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• 1. [Article] Stormwater Solutions for Improving Water Quality: Supporting the Development of the Amazon Creek Initiative

  The Long Tom Watershed Council (LTWC) is a non-profit organization in Eugene, Oregon that serves to protect and enhance watershed health in the Long Tom River Basin. The Amazon Creek Initiative was launched ...

  Citation × Citation Citation Abstract Copy Title: Stormwater Solutions for Improving Water Quality: Supporting the Development of the Amazon Creek Initiative Author: Larson, Kristen M. The Long Tom Watershed Council (LTWC) is a non-profit organization in Eugene, Oregon that serves to protect and enhance watershed health in the Long Tom River Basin. The Amazon Creek Initiative was launched by the LTWC in 2011 as Oregon’s newest Pesticide Stewardship Partner. Goals of the initiative are to improve water quality and habitat function in Amazon Creek by encouraging voluntary retrofits of low-impact development (LID) and through outreach and education of pollution prevention practices. This internship involved a series of projects in support of the development of the Amazon Creek Initiative. Accomplishments included surface water sampling, stakeholder research, development of communication tools, creation of an LID cost calculator, site visits and assessments of pesticide retailers, and a review of national efforts to train pesticide retail staff in integrated pest management. This work supports the Amazon Creek Initiative as it moves towards implementation and provided diverse learning opportunities in non-profit and watershed council operations, communicating a scientific message, and low-impact development solutions to stormwater management. Title: Stormwater Solutions for Improving Water Quality: Supporting the Development of the Amazon Creek Initiative Author: Larson, Kristen M. The Long Tom Watershed Council (LTWC) is a non-profit organization in Eugene, Oregon that serves to protect and enhance watershed health in the Long Tom River Basin. The Amazon Creek Initiative was launched by the LTWC in 2011 as Oregon’s newest Pesticide Stewardship Partner. Goals of the initiative are to improve water quality and habitat function in Amazon Creek by encouraging voluntary retrofits of low-impact development (LID) and through outreach and education of pollution prevention practices. This internship involved a series of projects in support of the development of the Amazon Creek Initiative. Accomplishments included surface water sampling, stakeholder research, development of communication tools, creation of an LID cost calculator, site visits and assessments of pesticide retailers, and a review of national efforts to train pesticide retail staff in integrated pest management. This work supports the Amazon Creek Initiative as it moves towards implementation and provided diverse learning opportunities in non-profit and watershed council operations, communicating a scientific message, and low-impact development solutions to stormwater management. Close

• 2. [Article] Probabilistic assessment of wildfire hazard and municipal watershed exposure

  This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springer.com/earth+sciences+and+geography/natural+hazards/journal/11069. To the best ...

  Citation × Citation Citation Abstract Copy Title: Probabilistic assessment of wildfire hazard and municipal watershed exposure Author: Thompson, Matthew P., Marcille, Kate, Calkin, David E., Scott, Joe, Helmbrecht, Don This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springer.com/earth+sciences+and+geography/natural+hazards/journal/11069. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Title: Probabilistic assessment of wildfire hazard and municipal watershed exposure Author: Thompson, Matthew P., Marcille, Kate, Calkin, David E., Scott, Joe, Helmbrecht, Don This is the publisher’s final pdf. The published article is copyrighted by Springer and can be found at: http://www.springer.com/earth+sciences+and+geography/natural+hazards/journal/11069. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. Close

• 3. [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

• 4. [Article] Boating in Alaska's Prince William Sound : modeling and assessment of recreational use

  This study measures the recreational boating use in Prince William Sound, Alaska. Improved access conditions to the Sound over the last decade coupled with a statewide increase in outdoor recreation participation ...

  Citation × Citation Citation Abstract Copy Title: Boating in Alaska's Prince William Sound : modeling and assessment of recreational use Author: Wolfe, Phillip E. This study measures the recreational boating use in Prince William Sound, Alaska. Improved access conditions to the Sound over the last decade coupled with a statewide increase in outdoor recreation participation among both resident and out of state tourists have made the Sound a focal point for recreational boating in Alaska. The goal study is to provide baseline data for future assessment of recreational use in the Sound and evaluation of management issues. A primary objective is to determine the type of users, level of use and spatial distribution of recreational use in the Sound. Accurate information on visitor use aids management with a particular emphasis on maintaining the wilderness quality as well as providing ecological protection throughout the Sound. As such, a second objective of this study is to determine the potential interactions between recreation use and five wildlife species which aids in the mission of the recovery of the Sound from the Exxon Valdez oil spill. A large marine environment with highly dispersed recreation use, however, poses difficulties in applying conventional methods of visitor monitoring and identifying where potential conflicts may occur. This study is the first to address recreational use across the entire Sound by employing recreational modeling techniques. Survey participants provided mapped travel diaries detailing the location of their stops and the various activities in which they participated. These diaries were digitized and analyzed using GIS. A total of 2085 surveys were distributed with a 27% sample rate and 31% return rate. Results indicate that use levels are highest in the western portion of the Sound. Nearly 75% of trips reported participating in water-based activities. Rates of participation in recreational activities varied based on vessel type. Although landbased activities were reported relatively infrequently, their location and impact on the Sound are of significant interest to the Chugach National Forest. Recreation use in proximity to known wildlife sites was limited. Several areas such as Naked Island and Dutch Group, however have a high concentration of both black oystercatchers and pigeon guillemot nest sites and relatively high visitor use associated with them. Results of this study are intended to aid in the development of a framework, at an appropriate scale, to manage the future growth of recreation use in the Sound. Title: Boating in Alaska's Prince William Sound : modeling and assessment of recreational use Author: Wolfe, Phillip E. This study measures the recreational boating use in Prince William Sound, Alaska. Improved access conditions to the Sound over the last decade coupled with a statewide increase in outdoor recreation participation among both resident and out of state tourists have made the Sound a focal point for recreational boating in Alaska. The goal study is to provide baseline data for future assessment of recreational use in the Sound and evaluation of management issues. A primary objective is to determine the type of users, level of use and spatial distribution of recreational use in the Sound. Accurate information on visitor use aids management with a particular emphasis on maintaining the wilderness quality as well as providing ecological protection throughout the Sound. As such, a second objective of this study is to determine the potential interactions between recreation use and five wildlife species which aids in the mission of the recovery of the Sound from the Exxon Valdez oil spill. A large marine environment with highly dispersed recreation use, however, poses difficulties in applying conventional methods of visitor monitoring and identifying where potential conflicts may occur. This study is the first to address recreational use across the entire Sound by employing recreational modeling techniques. Survey participants provided mapped travel diaries detailing the location of their stops and the various activities in which they participated. These diaries were digitized and analyzed using GIS. A total of 2085 surveys were distributed with a 27% sample rate and 31% return rate. Results indicate that use levels are highest in the western portion of the Sound. Nearly 75% of trips reported participating in water-based activities. Rates of participation in recreational activities varied based on vessel type. Although landbased activities were reported relatively infrequently, their location and impact on the Sound are of significant interest to the Chugach National Forest. Recreation use in proximity to known wildlife sites was limited. Several areas such as Naked Island and Dutch Group, however have a high concentration of both black oystercatchers and pigeon guillemot nest sites and relatively high visitor use associated with them. Results of this study are intended to aid in the development of a framework, at an appropriate scale, to manage the future growth of recreation use in the Sound. Close

• 5. [Article] The importance of lake-specific characteristics for water quality across the continental United States

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournal...

  Citation × Citation Citation Abstract Copy Title: The importance of lake-specific characteristics for water quality across the continental United States Author: Read, Emily K., Patil, Vijay P., Oliver, Samantha K., et al., Winters, Kirsten M. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournals.org/loi/ecap Title: The importance of lake-specific characteristics for water quality across the continental United States Author: Read, Emily K., Patil, Vijay P., Oliver, Samantha K., et al., Winters, Kirsten M. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by the Ecological Society of America. The published article can be found at: http://www.esajournals.org/loi/ecap Close

• 6. [Article] Transboundary river floods : vulnerability of continents, international river basins and countries

  Floods are the most frequent and damaging of all types of natural disasters and annually affect the lives of millions all over the globe. However, researchers seem to have overlooked the fact that floods ...

  Citation × Citation Citation Abstract Copy Title: Transboundary river floods : vulnerability of continents, international river basins and countries Author: Bakker, Marloes H.N. Floods are the most frequent and damaging of all types of natural disasters and annually affect the lives of millions all over the globe. However, researchers seem to have overlooked the fact that floods do not recognize national boundaries. Therefore, the phenomena of shared, or transboundary floods occurring in international river basins (IRBs) is rarely touched upon. Consequently, vulnerability to shared floods is poorly understood and not much is known about the present quantity and quality of institutional capacity to deal with such events. Hence the primary purpose of the present work is to fill this gap in knowledge. We explore transboundary river flood events and related institutional capacity in more detail, starting at a global scale, zooming in on international river basins (IRBs) and ending with a country-scale perspective. The first section assesses how many of all floods were riverine and how much of these were shared between two or more countries. The results show that transboundary floods are more severe in their magnitude, affect larger areas, result in higher death tolls, and cause more financial damage than non-shared river floods do. The second section reveals an alarmingly low institutional capacity related to transboundary river floods: more than 15% of the IRBs do not have any type of institutional capacity in the form of a river basin institution, nor any focused on floods. The third section examines flood events, international water treaties signed and institutions created in the Netherlands and Mozambique. The comparison indicates that lower levels of development or the absence of development capital do not necessarily have to result in future (shared) flood-related disasters. Collectively, these results significantly increase our current knowledge on vulnerability to –transboundary– river floods and indicate that there might be more need for official international institutions dealing with these events. However, selecting the one country, continent or IRB that is the most vulnerable to –transboundary– river floods is impossible since the answer greatly depends upon the specific definition of vulnerability. This indicates that vulnerability to floods is a complex phenomenon that cannot be explained by using the results of only this study. Title: Transboundary river floods : vulnerability of continents, international river basins and countries Author: Bakker, Marloes H.N. Floods are the most frequent and damaging of all types of natural disasters and annually affect the lives of millions all over the globe. However, researchers seem to have overlooked the fact that floods do not recognize national boundaries. Therefore, the phenomena of shared, or transboundary floods occurring in international river basins (IRBs) is rarely touched upon. Consequently, vulnerability to shared floods is poorly understood and not much is known about the present quantity and quality of institutional capacity to deal with such events. Hence the primary purpose of the present work is to fill this gap in knowledge. We explore transboundary river flood events and related institutional capacity in more detail, starting at a global scale, zooming in on international river basins (IRBs) and ending with a country-scale perspective. The first section assesses how many of all floods were riverine and how much of these were shared between two or more countries. The results show that transboundary floods are more severe in their magnitude, affect larger areas, result in higher death tolls, and cause more financial damage than non-shared river floods do. The second section reveals an alarmingly low institutional capacity related to transboundary river floods: more than 15% of the IRBs do not have any type of institutional capacity in the form of a river basin institution, nor any focused on floods. The third section examines flood events, international water treaties signed and institutions created in the Netherlands and Mozambique. The comparison indicates that lower levels of development or the absence of development capital do not necessarily have to result in future (shared) flood-related disasters. Collectively, these results significantly increase our current knowledge on vulnerability to –transboundary– river floods and indicate that there might be more need for official international institutions dealing with these events. However, selecting the one country, continent or IRB that is the most vulnerable to –transboundary– river floods is impossible since the answer greatly depends upon the specific definition of vulnerability. This indicates that vulnerability to floods is a complex phenomenon that cannot be explained by using the results of only this study. Close

• 7. [Article] Essays on land use regulation

  This dissertation consists of three papers on land use economics and regulation. The first paper focuses on the environmental impacts of land use and their implications for the design on water quality ...

  Citation × Citation Citation Abstract Copy Title: Essays on land use regulation Author: Hascic, Ivan This dissertation consists of three papers on land use economics and regulation. The first paper focuses on the environmental impacts of land use and their implications for the design on water quality trading policies. The second and third papers address local land use regulations and their impact on land values and land use patterns. The first paper provides a national-scale, watershed-level assessment of land use impacts on water quality and aquatic ecosystems in the United States. The results suggest that the level of conventional water pollution in a watershed is significantly affected by the amount of land allocated to intensive agriculture and urban development, while the level of toxic water pollution is significantly affected by the amount of land allocated to transportation and mining. Implications of the results for the design and implementation of water quality trading policies are discussed. The second paper develops an empirical framework to conduct an exploratory analysis of effects of land use regulations on land values and land use patterns in a GIS-based landscape near Eugene, Oregon. All the land use regulations considered in this study, including exclusive farm use zoning, forest zoning, urban growth boundary designation, residential density zoning, commercial zoning, and industrial zoning, are found to affect land value and use both inside and outside of the designated zones. While there are many issues this framework does not address, preliminary results indicate that regulations (except commercial zoning) tend to increase the value of land outside the designated zones, but reduce the value of land inside the designated zones. The framework is applied to measure the reduction in value due to regulations vs. the value of individual exemptions at the parcel level to illuminate the controversy surrounding Oregon's Measure 37. The reductions in value due to regulations are found to be considerably smaller than the values of individual exemptions for almost all regulations contested in the Measure 37 claims. The third paper evaluates the efficiency of the current system of land use regulation, analyzes the possible changes to the regulatory structure, and studies the role of spatial and temporal interaction among neighboring land uses. Title: Essays on land use regulation Author: Hascic, Ivan This dissertation consists of three papers on land use economics and regulation. The first paper focuses on the environmental impacts of land use and their implications for the design on water quality trading policies. The second and third papers address local land use regulations and their impact on land values and land use patterns. The first paper provides a national-scale, watershed-level assessment of land use impacts on water quality and aquatic ecosystems in the United States. The results suggest that the level of conventional water pollution in a watershed is significantly affected by the amount of land allocated to intensive agriculture and urban development, while the level of toxic water pollution is significantly affected by the amount of land allocated to transportation and mining. Implications of the results for the design and implementation of water quality trading policies are discussed. The second paper develops an empirical framework to conduct an exploratory analysis of effects of land use regulations on land values and land use patterns in a GIS-based landscape near Eugene, Oregon. All the land use regulations considered in this study, including exclusive farm use zoning, forest zoning, urban growth boundary designation, residential density zoning, commercial zoning, and industrial zoning, are found to affect land value and use both inside and outside of the designated zones. While there are many issues this framework does not address, preliminary results indicate that regulations (except commercial zoning) tend to increase the value of land outside the designated zones, but reduce the value of land inside the designated zones. The framework is applied to measure the reduction in value due to regulations vs. the value of individual exemptions at the parcel level to illuminate the controversy surrounding Oregon's Measure 37. The reductions in value due to regulations are found to be considerably smaller than the values of individual exemptions for almost all regulations contested in the Measure 37 claims. The third paper evaluates the efficiency of the current system of land use regulation, analyzes the possible changes to the regulatory structure, and studies the role of spatial and temporal interaction among neighboring land uses. Close

• 8. [Article] An Ecoregion-Based Reference Condition and Classification Scheme for Determining Nutrient Criteria in Oregon Lakes

  The anthropogenic introduction of nutrients to water bodies has been shown to alter the structure and function of natural aquatic ecosystems, yet national EPA lake and reservoir nutrient criteria remain ...

  Citation × Citation Citation Abstract Copy Title: An Ecoregion-Based Reference Condition and Classification Scheme for Determining Nutrient Criteria in Oregon Lakes Author: Brenner, Jacqueline M. The anthropogenic introduction of nutrients to water bodies has been shown to alter the structure and function of natural aquatic ecosystems, yet national EPA lake and reservoir nutrient criteria remain too broad for effective regional water quality management. This study uses a reference site approach to propose numeric nutrient criteria for concentrations of total nitrogen (TN) and total phosphorus (TP) specifically applicable to lakes and reservoirs in Oregon. Oregon lake watersheds with existing lakewater nutrient data were characterized using GIS techniques to eliminate lakes with known point and non-point sources of anthropogenic nutrient contributions, resulting in 98 minimally or least-altered Oregon lakes. These minimally altered lakes were used as reference sites for their corresponding Omernik Level III ecoregion based on majority ecoregion composition of the lake watershed. CART regression and other statistical procedures were used to relate existing data on summer nutrient concentrations to reference site factors, including: water residence time, soil properties, elevation, lake depth, precipitation, and watershed deciduous forests and wetlands. Lake classifications from this analysis were only significantly related to precipitation and supported aggregate ecoregion groupings of the Western Forested Mountains (Coast Range, Willamette Valley, Cascades, Klamath Mountains, and Blue Mountains), Xeric West (Northern Basin and Range, Columbia Plateau, and Snake River Plain), and Eastern Cascades were used to set ecoregional criteria for TP. For TN, the Eastern Cascades were not significantly different from the Xeric West and aggregated into the Xeric West ecoregion. As per EPA guidelines, the 75th percentile of reference site nutrient concentrations in an ecoregion were used to set ecoregional nutrient criteria with the following results; Western Forested Mountains: 11 μg TP/L and 277 μg TN/L; Eastern Cascades: 78.5 μg TP/L; and Xeric West: 490 μg TP/L and 760 μgTN/L. Nutrient concentrations in a random sample of Oregon lakes taken from EPA's 2007 and 2012 National Lake Assessment surveys were assessed using the proposed criteria. Statewide, 21- 37% of lakes had TP below criteria and 40 - 64% of lakes had TN below criteria in the two surveys. These results contribute to nutrient management efforts and inform agency scientists and decision makers regarding the complexity of nutrient – land use relationships in lakes and their watersheds. Title: An Ecoregion-Based Reference Condition and Classification Scheme for Determining Nutrient Criteria in Oregon Lakes Author: Brenner, Jacqueline M. The anthropogenic introduction of nutrients to water bodies has been shown to alter the structure and function of natural aquatic ecosystems, yet national EPA lake and reservoir nutrient criteria remain too broad for effective regional water quality management. This study uses a reference site approach to propose numeric nutrient criteria for concentrations of total nitrogen (TN) and total phosphorus (TP) specifically applicable to lakes and reservoirs in Oregon. Oregon lake watersheds with existing lakewater nutrient data were characterized using GIS techniques to eliminate lakes with known point and non-point sources of anthropogenic nutrient contributions, resulting in 98 minimally or least-altered Oregon lakes. These minimally altered lakes were used as reference sites for their corresponding Omernik Level III ecoregion based on majority ecoregion composition of the lake watershed. CART regression and other statistical procedures were used to relate existing data on summer nutrient concentrations to reference site factors, including: water residence time, soil properties, elevation, lake depth, precipitation, and watershed deciduous forests and wetlands. Lake classifications from this analysis were only significantly related to precipitation and supported aggregate ecoregion groupings of the Western Forested Mountains (Coast Range, Willamette Valley, Cascades, Klamath Mountains, and Blue Mountains), Xeric West (Northern Basin and Range, Columbia Plateau, and Snake River Plain), and Eastern Cascades were used to set ecoregional criteria for TP. For TN, the Eastern Cascades were not significantly different from the Xeric West and aggregated into the Xeric West ecoregion. As per EPA guidelines, the 75th percentile of reference site nutrient concentrations in an ecoregion were used to set ecoregional nutrient criteria with the following results; Western Forested Mountains: 11 μg TP/L and 277 μg TN/L; Eastern Cascades: 78.5 μg TP/L; and Xeric West: 490 μg TP/L and 760 μgTN/L. Nutrient concentrations in a random sample of Oregon lakes taken from EPA's 2007 and 2012 National Lake Assessment surveys were assessed using the proposed criteria. Statewide, 21- 37% of lakes had TP below criteria and 40 - 64% of lakes had TN below criteria in the two surveys. These results contribute to nutrient management efforts and inform agency scientists and decision makers regarding the complexity of nutrient – land use relationships in lakes and their watersheds. Close

• 9. [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

• 10. [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