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• 71. [Article] A Method of Analysis of Biological Resource Use Systems Under the Convention on Biological Diversity

  The 1992 Convention on Biological Diversity (CBD) establishes a new legal framework for the management of biological resource use, for example in fisheries. The signatory states to the CBD have agreed ...

  Citation × Citation Citation Abstract Copy Title: A Method of Analysis of Biological Resource Use Systems Under the Convention on Biological Diversity Author: Hummel, Matthias E. Year: 2001 The 1992 Convention on Biological Diversity (CBD) establishes a new legal framework for the management of biological resource use, for example in fisheries. The signatory states to the CBD have agreed upon several major principles which become legally binding following ratification of the Convention by the national legislature. In terms of resource management, two of these principles are especially remarkable: 1. a concept of sustainability which includes distributional considerations; 2. an ‘ecosystem approach’ that calls for the integration of aspects of community ecology into management schemes. Unfortunately, current approaches to the management of biological resource use fall somewhat short of satisfying these two principles. I try to rectify this, developing a method of analysis that integrates neoclassical resource economics, property rights theory and community ecology into one theoretical concept which can be applied to such distinctive problems as overexploitation, negative impact on ecosystems by resource use, and conflicts among resource users. This method of analysis will make it possible to determine whether a specified biological resource use system and its accompanying management structures meet the requirements set out by the CBD. Title: A Method of Analysis of Biological Resource Use Systems Under the Convention on Biological Diversity Author: Hummel, Matthias E. Year: 2001 The 1992 Convention on Biological Diversity (CBD) establishes a new legal framework for the management of biological resource use, for example in fisheries. The signatory states to the CBD have agreed upon several major principles which become legally binding following ratification of the Convention by the national legislature. In terms of resource management, two of these principles are especially remarkable: 1. a concept of sustainability which includes distributional considerations; 2. an ‘ecosystem approach’ that calls for the integration of aspects of community ecology into management schemes. Unfortunately, current approaches to the management of biological resource use fall somewhat short of satisfying these two principles. I try to rectify this, developing a method of analysis that integrates neoclassical resource economics, property rights theory and community ecology into one theoretical concept which can be applied to such distinctive problems as overexploitation, negative impact on ecosystems by resource use, and conflicts among resource users. This method of analysis will make it possible to determine whether a specified biological resource use system and its accompanying management structures meet the requirements set out by the CBD. Close

• 72. [Article] The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA

  This is the publisher’s final pdf. The published article is copyrighted by Mycological Society of America and can be found at: http://msafungi.org/mycologia/

  Citation × Citation Citation Abstract Copy Title: The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA Author: Sims, Laura Lee, Reeser, Paul, Hansen, Everett M., Sutton, Wendy This is the publisher’s final pdf. The published article is copyrighted by Mycological Society of America and can be found at: http://msafungi.org/mycologia/ Title: The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA Author: Sims, Laura Lee, Reeser, Paul, Hansen, Everett M., Sutton, Wendy This is the publisher’s final pdf. The published article is copyrighted by Mycological Society of America and can be found at: http://msafungi.org/mycologia/ Close

• 73. [Article] Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework?

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society ...

  Citation × Citation Citation Abstract Copy Title: Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework? Author: Johnson, Dustin D., Boyd, Chad S., Kerby, Jay D., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/. Title: Of Grouse and Golden Eggs: Can Ecosystems Be Managed Within a Species-Based Regulatory Framework? Author: Johnson, Dustin D., Boyd, Chad S., Kerby, Jay D., Svejcar, Tony J., Davies, Kirk W. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by the Society for Range Management and can be found at: http://www.srmjournals.org/. Close

• 74. [Article] Interconnectedness of Forest Ecosystem Services, Environmental Corporate Impacts, and Corporate Social Responsibility in the Amazon Rainforest

  The ecosystem services provided by our forest resources and woodlands are multiple and diverse on all spatial and temporal levels, and include provision, regulating, cultural, and supporting services ...

  Citation × Citation Citation Abstract Copy Title: Interconnectedness of Forest Ecosystem Services, Environmental Corporate Impacts, and Corporate Social Responsibility in the Amazon Rainforest Author: Dancé, Raúl The ecosystem services provided by our forest resources and woodlands are multiple and diverse on all spatial and temporal levels, and include provision, regulating, cultural, and supporting services (Hanson, et al. WRI, 2008). Human activities are proximate and direct drivers of deforestation and forest degradation. In the Latin American region, around 40 million hectares, roughly the size of Germany, of forest were converted to other uses in the last decade (FAO, FRA 2010). This massive loss of forest resources has caused a huge concern and reaction of many governments, institutions, consumers and other stakeholders that require companies to implement responsible practices to favor the society and the environment (Porter and Kramer, 2006). Some companies are aware of their negative impacts on the environment and the potential risks for their businesses so they have taken the path of Corporate Social Responsibility (CSR) to measure, prevent, mitigate or compensate those impacts, being the Global Reporting Initiative - GRI standard the most widely adopted reporting framework (KPMG Survey of CSR, 2013). The main goal of this research was to analyze the CSR Sustainability Reports of the top twenty-one (21) corporations in Latin America linked with the four commodities associated with Amazon deforestation (soy, beef, paper/pulp and palm oil) to assess if their CSR activities offset their impacts on environment, therefore the ecosystem balance is maintained in the Amazon rainforest. The study presented a "Sustainability Model in the Amazon" to find interconnections among forest ecosystem services, environmental corporate impacts, and CSR activities. It was also examined the level of dependence of commodities production on forest ecosystem services; it was graded sustainability reports of each corporation to assess fulfillment with PSI and GRI; finally, it was found the connections between the environmental aspects of CSR Standard with the four categories of forest ecosystem services to assess which of them are better represented in the standard. The findings of this research have identified that corporations have a high level of dependence for at least twelve (12) of the thirty-two (32) forest ecosystem services that are essential for commodities production. It was assessed that 70 percent of the thirty-two (32) FES were adversely affected by the economic activities and only 15 percent of them were enhanced. It was also possible to score the fulfillment of each economic sector with the GRI, obtaining the following results: Agricultural products (B); Palm oil Consumers (B+) Animal breeding sector (B+); and Plantations (A-). This pattern suggest an increasing risk of current business practices against the environmental balance, therefore, more efforts are needed to guarantee the sustainability of the forest ecosystem services in the Amazon basin. Title: Interconnectedness of Forest Ecosystem Services, Environmental Corporate Impacts, and Corporate Social Responsibility in the Amazon Rainforest Author: Dancé, Raúl The ecosystem services provided by our forest resources and woodlands are multiple and diverse on all spatial and temporal levels, and include provision, regulating, cultural, and supporting services (Hanson, et al. WRI, 2008). Human activities are proximate and direct drivers of deforestation and forest degradation. In the Latin American region, around 40 million hectares, roughly the size of Germany, of forest were converted to other uses in the last decade (FAO, FRA 2010). This massive loss of forest resources has caused a huge concern and reaction of many governments, institutions, consumers and other stakeholders that require companies to implement responsible practices to favor the society and the environment (Porter and Kramer, 2006). Some companies are aware of their negative impacts on the environment and the potential risks for their businesses so they have taken the path of Corporate Social Responsibility (CSR) to measure, prevent, mitigate or compensate those impacts, being the Global Reporting Initiative - GRI standard the most widely adopted reporting framework (KPMG Survey of CSR, 2013). The main goal of this research was to analyze the CSR Sustainability Reports of the top twenty-one (21) corporations in Latin America linked with the four commodities associated with Amazon deforestation (soy, beef, paper/pulp and palm oil) to assess if their CSR activities offset their impacts on environment, therefore the ecosystem balance is maintained in the Amazon rainforest. The study presented a "Sustainability Model in the Amazon" to find interconnections among forest ecosystem services, environmental corporate impacts, and CSR activities. It was also examined the level of dependence of commodities production on forest ecosystem services; it was graded sustainability reports of each corporation to assess fulfillment with PSI and GRI; finally, it was found the connections between the environmental aspects of CSR Standard with the four categories of forest ecosystem services to assess which of them are better represented in the standard. The findings of this research have identified that corporations have a high level of dependence for at least twelve (12) of the thirty-two (32) forest ecosystem services that are essential for commodities production. It was assessed that 70 percent of the thirty-two (32) FES were adversely affected by the economic activities and only 15 percent of them were enhanced. It was also possible to score the fulfillment of each economic sector with the GRI, obtaining the following results: Agricultural products (B); Palm oil Consumers (B+) Animal breeding sector (B+); and Plantations (A-). This pattern suggest an increasing risk of current business practices against the environmental balance, therefore, more efforts are needed to guarantee the sustainability of the forest ecosystem services in the Amazon basin. Close

• 75. [Article] Quantification of vegetation diversity and variation on intact and degraded rangelands

  Vegetation diversity in the Wyoming big sagebrush/Thurber needlegrass (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young/Achnatherum thurberianum (Piper) Barkworth. syn. Stipa thurberiana Piper) ...

  Citation × Citation Citation Abstract Copy Title: Quantification of vegetation diversity and variation on intact and degraded rangelands Author: Dysart, Patricia L. Vegetation diversity in the Wyoming big sagebrush/Thurber needlegrass (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young/Achnatherum thurberianum (Piper) Barkworth. syn. Stipa thurberiana Piper) plant association was studied across a condition class gradient in southeastern Oregon. All observable vascular plant species were counted during 6 seasons and 2 years and diversity indices were calculated using both density and percent cover. Soil surface characteristics were evaluated once per year for 3 years. The measures of vegetation diversity evaluated in this thesis are: Species Richness, Simpson's Index, Shannon's Index, and Hill's diversity numbers, NO, NI, N2, and evenness ratio E5. Functional categories were addressed using Raunkiaer's Biological Classification system (1934) and life form classes used by the USDA. Soil surface patterns were evaluated using types described by Eckert et al. (1986a). High seasonal and yearly variation exhibited by all classification schemes studied (species richness counts, diversity indices, functional groups, and soil surface microtopography) confounded their ability to consistently distinguish among condition classes. Highest diversity was obtained in the spring and least in the fall. A significant correlation was obtained between diversity and a modified condition class index calculated using actual field data by season, and showed that based on diversity, sites might be classified as poor in one year and good in the next. Five distinct soil surface types showed apparent trends across the gradient, but no statistically significant results were obtained between the amount of cover of any of the soil surface types and range site condition. Significant natural changes in the amount of cover by soil surface microtopography category did occur in the year following grazing exclusion regardless of range condition. This may indicate system resilience is initially high and that recovery thresholds may be approached quickly regardless of initial range condition. Our results indicate that in ecosystems where distinct seasonal changes affect plant community composition, species richness numbers and diversity indices should be used with caution as a criterion for ecological assessment. An a priori delineation of the temporal scale for measurement is an essential condition of using any vegetation or soil indicator as an evaluation tool. Title: Quantification of vegetation diversity and variation on intact and degraded rangelands Author: Dysart, Patricia L. Vegetation diversity in the Wyoming big sagebrush/Thurber needlegrass (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young/Achnatherum thurberianum (Piper) Barkworth. syn. Stipa thurberiana Piper) plant association was studied across a condition class gradient in southeastern Oregon. All observable vascular plant species were counted during 6 seasons and 2 years and diversity indices were calculated using both density and percent cover. Soil surface characteristics were evaluated once per year for 3 years. The measures of vegetation diversity evaluated in this thesis are: Species Richness, Simpson's Index, Shannon's Index, and Hill's diversity numbers, NO, NI, N2, and evenness ratio E5. Functional categories were addressed using Raunkiaer's Biological Classification system (1934) and life form classes used by the USDA. Soil surface patterns were evaluated using types described by Eckert et al. (1986a). High seasonal and yearly variation exhibited by all classification schemes studied (species richness counts, diversity indices, functional groups, and soil surface microtopography) confounded their ability to consistently distinguish among condition classes. Highest diversity was obtained in the spring and least in the fall. A significant correlation was obtained between diversity and a modified condition class index calculated using actual field data by season, and showed that based on diversity, sites might be classified as poor in one year and good in the next. Five distinct soil surface types showed apparent trends across the gradient, but no statistically significant results were obtained between the amount of cover of any of the soil surface types and range site condition. Significant natural changes in the amount of cover by soil surface microtopography category did occur in the year following grazing exclusion regardless of range condition. This may indicate system resilience is initially high and that recovery thresholds may be approached quickly regardless of initial range condition. Our results indicate that in ecosystems where distinct seasonal changes affect plant community composition, species richness numbers and diversity indices should be used with caution as a criterion for ecological assessment. An a priori delineation of the temporal scale for measurement is an essential condition of using any vegetation or soil indicator as an evaluation tool. Close

• 76. [Article] Enhancing the effectiveness of conservation easements through trust building, partner coordination, and cooperation

  2 pages

  Citation × Citation Citation Abstract Copy Title: Enhancing the effectiveness of conservation easements through trust building, partner coordination, and cooperation Author: University of Oregon. Ecosystem Workforce Program Year: 2016, 2013 2 pages Title: Enhancing the effectiveness of conservation easements through trust building, partner coordination, and cooperation Author: University of Oregon. Ecosystem Workforce Program Year: 2016, 2013 2 pages Close

• 77. [Article] Interactive effects of silvicultural herbicides and cervid herbivory on early seral plant communities of the northern Oregon Coast Range

  Intensive forest management (IFM, dense conifer plantings and herbicide applications) may alter the characteristics of early seral plant communities that function as major habitat resources for a host ...

  Citation × Citation Citation Abstract Copy Title: Interactive effects of silvicultural herbicides and cervid herbivory on early seral plant communities of the northern Oregon Coast Range Author: Stokely, Thomas Intensive forest management (IFM, dense conifer plantings and herbicide applications) may alter the characteristics of early seral plant communities that function as major habitat resources for a host of wildlife species, including cervid herbivores such as Cervus elaphus and Odocoileus hemionus. Such large herbivores can also substantially affect plant community characteristics and succession, especially in disturbed early seral habitats. I hypothesized that the effect of cervid herbivory on early seral plant communities is mediated by the effect of silvicultural herbicide treatments. If that is the case, intensively treated stands with low plant cover and diversity should be most susceptible to herbivory, as cervids are less selective and herbivory impacts are highly concentrated where forage has been diminished. To test this hypothesis, I experimentally established paired 225 m² cervid Exclusion and Open-Herbivory treatment plots in 28, 12-15 ha early seral plantation stands throughout the northern Oregon Coast Range, USA, representing a gradient in IFM. The gradient included three herbicide treatments and a no-spray Control applied at the stand scale and replicated using a randomized complete block design. I compared estimates of cover, height and diversity for entire plant communities and specific functional groups among herbivory and herbicide treatments using mixed-effects models with a blocked split-plot design. I found convincing evidence that the effect of herbivory was mediated by herbicide treatment. No-spray Control stands were too vigorous, diverse and rich with native perennial herb and deciduous shrub forage to be substantially impacted by cervid herbivory. The herbaceous specific, Light herbicide treatment reduced Shannon diversity and the cover and richness of native-perennial herbs, releasing deciduous shrub height growth where cervids where excluded. Highly selective herbivory suppressed the shrub height response by 20.5 cm, increasing the abundance and richness of introduced herb species. The broad spectrum, Moderate herbicide treatment reduced diversity, forage cover and diminished the cover and richness of deciduous shrubs and native-perennial herbs, favoring the dominance of introduced-ruderal herbs. Herbivory in the Moderate treatment reduced total cover by 17.7 percent cover, moderate-quality forage cover by 13.2 percent cover and native perennial herb richness by 1.5 species, while suppressing the cover of introduced-ruderal herbs by 4.58 percent cover and reducing the height of ferns and introduced-perennial herbs by 19.9 and 17.3 cm, respectively. Plant communities subject to the Heavy treatment were the most depauperate of all and herbivory exacerbated the effect of this treatment on native-perennial herbs only. Average height of dominant vegetation was consistently lower with cervid access across all stands, especially with Moderate herbicide treatment. My results provide evidence that by reducing diversity and the abundance of native forage species, herbicide treatments altered herbivory selectivity and pressure. The alteration of herbivory pressure in turn influenced the outcome of herbicide treatments, resulting in an exacerbated effect with Moderate and Heavy treatments. The effect of herbivory in controlling vegetation in managed stands may have positive implications for conifer seedling growth, constituting a possible 'ecosystem service' by cervids in the Pacific Northwest. This 'service' may be to the detriment of biodiversity and other early seral associates when coupled with common intensive forest management practices. Title: Interactive effects of silvicultural herbicides and cervid herbivory on early seral plant communities of the northern Oregon Coast Range Author: Stokely, Thomas Intensive forest management (IFM, dense conifer plantings and herbicide applications) may alter the characteristics of early seral plant communities that function as major habitat resources for a host of wildlife species, including cervid herbivores such as Cervus elaphus and Odocoileus hemionus. Such large herbivores can also substantially affect plant community characteristics and succession, especially in disturbed early seral habitats. I hypothesized that the effect of cervid herbivory on early seral plant communities is mediated by the effect of silvicultural herbicide treatments. If that is the case, intensively treated stands with low plant cover and diversity should be most susceptible to herbivory, as cervids are less selective and herbivory impacts are highly concentrated where forage has been diminished. To test this hypothesis, I experimentally established paired 225 m² cervid Exclusion and Open-Herbivory treatment plots in 28, 12-15 ha early seral plantation stands throughout the northern Oregon Coast Range, USA, representing a gradient in IFM. The gradient included three herbicide treatments and a no-spray Control applied at the stand scale and replicated using a randomized complete block design. I compared estimates of cover, height and diversity for entire plant communities and specific functional groups among herbivory and herbicide treatments using mixed-effects models with a blocked split-plot design. I found convincing evidence that the effect of herbivory was mediated by herbicide treatment. No-spray Control stands were too vigorous, diverse and rich with native perennial herb and deciduous shrub forage to be substantially impacted by cervid herbivory. The herbaceous specific, Light herbicide treatment reduced Shannon diversity and the cover and richness of native-perennial herbs, releasing deciduous shrub height growth where cervids where excluded. Highly selective herbivory suppressed the shrub height response by 20.5 cm, increasing the abundance and richness of introduced herb species. The broad spectrum, Moderate herbicide treatment reduced diversity, forage cover and diminished the cover and richness of deciduous shrubs and native-perennial herbs, favoring the dominance of introduced-ruderal herbs. Herbivory in the Moderate treatment reduced total cover by 17.7 percent cover, moderate-quality forage cover by 13.2 percent cover and native perennial herb richness by 1.5 species, while suppressing the cover of introduced-ruderal herbs by 4.58 percent cover and reducing the height of ferns and introduced-perennial herbs by 19.9 and 17.3 cm, respectively. Plant communities subject to the Heavy treatment were the most depauperate of all and herbivory exacerbated the effect of this treatment on native-perennial herbs only. Average height of dominant vegetation was consistently lower with cervid access across all stands, especially with Moderate herbicide treatment. My results provide evidence that by reducing diversity and the abundance of native forage species, herbicide treatments altered herbivory selectivity and pressure. The alteration of herbivory pressure in turn influenced the outcome of herbicide treatments, resulting in an exacerbated effect with Moderate and Heavy treatments. The effect of herbivory in controlling vegetation in managed stands may have positive implications for conifer seedling growth, constituting a possible 'ecosystem service' by cervids in the Pacific Northwest. This 'service' may be to the detriment of biodiversity and other early seral associates when coupled with common intensive forest management practices. Close

• 78. [Article] TomasFionaFisheriesWildlifeTropicalizationTemperateMarine.pdf

  Citation × Citation Citation Abstract Copy Title: TomasFionaFisheriesWildlifeTropicalizationTemperateMarine.pdf Author: Tomas, Fiona, Vergés, Adriana, Ballesteros, Enric, et al., Poore, Alistair G., Steinberg, Peter D., Campbell, Alexandra H., Hay, Mark E. Title: TomasFionaFisheriesWildlifeTropicalizationTemperateMarine.pdf Author: Tomas, Fiona, Vergés, Adriana, Ballesteros, Enric, et al., Poore, Alistair G., Steinberg, Peter D., Campbell, Alexandra H., Hay, Mark E. Close

• 79. [Article] TomasFionaFisheriesWildlifeTropicalizationTemperateMarine(SupplementaryMaterialTableS1).pdf

  Citation × Citation Citation Abstract Copy Title: TomasFionaFisheriesWildlifeTropicalizationTemperateMarine(SupplementaryMaterialTableS1).pdf Author: Tomas, Fiona, Vergés, Adriana, Ballesteros, Enric, et al., Poore, Alistair G., Steinberg, Peter D., Campbell, Alexandra H., Hay, Mark E. Title: TomasFionaFisheriesWildlifeTropicalizationTemperateMarine(SupplementaryMaterialTableS1).pdf Author: Tomas, Fiona, Vergés, Adriana, Ballesteros, Enric, et al., Poore, Alistair G., Steinberg, Peter D., Campbell, Alexandra H., Hay, Mark E. Close

• 80. [Article] Activity and phylogenetic diversity of bacterial cells with high and low nucleic acid content and electron transport system activity in an upwelling ecosystem

  We evaluated whether bacteria with higher cell-specific nucleic acid content (HNA) or an active electron transport system, i.e., positive for reduction of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), ...

  Citation × Citation Citation Abstract Copy Title: Activity and phylogenetic diversity of bacterial cells with high and low nucleic acid content and electron transport system activity in an upwelling ecosystem Author: Sherr, Barry F., Longnecker, K., Sherr, Evelyn We evaluated whether bacteria with higher cell-specific nucleic acid content (HNA) or an active electron transport system, i.e., positive for reduction of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), were responsible for the bulk of bacterioplankton metabolic activity. We also examined whether the phylogenetic diversity of HNA and CTC-positive cells differed from the diversity of Bacteria with low nucleic acid content (LNA). Bacterial assemblages were sampled both in eutrophic shelf waters and in mesotrophic offshore waters in the Oregon coastal upwelling region. Cytometrically sorted HNA, LNA, and CTC-positive cells were assayed for their cell-specific [³H]leucine incorporation rates. Phylogenetic diversity in sorted non-radioactively labeled samples was assayed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes. Cell-specific rates of leucine incorporation of HNA and CTC-positive cells were on average only slightly greater than the cell-specific rates of LNA cells. HNA cells accounted for most bacterioplankton substrate incorporation due to high abundances, while the low abundances of CTC-positive cells resulted in only a small contribution by these cells to total bacterial activity. The proportion of the total bacterial leucine incorporation attributable to LNA cells was higher in offshore regions than in shelf waters. Sequence data obtained from DGGE bands showed broadly similar phylogenetic diversity across HNA, LNA, and CTC-positive cells, with between-sample and between-region variability in the distribution of phylotypes. Our results suggest that LNA bacteria are not substantially different from HNA bacteria in either cell-specific rates of substrate incorporation or phylogenetic composition and that they can be significant contributors to bacterial metabolism in the sea. Title: Activity and phylogenetic diversity of bacterial cells with high and low nucleic acid content and electron transport system activity in an upwelling ecosystem Author: Sherr, Barry F., Longnecker, K., Sherr, Evelyn We evaluated whether bacteria with higher cell-specific nucleic acid content (HNA) or an active electron transport system, i.e., positive for reduction of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), were responsible for the bulk of bacterioplankton metabolic activity. We also examined whether the phylogenetic diversity of HNA and CTC-positive cells differed from the diversity of Bacteria with low nucleic acid content (LNA). Bacterial assemblages were sampled both in eutrophic shelf waters and in mesotrophic offshore waters in the Oregon coastal upwelling region. Cytometrically sorted HNA, LNA, and CTC-positive cells were assayed for their cell-specific [³H]leucine incorporation rates. Phylogenetic diversity in sorted non-radioactively labeled samples was assayed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes. Cell-specific rates of leucine incorporation of HNA and CTC-positive cells were on average only slightly greater than the cell-specific rates of LNA cells. HNA cells accounted for most bacterioplankton substrate incorporation due to high abundances, while the low abundances of CTC-positive cells resulted in only a small contribution by these cells to total bacterial activity. The proportion of the total bacterial leucine incorporation attributable to LNA cells was higher in offshore regions than in shelf waters. Sequence data obtained from DGGE bands showed broadly similar phylogenetic diversity across HNA, LNA, and CTC-positive cells, with between-sample and between-region variability in the distribution of phylotypes. Our results suggest that LNA bacteria are not substantially different from HNA bacteria in either cell-specific rates of substrate incorporation or phylogenetic composition and that they can be significant contributors to bacterial metabolism in the sea. Close