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• 21. [Article] Clover Creek restoration

  This project included 8 miles of fencing, 18 stock water tanks, 10 acres of riparian planting, 1 hardened crossing and 1 culvert crossing. Six landowners participated in the project.

  Citation × Citation Citation Abstract Copy Title: Clover Creek restoration Author: Partnership for the Umpqua Rivers This project included 8 miles of fencing, 18 stock water tanks, 10 acres of riparian planting, 1 hardened crossing and 1 culvert crossing. Six landowners participated in the project. Title: Clover Creek restoration Author: Partnership for the Umpqua Rivers This project included 8 miles of fencing, 18 stock water tanks, 10 acres of riparian planting, 1 hardened crossing and 1 culvert crossing. Six landowners participated in the project. Close

• 22. [Article] A guide to placing large wood in streams

  Citation × Citation Citation Abstract Copy Title: A guide to placing large wood in streams Author: Oregon. Forest Practices Section, Oregon. Habitat Conservation Division Title: A guide to placing large wood in streams Author: Oregon. Forest Practices Section, Oregon. Habitat Conservation Division Close

• 23. [Article] Stocking levels and seedling heights on clearcuts in relation to habitat type in the Western Cascades of Oregon

  Stocking characteristics and heights attained by tree seedlings at ages five and seven were measured on 45 study units, representing five habitat types, established on clearcuts in the Abies amabilis zone ...

  Citation × Citation Citation Abstract Copy Title: Stocking levels and seedling heights on clearcuts in relation to habitat type in the Western Cascades of Oregon Author: Sullivan, Michael James Stocking characteristics and heights attained by tree seedlings at ages five and seven were measured on 45 study units, representing five habitat types, established on clearcuts in the Abies amabilis zone in the Western Cascades of Oregon. The study units ranged from six to 30 acres in size, seven to 15 years in age (time elapsed since harvest), and occupied a variety of slope aspects, inclinations, and topographic positions. A restricted random sampling procedure and circular one-milacre plots were employed to collect data. Mean post-harvest stocking levels (on a one-milacre basis) ranged from 14.4% in the Abies amabilis-Tsuga mertensiana/ Xerophyiium tenax habitat type to 48.3% in the Abies amabilis/Rhododendron macrophyllum-Vaccinium alaskaense/Cornus canadensis habitat type, and mean advance stocking levels ranged from 2.0% in the Abies amabiiis/Vaccinium membranaceum/ Xerophyiium tenax habitat type to 16.5% in the Abies/ Rhododendron-Vaccinium/Cornus habitat type. Differences in mean post-harvest stocking among the habitat types were found to be inversely correlated with differences in mean radiation indices and mean elevations. Differences were also found among the habitat types in the comparative stocking levels of individual tree species. Abies procera (noble fir) stocking was generally less than or equal to that of Pseudotsuga menziesii (Douglas-fir) in habitat types typically positioned on lower-to mid-slopes, but much greater than that of Pseudotsuga menziesii in habitat types which are typically located on or near ridgetops. Mean heights of tree seedlings were found to vary considerably among tree species and habitat types. Pseudotsuga menziesii seedlings generally grow to roughly equivalent or to greater heights than do Abies procera seedlings in all habitat types. Both Pseudotsuga menziesii and Abies procera seedlings attained greatest heights in the Abies amabilis/ Achlys triphylla habitat type, and lowest heights in an undocumented Abies amabilis/Rhododendron macrophyllum-Vaccinium membranaceum habitat type. The structure and composition of successional plant communities which developed following clearcutting was also found to vary considerably among habitat types. Clearcuts in habitat types typically located on lower-to mid-slopes were occupied by plant communities often dominated by shrubs, whereas plant communities dominated by herbs usually occupied clearcuts located in habitat types typically positioned on or near ridgetops. The results of this research imply that each habitat type seems best suited for specific silvicultural practices. Habitat type classification and mapping can be a productive tool for foresters involved with the regeneration management of Abies amabilis zone forests of the Western Cascades of Oregon. Title: Stocking levels and seedling heights on clearcuts in relation to habitat type in the Western Cascades of Oregon Author: Sullivan, Michael James Stocking characteristics and heights attained by tree seedlings at ages five and seven were measured on 45 study units, representing five habitat types, established on clearcuts in the Abies amabilis zone in the Western Cascades of Oregon. The study units ranged from six to 30 acres in size, seven to 15 years in age (time elapsed since harvest), and occupied a variety of slope aspects, inclinations, and topographic positions. A restricted random sampling procedure and circular one-milacre plots were employed to collect data. Mean post-harvest stocking levels (on a one-milacre basis) ranged from 14.4% in the Abies amabilis-Tsuga mertensiana/ Xerophyiium tenax habitat type to 48.3% in the Abies amabilis/Rhododendron macrophyllum-Vaccinium alaskaense/Cornus canadensis habitat type, and mean advance stocking levels ranged from 2.0% in the Abies amabiiis/Vaccinium membranaceum/ Xerophyiium tenax habitat type to 16.5% in the Abies/ Rhododendron-Vaccinium/Cornus habitat type. Differences in mean post-harvest stocking among the habitat types were found to be inversely correlated with differences in mean radiation indices and mean elevations. Differences were also found among the habitat types in the comparative stocking levels of individual tree species. Abies procera (noble fir) stocking was generally less than or equal to that of Pseudotsuga menziesii (Douglas-fir) in habitat types typically positioned on lower-to mid-slopes, but much greater than that of Pseudotsuga menziesii in habitat types which are typically located on or near ridgetops. Mean heights of tree seedlings were found to vary considerably among tree species and habitat types. Pseudotsuga menziesii seedlings generally grow to roughly equivalent or to greater heights than do Abies procera seedlings in all habitat types. Both Pseudotsuga menziesii and Abies procera seedlings attained greatest heights in the Abies amabilis/ Achlys triphylla habitat type, and lowest heights in an undocumented Abies amabilis/Rhododendron macrophyllum-Vaccinium membranaceum habitat type. The structure and composition of successional plant communities which developed following clearcutting was also found to vary considerably among habitat types. Clearcuts in habitat types typically located on lower-to mid-slopes were occupied by plant communities often dominated by shrubs, whereas plant communities dominated by herbs usually occupied clearcuts located in habitat types typically positioned on or near ridgetops. The results of this research imply that each habitat type seems best suited for specific silvicultural practices. Habitat type classification and mapping can be a productive tool for foresters involved with the regeneration management of Abies amabilis zone forests of the Western Cascades of Oregon. Close

• 24. [Article] Habitat selection by American martens (Martes americana) in coastal northwestern California

  The Humboldt marten, Martes americana humboldtensis, has undergone a dramatic decline throughout its historical distribution in coastal Northwestern California. There is currently only one known population ...

  Citation × Citation Citation Abstract Copy Title: Habitat selection by American martens (Martes americana) in coastal northwestern California Author: Slauson, Keith M. The Humboldt marten, Martes americana humboldtensis, has undergone a dramatic decline throughout its historical distribution in coastal Northwestern California. There is currently only one known population occupying an area occurring in <5% of the historical distribution of the subspecies. Conservation and management efforts to benefit this population are hampered by lack of information on the habitat ecology of martens in the coastal forest of northwestern California. Furthermore there have been no investigations of the habitat ecology of marten populations anywhere in the coastal forests of the Pacific States. I investigated habitat relationships of the only known population of martens within the historical distribution of M a. humboldtensis at three spatial scales (microhabitat, stand, and home range) and in relation to four forest management regimes (industrial timberlands, and U. S. Forest Service (USFS) matrix lands, late-successional reserves, and wilderness). Over 12 months of fieldwork during 2000 and 2001, I detected martens at 26 of 159 track plate sample units distributed on a systematic grid located over the region known to be occupied by the population. I used an information-theoretic approach to rank 56 a priori candidate models that described hypothesized habitat relationships at each spatial scale. Marten detections occurred in two distinct habitat types, those with forests on serpentine soils and forests associated with more productive soil types, which are more common in the region. At the microhabitat scale in serpentine habitats, martens were detected at sites with dense shrub cover, sparse tree cover, and abundant surface rocks. Dense shrub cover and abundant surface rocks may provide key overhead and escape cover for martens in serpentine habitats. At the microhabitat scale in non-serpentine habitats martens were detected at sites having the most mesic aspects, with dense tree and shrub cover, and with a higher abundance of large diameter snags. At the stand scale martens selected conifer-dominated stands with dense shrub cover in the latest seral stages (old growth and late-mature) in non-serpentine habitats and variable seral stages in serpentine habitats. At the home-range scale the probability of detecting a marten decreased with increasing amounts of logging within 1-km of the sample unit and increased with increasing maximum patch size of old growth, old growth plus late-mature, or serpentine habitat within 1-km of the sample unit. Martens were detected significantly more frequently in USFS lands than in private industrial timberlands. Within USFS lands, martens were detected most frequently in matrix and late-successional reserves, and least frequently in the wilderness area. This study provides new information on the habitat ecology of martens in the coastal forests of northwestern California. It demonstrates the importance of investigating marten habitat at multiple spatial scales and provides insights to linkages among scales and how martens respond to forest management. It also provides information to aid conservation and restoration of martens in northwestern California through identification of areas currently occupied or with suitable habitat, information to identify suitable habitat in areas outside the study area, and information to guide conservation planning for martens and site-specific habitat restoration. Title: Habitat selection by American martens (Martes americana) in coastal northwestern California Author: Slauson, Keith M. The Humboldt marten, Martes americana humboldtensis, has undergone a dramatic decline throughout its historical distribution in coastal Northwestern California. There is currently only one known population occupying an area occurring in <5% of the historical distribution of the subspecies. Conservation and management efforts to benefit this population are hampered by lack of information on the habitat ecology of martens in the coastal forest of northwestern California. Furthermore there have been no investigations of the habitat ecology of marten populations anywhere in the coastal forests of the Pacific States. I investigated habitat relationships of the only known population of martens within the historical distribution of M a. humboldtensis at three spatial scales (microhabitat, stand, and home range) and in relation to four forest management regimes (industrial timberlands, and U. S. Forest Service (USFS) matrix lands, late-successional reserves, and wilderness). Over 12 months of fieldwork during 2000 and 2001, I detected martens at 26 of 159 track plate sample units distributed on a systematic grid located over the region known to be occupied by the population. I used an information-theoretic approach to rank 56 a priori candidate models that described hypothesized habitat relationships at each spatial scale. Marten detections occurred in two distinct habitat types, those with forests on serpentine soils and forests associated with more productive soil types, which are more common in the region. At the microhabitat scale in serpentine habitats, martens were detected at sites with dense shrub cover, sparse tree cover, and abundant surface rocks. Dense shrub cover and abundant surface rocks may provide key overhead and escape cover for martens in serpentine habitats. At the microhabitat scale in non-serpentine habitats martens were detected at sites having the most mesic aspects, with dense tree and shrub cover, and with a higher abundance of large diameter snags. At the stand scale martens selected conifer-dominated stands with dense shrub cover in the latest seral stages (old growth and late-mature) in non-serpentine habitats and variable seral stages in serpentine habitats. At the home-range scale the probability of detecting a marten decreased with increasing amounts of logging within 1-km of the sample unit and increased with increasing maximum patch size of old growth, old growth plus late-mature, or serpentine habitat within 1-km of the sample unit. Martens were detected significantly more frequently in USFS lands than in private industrial timberlands. Within USFS lands, martens were detected most frequently in matrix and late-successional reserves, and least frequently in the wilderness area. This study provides new information on the habitat ecology of martens in the coastal forests of northwestern California. It demonstrates the importance of investigating marten habitat at multiple spatial scales and provides insights to linkages among scales and how martens respond to forest management. It also provides information to aid conservation and restoration of martens in northwestern California through identification of areas currently occupied or with suitable habitat, information to identify suitable habitat in areas outside the study area, and information to guide conservation planning for martens and site-specific habitat restoration. Close

• 25. [Article] An analysis of guild structure of avian communities, Columbia River, Oregon

  Effects of habitat and season on guild structure of avian communities were examined for islands in the estuary zone of the Columbia River, Oregon. Bird species were classified into guilds according to ...

  Citation × Citation Citation Abstract Copy Title: An analysis of guild structure of avian communities, Columbia River, Oregon Author: Noyes, Cecilia Lea Barham Effects of habitat and season on guild structure of avian communities were examined for islands in the estuary zone of the Columbia River, Oregon. Bird species were classified into guilds according to their major food item, typical foraging substrate, and foraging behavior. Variation in community structure indices (number of guilds, guild diversity, evenness, bird density, and biomass) among habitats and seasons were analyzed with multivariate analysis of variance and discriminant function analysis. Cluster analysis was used to examine patterns of guild distribution among habitats and seasons. Four habitat-bird community associations (tree-shrub, upland, beach-low marsh, and high marsh) were described based on results from this study. High guild evenness within tree-shrub habitats during the breeding season (spring and summer) distinguished tree-shrub bird communities from communities within the 3 other habitats. Relatively stable bird density within tree-shrub habitats was attributed to high vegetation heterogeniety and later successional stage of tree-shrub habitats. Seasonal variation of community structure indices was greatest within upland habitats. Comparison of seasonal patterns in number of guilds, guild evenness, bird density, and guild composition between tree-shrub and upland habitats suggested greater stability of food resource productivity, availability, and diversity within tree-shrub habitats. Differences in avian community structure between the 2 terrestrial seral stages (tree-shrub and upland) were ascribed to differences in successional stage and vegetation complexity. High avian biomass distinguished bird communities of beach-low marsh habitats and was probably related to high productivity typical of estuary systems. Seasonal variation of community structure, primarily a winter reduction in bird density, was least definitive in beach-low marsh habitats. Lack of winter reduction in number of guilds and seasonal changes in guild composition suggested low winter density was related to reduced availability of food resources as affected by tidal inundation, low temperatures, and ice on the river. Bird communities associated with the high marsh habitat were characterized from all other bird community-habitat associations by greater number of guilds. Less extensive tidal inundation, greater vegetation complexity and more edge effect in the high marsh habitat than in beach-low marsh habitats seemed to affect greater occurrence of terrestrial associated guilds. Results of this study indicated description of avian community structure on the basis of food-resource defined guilds was useful in interpreting how environmental (habitat and season) variation may affect bird communities. Validity of inferences from this study requires more detailed analysis of the bird communities and their habitats. Thus, the guild approach as used in this research is most appropriate for preliminary examination of communities, indicating areas where more specific study should increase understanding of the structure and functioning of avian communities. Title: An analysis of guild structure of avian communities, Columbia River, Oregon Author: Noyes, Cecilia Lea Barham Effects of habitat and season on guild structure of avian communities were examined for islands in the estuary zone of the Columbia River, Oregon. Bird species were classified into guilds according to their major food item, typical foraging substrate, and foraging behavior. Variation in community structure indices (number of guilds, guild diversity, evenness, bird density, and biomass) among habitats and seasons were analyzed with multivariate analysis of variance and discriminant function analysis. Cluster analysis was used to examine patterns of guild distribution among habitats and seasons. Four habitat-bird community associations (tree-shrub, upland, beach-low marsh, and high marsh) were described based on results from this study. High guild evenness within tree-shrub habitats during the breeding season (spring and summer) distinguished tree-shrub bird communities from communities within the 3 other habitats. Relatively stable bird density within tree-shrub habitats was attributed to high vegetation heterogeniety and later successional stage of tree-shrub habitats. Seasonal variation of community structure indices was greatest within upland habitats. Comparison of seasonal patterns in number of guilds, guild evenness, bird density, and guild composition between tree-shrub and upland habitats suggested greater stability of food resource productivity, availability, and diversity within tree-shrub habitats. Differences in avian community structure between the 2 terrestrial seral stages (tree-shrub and upland) were ascribed to differences in successional stage and vegetation complexity. High avian biomass distinguished bird communities of beach-low marsh habitats and was probably related to high productivity typical of estuary systems. Seasonal variation of community structure, primarily a winter reduction in bird density, was least definitive in beach-low marsh habitats. Lack of winter reduction in number of guilds and seasonal changes in guild composition suggested low winter density was related to reduced availability of food resources as affected by tidal inundation, low temperatures, and ice on the river. Bird communities associated with the high marsh habitat were characterized from all other bird community-habitat associations by greater number of guilds. Less extensive tidal inundation, greater vegetation complexity and more edge effect in the high marsh habitat than in beach-low marsh habitats seemed to affect greater occurrence of terrestrial associated guilds. Results of this study indicated description of avian community structure on the basis of food-resource defined guilds was useful in interpreting how environmental (habitat and season) variation may affect bird communities. Validity of inferences from this study requires more detailed analysis of the bird communities and their habitats. Thus, the guild approach as used in this research is most appropriate for preliminary examination of communities, indicating areas where more specific study should increase understanding of the structure and functioning of avian communities. Close

• 26. [Article] Response of trout, sculpins, and salamanders to experimental manipulation of large wood in Cascade Mountain streams

  Response of aquatic vertebrates to increased pool habitat complexity due to abundance of large wood was evaluated experimentally in three streams in the Cascade Mountains of Oregon. No difference in aquatic ...

  Citation × Citation Citation Abstract Copy Title: Response of trout, sculpins, and salamanders to experimental manipulation of large wood in Cascade Mountain streams Author: Burgess, Jack A. Response of aquatic vertebrates to increased pool habitat complexity due to abundance of large wood was evaluated experimentally in three streams in the Cascade Mountains of Oregon. No difference in aquatic vertebrate density was detected among treatments, though there was a trend of increasing aquatic vertebrate density with increasing large wood abundance. The small change in density of aquatic vertebrate species may have been due to the overriding influence of the high habitat heterogeneity associated with cobble/boulder substrate in these streams. Large wood may have a stronger influence in simpler streams with smaller particle size, in differing environmental regimes, or at spatial scales larger than channel unit. Mark-recapture estimates, catchability-based estimates, and maximum likelihood multiple removal estimates were compared in all three streams. Physical heterogeneity influenced efficiency of capture. The single pass catchability-based estimates were larger than mark-recapture estimates and maximum likelihood multiple removal estimates. Mark-recapture estimates were larger than maximum likelihood multiple removal estimates. The mark-recapture method gives more reliable and accurate estimates than maximum likelihood multiple removal method, but both methods may substantially underestimate the population. Taxon, fish length, and habitat variables influenced catchability for the population estimators examined. Probability of capture of vertebrates for the catchability-based estimator consistently decreased with increasing habitat complexity. Understanding factors that affect the accuracy of population estimators and the impact that habitat may have on catchability will assist fisheries scientists and managers in making informed decisions regarding the selection of a population estimation method. Research on habitat restoration and habitat relationships must recognize limitations of population estimators and catchability. Recognition of the limitations of population estimators and catchability should allow resource scientists to design more reliable monitoring and evaluation of habitat restoration projects. Title: Response of trout, sculpins, and salamanders to experimental manipulation of large wood in Cascade Mountain streams Author: Burgess, Jack A. Response of aquatic vertebrates to increased pool habitat complexity due to abundance of large wood was evaluated experimentally in three streams in the Cascade Mountains of Oregon. No difference in aquatic vertebrate density was detected among treatments, though there was a trend of increasing aquatic vertebrate density with increasing large wood abundance. The small change in density of aquatic vertebrate species may have been due to the overriding influence of the high habitat heterogeneity associated with cobble/boulder substrate in these streams. Large wood may have a stronger influence in simpler streams with smaller particle size, in differing environmental regimes, or at spatial scales larger than channel unit. Mark-recapture estimates, catchability-based estimates, and maximum likelihood multiple removal estimates were compared in all three streams. Physical heterogeneity influenced efficiency of capture. The single pass catchability-based estimates were larger than mark-recapture estimates and maximum likelihood multiple removal estimates. Mark-recapture estimates were larger than maximum likelihood multiple removal estimates. The mark-recapture method gives more reliable and accurate estimates than maximum likelihood multiple removal method, but both methods may substantially underestimate the population. Taxon, fish length, and habitat variables influenced catchability for the population estimators examined. Probability of capture of vertebrates for the catchability-based estimator consistently decreased with increasing habitat complexity. Understanding factors that affect the accuracy of population estimators and the impact that habitat may have on catchability will assist fisheries scientists and managers in making informed decisions regarding the selection of a population estimation method. Research on habitat restoration and habitat relationships must recognize limitations of population estimators and catchability. Recognition of the limitations of population estimators and catchability should allow resource scientists to design more reliable monitoring and evaluation of habitat restoration projects. Close

• 27. [Article] A study of the Columbian black-tailed deer Odocolieus hemionus columbianus (Richardson) and its habitat in Oregon

  Citation × Citation Citation Abstract Copy Title: A study of the Columbian black-tailed deer Odocolieus hemionus columbianus (Richardson) and its habitat in Oregon Author: Lindzey, James Shotwell Title: A study of the Columbian black-tailed deer Odocolieus hemionus columbianus (Richardson) and its habitat in Oregon Author: Lindzey, James Shotwell Close

• 28. [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

• 29. [Article] Oak habitat user guide.pdf

  Citation × Citation Citation Abstract Copy Title: Oak habitat user guide.pdf Author: Defenders of Wildlife Title: Oak habitat user guide.pdf Author: Defenders of Wildlife Close

• 30. [Article] Structure-forming benthic invertebrates : habitat distributions on the continental margin of Oregon and Washington

  Structure-forming invertebrates belong to a polyphyletic group of primarily sessile and sedentary megafauna that can significantly enhance the complexity of physical habitats. A number of these organisms, ...

  Citation × Citation Citation Abstract Copy Title: Structure-forming benthic invertebrates : habitat distributions on the continental margin of Oregon and Washington Author: Strom, Natalie A. Structure-forming invertebrates belong to a polyphyletic group of primarily sessile and sedentary megafauna that can significantly enhance the complexity of physical habitats. A number of these organisms, including cold-water corals and sponges, are known to be slow growing and vulnerable to physical disturbance. In addition, as filter feeders, these invertebrates can indicate areas of consistently favorable conditions for feeding and growth. This study provides the first quantitative analysis of structure-forming invertebrate communities in many areas along the continental margin of Oregon and Washington. Geological surveys during 1992-95, using the occupied submersible, Delta, sampled an extensive area in this region, primarily on and around rock outcrops. The videos from these surveys were analyzed to inventory and catalog sessile structure-forming invertebrates and to document their associations with geological habitat types. Detailed data on geological substrate, invertebrate diversity, abundance, and density were compiled and analyzed. It was found that geological substrate and depth were reliable indicators of suitable habitat for most species included in the study. Gorgonian corals tended to concentrate in high densities in depths between 200-250m, at the southern edges of submerged rocky banks, and where hard rocky substrate was covered with a thick layer of sediment. Because of recent fishery regulation changes, this information can be used as baseline data for future studies on the effectiveness of closed areas on the recovery of structure-forming invertebrates from disturbance, particularly bottom trawling. Title: Structure-forming benthic invertebrates : habitat distributions on the continental margin of Oregon and Washington Author: Strom, Natalie A. Structure-forming invertebrates belong to a polyphyletic group of primarily sessile and sedentary megafauna that can significantly enhance the complexity of physical habitats. A number of these organisms, including cold-water corals and sponges, are known to be slow growing and vulnerable to physical disturbance. In addition, as filter feeders, these invertebrates can indicate areas of consistently favorable conditions for feeding and growth. This study provides the first quantitative analysis of structure-forming invertebrate communities in many areas along the continental margin of Oregon and Washington. Geological surveys during 1992-95, using the occupied submersible, Delta, sampled an extensive area in this region, primarily on and around rock outcrops. The videos from these surveys were analyzed to inventory and catalog sessile structure-forming invertebrates and to document their associations with geological habitat types. Detailed data on geological substrate, invertebrate diversity, abundance, and density were compiled and analyzed. It was found that geological substrate and depth were reliable indicators of suitable habitat for most species included in the study. Gorgonian corals tended to concentrate in high densities in depths between 200-250m, at the southern edges of submerged rocky banks, and where hard rocky substrate was covered with a thick layer of sediment. Because of recent fishery regulation changes, this information can be used as baseline data for future studies on the effectiveness of closed areas on the recovery of structure-forming invertebrates from disturbance, particularly bottom trawling. Close