest research is organized, who does it, and who pays for it. It seems inevitable that much traditional forestry research concerned with sustainability and productivity enhancement at the stand level, will be taken over by the private sector. However, there is going to be a major challenge in finding resources for research in support of the public goods values of forests at both the local, national and global levels. There is a widely held view that we are in the midst of a world forest crisis. It is not a crisis of declining production but one of erosion of public goods, environmental values of forests. So far, we have not seen a concerted scientific response to this crisis. The Inter-Governmental Panel on Forests (IPF) has given us the mandate to orchestrate such a response and the World Forestry Congress is a valuable opportunity to provide impetus to a new vision of forest science for the 21st century.

• Private Native Forestry: Silviculture, Sustainability and Incentives for Vegetation Management

  Authors: David Thompson, Alex Jay, Mike Connell, Phil Norman, Jerome K. Vanclay

  Timber supplies from public native forests have declined significantly in recent decades. Consequently, wood processors are increasingly dependent on private land to maintain their throughput ofTimber supplies from public native forests have declined significantly in recent decades. Consequently, wood processors are increasingly dependent on private land to maintain their throughput of native species logs. In some regions of Australia, more than 50 per cent of native forest industry log supply comes from private property. There is concern that this increased demand brings with it the increased risk of high grading in private forests - repeated removal of only merchantable stock, leaving an increasing proportion of poor quality trees which may be detrimental to both future timber yields and habitat quality. Nevertheless, this market situation also represents a commercial opportunity for private landholders and some additional incentive for them to better manage their forests for long-term sustainability. However, this needs to be supported by a policy and regulatory framework that provides incentives for private forest owners to manage their forests sustainably. Environmental policy settings and broader economic drivers can over-ride this opportunity. A range of biodiversity/habitat sustainability indicators have been developed to gauge the impacts of clearing for agriculture and in some states, for forestry operations in native forests. In Australia, these have principally been developed with a focus on public land, but, as additional scrutiny is brought to bear on private landholders, they are increasingly focused on private native forestry (PNF). Implementation of indicators may increase both the direct costs and the constraints on private native forest managers. It seems likely that returns from timber production alone may be insufficient to ensure best practice silviculture in private native forests. Incentives, available to the landowner, which recognize the public environmental goods being provided by well managed forests, may be one solution to the problem. This will require some quantification of how alternative forest management systems impact on those 'public good' values. Others suggest that government price setting arrangements for public forest timber maintain artificially low prices which reduce private forest management incentives. This paper is a progress report on several linked projects funded through RIRDC JVAP, which field test sustainability indicators, investigate the tradeoffs between commercial timber production and habitat/biodiversity conservation and examine options for improved private native forest management through commercial incentives.

• Spatial Regression Analysis of Deforestation in Santa Cruz, Bolivia

  Authors: David Kaimowitz, P. Mendez, Atie Puntodewo, Jerome K. Vanclay

  This paper applies a spatial economic regression model to analyze the relation between deforestation in the period from 1989 to 1994 and access to roads and markets, ecological conditions, landThis paper applies a spatial economic regression model to analyze the relation between deforestation in the period from 1989 to 1994 and access to roads and markets, ecological conditions, land tenure, and zoning policies in Santa Cruz, Bolivia. The data comes from a Geographic Information System (GIS) compiled by the Natural Resources Department of the Santa Cruz Government. Locations closer to roads and the City of Santa Cruz and that have more fertile soils and higher rainfall have a greater probability of being deforested. The same also applies to colonization areas. National parks and areas occupied by indigenous people do not have significantly less deforestation than sites with similar acess and ecological conditions. Forest concessions, on the other hand seem to protect forests.