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• 31. [Article] Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem

  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 article was published by the Public Library ...

  Citation × Citation Citation Abstract Copy Title: Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem Author: Parks, Catherine G., DelCurto, Tim, Mata-González, Ricardo, Naylor, Bridgett J., McCune, Bruce, Averett, Joshua P. 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 article was published by the Public Library of Science and is in the public domain. The published article can be found at: http://www.plosone.org/ Title: Non-Native Plant Invasion along Elevation and Canopy Closure Gradients in a Middle Rocky Mountain Ecosystem Author: Parks, Catherine G., DelCurto, Tim, Mata-González, Ricardo, Naylor, Bridgett J., McCune, Bruce, Averett, Joshua P. 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 article was published by the Public Library of Science and is in the public domain. The published article can be found at: http://www.plosone.org/ Close

• 32. [Article] Spatiotemporal Drivers of Seabird Distribution at the Pacific Marine Energy Center off Newport, Oregon

  The central Oregon coast was selected as an ideal site for wave energy development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) ...

  Citation × Citation Citation Abstract Copy Title: Spatiotemporal Drivers of Seabird Distribution at the Pacific Marine Energy Center off Newport, Oregon Author: Porquez, Jessica M. The central Oregon coast was selected as an ideal site for wave energy development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development of wave energy sites might impact marine birds. We used vessel-based strip transect surveys to detect spatial and temporal patterns of seabirds during 28 surveys of NETS and SETS from 2013-2015. We also conducted 29 surveys along the Newport Hydrographic Line (NHL) (2006-2009, 2013-2015), a cross-shelf oceanographic sampling line that extends 40 km west of NETS. We collected in situ measurements of surface conductivity, temperature and fluorescence to test correlations between spatial variables and seabird abundance. Common murres (Uria aalge) were the most abundant resident species (70%) while sooty shearwaters (Puffinus griseus) were the most abundant migratory species (78%). We identified 7 focal species (common murres, sooty shearwaters, Brandt's and pelagic cormorants (Phalacrocorax penicillatus and pelagicus), western gull (Larus occidentalis), Cassin's auklet (Ptychoramphus aleuticus), and red-necked phalaropes (Phalaropus lobatus), 5 foraging niches and 3 species of interest for analysis. We used non-metric multidimensional scaling ordinations to assess seasonal shifts in the seabird community at a focal species and foraging group level. Both ordinations depicted strong seasonal gradients with distinct seasonal communities. Focal species were also driven by a distance to shore gradient, while foraging niches were more influenced by foraging type (diving versus surface feeding). The shoreward shift or outward dispersal of species appears driven by a combination of factors, including the diffusion of nearshore concentration of murres and cormorants on Yaquina Head post chick fledging, and the inshore movement of migratory species with the onset of upwelling and greater prey abundance. We employed generalized additive mixed models for the focal species, and tested for correlations with in situ data (salinity, temperature and fluorescence), depth, substrate, season, and a random 'site' effect. We identified correlations between several species and measured oceanographic variables, which indicated species' selection of specific water masses. With Inverse Distance Weighted maps we detected high use zones by sooty shearwaters and common murres outside of both site boundaries, except during the spring and summer, when murres occur densely within the NETS. None of our observed species of concern (brown pelicans (Pelicanus occidentalis), black footed albatrosses (Phoebastria nigiripes) and marbled murrelets, (Brachyramphus marmoratus)) were detected within either site boundary. Rather, pelicans and murrelets were observed inshore of the SETS and south of the NETS, and albatrosses were all detected west of the sites. We observed overall low abundance of focal species within the sites, relative to adjacent areas, although the whole study area appears to be productive foraging habitat used by many species. As a baseline characterization of the seabird community off Newport, this work can help inform citing and permitting processes of similar wave energy test facilities and provide a platform for continued monitoring of seabirds in the area. Title: Spatiotemporal Drivers of Seabird Distribution at the Pacific Marine Energy Center off Newport, Oregon Author: Porquez, Jessica M. The central Oregon coast was selected as an ideal site for wave energy development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development of wave energy sites might impact marine birds. We used vessel-based strip transect surveys to detect spatial and temporal patterns of seabirds during 28 surveys of NETS and SETS from 2013-2015. We also conducted 29 surveys along the Newport Hydrographic Line (NHL) (2006-2009, 2013-2015), a cross-shelf oceanographic sampling line that extends 40 km west of NETS. We collected in situ measurements of surface conductivity, temperature and fluorescence to test correlations between spatial variables and seabird abundance. Common murres (Uria aalge) were the most abundant resident species (70%) while sooty shearwaters (Puffinus griseus) were the most abundant migratory species (78%). We identified 7 focal species (common murres, sooty shearwaters, Brandt's and pelagic cormorants (Phalacrocorax penicillatus and pelagicus), western gull (Larus occidentalis), Cassin's auklet (Ptychoramphus aleuticus), and red-necked phalaropes (Phalaropus lobatus), 5 foraging niches and 3 species of interest for analysis. We used non-metric multidimensional scaling ordinations to assess seasonal shifts in the seabird community at a focal species and foraging group level. Both ordinations depicted strong seasonal gradients with distinct seasonal communities. Focal species were also driven by a distance to shore gradient, while foraging niches were more influenced by foraging type (diving versus surface feeding). The shoreward shift or outward dispersal of species appears driven by a combination of factors, including the diffusion of nearshore concentration of murres and cormorants on Yaquina Head post chick fledging, and the inshore movement of migratory species with the onset of upwelling and greater prey abundance. We employed generalized additive mixed models for the focal species, and tested for correlations with in situ data (salinity, temperature and fluorescence), depth, substrate, season, and a random 'site' effect. We identified correlations between several species and measured oceanographic variables, which indicated species' selection of specific water masses. With Inverse Distance Weighted maps we detected high use zones by sooty shearwaters and common murres outside of both site boundaries, except during the spring and summer, when murres occur densely within the NETS. None of our observed species of concern (brown pelicans (Pelicanus occidentalis), black footed albatrosses (Phoebastria nigiripes) and marbled murrelets, (Brachyramphus marmoratus)) were detected within either site boundary. Rather, pelicans and murrelets were observed inshore of the SETS and south of the NETS, and albatrosses were all detected west of the sites. We observed overall low abundance of focal species within the sites, relative to adjacent areas, although the whole study area appears to be productive foraging habitat used by many species. As a baseline characterization of the seabird community off Newport, this work can help inform citing and permitting processes of similar wave energy test facilities and provide a platform for continued monitoring of seabirds in the area. Close

• 33. [Article] Marine resource surveys on the continental shelf and upper slope off Washington, 1975-76 : completion report July 1, 1975 to September 30, 1977

  Groundfish surveys off the Washington coast were conducted in September of 1975 and 1976 between Cape Flattery and the Columbia River. The primary purposes of the surveys were to obtain estimates of biomass ...

  Citation × Citation Citation Abstract Copy Title: Marine resource surveys on the continental shelf and upper slope off Washington, 1975-76 : completion report July 1, 1975 to September 30, 1977 Author: Barss, William H., United States. National Marine Fisheries Service, Ten Eyck, Neil, Demory, Robert L., Oregon. Dept. of Fish and Wildlife Groundfish surveys off the Washington coast were conducted in September of 1975 and 1976 between Cape Flattery and the Columbia River. The primary purposes of the surveys were to obtain estimates of biomass and further our knowledge on population parameters of important groundfish species, especially flatfish, occupying the continental shelf and upper continental slope. Survey design was based on a 5x6 N. mi grid with a random starting point. Samples were obtained for age, size and sex composition from important flatfish species. Weights were obtained from all species of fish. Estimates of biomass, all species, were 143,447 and 147,303 metric tons in 1975 and 1976, respectively. Pacific hake and English sole were the most abundant species. Estimates of biomass and potential yield were determined for six species of flatfish. Data indicate that most flatfish species are not fully exploited, but several species may be nearing full utilization. Increased yield could be obtained without increased fishing effort if market demand would increase on certain under-utilized species. Several population parameters were obtained. Age, length-weight constants, total annual and fishing mortality rates and exploitation rate were estimated for six species of flatfish. Distribution and abundance was depicted for major species by catch maps. Distribution of some species was closely correlated with depth and sediment type. Increase in mean weight was associated with increasing depth for many species, Strong year classes were indicated for several species. Data suggests that the Astoria Canyon may separate Dover sole and also arrowtooth flounder stocks. Title: Marine resource surveys on the continental shelf and upper slope off Washington, 1975-76 : completion report July 1, 1975 to September 30, 1977 Author: Barss, William H., United States. National Marine Fisheries Service, Ten Eyck, Neil, Demory, Robert L., Oregon. Dept. of Fish and Wildlife Groundfish surveys off the Washington coast were conducted in September of 1975 and 1976 between Cape Flattery and the Columbia River. The primary purposes of the surveys were to obtain estimates of biomass and further our knowledge on population parameters of important groundfish species, especially flatfish, occupying the continental shelf and upper continental slope. Survey design was based on a 5x6 N. mi grid with a random starting point. Samples were obtained for age, size and sex composition from important flatfish species. Weights were obtained from all species of fish. Estimates of biomass, all species, were 143,447 and 147,303 metric tons in 1975 and 1976, respectively. Pacific hake and English sole were the most abundant species. Estimates of biomass and potential yield were determined for six species of flatfish. Data indicate that most flatfish species are not fully exploited, but several species may be nearing full utilization. Increased yield could be obtained without increased fishing effort if market demand would increase on certain under-utilized species. Several population parameters were obtained. Age, length-weight constants, total annual and fishing mortality rates and exploitation rate were estimated for six species of flatfish. Distribution and abundance was depicted for major species by catch maps. Distribution of some species was closely correlated with depth and sediment type. Increase in mean weight was associated with increasing depth for many species, Strong year classes were indicated for several species. Data suggests that the Astoria Canyon may separate Dover sole and also arrowtooth flounder stocks. Close

• 34. [Article] A plant association classification for McDonald-Dunn Forest

  The purpose of this study was to develop a plant association classification for the mature coniferous forests of the McDonald and Paul M. Dunn Research Forests. A secondary objective was to quantify diversity ...

  Citation × Citation Citation Abstract Copy Title: A plant association classification for McDonald-Dunn Forest Author: Hubbard, Connie J. The purpose of this study was to develop a plant association classification for the mature coniferous forests of the McDonald and Paul M. Dunn Research Forests. A secondary objective was to quantify diversity within the plant associations. This Forest is approximately 11,000 acres and is located 6 miles to the north of Corvallis Oregon. This forest is owned and managed by the College of Forestry at Oregon State University. This study, and a companion study by Leavell (1991), was funded by the Research Forest to broaden their understanding of the plant communities on the Forest. The companion study developed relationships between the plant associations and the environment. Classification was based on 108 plots, using percent cover of trees, shrubs, forbs, and grasses. This sampling density of approximately 1 plot per 100 acres is much greater than most community classifications in the area (Hemstrom & Logan, 1986; Hemstrom et al., 1987; Topik et al., 1988; Juday, 1976). A total of 117 vascular plant species were encountered; 68 of these were used in classification. Stands sampled for this classification were primarily seral, yet the most mature available. Few climax stands were available for sampling. Plant associations were developed using TWINSPAN, a two-way indicator species analysis (Hill, 1979b). Six plant associations were developed and described in this study: Tsuga heterophylla/Acer circinatum-Gaultheria shallon Abies grandis/Acer circinatum-Gaultheria shallon Abies grandis/Disporum hookeri-Thalictrum occidentale Abies grandis/Polystichum munituin Abies qrandis/Rubus ursinus-Rhus diversiloba Abies randis/Brachypodium sylvaticum One plant association, Abies grandis/Acer circinatum- Gaultheria shallon, parallels a previously described plant association described by Juday in the Valley Margin Zone (Juday, 1976). The other 5 plant associations described in this study are original descriptions. The TSHE/ACCI-GASH, ABGR/ACCI-GASH, and the ABGR/RUURRHDI plant associations are shrub-dominated. ABGR/DIHOTHOC and ABGR/POMU are forb-domjnated associations, and ABGR/BRSY is a grass-dominated plant association. Plant associations were shown to have significant differences in species richness, heterogeneity, evenness, and in vertical structure. Average species richness per plot is highest in the ABGR/ACCI-GASH and ABGR/DIHO-THOC plant associations, which also has high relative diversity (Shannon's index) and evenness. Species richness is lowest in the TSHE/ACCI-GASH plant association, probably because it was represented only by seral stands. Structural diversity included an analysis of snags. Snag number, size, and distribution were not related to plant associations. Current snag levels indicate that at most, 30 percent of the maximun populations for six woodpecker species could be supported on this Forest. A description of each plant association is given. The description for each includes: extent, location, characteristic species, species richness and percent cover within four strata (trees, shrubs, forbs, and grasses), heterogeneity (Shannon' s diversity index), and an evenness measure. Title: A plant association classification for McDonald-Dunn Forest Author: Hubbard, Connie J. The purpose of this study was to develop a plant association classification for the mature coniferous forests of the McDonald and Paul M. Dunn Research Forests. A secondary objective was to quantify diversity within the plant associations. This Forest is approximately 11,000 acres and is located 6 miles to the north of Corvallis Oregon. This forest is owned and managed by the College of Forestry at Oregon State University. This study, and a companion study by Leavell (1991), was funded by the Research Forest to broaden their understanding of the plant communities on the Forest. The companion study developed relationships between the plant associations and the environment. Classification was based on 108 plots, using percent cover of trees, shrubs, forbs, and grasses. This sampling density of approximately 1 plot per 100 acres is much greater than most community classifications in the area (Hemstrom & Logan, 1986; Hemstrom et al., 1987; Topik et al., 1988; Juday, 1976). A total of 117 vascular plant species were encountered; 68 of these were used in classification. Stands sampled for this classification were primarily seral, yet the most mature available. Few climax stands were available for sampling. Plant associations were developed using TWINSPAN, a two-way indicator species analysis (Hill, 1979b). Six plant associations were developed and described in this study: Tsuga heterophylla/Acer circinatum-Gaultheria shallon Abies grandis/Acer circinatum-Gaultheria shallon Abies grandis/Disporum hookeri-Thalictrum occidentale Abies grandis/Polystichum munituin Abies qrandis/Rubus ursinus-Rhus diversiloba Abies randis/Brachypodium sylvaticum One plant association, Abies grandis/Acer circinatum- Gaultheria shallon, parallels a previously described plant association described by Juday in the Valley Margin Zone (Juday, 1976). The other 5 plant associations described in this study are original descriptions. The TSHE/ACCI-GASH, ABGR/ACCI-GASH, and the ABGR/RUURRHDI plant associations are shrub-dominated. ABGR/DIHOTHOC and ABGR/POMU are forb-domjnated associations, and ABGR/BRSY is a grass-dominated plant association. Plant associations were shown to have significant differences in species richness, heterogeneity, evenness, and in vertical structure. Average species richness per plot is highest in the ABGR/ACCI-GASH and ABGR/DIHO-THOC plant associations, which also has high relative diversity (Shannon's index) and evenness. Species richness is lowest in the TSHE/ACCI-GASH plant association, probably because it was represented only by seral stands. Structural diversity included an analysis of snags. Snag number, size, and distribution were not related to plant associations. Current snag levels indicate that at most, 30 percent of the maximun populations for six woodpecker species could be supported on this Forest. A description of each plant association is given. The description for each includes: extent, location, characteristic species, species richness and percent cover within four strata (trees, shrubs, forbs, and grasses), heterogeneity (Shannon' s diversity index), and an evenness measure. Close

• 35. [Article] Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions

  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: Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions Author: Fisher, Joseph P., Emmett, Robert L., Morgan, Cheryl A., Casillas, Ed, Brodeur, Richard D. 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: Species composition and community structure of pelagic nekton off Oregon and Washington under variable oceanographic conditions Author: Fisher, Joseph P., Emmett, Robert L., Morgan, Cheryl A., Casillas, Ed, Brodeur, Richard D. 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

• 36. [Article] Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest

  Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape ...

  Citation × Citation Citation Abstract Copy Title: Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest Author: Yost, Andrew Charles Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape scale disturbance. A number of statistical modeling tools are available to construct predictive models and maps from response data, a set of predictor variables, and a predefined statistical distribution. Non-Parametric Multiplicative Regression (NPMR) is a probability modeling system that finds the best multiplicative set of predictor variables. The best set maximizes the Bayes Factor value which is a ratio based on modeled estimates and a species' average frequency of occurrence. This study demonstrates predictive vegetation modeling and mapping using NPMR and species presence/absence data collected from 610 plots located across an industrial managed forest landscape in Northeast Oregon. Plots were stratified with a random sampling design. Four modeling approaches were taken to compare the predictive power of spatial coordinates in combination with a set of topographically-derived and stand structural predictor variables. Spatial coordinates were often the most powerful predictors and the modeling approach with physiographic and stand structural variables together was frequently the most improved relative to the average frequency of occurrence. Comparisons between Logistic Regression (LR) and NPMR models were conducted for the species Clintonia unflora (CLUN) and Pinus ponderosa (PIPO). NPMR performed better for CLUN when the best predictor variables selected by NPMR were used to construct a LR model. For PIPO, the performance of NPMR was comparable to LR when the set of predictor variables used to build the LR model was based on whether the response in probability to each variable was monotonic. Species-level GIS probability maps were produced with the application of the physiographic models and a corresponding set of GIS raster files. GIS overlays of indicator species maps were used to construct plant association group (PAG) maps. Intersections of PAG layers resulted in quantitative mapping of intergrade between types. PAG layers were often significant predictor variables in probability models for 70 understory and five conifer species produced with Logistic Regression (LR) using a forward step-wise process. Potential applications of both NPMR and LR models with the Forest Vegetation Simulator are discussed. Title: Probabilistic modeling of understory vegetation species in a northeastern Oregon industrial forest Author: Yost, Andrew Charles Managing forest ecosystems for sustainable, multiple use requires forest resource managers to understand how species composition and distribution vary across environmental gradients and respond to landscape scale disturbance. A number of statistical modeling tools are available to construct predictive models and maps from response data, a set of predictor variables, and a predefined statistical distribution. Non-Parametric Multiplicative Regression (NPMR) is a probability modeling system that finds the best multiplicative set of predictor variables. The best set maximizes the Bayes Factor value which is a ratio based on modeled estimates and a species' average frequency of occurrence. This study demonstrates predictive vegetation modeling and mapping using NPMR and species presence/absence data collected from 610 plots located across an industrial managed forest landscape in Northeast Oregon. Plots were stratified with a random sampling design. Four modeling approaches were taken to compare the predictive power of spatial coordinates in combination with a set of topographically-derived and stand structural predictor variables. Spatial coordinates were often the most powerful predictors and the modeling approach with physiographic and stand structural variables together was frequently the most improved relative to the average frequency of occurrence. Comparisons between Logistic Regression (LR) and NPMR models were conducted for the species Clintonia unflora (CLUN) and Pinus ponderosa (PIPO). NPMR performed better for CLUN when the best predictor variables selected by NPMR were used to construct a LR model. For PIPO, the performance of NPMR was comparable to LR when the set of predictor variables used to build the LR model was based on whether the response in probability to each variable was monotonic. Species-level GIS probability maps were produced with the application of the physiographic models and a corresponding set of GIS raster files. GIS overlays of indicator species maps were used to construct plant association group (PAG) maps. Intersections of PAG layers resulted in quantitative mapping of intergrade between types. PAG layers were often significant predictor variables in probability models for 70 understory and five conifer species produced with Logistic Regression (LR) using a forward step-wise process. Potential applications of both NPMR and LR models with the Forest Vegetation Simulator are discussed. Close

• 37. [Article] Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon

  The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of ...

  Citation × Citation Citation Abstract Copy Title: Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon Author: Streatfeild, Rosemary Welch The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of vegetation to environment, and (4) establish a baseline dataset for future trend analysis in order that response of different plant species to fire frequencies may be assessed. I used historical records, aerial photographs, interviews, and literature to ascertain land use and vegetation history. I assumed that the RNA had been maintained as prairie by periodic aboriginal burning. Fire ignited by settlers continued as a management tool into the late 19th century. Grazing was a major disturbance in the late 19th and early 20th centuries, and plowing or some other soil disturbance on the raised elongated mounds may have occurred. With removal of livestock grazing in the early 1960s and only a sporadic burning program, shrub cover increased markedly over the past several decades. I surveyed vegetation in the summer of 1991 in 36 random permanent plots. 1 classified species cover with two-way indicator species analysis, identifying two major communities. One is dominated by tall dense Rosa eg'lanteria, Hypericum perforatum, and many alien weedy species located on slightly elevated mounds, and the other is dominated by shorter but also dense Rosa eglanteria, Deschampsia cespitosa, and many species with wetland affinity on intermounds. Monotypic patches of Spiraea douglasii also occur on intermounds. Species composition strongly correlates with raicrotopography related to an indirect soil moisture index based on wetland status of individual species. Composition correlates less strongly with year since last burn. I confirmed vegetation-environment relations by null hypothesis analysis, tested by multi-response permutation procedure. Vegetation significantly differs on mounds vs. intermounds and vegetation significantly reflects burning history. I ordinated floristic data by non-metric scaling. I also tallied nested frequency data as a baseline for future trend analysis in order to assess change in vegetation in response to fire frequency. Frequency change of Rosa eglanteria will best be detected by change in a 0.01 m2 plot size, Holcus lanatus by a 0.10 m2 plot, and remaining species by a 1.00 m2 plot. Title: Ecological survey and interpretation of the Willamette Floodplain Research Natural Area, W.L. Finley National Wildlife Refuge, Oregon Author: Streatfeild, Rosemary Welch The purpose of this study was to: (1) evaluate land use and vegetation history of the Willamette Floodplain Research Natural Area; (2) characterize present day vegetation; (3) evaluate the relation of vegetation to environment, and (4) establish a baseline dataset for future trend analysis in order that response of different plant species to fire frequencies may be assessed. I used historical records, aerial photographs, interviews, and literature to ascertain land use and vegetation history. I assumed that the RNA had been maintained as prairie by periodic aboriginal burning. Fire ignited by settlers continued as a management tool into the late 19th century. Grazing was a major disturbance in the late 19th and early 20th centuries, and plowing or some other soil disturbance on the raised elongated mounds may have occurred. With removal of livestock grazing in the early 1960s and only a sporadic burning program, shrub cover increased markedly over the past several decades. I surveyed vegetation in the summer of 1991 in 36 random permanent plots. 1 classified species cover with two-way indicator species analysis, identifying two major communities. One is dominated by tall dense Rosa eg'lanteria, Hypericum perforatum, and many alien weedy species located on slightly elevated mounds, and the other is dominated by shorter but also dense Rosa eglanteria, Deschampsia cespitosa, and many species with wetland affinity on intermounds. Monotypic patches of Spiraea douglasii also occur on intermounds. Species composition strongly correlates with raicrotopography related to an indirect soil moisture index based on wetland status of individual species. Composition correlates less strongly with year since last burn. I confirmed vegetation-environment relations by null hypothesis analysis, tested by multi-response permutation procedure. Vegetation significantly differs on mounds vs. intermounds and vegetation significantly reflects burning history. I ordinated floristic data by non-metric scaling. I also tallied nested frequency data as a baseline for future trend analysis in order to assess change in vegetation in response to fire frequency. Frequency change of Rosa eglanteria will best be detected by change in a 0.01 m2 plot size, Holcus lanatus by a 0.10 m2 plot, and remaining species by a 1.00 m2 plot. Close

• 38. [Article] Zooplankton of the Galapagos Islands

  The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish ...

  Citation × Citation Citation Abstract Copy Title: Zooplankton of the Galapagos Islands Author: Figueroa, Diego The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish the distribution and community structure of zooplankton in the Archipelago. I collected zooplankton samples by vertical tows over the Galapagos shelf during the islands’ cold and warm seasons. Abundance was determined and copepods and euphausiids were identified to species. Hydrographic, nutrient and chlorophyll profiles were obtained for some sites. Non-metric Multidimensional Scaling (NMS) ordinations, Multi-Response Permutation Procedures (MRPP) and Indicator Species Analyses (ISA) were used to determine trends in community composition. Two marine systems were identified: 1) a nutrient-rich upwelling system with a shallow mixed layer and a diatom dominated phytoplankton community in the west and 2) a non-upwelling system with a deeper mixed layer, lower surface nutrient concentrations and a phytoplankton community dominated by small cells in the east. During the cold season three distinct zooplankton communities were observed that divide into western, central, and southeastern regions. During the warm season, the community in the west was replaced by a mix of species from the central region and abundance decreased. The diverse zooplankton community with varying geographical and seasonal affinities reflects the advective sources of surrounding waters. In addition to diverse oceanic environments, the Galapagos also have a unique set of inland pools known as anchialine habitats. I collected zooplankton from various anchialine pools in three different islands. These pools contain species of specialized cave-dwellers including undescribed species of Ridgewayia and Pseudocyclops (calanoid copepods). I describe these species and apply morphological and molecular methods to determine phylogenetic relationships and patterns of colonization. The mitochondrial gene cytochrome c oxidase subunit I (COI) and the nuclear internal transcribed spacer 1 (ITS1) were used for phylogenetic analyses. The ITS1gene successfully reconstructed phylogenies, but the COI gene was highly conserved across these two families. This gene may not be appropriate as the current standard for “bar-coding” all marine species. These anchialine copepods are a result of several independent colonization events with phylogenetic ties to extant species in the western Pacific and Caribbean. Title: Zooplankton of the Galapagos Islands Author: Figueroa, Diego The marine climate of the Galapagos is spatially and seasonally heterogeneous. A taxonomically comprehensive study of Galapagos zooplankton has never been done. This study is an initial effort to establish the distribution and community structure of zooplankton in the Archipelago. I collected zooplankton samples by vertical tows over the Galapagos shelf during the islands’ cold and warm seasons. Abundance was determined and copepods and euphausiids were identified to species. Hydrographic, nutrient and chlorophyll profiles were obtained for some sites. Non-metric Multidimensional Scaling (NMS) ordinations, Multi-Response Permutation Procedures (MRPP) and Indicator Species Analyses (ISA) were used to determine trends in community composition. Two marine systems were identified: 1) a nutrient-rich upwelling system with a shallow mixed layer and a diatom dominated phytoplankton community in the west and 2) a non-upwelling system with a deeper mixed layer, lower surface nutrient concentrations and a phytoplankton community dominated by small cells in the east. During the cold season three distinct zooplankton communities were observed that divide into western, central, and southeastern regions. During the warm season, the community in the west was replaced by a mix of species from the central region and abundance decreased. The diverse zooplankton community with varying geographical and seasonal affinities reflects the advective sources of surrounding waters. In addition to diverse oceanic environments, the Galapagos also have a unique set of inland pools known as anchialine habitats. I collected zooplankton from various anchialine pools in three different islands. These pools contain species of specialized cave-dwellers including undescribed species of Ridgewayia and Pseudocyclops (calanoid copepods). I describe these species and apply morphological and molecular methods to determine phylogenetic relationships and patterns of colonization. The mitochondrial gene cytochrome c oxidase subunit I (COI) and the nuclear internal transcribed spacer 1 (ITS1) were used for phylogenetic analyses. The ITS1gene successfully reconstructed phylogenies, but the COI gene was highly conserved across these two families. This gene may not be appropriate as the current standard for “bar-coding” all marine species. These anchialine copepods are a result of several independent colonization events with phylogenetic ties to extant species in the western Pacific and Caribbean. Close

• 39. [Article] Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon

  Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address ...

  Citation × Citation Citation Abstract Copy Title: Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon Author: Tomas, Walfrido Moraes Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address habitat and microhabitat features that sustain both livestock production and wildlife diversity. I conducted a study to determine how small mammal distributions and abundance differ among 3 structurally different riparian habitats in eastern Oregon. The 3 habitat types, herbaceous, discontinuous willow, and continuous willow, represent a range of habitats typical of riparian zones in central and eastern Oregon. I estimated small mammal population sizes in 9 trap grids placed in riparian zones using capture-recapture techniques. Four species of small mammals were captured during 7 trapping periods from August 1994 to September 1995. Small mammal distributions and population sizes of each species varied both within and among riparian pastures. Montane voles (Microtus montanus) were the most abundant species in all grids. Deer mice (Peromyscus maniculatus) had high population sizes in grids with low montane vole populations and moderate to high willow cover. Competition with voles appeared to occur in riparian habitats of Bear Valley, and influenced the distribution and numbers of deer mice. Western jumping mice (Zapus princeps) were captured at relatively low numbers and almost exclusively in continuous willow habitats. Vagrant shrews (Sorex vagrans) were captured on all grids, and population sizes were small. Haying negatively affected survival rates of voles. Biomass, vegetation height, and percent ground cover were the habitat variables most frequently associated with occurrence of montane voles in Bear Valley. The probability of occurrence of this species was positively correlated with these habitat variables. Deer mice probability of occurrence was positively correlated with percent ground cover, plant biomass, and soil moisture. Most deer mice captures occurred in continuous willow habitats, and the number of captures increased with willow basal cover (R²=0.7579, P<0.001). Western jumping mice occurrence was positively correlated with plant biomass and soil moisture, and negatively correlated with distance from willow and percent ground cover. Western jumping mice also were more frequently captured in willow than nonwillow vegetation associations (P=0.054) within continuous willow habitats. Vagrant shrews were positively associated with plant biomass, vegetation height, and soil moisture. Small mammal habitat associations from my study sites in Bear Valley are in agreement with the literature, suggesting relatively consistent patterns in species-habitat associations. Distribution of small mammal species differed among pastures probably as a result of historical management practices. Alterations of riparian zone structure from historical management practices were evident in the study area, including elimination or decreased willow density, channel entrenchment, and invasion of riparian areas by xeric vegetation. Western jumping mice are apparently the most sensitive species in this area, requiring dense willow stands, suggesting that jumping mice could serve as an indicator species for riparian habitat condition. Title: Small mammal distribution, abundance and habitat selection in managed riparian habitats of Bear Valley, eastern Oregon Author: Tomas, Walfrido Moraes Riparian zones are critical habitats for management because of their importance for both cattle production and wildlife, and a high potential for resource conflicts. Riparian management should address habitat and microhabitat features that sustain both livestock production and wildlife diversity. I conducted a study to determine how small mammal distributions and abundance differ among 3 structurally different riparian habitats in eastern Oregon. The 3 habitat types, herbaceous, discontinuous willow, and continuous willow, represent a range of habitats typical of riparian zones in central and eastern Oregon. I estimated small mammal population sizes in 9 trap grids placed in riparian zones using capture-recapture techniques. Four species of small mammals were captured during 7 trapping periods from August 1994 to September 1995. Small mammal distributions and population sizes of each species varied both within and among riparian pastures. Montane voles (Microtus montanus) were the most abundant species in all grids. Deer mice (Peromyscus maniculatus) had high population sizes in grids with low montane vole populations and moderate to high willow cover. Competition with voles appeared to occur in riparian habitats of Bear Valley, and influenced the distribution and numbers of deer mice. Western jumping mice (Zapus princeps) were captured at relatively low numbers and almost exclusively in continuous willow habitats. Vagrant shrews (Sorex vagrans) were captured on all grids, and population sizes were small. Haying negatively affected survival rates of voles. Biomass, vegetation height, and percent ground cover were the habitat variables most frequently associated with occurrence of montane voles in Bear Valley. The probability of occurrence of this species was positively correlated with these habitat variables. Deer mice probability of occurrence was positively correlated with percent ground cover, plant biomass, and soil moisture. Most deer mice captures occurred in continuous willow habitats, and the number of captures increased with willow basal cover (R²=0.7579, P<0.001). Western jumping mice occurrence was positively correlated with plant biomass and soil moisture, and negatively correlated with distance from willow and percent ground cover. Western jumping mice also were more frequently captured in willow than nonwillow vegetation associations (P=0.054) within continuous willow habitats. Vagrant shrews were positively associated with plant biomass, vegetation height, and soil moisture. Small mammal habitat associations from my study sites in Bear Valley are in agreement with the literature, suggesting relatively consistent patterns in species-habitat associations. Distribution of small mammal species differed among pastures probably as a result of historical management practices. Alterations of riparian zone structure from historical management practices were evident in the study area, including elimination or decreased willow density, channel entrenchment, and invasion of riparian areas by xeric vegetation. Western jumping mice are apparently the most sensitive species in this area, requiring dense willow stands, suggesting that jumping mice could serve as an indicator species for riparian habitat condition. Close

• 40. [Article] Population dynamics of three early seral herb species in Pacific Northwest forests

  I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and ...

  Citation × Citation Citation Abstract Copy Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Title: Population dynamics of three early seral herb species in Pacific Northwest forests Author: Hanson, D. Eric I investigated the population dynamics of fireweed (Epilobium angustfolium), foxglove (Digitalis purpurea) , and woodland groundsel (Senecio sylvaticus) to understand their colonization, persistence, and extirpation in Pacific Northwest Douglas-fir forests. Factors affecting the species' frequency and abundance in forest communities were evaluated. Their population dynamics were modeled and field experiments examined nitrogen fertilization and competition effects on population parameters. Experimental variation made the population models stochastic and sequential transition matrices incorporated the effects of competition into them. Plant community ordination suggested a negative relationship between foxglove and elevation. Indicator species analysis revealed that foxglove is favored by disturbance, i.e., broadcast silvicultural treatments, and by high site productivity, while fireweed responds to low productivity and lack of disturbance. Regression analysis related the species' frequency and cover to factors such as stand age, elevation, and UTM meters east. Simulated woodland groundsel population increased most rapidly. Increased competition tended to reduce its biomass accumulation and seed production per plant but did not affect seeds produced per unit area. Competition also reduced established immature plant survival. Incorporating these factors into the population model, the rate of population growth declined. The projected foxglove population grew at a lower rate than did woodland groundsel but faster than fireweed. Foxglove was adversely affected by competition, which generally reduced its size, biomass, and seed production. Interspecific competition reduced established plant survival, rosette persistence, perenniation, and flowering. Nitrogen fertilization stimulated seed germination, rosette persistence, and flowering but decreased perenniation. Nitrogen fertilization rate did not influence population growth when modeled but application timing did. Nitrogen applied at transplanting resulted in extinction of the population. Transplanting one year after fertilization resulted in constant population growth. Fireweed, with the most complex life cycle, had the lowest population growth rate. Its persistence was entirely due to vegetative reproduction--without it the population would rapidly become extinct. Competition and fertilization had little effect on this species and population projections based on the field experiments indicated constant growth. These results suggest life history and competitive ability regulate succession of pioneer species in Douglas-fir forests and increases population persistence comes at the expense of their growth rate. Close