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• 61. [Image] The Third Klamath Basin Watershed Restoration and Research Conference

  	Cover title; "March 1999."
  	Citation × Citation Citation Abstract Copy Title: The Third Klamath Basin Watershed Restoration and Research Conference Year: 1999, 2004 Cover title; "March 1999." Title: The Third Klamath Basin Watershed Restoration and Research Conference Year: 1999, 2004 Cover title; "March 1999." Close

• 62. [Article] Effects of cork oak (Quercus suber L.) canopy cover on seasonal herbage production, foliar cover, and nutritive quality in the Mamora National Forest of Morocco

  This research was conducted in the Mamora National Forest of Morocco to: (1) Evaluate the effect of cork oak (Quercus suber L.) crown cover on seasonal herbage production, nutritive quality, and foliar ...

  Citation × Citation Citation Abstract Copy Title: Effects of cork oak (Quercus suber L.) canopy cover on seasonal herbage production, foliar cover, and nutritive quality in the Mamora National Forest of Morocco Author: Ibnattya, Abdelhai Andaloussi This research was conducted in the Mamora National Forest of Morocco to: (1) Evaluate the effect of cork oak (Quercus suber L.) crown cover on seasonal herbage production, nutritive quality, and foliar cover on two distinctive sites in each of two years (1982, 1983) and to (2) assess the effects of one and two growing seasons' protection from grazing on herbage production and foliar cover. Sites differed in the dominance (81% cover) of a 1.5-3m tall legumeshrub (Genista linifolia L.) on one (G) and the near absence of this layer on the other (NG). Understory herbage yields on G were over twice as much as the NG regardless of oak cover, plant phenology or years. On the G yields were similar from 25% to full oak canopy cover and declined approximately one-third at less than 25%. Yields on the NG were essentially the same regardless of canopy cover. Yields peaked at the pre-reproductive phase and then declined by approximately one-third by maturity. Herbage under canopied stands contained more crude protein, fat and water but less crude fiber than in the open. Nutritive quality of herbage from the G site was approximately three times greater than that from the NG. Living vegetation ground cover was 70% at canopy cover of 25% or less but was 85% above 25% canopy. Annual grasses decreased in cover from 57% to 30% as crown cover decreased. Annual forbs were less under the densest canopy but were approximately 30% as canopy declined. Perennials tended to be similar (13%) under all canopy treatments. Foliar cover was higher on the G site. Vegetation and soil characteristics showed G having higher production potential. The amount of rest from grazing had pronounced effects. Average herbage yields were 30% more protected two growing seasons as compared to one. Percent cover of annual grasses, perennial grasses and oak seedlings was higher when contrasting two to one seasons' protection. Results suggest that both tree canopy cover and site characteristics such as intermediate shrub layer were major determinants in affecting herbage yields, quality, cover and composition. Rest from grazing also had important effects. Such information will be helpful in developing future Mamora management plan. Title: Effects of cork oak (Quercus suber L.) canopy cover on seasonal herbage production, foliar cover, and nutritive quality in the Mamora National Forest of Morocco Author: Ibnattya, Abdelhai Andaloussi This research was conducted in the Mamora National Forest of Morocco to: (1) Evaluate the effect of cork oak (Quercus suber L.) crown cover on seasonal herbage production, nutritive quality, and foliar cover on two distinctive sites in each of two years (1982, 1983) and to (2) assess the effects of one and two growing seasons' protection from grazing on herbage production and foliar cover. Sites differed in the dominance (81% cover) of a 1.5-3m tall legumeshrub (Genista linifolia L.) on one (G) and the near absence of this layer on the other (NG). Understory herbage yields on G were over twice as much as the NG regardless of oak cover, plant phenology or years. On the G yields were similar from 25% to full oak canopy cover and declined approximately one-third at less than 25%. Yields on the NG were essentially the same regardless of canopy cover. Yields peaked at the pre-reproductive phase and then declined by approximately one-third by maturity. Herbage under canopied stands contained more crude protein, fat and water but less crude fiber than in the open. Nutritive quality of herbage from the G site was approximately three times greater than that from the NG. Living vegetation ground cover was 70% at canopy cover of 25% or less but was 85% above 25% canopy. Annual grasses decreased in cover from 57% to 30% as crown cover decreased. Annual forbs were less under the densest canopy but were approximately 30% as canopy declined. Perennials tended to be similar (13%) under all canopy treatments. Foliar cover was higher on the G site. Vegetation and soil characteristics showed G having higher production potential. The amount of rest from grazing had pronounced effects. Average herbage yields were 30% more protected two growing seasons as compared to one. Percent cover of annual grasses, perennial grasses and oak seedlings was higher when contrasting two to one seasons' protection. Results suggest that both tree canopy cover and site characteristics such as intermediate shrub layer were major determinants in affecting herbage yields, quality, cover and composition. Rest from grazing also had important effects. Such information will be helpful in developing future Mamora management plan. Close

• 63. [Image] Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005

  	Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, ...
  	Citation × Citation Citation Abstract Copy Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Title: Water quality conditions in Upper Klamath and Agency Lakes, Oregon, 2005 Author: Hoilman, Gene R Year: 2008 Agency Lakes. Oregon. 2005 M.Wood By Gene R. Hoilman, Mary K. Lindenberg, and Tamara Abstract During June-October 2005, water quality data were collected from Upper Klamath and Agency Lakes In Oregon, and meteorological data were collected around and within Upper Klamath Lake. Data recorded at two continuous water quality monitors In Agency Lake showed similar temperature patterns throughout the field season, but data recorded at the northern site showed more day-to-day variability for dissolved oxygen concentration and saturation after late June and more day-to-day variability for pH and specific conductance values after mid-July. Data recorded from the northern and southern parts of Agency Lake showed more comparable day-to-day variability in dissolved oxygen concentrations and pH from September through the end of the monitoring period. For Upper Klamath Lake, seasonal (late July through early August) lows of dissolved oxygen concentrations and saturation were coincident with a seasonal low of pH values and seasonal highs of ammonia and orthophosphate concentrations, specific conductance values, and water temperatures. Patterns in these parameters, excluding water temperature, were associated with bloom dynamics of the cyanobacterium (blue-green alga) Aphanizomenonflos-aquae in Upper Klamath Lake. In Upper Klamath Lake, water temperature in excess of 28 degrees Celsius (a high stress threshold for Upper Klamath Lake suckers) was recorded only once at one site during the field season. Large areas of Upper Klamath Lake had periods of dissolved oxygen concentration of less than 4 milligrams per liter and pH value greater than 9.7, but these conditions were not persistent throughout days at most sites. Dissolved oxygen concentrations in Upper Klamath Lake on time scales of days and months appeared to be influenced, in part, by bathymetry and prevailing current flow patterns. Diel patterns of water column stratification were evident, even at the deepest sites. This diel pattern of stratification was attributable to diel wind speed patterns and the shallow nature of most of Upper Klamath Lake. Timing of the daily extreme values of dissolved oxygen concentration, pH, and water temperature was less distinct with increased water column depth. Chlorophyll a concentrations varied spatially and temporally throughout Upper Klamath Lake. Location greatly affected algal concentrations, in turn affecting nutrient and dissolved oxygen concentrations—some of the highest chlorophyll a concentrations were associated with the lowest dissolved oxygen concentrations and the highest un-ionized ammonia concentrations. The occurrence of the low dissolved oxygen and high un-ionized ammonia concentrations coincided with a decline in algae resulting from cell death, as rn.easu.red by concentrations of chlorophyll a. Dissolved oxygen production, rates in. experim.en.ts were as high as 1.47 milligrams of oxygen per liter per hour, and consumption rates were as much as -0.73 milligrams of oxygen per liter per hour. Dissolved oxygen, consumption rates measured in. this study were comparable to those measured in a 2002 Upper Klamath Lake study, and a higher rate of dissolved oxygen consumption was recorded in. dark bottles positioned higher in the water column. Data, though, inconclusive, indicated that a decreasing trend of dissolved oxygen productivity through July could have contributed to the decreasing dissolved oxygen concentrations and percent saturation recorded in Upper Klamath Lake during this time. Phytoplankton self-shading was evident from, a general inverse relation between depth of photic zone and chlorophyll a concentrations. This shading caused net dissolved oxygen consumption during daylight hours in lower parts of the water column that would otherwise have been in the photic zone. Meteorological data collected in and around Upper Klamath Lake showed that winds were likely to come from a broad range of westerly directions in the northern one-third of the lake, but tended to come from a narrow range of northwesterly directions over the main body of the lake farther south. Close

• 64. [Article] Simplified Framework Evaluation of Large Water Resource Project Impacts

  The document most frequently used to support a water resource project's economic feasibility is the commercial benefit-cost analysis, which quantifies tangible and direct project consequences. The objective ...

  Citation × Citation Citation Abstract Copy Title: Simplified Framework Evaluation of Large Water Resource Project Impacts Author: Clowes, Brian Woodbridge Year: 1988 The document most frequently used to support a water resource project's economic feasibility is the commercial benefit-cost analysis, which quantifies tangible and direct project consequences. The objective of this type of analysis is simply to maximize net monetary benefits. This analysis assigns an arbitrary monetary value to ecological and social disruptions, if it does not ignore these effects entirely. An improvement on this method is the social benefit-cost analysis, which assesses sane intangible costs such as air and noise pollution. Unfortunately, even the social analysis usually neglects the sometimes profound effects that a large water resource project has upon quality of life, particularly with regards to massive relocations. The purpose of this dissertation is to resolve these problems by presenting a method by which a water resource study team may use five unique viewpoints - technical, organizational, personal, social, and environmental - to quantify and compare the true benefits and costs of project construction and operation. The study team begins by rigorously documenting the three general categories of project consequence (economic, social and environmental) and assigning each benefit or cost a relative value within category according to perceived positive or negative effects. The second step is to use these quantifications to produce three impact vs. dam height curves. The final and most difficult step in this study process is to assign a relative weight to the respective economic, social, and enviromental impact clusters, depending on national priorities and the biases and personal viewpoints of the decisiomaker (s). The final product of this procedure is a single curve which is used to further investigate and assess the overall feasibility of a water resource project and the 'optimum' range of dam heights. All of the possible impacts of a large water resource project, whether they be tangible or intangible, should be investigated in order to produce an authentic indicator of project efficiency. The only way to insure that all impacts are properly accounted for is to perform an exhaustive examination of a water resource project from the five perspectives mentioned above. The body of this dissertation is an example analysis based upon the proposed Three Gorge Dam and Reservoir on the Yangtze River in the People's Republic of China. This project will be the world's largest power plant at 13,000 megawatts. Because of its size, anticipated impacts, and the interest it has generated all over the world, the Three Gorge project is considered the ideal subject of a comprehensive multiple perspective analysis as described in this study. Title: Simplified Framework Evaluation of Large Water Resource Project Impacts Author: Clowes, Brian Woodbridge Year: 1988 The document most frequently used to support a water resource project's economic feasibility is the commercial benefit-cost analysis, which quantifies tangible and direct project consequences. The objective of this type of analysis is simply to maximize net monetary benefits. This analysis assigns an arbitrary monetary value to ecological and social disruptions, if it does not ignore these effects entirely. An improvement on this method is the social benefit-cost analysis, which assesses sane intangible costs such as air and noise pollution. Unfortunately, even the social analysis usually neglects the sometimes profound effects that a large water resource project has upon quality of life, particularly with regards to massive relocations. The purpose of this dissertation is to resolve these problems by presenting a method by which a water resource study team may use five unique viewpoints - technical, organizational, personal, social, and environmental - to quantify and compare the true benefits and costs of project construction and operation. The study team begins by rigorously documenting the three general categories of project consequence (economic, social and environmental) and assigning each benefit or cost a relative value within category according to perceived positive or negative effects. The second step is to use these quantifications to produce three impact vs. dam height curves. The final and most difficult step in this study process is to assign a relative weight to the respective economic, social, and enviromental impact clusters, depending on national priorities and the biases and personal viewpoints of the decisiomaker (s). The final product of this procedure is a single curve which is used to further investigate and assess the overall feasibility of a water resource project and the 'optimum' range of dam heights. All of the possible impacts of a large water resource project, whether they be tangible or intangible, should be investigated in order to produce an authentic indicator of project efficiency. The only way to insure that all impacts are properly accounted for is to perform an exhaustive examination of a water resource project from the five perspectives mentioned above. The body of this dissertation is an example analysis based upon the proposed Three Gorge Dam and Reservoir on the Yangtze River in the People's Republic of China. This project will be the world's largest power plant at 13,000 megawatts. Because of its size, anticipated impacts, and the interest it has generated all over the world, the Three Gorge project is considered the ideal subject of a comprehensive multiple perspective analysis as described in this study. Close

• 65. [Image] Lost River and shortnose sucker : proposed critical habitat : biological support document : draft

  	Proposed rule from Federal Register, vol. 59, no. 230, December 1, 1994, pages 61744-61759, inserted after p. 35; Includes biliographical references (p. 31-35)
  	Citation × Citation Citation Abstract Copy Title: Lost River and shortnose sucker : proposed critical habitat : biological support document : draft Author: U.S. Fish and Wildlife Service. Portland Field Office Year: 1994, 2004 Proposed rule from Federal Register, vol. 59, no. 230, December 1, 1994, pages 61744-61759, inserted after p. 35; Includes biliographical references (p. 31-35) Title: Lost River and shortnose sucker : proposed critical habitat : biological support document : draft Author: U.S. Fish and Wildlife Service. Portland Field Office Year: 1994, 2004 Proposed rule from Federal Register, vol. 59, no. 230, December 1, 1994, pages 61744-61759, inserted after p. 35; Includes biliographical references (p. 31-35) Close

• 66. [Article] Temperature and infiltration characterization of a constructed wetland for wastewater treatment

  The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination ...

  Citation × Citation Citation Abstract Copy Title: Temperature and infiltration characterization of a constructed wetland for wastewater treatment Author: Gregory, Christopher T. (Christopher Thomas) The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination System (NPDES) permit, the WWTP will require additional reduction of temperature and ammonia levels in the summer, especially in the critical month of September. The present research focuses on the performance of a 0.15 ha constructed pilot wetland during the summer and early fall of 2009. The wetland was intended to demonstrate the feasibility of using treatment wetlands to lower temperature and ammonia during an annual operational period (approximately June through October). Point sensors and a fiber optic distributed temperature sensor (DTS) were used to assess temperature treatment during the study. Infiltration was monitored to characterize the hydrogeologic behavior of the site. A wetland water budget was used to determine system-wide infiltration, and heat pulses applied to a subsurface fiber optic cable were used to assess infiltrative variability. The results showed that temperature reduction in the pilot wetland was marginal over the study period. In the September critical month, significantly more treatment occurred in the WWTP storage lagoon than in the wetland (about 4°C cooling compared to 1.2°C in the wetland). Decreasing the hydraulic retention time from 2.5 to 0.5 days in mid-September did not change the average temperature treatment. DTS data demonstrated that all temperature reduction occurred in the first half of the wetland. Infiltration was greater than outflow for most of the study, and steadily decreased through time. The highest and lowest infiltration velocities were within a factor of 2, and this range also declined between November 2008 and June 2009. Potential explanations for decreasing infiltration include soil clogging and settling. The study showed the utility of DTS for assessing the spatial and temporal variability of infiltration processes. Title: Temperature and infiltration characterization of a constructed wetland for wastewater treatment Author: Gregory, Christopher T. (Christopher Thomas) The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination System (NPDES) permit, the WWTP will require additional reduction of temperature and ammonia levels in the summer, especially in the critical month of September. The present research focuses on the performance of a 0.15 ha constructed pilot wetland during the summer and early fall of 2009. The wetland was intended to demonstrate the feasibility of using treatment wetlands to lower temperature and ammonia during an annual operational period (approximately June through October). Point sensors and a fiber optic distributed temperature sensor (DTS) were used to assess temperature treatment during the study. Infiltration was monitored to characterize the hydrogeologic behavior of the site. A wetland water budget was used to determine system-wide infiltration, and heat pulses applied to a subsurface fiber optic cable were used to assess infiltrative variability. The results showed that temperature reduction in the pilot wetland was marginal over the study period. In the September critical month, significantly more treatment occurred in the WWTP storage lagoon than in the wetland (about 4°C cooling compared to 1.2°C in the wetland). Decreasing the hydraulic retention time from 2.5 to 0.5 days in mid-September did not change the average temperature treatment. DTS data demonstrated that all temperature reduction occurred in the first half of the wetland. Infiltration was greater than outflow for most of the study, and steadily decreased through time. The highest and lowest infiltration velocities were within a factor of 2, and this range also declined between November 2008 and June 2009. Potential explanations for decreasing infiltration include soil clogging and settling. The study showed the utility of DTS for assessing the spatial and temporal variability of infiltration processes. Close

• 67. [Image] Klamath Basin summary of recent federal government activities, March 2003

  	The Department of the Interior, Klamath River Basin Work Plans and Reports
  	Citation × Citation Citation Abstract Copy Title: Klamath Basin summary of recent federal government activities, March 2003 Author: United States. Dept. of the Interior Year: 2003, 2005 The Department of the Interior, Klamath River Basin Work Plans and Reports Title: Klamath Basin summary of recent federal government activities, March 2003 Author: United States. Dept. of the Interior Year: 2003, 2005 The Department of the Interior, Klamath River Basin Work Plans and Reports Close

• 68. [Article] Methods for multi-spatial scale characterization riparian corridors

  This paper describes the application of aerial photography and GIS technology to develop flexible and transferable methods for multi-spatial scale characterization and analysis of riparian corridors. Relationships ...

  Citation × Citation Citation Abstract Copy Title: Methods for multi-spatial scale characterization riparian corridors Author: Moser, Thomas J., Lindeman, Dale R., Schuft, Michael, Van Sickle, John, Wigington, P.J. This paper describes the application of aerial photography and GIS technology to develop flexible and transferable methods for multi-spatial scale characterization and analysis of riparian corridors. Relationships between structural attributes of riparian corridors and indicators of stream ecological conditions are not well established. As part of a research project focused on assessing riparian-stream systems in agricultural landscapes of Oregon's Willamette Valley, GIS land cover/land use databases were created from 1997 aerial photography and digital orthophotography for 23 predominantly agricultural watersheds, including detailed land cover-land use coverages within 150 m of perennial and intermittent streams. GIS functions were used to partition the stream networks at various lateral-longitudinal scales to quantify land cover/land use and to generate functionally relevant metrics of riparian vegetation, such as its composition, width, and continuity. The methods developed provide considerable flexibility for generating metrics characterizing attributes of riparian corridors and for exploring relationships among these metrics and indicators of stream ecological condition. Title: Methods for multi-spatial scale characterization riparian corridors Author: Moser, Thomas J., Lindeman, Dale R., Schuft, Michael, Van Sickle, John, Wigington, P.J. This paper describes the application of aerial photography and GIS technology to develop flexible and transferable methods for multi-spatial scale characterization and analysis of riparian corridors. Relationships between structural attributes of riparian corridors and indicators of stream ecological conditions are not well established. As part of a research project focused on assessing riparian-stream systems in agricultural landscapes of Oregon's Willamette Valley, GIS land cover/land use databases were created from 1997 aerial photography and digital orthophotography for 23 predominantly agricultural watersheds, including detailed land cover-land use coverages within 150 m of perennial and intermittent streams. GIS functions were used to partition the stream networks at various lateral-longitudinal scales to quantify land cover/land use and to generate functionally relevant metrics of riparian vegetation, such as its composition, width, and continuity. The methods developed provide considerable flexibility for generating metrics characterizing attributes of riparian corridors and for exploring relationships among these metrics and indicators of stream ecological condition. Close

• 69. [Image] Draft upper Williamson River Watershed assessment

  	"Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council."
  	Citation × Citation Citation Abstract Copy Title: Draft upper Williamson River Watershed assessment Author: David Evans and Associates, Inc. Year: 2004, 2005 "Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council." Title: Draft upper Williamson River Watershed assessment Author: David Evans and Associates, Inc. Year: 2004, 2005 "Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council." Close

• 70. [Article] Habitat segregation of two ambystomatids in mountain ponds, Mount Rainier National Park

  Ambystoma macrodactylum (long-toed salamander) and A. gracile (northwestern salamander) are two common salamander species occupying key trophic positions in mountain ponds of Mount Rainier National Park. ...

  Citation × Citation Citation Abstract Copy Title: Habitat segregation of two ambystomatids in mountain ponds, Mount Rainier National Park Author: Brokes, Brendan J. Ambystoma macrodactylum (long-toed salamander) and A. gracile (northwestern salamander) are two common salamander species occupying key trophic positions in mountain ponds of Mount Rainier National Park. The objective of this research was to document and evaluate the distributions and abundances of the two species, relative to habitat characteristics of ponds in the park. Amphibian distributions and abundances were assessed in 20 ponds from June through September 1993 to 1996. Nutrient concentrations (total nitrogen, Kjeldahl-N, total phosphorus, and orthophosphate-P), habitat characteristics (surface area, depth, elevation, substratum organic content lost on ignition, amount of coarse woody debris, aquatic vegetation, and bottom firmness), and water quality (temperature, dissolved oxygen, alkalinity, conductivity, and pH) were measured. Distinct habitat associations were found for each Ambystoma species. Ponds with one species only were different in surface area, maximum depth, substratum organic content, and elevation. Ponds with A. macrodactylum were small, shallow, high in elevation, and had firm sediments low in organic matter relative to A. gracile ponds. Ambystoma macrodactylum ponds typically contained little coarse woody debris relative to the amount of aquatic vegetation. Ambystoma gracile ponds were large, deep, low in elevation, had flocculent sediment high in organic content, abundant coarse woody debris, and little aquatic vegetation relative to A. macrodactylum ponds. Two ponds supported reproducing populations of both species and exhibited habitat characteristics intermediate to the allopatric pond types. These findings suggest that habitat complexity plays an important role in the segregation of A. macrodactylum and A. gracile. Title: Habitat segregation of two ambystomatids in mountain ponds, Mount Rainier National Park Author: Brokes, Brendan J. Ambystoma macrodactylum (long-toed salamander) and A. gracile (northwestern salamander) are two common salamander species occupying key trophic positions in mountain ponds of Mount Rainier National Park. The objective of this research was to document and evaluate the distributions and abundances of the two species, relative to habitat characteristics of ponds in the park. Amphibian distributions and abundances were assessed in 20 ponds from June through September 1993 to 1996. Nutrient concentrations (total nitrogen, Kjeldahl-N, total phosphorus, and orthophosphate-P), habitat characteristics (surface area, depth, elevation, substratum organic content lost on ignition, amount of coarse woody debris, aquatic vegetation, and bottom firmness), and water quality (temperature, dissolved oxygen, alkalinity, conductivity, and pH) were measured. Distinct habitat associations were found for each Ambystoma species. Ponds with one species only were different in surface area, maximum depth, substratum organic content, and elevation. Ponds with A. macrodactylum were small, shallow, high in elevation, and had firm sediments low in organic matter relative to A. gracile ponds. Ambystoma macrodactylum ponds typically contained little coarse woody debris relative to the amount of aquatic vegetation. Ambystoma gracile ponds were large, deep, low in elevation, had flocculent sediment high in organic content, abundant coarse woody debris, and little aquatic vegetation relative to A. macrodactylum ponds. Two ponds supported reproducing populations of both species and exhibited habitat characteristics intermediate to the allopatric pond types. These findings suggest that habitat complexity plays an important role in the segregation of A. macrodactylum and A. gracile. Close