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• 11. [Article] Biodiversity in managed forests of western Oregon : species assemblages in leave islands, thinned, and unthinned forests

  Both leave islands, or green tree retention clusters, and thinning prescriptions have been proposed as alternative silvicultural strategies designed to sustain the structural and biological diversity of ...

  Citation × Citation Citation Abstract Copy Title: Biodiversity in managed forests of western Oregon : species assemblages in leave islands, thinned, and unthinned forests Author: Wessell, Stephanie J. Both leave islands, or green tree retention clusters, and thinning prescriptions have been proposed as alternative silvicultural strategies designed to sustain the structural and biological diversity of managed forests. However, the relationship of the physical structure of leave islands and thinned forests to their associated microclimates, flora, and fauna remain largely unknown. We evaluated habitat and biota after forest thinning from 600 to 200 trees per hectare with three sizes of leave islands. Specifically, we used analysis of variance, species occupancy pattern assessments, and community analysis methods to examine differences in habitat and vascular plant, arthropod, amphibian, and mollusk abundance and diversity with respect to thinning and leave island size in four western Oregon managed forest stands. We found multiple treatment effects of thinning and leave island size relative to microclimate and vascular plant diversity and ground cover. The microclimate and vascular plant species composition differed between thinned and unthinned forest while conditions within leave islands approximated conditions in unthinned forest. Proportions of exotic and early-successional species and species ground cover were higher in thinned forest than unthinned forest and higher in small leave islands than larger leave islands. Treatment effects on arthropod, amphibian, and mollusk density were mixed. Of 118 parameters analyzed, negative effects of thinning on faunal species were detected for five arthropod species, low-mobility arthropod captures, one salamander species, one salamander family (Plethodontidae), amphibian species richness, and one mollusk species. Of 83 parameters assessed, positive effects of leave island size were found for arthropod species richness, overall density, density within six functional group measures, and for six species groups. Treatment effects of leave island size were mixed for amphibians and mollusks with positive effects of leave island size for overall mollusk density, snail density, and density within three mollusk species groups. Indicator species analyses identified seven vascular plant and two arthropod species indicative of thinned forest, 0.2 ha and 0.4 ha leave islands. Assessments of species occupancy patterns revealed insights regarding the potential utility of managing the forest matrix for habitat heterogeneity. For example, 71(19%) taxa occurred only in leave islands and 139 (37%) taxa occurred only in leave islands and unthinned forest. These patterns may indicate occurrences of rare species and do not necessarily indicate associations with these unthinned forest types. Community analyses highlighted the importance of addressing multiple spatial scales in forest management prescriptions by identifying distinct biotic assemblages occurring at forest type, study site, and mountain range scales. Our results suggest that leave islands may provide refugia for some low-mobility, ecologically sensitive species in managed forests of the Pacific Northwest. Title: Biodiversity in managed forests of western Oregon : species assemblages in leave islands, thinned, and unthinned forests Author: Wessell, Stephanie J. Both leave islands, or green tree retention clusters, and thinning prescriptions have been proposed as alternative silvicultural strategies designed to sustain the structural and biological diversity of managed forests. However, the relationship of the physical structure of leave islands and thinned forests to their associated microclimates, flora, and fauna remain largely unknown. We evaluated habitat and biota after forest thinning from 600 to 200 trees per hectare with three sizes of leave islands. Specifically, we used analysis of variance, species occupancy pattern assessments, and community analysis methods to examine differences in habitat and vascular plant, arthropod, amphibian, and mollusk abundance and diversity with respect to thinning and leave island size in four western Oregon managed forest stands. We found multiple treatment effects of thinning and leave island size relative to microclimate and vascular plant diversity and ground cover. The microclimate and vascular plant species composition differed between thinned and unthinned forest while conditions within leave islands approximated conditions in unthinned forest. Proportions of exotic and early-successional species and species ground cover were higher in thinned forest than unthinned forest and higher in small leave islands than larger leave islands. Treatment effects on arthropod, amphibian, and mollusk density were mixed. Of 118 parameters analyzed, negative effects of thinning on faunal species were detected for five arthropod species, low-mobility arthropod captures, one salamander species, one salamander family (Plethodontidae), amphibian species richness, and one mollusk species. Of 83 parameters assessed, positive effects of leave island size were found for arthropod species richness, overall density, density within six functional group measures, and for six species groups. Treatment effects of leave island size were mixed for amphibians and mollusks with positive effects of leave island size for overall mollusk density, snail density, and density within three mollusk species groups. Indicator species analyses identified seven vascular plant and two arthropod species indicative of thinned forest, 0.2 ha and 0.4 ha leave islands. Assessments of species occupancy patterns revealed insights regarding the potential utility of managing the forest matrix for habitat heterogeneity. For example, 71(19%) taxa occurred only in leave islands and 139 (37%) taxa occurred only in leave islands and unthinned forest. These patterns may indicate occurrences of rare species and do not necessarily indicate associations with these unthinned forest types. Community analyses highlighted the importance of addressing multiple spatial scales in forest management prescriptions by identifying distinct biotic assemblages occurring at forest type, study site, and mountain range scales. Our results suggest that leave islands may provide refugia for some low-mobility, ecologically sensitive species in managed forests of the Pacific Northwest. Close

• 12. [Article] Forest associations and secondary plant succession in the southern Oregon coastal range

  Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession ...

  Citation × Citation Citation Abstract Copy Title: Forest associations and secondary plant succession in the southern Oregon coastal range Author: Bailey, Arthur Wesley, 1938- Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession by habitat-type were a necessary first step in investigations into browsing of conifers by elk. The study was jointly conducted by the Oregon State Game Commission and the Weyerhaeuser Company. Vegetation, soils, and physiography were studied together. Vegetation cover data, recorded in thirty-two, 275 to 500-year-old forest stands, formed the basis of a synecological classification. Lightspots are a natural component of these forests. The dense forest and a lightspot were separately sampled in each stand. Light-spot cover data were analyzed separately in an association table. Lightspot data were compared with dense forest data to check validity of the phytosociological classification. This approach increased phytosociological understanding of these forests. The climax dominant tree and shrub and herb layer species with highest cover are used in naming the following associations (in order of increasing xerism): Thuja/Adiantum-Athyrium Tsuga/Polystichum/Oxalis Tsuga/Acer/Berberis Tsuga-Pseudotsuga/Rhododendron/Berberis Pseudotsuga/Holodiscus/Gaultheria. The exceptions are Adiantum pedatum and Athyrium filix-femina, high constancy, low cover, indicator species, used in naming the Thuja/Adiantum-Athyrium association. Polystichum munitum and Oxalis oregana dominate the herb layer of this association. Associations will be referred to in the abstract by a two-part name. The Adiantum-Athyrium association has the following additional indicator species: Blechnum spicant and Marah oreganus. Stands usually occur near the bottoms of lower elevation canyons. The moist, stony, Slickrock soil series underlies most stands. The Polystichum/Oxalis association is the most widespread and variable community studied. Tiarella trifoliata has high indicator value for this association. The presence of any one of Stellaria crispa, Montia sibirica, Dicentra formosa or Athyrium filix-femina in lightspots effectively differentiates stands of this association from related ones of the Acer/Berberis association. Stands frequently occur on lower and middle slopes and are usually underlain by the Matson or Apt soil series. In the Acer/Berberis association, Acer circinatum has high cover only in lightspots. Most stands are found on the Millicoma or Matson soil series. Stands occur on lower and middle slopes. Stands of the Rhododendron/Berberis association usually occur on south-facing, upper slopes and ridgetops where high winds frequently cause blowdown. The resultant large openings allow regeneration of Pseudotsuga menziesii. Rhododendron macrophyllum has low cover in the dense forest but high cover in lightspots. Allotropa virgata, a low constancy (saprophyte), has high fidelity to the association. The Millicoma, Matson or Ivers soil series underlie most stands. The Holodiscus/Gaultheria association has the following high fidelity species: Philadelphus lewisii, Symphoricarpos mollis, Madia gracilis, Hierochloe occidentalis, Ligusticum apiifolium, and Lonicera hispidula. This is the only association studied in which the lightspot phenomenon was not important. With the exception of Pseudotsuga menziesii regeneration, understory vegetation did not increase in cover when the tree canopy was removed. Stands usually occur on south-facing, upper slopes and ridgetops. The Digger or Agony soil series are associated with most stands. The successional influence of soil-surface disturbance caused by logging was studied in 1 to 15-year-old stands of the Polystichum/Oxalis and Rhododendron/Berberis habitat-types. In the Polystichum/Oxalis habitat-type, the vegetative dominants by years since logging are: Senecio sylvaticus--first year; Deschampsia elongata--years 2 to 4; Aira caryophyllea, Rubus ursinus, Hypochaeris radicata and Crepis capillaris share dominance--years 5 to 9; Hypochaeris radicata and Pteridium aquilinum share dominance--years 10 to 15. Pseudotsuga menziesii increased to 16 percent cover in the 10 to 15-year period. Disturbed areas of the Rhododendron/Berberis habitat-type have more than 65 percent bare ground for two years after logging. The vegetation dominants by years are: Deschampsia elongata--years 3 to 4; Hypochaeris radicata and Rubus ursinus--years 5 to 7; and Pseudotsuga menziesii--years 8 to 15. Other high cover species in the 8 to 15-year period are Thermopsis montana, Rubus ursinus, and Pteridium aquilinum. Selected stages in secondary succession were studied from one year after logging to climax in the two most important habitat-types. In the Polystichum/Oxalis habitat-type, Pseudotsuga menziesii is the seral tree dominant but is replaced by Tsuga heterophylla in climax. The tall shrub Acer circinatum has high cover in those serai stages with a comparatively open tree canopy. The herb layer is dominated throughout secondary succession by Polystichum munitum and Oxalis oregana. The tree layer of serai stands of the Rhododendron/Berberis habitat-type is dominated by Pseudotsuga menziesii. Either Tsuga heterophylla or Pseudotsuga menziesii dominate near-climax stands. The shrub layer dominant is Rhododendron macrophyllum throughout secondary succession. It has low cover in the dense forest but high cover in lightspots of near-climax stands. Berberis nervosa has nearly constant coverage throughout secondary succession in the Rhododendron/Berberis habitat-type and is the herb layer dominant in near-climax stands. Herb layer dominants in early serai stages are: Senecio sylvaticus--year 1; Erechtites prenanthoides--year 2; Rubus ursinus and Gaultheria shallon--years 4-15. Classification and recognition of habitat-types are possible throughout secondary succession from logging to climax on the basis of the same indicator species. The dominance level of some species changes with seral stage, but the change is predictable. Preferred elk food is about twice as abundant in the Polystichum/Oxalis as the Rhododendron/Berberis habitat-type. Nutritious, preferred elk food is most available in the 4 to 9-year period of secondary succession. Present logging methods which leave a mosaic of intermingled disturbed and undisturbed areas create a habitat beneficial to elk. The animals forage on disturbed areas for preferred invader species and on adjacent undisturbed areas for forest remnant species. Title: Forest associations and secondary plant succession in the southern Oregon coastal range Author: Bailey, Arthur Wesley, 1938- Forest associations, secondary succession, and relationships of plant communities to Roosevelt elk were investigated. Stratification of vegetation into ecological units and an understanding of secondary succession by habitat-type were a necessary first step in investigations into browsing of conifers by elk. The study was jointly conducted by the Oregon State Game Commission and the Weyerhaeuser Company. Vegetation, soils, and physiography were studied together. Vegetation cover data, recorded in thirty-two, 275 to 500-year-old forest stands, formed the basis of a synecological classification. Lightspots are a natural component of these forests. The dense forest and a lightspot were separately sampled in each stand. Light-spot cover data were analyzed separately in an association table. Lightspot data were compared with dense forest data to check validity of the phytosociological classification. This approach increased phytosociological understanding of these forests. The climax dominant tree and shrub and herb layer species with highest cover are used in naming the following associations (in order of increasing xerism): Thuja/Adiantum-Athyrium Tsuga/Polystichum/Oxalis Tsuga/Acer/Berberis Tsuga-Pseudotsuga/Rhododendron/Berberis Pseudotsuga/Holodiscus/Gaultheria. The exceptions are Adiantum pedatum and Athyrium filix-femina, high constancy, low cover, indicator species, used in naming the Thuja/Adiantum-Athyrium association. Polystichum munitum and Oxalis oregana dominate the herb layer of this association. Associations will be referred to in the abstract by a two-part name. The Adiantum-Athyrium association has the following additional indicator species: Blechnum spicant and Marah oreganus. Stands usually occur near the bottoms of lower elevation canyons. The moist, stony, Slickrock soil series underlies most stands. The Polystichum/Oxalis association is the most widespread and variable community studied. Tiarella trifoliata has high indicator value for this association. The presence of any one of Stellaria crispa, Montia sibirica, Dicentra formosa or Athyrium filix-femina in lightspots effectively differentiates stands of this association from related ones of the Acer/Berberis association. Stands frequently occur on lower and middle slopes and are usually underlain by the Matson or Apt soil series. In the Acer/Berberis association, Acer circinatum has high cover only in lightspots. Most stands are found on the Millicoma or Matson soil series. Stands occur on lower and middle slopes. Stands of the Rhododendron/Berberis association usually occur on south-facing, upper slopes and ridgetops where high winds frequently cause blowdown. The resultant large openings allow regeneration of Pseudotsuga menziesii. Rhododendron macrophyllum has low cover in the dense forest but high cover in lightspots. Allotropa virgata, a low constancy (saprophyte), has high fidelity to the association. The Millicoma, Matson or Ivers soil series underlie most stands. The Holodiscus/Gaultheria association has the following high fidelity species: Philadelphus lewisii, Symphoricarpos mollis, Madia gracilis, Hierochloe occidentalis, Ligusticum apiifolium, and Lonicera hispidula. This is the only association studied in which the lightspot phenomenon was not important. With the exception of Pseudotsuga menziesii regeneration, understory vegetation did not increase in cover when the tree canopy was removed. Stands usually occur on south-facing, upper slopes and ridgetops. The Digger or Agony soil series are associated with most stands. The successional influence of soil-surface disturbance caused by logging was studied in 1 to 15-year-old stands of the Polystichum/Oxalis and Rhododendron/Berberis habitat-types. In the Polystichum/Oxalis habitat-type, the vegetative dominants by years since logging are: Senecio sylvaticus--first year; Deschampsia elongata--years 2 to 4; Aira caryophyllea, Rubus ursinus, Hypochaeris radicata and Crepis capillaris share dominance--years 5 to 9; Hypochaeris radicata and Pteridium aquilinum share dominance--years 10 to 15. Pseudotsuga menziesii increased to 16 percent cover in the 10 to 15-year period. Disturbed areas of the Rhododendron/Berberis habitat-type have more than 65 percent bare ground for two years after logging. The vegetation dominants by years are: Deschampsia elongata--years 3 to 4; Hypochaeris radicata and Rubus ursinus--years 5 to 7; and Pseudotsuga menziesii--years 8 to 15. Other high cover species in the 8 to 15-year period are Thermopsis montana, Rubus ursinus, and Pteridium aquilinum. Selected stages in secondary succession were studied from one year after logging to climax in the two most important habitat-types. In the Polystichum/Oxalis habitat-type, Pseudotsuga menziesii is the seral tree dominant but is replaced by Tsuga heterophylla in climax. The tall shrub Acer circinatum has high cover in those serai stages with a comparatively open tree canopy. The herb layer is dominated throughout secondary succession by Polystichum munitum and Oxalis oregana. The tree layer of serai stands of the Rhododendron/Berberis habitat-type is dominated by Pseudotsuga menziesii. Either Tsuga heterophylla or Pseudotsuga menziesii dominate near-climax stands. The shrub layer dominant is Rhododendron macrophyllum throughout secondary succession. It has low cover in the dense forest but high cover in lightspots of near-climax stands. Berberis nervosa has nearly constant coverage throughout secondary succession in the Rhododendron/Berberis habitat-type and is the herb layer dominant in near-climax stands. Herb layer dominants in early serai stages are: Senecio sylvaticus--year 1; Erechtites prenanthoides--year 2; Rubus ursinus and Gaultheria shallon--years 4-15. Classification and recognition of habitat-types are possible throughout secondary succession from logging to climax on the basis of the same indicator species. The dominance level of some species changes with seral stage, but the change is predictable. Preferred elk food is about twice as abundant in the Polystichum/Oxalis as the Rhododendron/Berberis habitat-type. Nutritious, preferred elk food is most available in the 4 to 9-year period of secondary succession. Present logging methods which leave a mosaic of intermingled disturbed and undisturbed areas create a habitat beneficial to elk. The animals forage on disturbed areas for preferred invader species and on adjacent undisturbed areas for forest remnant species. Close

• 13. [Article] Onshore-offshore variations in copepod community structure off the Oregon coast during the summer upwelling season

  The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/

  Citation × Citation Citation Abstract Copy Title: Onshore-offshore variations in copepod community structure off the Oregon coast during the summer upwelling season Author: Emmett, Robert L., Morgan, Cheryl A., Peterson, William T. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Title: Onshore-offshore variations in copepod community structure off the Oregon coast during the summer upwelling season Author: Emmett, Robert L., Morgan, Cheryl A., Peterson, William T. The published version of this article is copyrighted by Inter-Research and can be found here: http://www.int-res.com/journals/meps/meps-home/ Close

• 14. [Article] Does Temperature-Mediated Reproductive Success Drive the Direction of Species Displacement in Two Invasive Species of Leafminer Fly?

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Public Library of Science. The published article can be found at: http://www.plosone.org/.

  Citation × Citation Citation Abstract Copy Title: Does Temperature-Mediated Reproductive Success Drive the Direction of Species Displacement in Two Invasive Species of Leafminer Fly? Author: Wang, Haihong, Xiang, Juncheng, Reitz, Stuart R., Smagghe, Guy, Lei, Zhongren This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Public Library of Science. The published article can be found at: http://www.plosone.org/. Title: Does Temperature-Mediated Reproductive Success Drive the Direction of Species Displacement in Two Invasive Species of Leafminer Fly? Author: Wang, Haihong, Xiang, Juncheng, Reitz, Stuart R., Smagghe, Guy, Lei, Zhongren This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Public Library of Science. The published article can be found at: http://www.plosone.org/. Close

• 15. [Article] Bird-vegetation associations in thinned and unthinned young Douglas-fir forests 10 years after thinning

  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 Elsevier ...

  Citation × Citation Citation Abstract Copy Title: Bird-vegetation associations in thinned and unthinned young Douglas-fir forests 10 years after thinning Author: Yegorova, Svetlana, Hagar, Joan, Puettmann, Klaus J., Betts, Matthew G. 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 Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management/. Title: Bird-vegetation associations in thinned and unthinned young Douglas-fir forests 10 years after thinning Author: Yegorova, Svetlana, Hagar, Joan, Puettmann, Klaus J., Betts, Matthew G. 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 Elsevier and can be found at: http://www.journals.elsevier.com/forest-ecology-and-management/. Close

• 16. [Article] The Effects of Disturbance History on Ground-Layer Plant Community Composition in British Columbia

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/forests

  Citation × Citation Citation Abstract Copy Title: The Effects of Disturbance History on Ground-Layer Plant Community Composition in British Columbia Author: Krawchuk, Meg A., Ton, Michael This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/forests Title: The Effects of Disturbance History on Ground-Layer Plant Community Composition in British Columbia Author: Krawchuk, Meg A., Ton, Michael This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/forests Close

• 17. [Article] Oceanographic conditions around the Galápagos Archipelago and their influence on cetacean community structure

  The objectives of this dissertation were to describe the complex oceanographic conditions around the Galápagos Archipelago (eastern equatorial Pacific), their seasonal variability, and their effects on ...

  Citation × Citation Citation Abstract Copy Title: Oceanographic conditions around the Galápagos Archipelago and their influence on cetacean community structure Author: Palacios, Daniel Mauricio The objectives of this dissertation were to describe the complex oceanographic conditions around the Galápagos Archipelago (eastern equatorial Pacific), their seasonal variability, and their effects on patterns of cetacean occurrence. The physical and ecological factors leading to a plume of high phytoplankton biomass in the wake of the Galápagos were investigated with principal component and regression analyses of water-column climatologies and satellite-derived ocean color. The results supported the notion that this "island-mass effect" is fueled by upwelling of the Equatorial Undercurrent (EUC) combined with natural iron enrichment from the island platform. Seasonal variability in long-term monthly fields of satellite-derived sea-surface temperature and ocean color was studied through harmonic analysis and empirical orthogonal function decomposition. Two annual cycles were identified in both variables. The intensification of the Equatorial Front and the South Equatorial Current in the second part of the year was the dominant signal in the data. A secondary cycle reaching its peak in the first part of the year was associated with the topographically induced upwelling of the EUC on the western side of the archipelago, and with advection of upwelled Panama Bight water on the eastern side. The occurrence of nine cetacean Species (including seven small and medium-sized delphinids, the sperm whale, and the Bryde's whale) in relation to environmental variability around the archipelago was described. Seasonally persistent sectors of the archipelago characterized by the presence of distinct species assemblages of stratified, upwelling, and nearshore environments were identified through cluster and indicator species analysis. The dominant pattern in species distribution, as extracted by a nonmetric multidimensional scaling procedure, was well correlated with the main environmental gradient (described by the degree of water-column stratification, chlorophyll-a concentration, and distance from the islands). The collective results of this study indicate that the ocean environment surrounding the Galápagos Archipelago is strongly influenced by equatorial flows. However, the archipelago also introduces a disturbance to these flows, creating localized and persistent conditions that favor the establishment of distinct biological communities around the islands. Title: Oceanographic conditions around the Galápagos Archipelago and their influence on cetacean community structure Author: Palacios, Daniel Mauricio The objectives of this dissertation were to describe the complex oceanographic conditions around the Galápagos Archipelago (eastern equatorial Pacific), their seasonal variability, and their effects on patterns of cetacean occurrence. The physical and ecological factors leading to a plume of high phytoplankton biomass in the wake of the Galápagos were investigated with principal component and regression analyses of water-column climatologies and satellite-derived ocean color. The results supported the notion that this "island-mass effect" is fueled by upwelling of the Equatorial Undercurrent (EUC) combined with natural iron enrichment from the island platform. Seasonal variability in long-term monthly fields of satellite-derived sea-surface temperature and ocean color was studied through harmonic analysis and empirical orthogonal function decomposition. Two annual cycles were identified in both variables. The intensification of the Equatorial Front and the South Equatorial Current in the second part of the year was the dominant signal in the data. A secondary cycle reaching its peak in the first part of the year was associated with the topographically induced upwelling of the EUC on the western side of the archipelago, and with advection of upwelled Panama Bight water on the eastern side. The occurrence of nine cetacean Species (including seven small and medium-sized delphinids, the sperm whale, and the Bryde's whale) in relation to environmental variability around the archipelago was described. Seasonally persistent sectors of the archipelago characterized by the presence of distinct species assemblages of stratified, upwelling, and nearshore environments were identified through cluster and indicator species analysis. The dominant pattern in species distribution, as extracted by a nonmetric multidimensional scaling procedure, was well correlated with the main environmental gradient (described by the degree of water-column stratification, chlorophyll-a concentration, and distance from the islands). The collective results of this study indicate that the ocean environment surrounding the Galápagos Archipelago is strongly influenced by equatorial flows. However, the archipelago also introduces a disturbance to these flows, creating localized and persistent conditions that favor the establishment of distinct biological communities around the islands. Close

• 18. [Article] Distribution and assemblages of demersal fish in Oman

  The Sultanate of Oman has 1700 km of coastline extending from the Arabian Gulf south to the Arabian Sea. The demersal fish distributions and assemblages have not previously been well defined. In winter, ...

  Citation × Citation Citation Abstract Copy Title: Distribution and assemblages of demersal fish in Oman Author: Ambusaidi, Hilal Saud The Sultanate of Oman has 1700 km of coastline extending from the Arabian Gulf south to the Arabian Sea. The demersal fish distributions and assemblages have not previously been well defined. In winter, variations in the oceanography of the area are minimal. In summer, however, the Arabian Sea is strongly influenced by the southwest monsoon. For this study the continental shelf off Oman was divided into eight regional areas and research trawl data on the distribution of demersal fish assemblages was studied using two forms of multivariate statistical analysis: two-way indicator species analysis and detrended correspondence analysis. The study was carried out to examine the influence on the species assemblages of geographical zonation, seasonal variation, and factors such as depth, time of day, and distance from untrawlable ground. There was seasonal variation in the fish assemblages and this variation was greatly influenced by the summer monsoon. Within each regional area depth appeared to be the major factor determining species distribution. In addition to the multivariate analyses, univariate techniques were applied to the catch rate data for forty commercial species to study in detail the influence of time of day and distance from untrawlable ground, factors which could potentially influence stock assessment estimates of fish biomass. Because the data were highly unbalanced, they were analyzed using General Linear Model with five factors, two continuous variables, and ten interaction terms to examine variation in the log-transformed catch rates. The factors time of day and distance from untrawlable ground, in combination with other factors, had significant effects on the catch rates for half of the species. Title: Distribution and assemblages of demersal fish in Oman Author: Ambusaidi, Hilal Saud The Sultanate of Oman has 1700 km of coastline extending from the Arabian Gulf south to the Arabian Sea. The demersal fish distributions and assemblages have not previously been well defined. In winter, variations in the oceanography of the area are minimal. In summer, however, the Arabian Sea is strongly influenced by the southwest monsoon. For this study the continental shelf off Oman was divided into eight regional areas and research trawl data on the distribution of demersal fish assemblages was studied using two forms of multivariate statistical analysis: two-way indicator species analysis and detrended correspondence analysis. The study was carried out to examine the influence on the species assemblages of geographical zonation, seasonal variation, and factors such as depth, time of day, and distance from untrawlable ground. There was seasonal variation in the fish assemblages and this variation was greatly influenced by the summer monsoon. Within each regional area depth appeared to be the major factor determining species distribution. In addition to the multivariate analyses, univariate techniques were applied to the catch rate data for forty commercial species to study in detail the influence of time of day and distance from untrawlable ground, factors which could potentially influence stock assessment estimates of fish biomass. Because the data were highly unbalanced, they were analyzed using General Linear Model with five factors, two continuous variables, and ten interaction terms to examine variation in the log-transformed catch rates. The factors time of day and distance from untrawlable ground, in combination with other factors, had significant effects on the catch rates for half of the species. Close

• 19. [Article] The LizLand model : geomorphic landform and surface composition analysis of lizard habitat in the California Mojave Desert

  This dissertation had three main objectives: 1) investigate the role of macro and micro geomorphology in determining lizard distributions in the Southern California Mojave Desert; 2) develop a spatially ...

  Citation × Citation Citation Abstract Copy Title: The LizLand model : geomorphic landform and surface composition analysis of lizard habitat in the California Mojave Desert Author: Heaton, Jill S. This dissertation had three main objectives: 1) investigate the role of macro and micro geomorphology in determining lizard distributions in the Southern California Mojave Desert; 2) develop a spatially explicit lizard habitat model based upon geomorphology; and, 3) determine the interactive effects of geomorphology, roads, and land use in defining lizard habitat. To achieve these objectives a new concept of reptile habitat was developed. Primary field data on presence/absence of lizards in relation to macro and micro geomorphology were collected for three conspicuous and widely distributed Mojave Desert lizard species: Cnemidophorus tigris, Callisaurus draconoides, and Uta stansburiana. Study sites were distributed between the Marine Air Ground Task Force Training Command Marine Corps Air Ground Combat Center (MCAGCC) and Joshua Tree National Park (JOTR) in the Southern California Mojave Desert. Chapter 2 develops a new concept of reptile habitat in and environments. This concept is based upon geomorphic landform and surface composition, which are used to distinguish lizard macro and micro-habitat components. The micro-habitat requirements of individual species are linked to macro geomorphic landforms via their mutual microhabitat characterizations. Chapter 3 describes the development of the spatially explicit LizLand habitat model. LizLand is based on the concept of reptile habitat developed and described in Chapter 2. Digital data used to construct the model include geomorphic landform, surface composition, hydrologic, and elevation data. The model is validated for MCAGCC using secondary species locational data and developed for two additional species for which no primary data were collected. The implications of LizLand for military land management are discussed. The final paper explores in greater depth the relationship between Callisaurus draconoides and the geomorphic landform habitat class alluvial plains. It compares C. draconoides observations on unpaved alluvial plain roads to surrounding habitats and observations between MCAGCC and JOTR. Finally, it considers the use of C. draconoides as an indicator species given its affinity for unpaved alluvial plain roads. Title: The LizLand model : geomorphic landform and surface composition analysis of lizard habitat in the California Mojave Desert Author: Heaton, Jill S. This dissertation had three main objectives: 1) investigate the role of macro and micro geomorphology in determining lizard distributions in the Southern California Mojave Desert; 2) develop a spatially explicit lizard habitat model based upon geomorphology; and, 3) determine the interactive effects of geomorphology, roads, and land use in defining lizard habitat. To achieve these objectives a new concept of reptile habitat was developed. Primary field data on presence/absence of lizards in relation to macro and micro geomorphology were collected for three conspicuous and widely distributed Mojave Desert lizard species: Cnemidophorus tigris, Callisaurus draconoides, and Uta stansburiana. Study sites were distributed between the Marine Air Ground Task Force Training Command Marine Corps Air Ground Combat Center (MCAGCC) and Joshua Tree National Park (JOTR) in the Southern California Mojave Desert. Chapter 2 develops a new concept of reptile habitat in and environments. This concept is based upon geomorphic landform and surface composition, which are used to distinguish lizard macro and micro-habitat components. The micro-habitat requirements of individual species are linked to macro geomorphic landforms via their mutual microhabitat characterizations. Chapter 3 describes the development of the spatially explicit LizLand habitat model. LizLand is based on the concept of reptile habitat developed and described in Chapter 2. Digital data used to construct the model include geomorphic landform, surface composition, hydrologic, and elevation data. The model is validated for MCAGCC using secondary species locational data and developed for two additional species for which no primary data were collected. The implications of LizLand for military land management are discussed. The final paper explores in greater depth the relationship between Callisaurus draconoides and the geomorphic landform habitat class alluvial plains. It compares C. draconoides observations on unpaved alluvial plain roads to surrounding habitats and observations between MCAGCC and JOTR. Finally, it considers the use of C. draconoides as an indicator species given its affinity for unpaved alluvial plain roads. Close

• 20. [Article] Vegetation and soil microbial communities three years after wildfire in spruce-fir forests of northwestern Wyoming

  The Normalized Burn Ratio and Composite Burn Index were used to classify burn severity in three sites that experienced lightning-ignited wildfire in the year 2000. The effect of burn severity (unburned, ...

  Citation × Citation Citation Abstract Copy Title: Vegetation and soil microbial communities three years after wildfire in spruce-fir forests of northwestern Wyoming Author: Hooke, Jennifer Suzanne The Normalized Burn Ratio and Composite Burn Index were used to classify burn severity in three sites that experienced lightning-ignited wildfire in the year 2000. The effect of burn severity (unburned, low, moderate, and high severity classes) was investigated on vegetation and soil microbial community composition. Vegetation communities showed a strong response to burn severity, with distinct communities associated with each burn severity class. Indicator Species Analysis was used to identify plant species associated with each burn severity class; one interesting result from ISA was that trembling aspen (Populus tremuloides) seedlings emerged as an indicator of the moderate severity class. Species richness and tree seedling density differed among burn severity classes. Soil microbial communities were analyzed using Phospholipid Fatty Acid analysis and showed moderate variation among burn severity classes and study sites. Total soil carbon and nitrogen did not differ with burn severity. The C:N ratio, total soil S, and soil pH differed significantly among burn severity classes. While the effect of burn severity is pronounced upon vegetation three years post-fire, effects on soil microbial communities are less evident. This could be attributed to the insulating properties of soils, the time elapsed after fire, or it could be an artifact of the sampling technique. Title: Vegetation and soil microbial communities three years after wildfire in spruce-fir forests of northwestern Wyoming Author: Hooke, Jennifer Suzanne The Normalized Burn Ratio and Composite Burn Index were used to classify burn severity in three sites that experienced lightning-ignited wildfire in the year 2000. The effect of burn severity (unburned, low, moderate, and high severity classes) was investigated on vegetation and soil microbial community composition. Vegetation communities showed a strong response to burn severity, with distinct communities associated with each burn severity class. Indicator Species Analysis was used to identify plant species associated with each burn severity class; one interesting result from ISA was that trembling aspen (Populus tremuloides) seedlings emerged as an indicator of the moderate severity class. Species richness and tree seedling density differed among burn severity classes. Soil microbial communities were analyzed using Phospholipid Fatty Acid analysis and showed moderate variation among burn severity classes and study sites. Total soil carbon and nitrogen did not differ with burn severity. The C:N ratio, total soil S, and soil pH differed significantly among burn severity classes. While the effect of burn severity is pronounced upon vegetation three years post-fire, effects on soil microbial communities are less evident. This could be attributed to the insulating properties of soils, the time elapsed after fire, or it could be an artifact of the sampling technique. Close