Francis E Putz

Publications of Francis E Putz

• 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. 07/2008; 6(7):e166.

• Nitrogen fertilizer and gender effects on the secondary metabolism of yaupon, a caffeine-containing North American holly.

  Authors: Matthew J Palumbo, Francis E Putz, Stephen T Talcott

  Oecologia. 03/2007; 151(1):1-9.

  Yaupon (Ilex vomitoria) is a caffeine-containing dioecious shrub native to the southeastern United States that was historically brewed into a stimulating beverage. We tested predictions of theYaupon (Ilex vomitoria) is a caffeine-containing dioecious shrub native to the southeastern United States that was historically brewed into a stimulating beverage. We tested predictions of the carbon/nutrient balance (CNB) hypothesis by determining whether nitrogen availability and gender influence production of caffeine and related alkaloids as well as phenolic compounds in leaves of pot-grown yaupon plants fertilized with ammonium nitrate. The CNB hypothesis predicts that additional nitrogen should result in increased alkaloid concentrations and decreased phenolic concentrations. An extension of the CNB hypothesis to dioecious plants predicts that females have higher C/N ratios and therefore higher phenolic concentrations and lower alkaloid concentrations than male conspecifics. In our study, caffeine and total alkaloid concentrations were 5-10 times higher in fertilized than control plants but did not vary by gender. Nevertheless, an observed interaction between gender and fertilization suggests that females respond more to fertilization than males in caffeine production. In addition, fertilized plants not only contained higher concentrations of alkaloids and total nitrogen but also allocated a larger proportion of their nitrogen to alkaloid production than control plants. Total phenolic concentrations were higher in control females than control males as predicted by the CNB hypothesis, but did not vary by treatment nor were there differences by gender among fertilized plants. We also found high correlations between antioxidant capacity and both classes of phenolic compounds detected in our study (cinnamic acid derivatives and flavonoids) indicating that in addition to their putative defensive function against herbivores, phenolics protect yaupon from oxidative stress. Explanation of the inconsistencies between our data and predictions of the CNB hypothesis may benefit from a re-appraisal of the physiological mechanisms by which resource availability affects secondary metabolism as well as consideration of the selective pressures to which secondary metabolism responds.

• Sustainable forestry in the tropics: panacea or folly?

  Authors: David Pearce, Francis E Putz, Jerome K Vanclay

  Forest Ecology and Management.

  The profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. [Scientific American 273 (1997) 34] have argued thatThe profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. [Scientific American 273 (1997) 34] have argued that not only does traditional selective logging provide higher returns but also incurs less damage to forests than sustainable forest management systems that involve harvesting of many species and the creation of large gaps in the forest canopy to foster regeneration of light-demanding species. They claimed that protected areas were the only viable way to conserve forest ecosystems and proposed that loggers be allowed to log forests selectively once, after which the forests should become parks. Here, we respond to the challenge posed by Rice et al. by exhaustively reviewing the evidence regarding the viability and desirability of sustainable forest management in the tropics. Following Rice et al., we use the term conventional timber harvesting to refer to existing practice, which typically pays little attention to maintaining long-term timber supply. Sustainable timber management implies taking steps to ensure forests continue to produce timber in the longer-term, while maintaining the full complement of environmental services and non-timber products of the forest.Empirical studies tend to confirm the conclusion of (Rice et al. [Scientific American 273 (1997) 34]) that although sustainable timber management sometimes provides reasonable rates of return, conventional timber harvesting is generally more profitable. This implies that without additional incentives, one cannot expect companies to adopt sustainable management. The shortsightedness of many loggers, the slow rise in international timber prices, political uncertainty, and tenure insecurity simply reinforce this tendency. However, we reject the claim that sustainable timber management generally damages forests more than conventional logging. Rice et al. base their conclusion largely on the particular case of mahogany extraction in Bolivia, and even there it may not hold. In many cases, sustainable timber management performs better in terms of carbon storage and bio-diversity conservation than conventional logging approaches, as well as producing more timber. If new carbon markets emerge, sustainable forest management might compete effectively with conventional timber harvesting. Timber certification systems may also provide a sufficient incentive for sustainable forest management in certain circumstances.

• Tree mortality and vine proliferation following a wildfire in a subhumid tropical forest in eastern Bolivia

  Authors: Michelle A Pinard, Francis E Putz, Juan Carlos Licona

  Forest Ecology and Management.

  In 1994, 1×106 ha of subhumid forest in eastern Bolivia burned in an uncontrolled wildfire; the objective of this study was to measure tree and liana mortality a year after this fire. About 60% ofIn 1994, 1×106 ha of subhumid forest in eastern Bolivia burned in an uncontrolled wildfire; the objective of this study was to measure tree and liana mortality a year after this fire. About 60% of 500 trees sampled were either killed or damaged by the fire. Proportionally more small trees (74% of trees >2 m tall but <5 cm dbh) were killed than large trees (27% of 10–40 cm, 16% of trees ≥40 cm dbh), and mortality varied with species. Basal cambial damage was found on 30–40% of living trees ≥10 cm dbh. About 75% of liana stems (1–8 cm dbh) were killed; 15% of the dead liana stems resprouted from the base. In lianas, basal resprouting of killed stems was independent of diameter class, whereas in trees smaller stems were more likely to resprout than larger stems. The proliferation of herbaceous vines plus lianas <1 cm dbh (mean density 21 000 ha-1) in the burned forest may impede tree regeneration and supply fine fuels capable of supporting frequent fires. Although anthropogenic and natural fires have probably played important roles in the development of tropical subhumid forests, the amount of damage and mortality observed in this study suggest that, in forests managed for timber production, fire-protection practices are warranted to reduce forest susceptibility to wildfire.

• Sustainable forestry in the tropics : panacea or folly?

  Authors: David W Pearce, Francis E Putz, Jerome K Vanclay

  Jerome K Vanclay.

  The profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. (1997) have argued that not only does traditionalThe profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. (1997) have argued that not only does traditional selective logging provide higher returns but also incurs less damage to forests than sustainable forest management systems that involve harvesting of many species and the creation of large gaps in the forest canopy to foster regeneration of light-demanding species. They claimed that protected areas were the only viable way to conserve forest ecosystems and proposed that loggers be allowed to log forests selectively once, after which the forests should become parks. Here we respond to the challenge posed by Rice et al. by exhaustively reviewing the evidence regarding the viability and desirability of sustainable forest management in the tropics. Following Rice et al., we use the term conventional timber harvesting to refer to existing practice, which typically pays little attention to maintaining long-term timber supply. Sustainable timber management implies taking steps to ensure forests continue to produce timber in the longer term, while maintaining the full complement of environmental services and non-timber products of the forest.Empirical studies tend to confirm the conclusion of Rice et al. (1997) that although sustainable timber management sometimes provides reasonable rates of return, conventional timber harvesting is generally more profitable. This implies that without additional incentives, one cannot expect companies to adopt sustainable management. The shortsightedness of many loggers, the slow rise in international timber prices, political uncertainty, and tenure insecurity simply reinforce this tendency. However, we reject the claim that sustainable timber management generally damages forests more than conventional logging. Rice et al. base their conclusion largely on the particular case of mahogany extraction in Bolivia, and even there it may not hold. In many cases, sustainable timber management performs better in terms of carbon storage and biodiversity conservation than conventional logging approaches, as well as producing more timber. If new carbon markets emerge, sustainable forest management might compete effectively with conventional timber harvesting. Timber certification systems may also provide a sufficient incentive for sustainable forest management in certain circumstances.

• Improved tropical forest management for carbon retention

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

  Jerome K Vanclay.

  Negotiations leading up to an international climate change agreement to replace the Kyoto Protocol in 2012 have included consideration of reduced emissions due to deforestation and degradationNegotiations leading up to an international climate change agreement to replace the Kyoto Protocol in 2012 have included consideration of reduced emissions due to deforestation and degradation (REDD). This option has figured prominently in the "road map" toward such an agreement that was agreed upon during the 13th Conference of Parties to the United Nations Framework Convention on Climate Change held in Bali in December 2007 (http://www.unfccc.int/). Most ongoing discussions of REDD focus on tropical deforestation, while the potential carbon saving from reduced forest degradation is mostly disregarded [1,2]. Given that carbon losses due to degradation could be of the same magnitude as those from deforestation, this disregard is worrisome [3,4]. We show here that substantial reductions of global CO2 emissions can be achieved by improving forest management in the tropics, and argue that this cost-effective approach to mitigation should be included in the new climate change agreement....

• Is sustainable forestry economically possible?

  Authors: David W Pearce, Francis E Putz, Jerome K Vanclay

  Jerome K Vanclay.

  Concern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United NationsConcern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United Nations Inter-governmental Forum on Forests of the UN Commission on Sustainable Development, and the World Commission on Forests and Sustainable Development. This concern reflects an appreciation of the ecological and economic functions of forests: as providers of timber and many non-timber predicts, as the habitat for much of the world's biological diversity, and as regulators of local, regional and global environments. These functions are at risk. Most of the forest clearance is in areas of high forest cover and high human population pressure in tropical areas for agriculture. In temperate and boreal areas the pressures from logging are more important. But in all areas, forestry itself has an important role to play both as a partial cause of deforestation, and, if practiced wisely, as a potential source of salvation for at least some of the world's forests. In terms of its causal role, forestry tends to open up primary forest areas, enabling colonists to move in, using roads forged by the timber companies. In some parts of the world, forests are converted not to agriculture but to biomass plantations of fast growing trees or to other agro-industries based on tree-crop plantations such as palm oil and rubber. Here the primary agent is not the peasant, but the richer elements of local and international society. How, then, can the world's forests be used more wisely? It is this admittedly grand and complex question that we seek to answer in this chapter.

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• A Sustainable Forest Future?

  Authors: David Pearce, Francis E Putz, Jerome K Vanclay

  Concern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United NationsConcern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United Nations Inter-governmental Forum on Forests of the UN Commission on Sustainable Development (1999), and the World Commission on Forests and Sustainable Development (1999). This concern reflects an appreciation of the ecological and economic functions of forests: as providers of timber and many non-timber predicts, as the habitat for much of the world's biological diversity, and as regulators of local, regional and global environments. These functions are at risk. Most of the forest clearance is in areas of high forest cover and high human population pressure in tropical areas for agriculture. In temperate and boreal areas the pressures from logging are more important. But in all areas, forestry itself has an important role to play both as a partial cause of deforestation, and, if practiced wisely, as a potential source of salvation for at least some of the world's forests. In terms of its causal role, forestry tends to open up primary forest areas, enabling colonists to move in, using roads forged by the timber companies. In some parts of the world, forests are converted not to agriculture but to biomass plantations of fast growing trees or to other agro-industries based on tree-crop plantations such as palm oil and rubber. Here the primary agent is not the peasant, but the richer elements of local and international society. How, then, can the world's forests be used more wisely? It is this admittedly grand and complex question that we seek to answer in this paper. Some argue for outright protection, caricatured perhaps in the phrase 'fence and forget'. Others argue for 'sustainable forest management', and still others for systems of forest management that rely on acceptance of an initial period of exploitation of valuable species followed by outright protection. The issue, then, is the optimal use of forested land , which begs the question of what is meant by 'optimal'. This is addressed shortly.

• Sustainable Forestry in the Tropics: Panacea or Folly?

  Authors: David Pearce, Francis E Putz, Jerome K Vanclay

  The profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. (1997) have argued that not only does traditionalThe profitability of uncontrolled logging can be a significant obstacle to sustainable forest management, especially in the tropics. Rice et al. (1997) have argued that not only does traditional selective logging provide higher returns but also incurs less damage to forests than sustainable forest management systems that involve harvesting of many species and the creation of large gaps in the forest canopy to foster regeneration of light-demanding species. They claimed that protected areas were the only viable way to conserve forest ecosystems and proposed that loggers be allowed to log forests selectively once, after which the forests should become parks. Here we respond to the challenge posed by Rice et al. by exhaustively reviewing the evidence regarding the viability and desirability of sustainable forest management in the tropics. Following Rice et al., we use the term conventional timber harvesting to refer to existing practice, which typically pays little attention to maintaining long-term timber supply. Sustainable timber management implies taking steps to ensure forests continue to produce timber in the longer term, while maintaining the full complement of environmental services and non-timber products of the forest. Empirical studies tend to confirm the conclusion of Rice et al. (1997) that although sustainable timber management sometimes provides reasonable rates of return, conventional timber harvesting is generally more profitable. This implies that without additional incentives, one cannot expect companies to adopt sustainable management. The shortsightedness of many loggers, the slow rise in international timber prices, political uncertainty, and tenure insecurity simply reinforce this tendency. However, we reject the claim that sustainable timber management generally damages forests more than conventional logging. Rice et al. base their conclusion largely on the particular case of mahogany extraction in Bolivia, and even there it may not hold. In many cases, sustainable timber management performs better in terms of carbon storage and biodiversity conservation than conventional logging approaches, as well as producing more timber. If new carbon markets emerge, sustainable forest management might compete effectively with conventional timber harvesting. Timber certification systems may also provide a sufficient incentive for sustainable forest management in certain circumstances.

• Is Sustainable Forestry Economically Possible?

  Authors: David Pearce, Francis E Putz, Jerome K Vanclay

  Concern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United NationsConcern about the rate at which the world's forests are being depleted is wide-spread. Recent international calls for radical efforts to reduce deforestation include the United Nations Inter-governmental Forum on Forests of the UN Commission on Sustainable Development, and the World Commission on Forests and Sustainable Development. This concern reflects an appreciation of the ecological and economic functions of forests: as providers of timber and many non-timber predicts, as the habitat for much of the world's biological diversity, and as regulators of local, regional and global environments. These functions are at risk. Most of the forest clearance is in areas of high forest cover and high human population pressure in tropical areas for agriculture. In temperate and boreal areas the pressures from logging are more important. But in all areas, forestry itself has an important role to play both as a partial cause of deforestation, and, if practiced wisely, as a potential source of salvation for at least some of the worldâ€â��������s forests. In terms of its causal role, forestry tends to open up primary forest areas, enabling colonists to move in, using roads forged by the timber companies. In some parts of the world, forests are converted not to agriculture but to biomass plantations of fast growing trees or to other agro-industries based on tree-crop plantations such as palm oil and rubber. Here the primary agent is not the peasant, but the richer elements of local and international society. How, then, can the world's forests be used more wisely? It is this admittedly grand and complex question that we seek to answer in this chapter.