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• 31. [Article] How sweet is the land? Modeling caloric landscapes for tropical hummingbirds

  Powerpoint presentation for the defense of this thesis.

  Citation × Citation Citation Abstract Copy Title: How sweet is the land? Modeling caloric landscapes for tropical hummingbirds Author: Birkett, Christina Nozomi Powerpoint presentation for the defense of this thesis. Title: How sweet is the land? Modeling caloric landscapes for tropical hummingbirds Author: Birkett, Christina Nozomi Powerpoint presentation for the defense of this thesis. Close

• 32. [Article] Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range

  Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological ...

  Citation × Citation Citation Abstract Copy Title: Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range Author: Boisjolie, Brett A. Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological systems. In the case of riparian lands in the Oregon Coast Range, policy requirements vary considerably across federal, state, and private land ownerships. Protective measures, such as the adoption of fixed buffer widths for maintaining vegetation, are intended to preserve natural processes important to instream habitat and water quality. However, the "policy landscape" of variable management standards can result in a fragmented approach to policy protection. This fragmentation complicates recovery efforts for threatened anadromous fish species such as coho salmon (Oncorhynchus kisutch), which require connectivity in suitable habitat segments throughout the river network. Taking a riverscape perspective, this study evaluates how aquatic protections vary across the river and its valley. To explore the patterns created from variable standard, the study first delineates categories of riparian management standards in the Oregon Coast Range. Using a geographic information system (GIS), these standards are mapped across the river networks of this region. The extent of each policy category is quantified in stream kilometers in order to evaluate policy efforts within and across the riverscapes of the Oregon Coast Range. A model of intrinsic potential for coho salmon habitat is used to identify the policy standards in stream reaches where flow, valley constraint, and channel gradient are appropriate for coho salmon habitat. A second model of the stream network (hydrography) is developed to evaluate how differences in stream delineation can influence policy patterns. Results indicate that riparian lands of the Oregon Coast Range are protected by variable standards for land management, including buffer widths that range from 0 to ~152m. In streams important to coho salmon, a lower proportion of the stream network was found to be protected by policy standards compared to the watershed and ESU scale. A lack of stream data central to policy application (fish use, stream flow duration, mean annual flow, water use) complicated our ability to attribute stream segments with specific land management requirements. The choice of hydrographic data was also found to influence the proportional extent of policies within riverscapes. This framework for assessing the spatial distribution of policies can provide insights for future studies of riverscape systems. Title: Policy Patterns across Riverscapes : Riparian Land Standards in the Oregon Coast Range Author: Boisjolie, Brett A. Land management policies are ideas about nature projected onto the landscape. Culminations of social, economic, and scientific influences, these policies create standards affecting the function of ecological systems. In the case of riparian lands in the Oregon Coast Range, policy requirements vary considerably across federal, state, and private land ownerships. Protective measures, such as the adoption of fixed buffer widths for maintaining vegetation, are intended to preserve natural processes important to instream habitat and water quality. However, the "policy landscape" of variable management standards can result in a fragmented approach to policy protection. This fragmentation complicates recovery efforts for threatened anadromous fish species such as coho salmon (Oncorhynchus kisutch), which require connectivity in suitable habitat segments throughout the river network. Taking a riverscape perspective, this study evaluates how aquatic protections vary across the river and its valley. To explore the patterns created from variable standard, the study first delineates categories of riparian management standards in the Oregon Coast Range. Using a geographic information system (GIS), these standards are mapped across the river networks of this region. The extent of each policy category is quantified in stream kilometers in order to evaluate policy efforts within and across the riverscapes of the Oregon Coast Range. A model of intrinsic potential for coho salmon habitat is used to identify the policy standards in stream reaches where flow, valley constraint, and channel gradient are appropriate for coho salmon habitat. A second model of the stream network (hydrography) is developed to evaluate how differences in stream delineation can influence policy patterns. Results indicate that riparian lands of the Oregon Coast Range are protected by variable standards for land management, including buffer widths that range from 0 to ~152m. In streams important to coho salmon, a lower proportion of the stream network was found to be protected by policy standards compared to the watershed and ESU scale. A lack of stream data central to policy application (fish use, stream flow duration, mean annual flow, water use) complicated our ability to attribute stream segments with specific land management requirements. The choice of hydrographic data was also found to influence the proportional extent of policies within riverscapes. This framework for assessing the spatial distribution of policies can provide insights for future studies of riverscape systems. Close

• 33. [Article] Carbon storage in a Pacific Northwest conifer forest ecosystem : a chronosequence approach

  As concern over global warming intensifies, sequestration and storage of atmospheric CO2 has become an important scientific and policy issue. Confusion persists, however, over interpretation of forest ...

  Citation × Citation Citation Abstract Copy Title: Carbon storage in a Pacific Northwest conifer forest ecosystem : a chronosequence approach Author: Janisch, Jack E. As concern over global warming intensifies, sequestration and storage of atmospheric CO2 has become an important scientific and policy issue. Confusion persists, however, over interpretation of forest carbon (C) source-sink dynamics, in part because conclusions drawn depend on temporal and spatial scales of analysis (e.g. day-week scale vs. successional-scale), type of disturbance, and methodology (e.g. massbased vs. flux-based). There is a need to resolve this confusion given that strategies for mitigating anthropogenic CO2 emissions are based on estimates of forest C fluxes during various stages of succession, over which C fluxes and stores may change. Empirical study of changes in forest C stores can help to resolve this confusion by clarifying the C sources-sink dynamics of forests in space and time. To better understand the impacts of disturbance on C source-sink dynamics, changes in C stores of an evergreen-dominated forest on the Wind River Ranger District in Southwestern Washington, U.S.A., were investigated along a 500-year chronosequence of 36 stands. Principle objectives were to evaluate 1) decomposition rates (k) of logs, stumps, and below-ground coarse roots, 2) net primary productivity (NPP) of dominant tree species' boles at the stand level, and 3) successional changes in net ecosystem productivity (NEP) for live trees and coarse woody debris (CWD), here called NEPW. In the case of decomposition, log and stump k values did not differ significantly within the two principle species studied, indicating substitution of log k values for stump k values in models of forest C budgets may be valid when stump decomposition data is lacking. Decomposition rates between species differed, with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) decomposing more slowly (k = 0.013 yr-1) relative to western hemlock (Tsuga heterophylla (Rafi) Sarg. (k = 0.036 yr-1). This difference in k between species was observed for both above-ground stumps and logs as well as below-ground coarse roots. Given our mean k estimates and adjusting for regenerating stand age, these stands are losing C at a rate of 0.16-0.83 Mg C ha-1 yr-1 (assuming all CWD is P. menziesii) to 0.13-1.68 Mg C ha-1 yr-1 (assuming all CWD is T. heterophylla) from stumps, logs, and snags. Including coarse roots increases these losses to 0.28-1.25 Mg C ha-1 yr-1 and 0.30-2.53 Mg C ha-1 yr-1, respectively. Based on these findings, if fragmentation of these decomposing C pools is ignored, and fragmented fractions have oxidized to CO2, stands thought to be net C sinks could in reality be net C sources to the atmosphere. Net primary production in tree boles (NPPb) of regenerating stands (so called second-growth) ranged between 0.15-5.28 Mg C ha-1 yr-1. NPPb of 500-year old stands ranged between 1.3-3.9 Mg C ha-1 yr-1, similar to NPPb of boles in 20-25 year old secondgrowth. Mean radial increment widths from old-growth stands indicated that NPPb of these stands (neglecting mortality) can increase, decrease, or remain relatively constant. Based on 5-year increments for the previous fifteen years, the majority of old-growth stands sampled showed small increases in radial growth over time. Timing of the transition from negative to positive of NEPW ranged between 0 and 57 years after disturbance and depended strongly on live-tree growth rates as well as the fate of CWD and harvested wood. Estimated maximum and minimum NEPW were 3.9 Mg C ha-1 yr-1 and 14.1 Mg C ha-1 yr-1, respectively. Maximum mean C stores of 393 Mg C ha-1 were reached approximately 200 years after disturbance. At a rotation age of 80 years, regenerating stands stored approximately 50% as much C in woody biomass as a 500-year old primary forest, indicating conversion of older forests to plantations released C to the atmosphere. Given the high biomass of mature and old-growth stands relative to younger regenerating stands in the forest studied, landscape C stores in live wood would appear to be maximized in stands of older age classes. Title: Carbon storage in a Pacific Northwest conifer forest ecosystem : a chronosequence approach Author: Janisch, Jack E. As concern over global warming intensifies, sequestration and storage of atmospheric CO2 has become an important scientific and policy issue. Confusion persists, however, over interpretation of forest carbon (C) source-sink dynamics, in part because conclusions drawn depend on temporal and spatial scales of analysis (e.g. day-week scale vs. successional-scale), type of disturbance, and methodology (e.g. massbased vs. flux-based). There is a need to resolve this confusion given that strategies for mitigating anthropogenic CO2 emissions are based on estimates of forest C fluxes during various stages of succession, over which C fluxes and stores may change. Empirical study of changes in forest C stores can help to resolve this confusion by clarifying the C sources-sink dynamics of forests in space and time. To better understand the impacts of disturbance on C source-sink dynamics, changes in C stores of an evergreen-dominated forest on the Wind River Ranger District in Southwestern Washington, U.S.A., were investigated along a 500-year chronosequence of 36 stands. Principle objectives were to evaluate 1) decomposition rates (k) of logs, stumps, and below-ground coarse roots, 2) net primary productivity (NPP) of dominant tree species' boles at the stand level, and 3) successional changes in net ecosystem productivity (NEP) for live trees and coarse woody debris (CWD), here called NEPW. In the case of decomposition, log and stump k values did not differ significantly within the two principle species studied, indicating substitution of log k values for stump k values in models of forest C budgets may be valid when stump decomposition data is lacking. Decomposition rates between species differed, with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) decomposing more slowly (k = 0.013 yr-1) relative to western hemlock (Tsuga heterophylla (Rafi) Sarg. (k = 0.036 yr-1). This difference in k between species was observed for both above-ground stumps and logs as well as below-ground coarse roots. Given our mean k estimates and adjusting for regenerating stand age, these stands are losing C at a rate of 0.16-0.83 Mg C ha-1 yr-1 (assuming all CWD is P. menziesii) to 0.13-1.68 Mg C ha-1 yr-1 (assuming all CWD is T. heterophylla) from stumps, logs, and snags. Including coarse roots increases these losses to 0.28-1.25 Mg C ha-1 yr-1 and 0.30-2.53 Mg C ha-1 yr-1, respectively. Based on these findings, if fragmentation of these decomposing C pools is ignored, and fragmented fractions have oxidized to CO2, stands thought to be net C sinks could in reality be net C sources to the atmosphere. Net primary production in tree boles (NPPb) of regenerating stands (so called second-growth) ranged between 0.15-5.28 Mg C ha-1 yr-1. NPPb of 500-year old stands ranged between 1.3-3.9 Mg C ha-1 yr-1, similar to NPPb of boles in 20-25 year old secondgrowth. Mean radial increment widths from old-growth stands indicated that NPPb of these stands (neglecting mortality) can increase, decrease, or remain relatively constant. Based on 5-year increments for the previous fifteen years, the majority of old-growth stands sampled showed small increases in radial growth over time. Timing of the transition from negative to positive of NEPW ranged between 0 and 57 years after disturbance and depended strongly on live-tree growth rates as well as the fate of CWD and harvested wood. Estimated maximum and minimum NEPW were 3.9 Mg C ha-1 yr-1 and 14.1 Mg C ha-1 yr-1, respectively. Maximum mean C stores of 393 Mg C ha-1 were reached approximately 200 years after disturbance. At a rotation age of 80 years, regenerating stands stored approximately 50% as much C in woody biomass as a 500-year old primary forest, indicating conversion of older forests to plantations released C to the atmosphere. Given the high biomass of mature and old-growth stands relative to younger regenerating stands in the forest studied, landscape C stores in live wood would appear to be maximized in stands of older age classes. Close

• 34. [Article] Drought, dispersal, and community dynamics in arid-land streams

  Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional ...

  Citation × Citation Citation Abstract Copy Title: Drought, dispersal, and community dynamics in arid-land streams Author: Bogan, Michael T. Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional processes; these processes act as filters that reduce the regional species pool down to the observed local community. In stream ecosystems, the natural flow regime (including the timing, magnitude, and duration of high and low flow events) is widely recognized as a primary regulator of local diversity and community composition. This is especially true in aridland streams, where low- and zero-flow events can occur frequently and for extended periods of time (months to years). Additionally, wetted habitat patches in arid-land stream networks are often fragmented within and among stream networks. Thus dispersal between isolated aquatic patches may also play a large role in regulating local communities. In my dissertation, I explored the roles that drought, dispersal, and local habitat factors play in structuring arid-land stream communities. I examined the impact of flow permanence and seasonal variation in flow and other abiotic factors on aquatic communities at both fine spatial scales over a long time period (8 years; Chapter 2) and at a broad spatial scale over a shorter time period (1-2 years; Chapter 4). Additionally, I quantified aquatic invertebrate aerial dispersal over moderate spatial scales (≤ 0.5 km) by conducting a colonization experiment using artificial stream pools placed along and inland from two arid-land streams (Chapter 4). Finally, I examined the roles of spatial isolation, microhabitat type, and local abiotic and biotic factors in structuring aquatic communities in freshwater oases scattered across one of the most arid regions of North America, the southern Sonoran Desert (Chapter 5). In Chapter 2, I found that severe drought caused an unprecedented drying event in isolated perennial stream pools, and that several additional drying events occurred over the following four years. This transition to intermittent flow caused the extirpation of several large, long-lived species with low dispersal abilities (including the top predator) and drove the local community into an alternative state. In the colonization experiment described in Chapter 3, I found that several arid-land stream invertebrate taxa disperse widely and frequently. The widespread dispersers identified by this experiment included several of the earliest colonist taxa observed following the severe drought described in Chapter 2. Other taxa, though, only dispersed overland after receiving an environmental cue (rainfall) or preferentially dispersed along stream corridors. In Chapter 4, where I examined invertebrate community structure across a large network of well-connected intermittent and perennial reaches, I found low diversity in intermittent reaches, regardless of their connectivity to diverse upstream perennial reaches. These species-poor, intermittent communities were composed of a unique suite of species with lifehistory adaptations that conferred desiccation resistance, including extended egg and larval diapause stages. The short flow duration of intermittent reaches (<100 days) likely precluded upstream perennial taxa from establishing populations in downstream intermittent reaches before drying occurred, while the relative predictability of flow timing (Dec-Apr) likely allowed for a small number of species to develop appropriate life-history traits (e.g., diapause stage, rapid development time) to exploit these temporally-fleeting habitats. In Chapter 5, I found over 220 species of aquatic animals (including ≥ 5 undescribed species) in the 19 desert oases that were sampled across the southern Sonoran Desert. Local community composition in these oases was strongly driven by microhabitat type. Additionally, native aquatic species richness and abundance in these oases were significantly reduced by the introduction of tilapia, an exotic fish species. The threats to arid-land streams presented by increased drought severity, anthropogenic water withdrawals, and local habitat degradation (e.g., introduced species, unmanaged recreational use) are grave across the southwestern US and northwestern Mexico. I hope that in addition to furthering our understanding of ecological processes in arid-land streams, this dissertation makes a small contribution towards the efforts to preserve these habitats. Title: Drought, dispersal, and community dynamics in arid-land streams Author: Bogan, Michael T. Understanding the mechanisms that regulate local species diversity and community structure is a perennial goal of ecology. Local community structure can be viewed as the result of numerous local and regional processes; these processes act as filters that reduce the regional species pool down to the observed local community. In stream ecosystems, the natural flow regime (including the timing, magnitude, and duration of high and low flow events) is widely recognized as a primary regulator of local diversity and community composition. This is especially true in aridland streams, where low- and zero-flow events can occur frequently and for extended periods of time (months to years). Additionally, wetted habitat patches in arid-land stream networks are often fragmented within and among stream networks. Thus dispersal between isolated aquatic patches may also play a large role in regulating local communities. In my dissertation, I explored the roles that drought, dispersal, and local habitat factors play in structuring arid-land stream communities. I examined the impact of flow permanence and seasonal variation in flow and other abiotic factors on aquatic communities at both fine spatial scales over a long time period (8 years; Chapter 2) and at a broad spatial scale over a shorter time period (1-2 years; Chapter 4). Additionally, I quantified aquatic invertebrate aerial dispersal over moderate spatial scales (≤ 0.5 km) by conducting a colonization experiment using artificial stream pools placed along and inland from two arid-land streams (Chapter 4). Finally, I examined the roles of spatial isolation, microhabitat type, and local abiotic and biotic factors in structuring aquatic communities in freshwater oases scattered across one of the most arid regions of North America, the southern Sonoran Desert (Chapter 5). In Chapter 2, I found that severe drought caused an unprecedented drying event in isolated perennial stream pools, and that several additional drying events occurred over the following four years. This transition to intermittent flow caused the extirpation of several large, long-lived species with low dispersal abilities (including the top predator) and drove the local community into an alternative state. In the colonization experiment described in Chapter 3, I found that several arid-land stream invertebrate taxa disperse widely and frequently. The widespread dispersers identified by this experiment included several of the earliest colonist taxa observed following the severe drought described in Chapter 2. Other taxa, though, only dispersed overland after receiving an environmental cue (rainfall) or preferentially dispersed along stream corridors. In Chapter 4, where I examined invertebrate community structure across a large network of well-connected intermittent and perennial reaches, I found low diversity in intermittent reaches, regardless of their connectivity to diverse upstream perennial reaches. These species-poor, intermittent communities were composed of a unique suite of species with lifehistory adaptations that conferred desiccation resistance, including extended egg and larval diapause stages. The short flow duration of intermittent reaches (<100 days) likely precluded upstream perennial taxa from establishing populations in downstream intermittent reaches before drying occurred, while the relative predictability of flow timing (Dec-Apr) likely allowed for a small number of species to develop appropriate life-history traits (e.g., diapause stage, rapid development time) to exploit these temporally-fleeting habitats. In Chapter 5, I found over 220 species of aquatic animals (including ≥ 5 undescribed species) in the 19 desert oases that were sampled across the southern Sonoran Desert. Local community composition in these oases was strongly driven by microhabitat type. Additionally, native aquatic species richness and abundance in these oases were significantly reduced by the introduction of tilapia, an exotic fish species. The threats to arid-land streams presented by increased drought severity, anthropogenic water withdrawals, and local habitat degradation (e.g., introduced species, unmanaged recreational use) are grave across the southwestern US and northwestern Mexico. I hope that in addition to furthering our understanding of ecological processes in arid-land streams, this dissertation makes a small contribution towards the efforts to preserve these habitats. Close

• 35. [Article] Terrestrial amphibian distribution, habitat associations and downed wood temperature profiles in managed headwater forests with riparian buffers in the Oregon Coast Range

  Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how ...

  Citation × Citation Citation Abstract Copy Title: Terrestrial amphibian distribution, habitat associations and downed wood temperature profiles in managed headwater forests with riparian buffers in the Oregon Coast Range Author: Kluber, Matthew R. Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how headwater forest taxa and their habitats are impacted by forest management practices. Several amphibian species associated with forested headwater systems have emerged as management concerns. Forest management strategies, such as harvests that remove only part of the canopy and retention of riparian buffer strips, may help ameliorate some of the negative effects on amphibians in managed forests. Pre-existing site conditions, such as legacy downed wood, also may play a role in buffering the impacts of silvicultural practices on terrestrial amphibians. Downed wood is an important habitat component for many amphibians, because the cool, moist microclimates of downed wood can provide refugia for terrestrial amphibians during warmer summer months. However, downed wood habitat suitability is another emerging concern as the rate of input and size of downed wood declines in managed forests. As part of the USDI Bureau of Land Managements Density Management Study, we investigated how untreated streamside buffers modify impacts of upland thinning on headwater forest terrestrial amphibians and their habitat at three sites in the Oregon Coast Range. To further assess habitat associations of these animals, we conducted a field experiment to address amphibian cover use, including downed wood, moss and coarse and fine substrates. In addition, we examined how temperature profiles inside small- and large-diameter downed wood and soil temperatures differed from ambient air temperatures. Temperatures of wood and soil were monitored at different slope positions (near streams and upslope) and overstory regimes (thinned and unthinned stands) to assess potential habitat suitability and buffering capabilities against seasonal temperature extremes for plethodontid salamanders. Our results suggest that pre-existing site conditions (e.g., amount of rocky or fine substrate) play an important role in determining the response of terrestrial amphibians to upland forest thinning. However, retention of stream buffers is important in maintaining unaltered stream and riparian conditions. Moderate thinning and preservation of vital habitat in riparian and nearby upland areas by way of variable-width buffers (15 m minimum width) may be sufficient in maintaining suitable habitat and microclimatic conditions vital to amphibian assemblages in managed headwater forests. Additionally, logs of a wide size range and soils may provide sufficient protection against thermal extremes harmful to plethodontid salamanders in thinned stands with limited overstory. However, this alone cannot support plethodontid salamanders. These salamanders require exposed areas (e.g., leaf litter, soil surface, rock faces) where much of their foraging and well as courtship occurs. Partial retention of the canopy through moderate thinning coupled with variable-width riparain buffers that may increase in width when suitable terrestrial habitat is encountered, may provide sufficient microhabitat, microclimate, and protection in maintaining terrestrial amphibian assemblages in managed headwater forests. Title: Terrestrial amphibian distribution, habitat associations and downed wood temperature profiles in managed headwater forests with riparian buffers in the Oregon Coast Range Author: Kluber, Matthew R. Western forests have become increasingly fragmented landscapes dominated by young stands. Given that western Oregon forests largely consist of headwater systems, there is a need to better understand how headwater forest taxa and their habitats are impacted by forest management practices. Several amphibian species associated with forested headwater systems have emerged as management concerns. Forest management strategies, such as harvests that remove only part of the canopy and retention of riparian buffer strips, may help ameliorate some of the negative effects on amphibians in managed forests. Pre-existing site conditions, such as legacy downed wood, also may play a role in buffering the impacts of silvicultural practices on terrestrial amphibians. Downed wood is an important habitat component for many amphibians, because the cool, moist microclimates of downed wood can provide refugia for terrestrial amphibians during warmer summer months. However, downed wood habitat suitability is another emerging concern as the rate of input and size of downed wood declines in managed forests. As part of the USDI Bureau of Land Managements Density Management Study, we investigated how untreated streamside buffers modify impacts of upland thinning on headwater forest terrestrial amphibians and their habitat at three sites in the Oregon Coast Range. To further assess habitat associations of these animals, we conducted a field experiment to address amphibian cover use, including downed wood, moss and coarse and fine substrates. In addition, we examined how temperature profiles inside small- and large-diameter downed wood and soil temperatures differed from ambient air temperatures. Temperatures of wood and soil were monitored at different slope positions (near streams and upslope) and overstory regimes (thinned and unthinned stands) to assess potential habitat suitability and buffering capabilities against seasonal temperature extremes for plethodontid salamanders. Our results suggest that pre-existing site conditions (e.g., amount of rocky or fine substrate) play an important role in determining the response of terrestrial amphibians to upland forest thinning. However, retention of stream buffers is important in maintaining unaltered stream and riparian conditions. Moderate thinning and preservation of vital habitat in riparian and nearby upland areas by way of variable-width buffers (15 m minimum width) may be sufficient in maintaining suitable habitat and microclimatic conditions vital to amphibian assemblages in managed headwater forests. Additionally, logs of a wide size range and soils may provide sufficient protection against thermal extremes harmful to plethodontid salamanders in thinned stands with limited overstory. However, this alone cannot support plethodontid salamanders. These salamanders require exposed areas (e.g., leaf litter, soil surface, rock faces) where much of their foraging and well as courtship occurs. Partial retention of the canopy through moderate thinning coupled with variable-width riparain buffers that may increase in width when suitable terrestrial habitat is encountered, may provide sufficient microhabitat, microclimate, and protection in maintaining terrestrial amphibian assemblages in managed headwater forests. Close

• 36. [Article] Road Ecology Course and Seminar Series

  The American road network is a major economic investment that is a major organizing force for human activity. The road system has profoundly altered ecological processes and, as a result, it is also an ...

  Citation × Citation Citation Abstract Copy Title: Road Ecology Course and Seminar Series Author: Sytsma, Mark D. Year: 2008 The American road network is a major economic investment that is a major organizing force for human activity. The road system has profoundly altered ecological processes and, as a result, it is also an important organizing force for ecosystems. Understanding the ecological consequences of road system design and use is critical to effective engineering and management of road systems to minimize impacts. I propose a new course within Environmental Science and Resources at PSU that will expose upper division undergraduate and graduate students to the fundamental concepts of road ecology through discussion, guest speakers, and field trips. I propose a student-led discussion course focusing on the book Road Ecology, edited by Forman et al. This book provides an introduction to the basic concepts underlying road impacts on the environment. Students will be required to read the book; discussion of each chapter will be led by a student who will make a presentation on results of a search of the primary literature on the subject of each chapter. The classroom discussion will be supplemented with guest speakers that will bring real- world examples to the classroom. Potential topics for guest speakers include: impacts of highway runoff and roadside spraying on water quality, impacts of roads on erosional processes, impacts of culverts on anadromous fish passage, mitigation of habitat fragmentation and road impacts on animal movements, and role of maintenance activities in facilitating weed invasions. Invited speakers will also be requested to provide a departmental seminar to communicate road ecology principles to a wider audience of undergraduate and graduate students in Environmental Science and Resources. Field trips to observe road impacts and mitigation measures will add to students understanding of road ecology. We will schedule field trips to observe impacts as well as efforts to mitigate environmental effects of roads. Students performance will be evaluated by participation in class discussions and field trips, and a term paper. Undergraduates will be required to write a literature review on an aspect of road ecology of their choosing. Graduate students will be required to write a proposal to investigate some aspect of road ecology. Following completion of the course students will have a broad understanding of the environmental impacts of road systems on ecological processes and methods of mitigating impacts. Graduate students will have a research proposal that may be appropriate for submittal to OTREC for funding. Title: Road Ecology Course and Seminar Series Author: Sytsma, Mark D. Year: 2008 The American road network is a major economic investment that is a major organizing force for human activity. The road system has profoundly altered ecological processes and, as a result, it is also an important organizing force for ecosystems. Understanding the ecological consequences of road system design and use is critical to effective engineering and management of road systems to minimize impacts. I propose a new course within Environmental Science and Resources at PSU that will expose upper division undergraduate and graduate students to the fundamental concepts of road ecology through discussion, guest speakers, and field trips. I propose a student-led discussion course focusing on the book Road Ecology, edited by Forman et al. This book provides an introduction to the basic concepts underlying road impacts on the environment. Students will be required to read the book; discussion of each chapter will be led by a student who will make a presentation on results of a search of the primary literature on the subject of each chapter. The classroom discussion will be supplemented with guest speakers that will bring real- world examples to the classroom. Potential topics for guest speakers include: impacts of highway runoff and roadside spraying on water quality, impacts of roads on erosional processes, impacts of culverts on anadromous fish passage, mitigation of habitat fragmentation and road impacts on animal movements, and role of maintenance activities in facilitating weed invasions. Invited speakers will also be requested to provide a departmental seminar to communicate road ecology principles to a wider audience of undergraduate and graduate students in Environmental Science and Resources. Field trips to observe road impacts and mitigation measures will add to students understanding of road ecology. We will schedule field trips to observe impacts as well as efforts to mitigate environmental effects of roads. Students performance will be evaluated by participation in class discussions and field trips, and a term paper. Undergraduates will be required to write a literature review on an aspect of road ecology of their choosing. Graduate students will be required to write a proposal to investigate some aspect of road ecology. Following completion of the course students will have a broad understanding of the environmental impacts of road systems on ecological processes and methods of mitigating impacts. Graduate students will have a research proposal that may be appropriate for submittal to OTREC for funding. Close

• 37. [Article] Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management

  The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented ...

  Citation × Citation Citation Abstract Copy Title: Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management Author: Scheller, Robert M., Van Tuyl, Steve, Clark, Kenneth L., Hom, John, La Puma, Inga Year: 2011 The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented and subject to frequent disturbance and forest management. Over long time periods (>50 years), the balance between oak and pine dominance is determined by fire frequency. As a consequence, the ability of the NJPB to sequester carbon may be contingent upon management activities as well as patterns of historic land use. We simulated 100 years of carbon change using three scenarios: (1) contemporary management as reflected in the recent (1991–2006) fire records, (2) an increase in the fire ignitions within the wildland urban interface areas of the NJPB reflecting increased prescribed fires, and (3) a longer response time to wildfires, reflecting a more liberal burning policy by the New Jersey Forest Fire Service. We used the LANDIS-II model coupled with CENTURY and the Dynamic Fire and Dynamic Biomass Fuels extensions to estimate forest carbon sequestration based on these three scenarios. Calibration and validation via comparison to monthly flux tower data indicated that the model reasonably captured the timing and magnitude of net ecosystem exchange in the absence of Gypsy moth defoliation (r2 = 0.89). Under all scenarios, our simulations suggest that forests of the NJPB will continue to accumulate carbon over the next 100 years under current climatic conditions. Although above ground net primary productivity, live carbon, and detrital carbon were roughly constant or increased only modestly, soil organic carbon continued to increase through time for all forest types except the highly xeric pine plains. Our simulated changes in management reflected only minor alterations to the fire regime and thus management may have only minor effects on total forest carbon budgets in the immediate future particularly when compared to recovery from historic disturbance patterns. Title: Carbon Sequestration in the New Jersey Pine Barrens Under Different Scenarios of Fire Management Author: Scheller, Robert M., Van Tuyl, Steve, Clark, Kenneth L., Hom, John, La Puma, Inga Year: 2011 The New Jersey Pine Barrens (NJPB) is the largest forested area along the northeastern coast of the United States. The NJPB are dominated by pine (Pinus spp.) and oak (Quercus spp.) stands that are fragmented and subject to frequent disturbance and forest management. Over long time periods (>50 years), the balance between oak and pine dominance is determined by fire frequency. As a consequence, the ability of the NJPB to sequester carbon may be contingent upon management activities as well as patterns of historic land use. We simulated 100 years of carbon change using three scenarios: (1) contemporary management as reflected in the recent (1991–2006) fire records, (2) an increase in the fire ignitions within the wildland urban interface areas of the NJPB reflecting increased prescribed fires, and (3) a longer response time to wildfires, reflecting a more liberal burning policy by the New Jersey Forest Fire Service. We used the LANDIS-II model coupled with CENTURY and the Dynamic Fire and Dynamic Biomass Fuels extensions to estimate forest carbon sequestration based on these three scenarios. Calibration and validation via comparison to monthly flux tower data indicated that the model reasonably captured the timing and magnitude of net ecosystem exchange in the absence of Gypsy moth defoliation (r2 = 0.89). Under all scenarios, our simulations suggest that forests of the NJPB will continue to accumulate carbon over the next 100 years under current climatic conditions. Although above ground net primary productivity, live carbon, and detrital carbon were roughly constant or increased only modestly, soil organic carbon continued to increase through time for all forest types except the highly xeric pine plains. Our simulated changes in management reflected only minor alterations to the fire regime and thus management may have only minor effects on total forest carbon budgets in the immediate future particularly when compared to recovery from historic disturbance patterns. Close

• 38. [Article] Creating Useful and Usable Climate Tools for Sagebrush Land Management Through Scientist and Manager Collaboration

  The sagebrush ecosystem, home to numerous plant and animal species including big sagebrush (Artemisia tridentata) and the endemic greater sage-grouse (Centrocercus urophasianus), has endured fragmentation ...

  Citation × Citation Citation Abstract Copy Title: Creating Useful and Usable Climate Tools for Sagebrush Land Management Through Scientist and Manager Collaboration Author: Brown, Melanie The sagebrush ecosystem, home to numerous plant and animal species including big sagebrush (Artemisia tridentata) and the endemic greater sage-grouse (Centrocercus urophasianus), has endured fragmentation and degradation of both quantity and quality due to the cumulative and synergistic relationships between an abundance of individual disturbances including grazing, invasive annuals and fire. Climate change may now be an additional threat that poses the greatest risk to these imperiled habitats. Natural resource agencies such as the Bureau of Land Management (BLM) seek to conserve sagelands through land management activities that ensure the survival of sage-grouse and continuity of the sagebrush biome. Web-based climate tools can help convey climate information that may be necessary for long-term land management, but these tools may not agree with the needs of land managers, may be too complex, or may be misinterpreted. To overcome barriers of user compatibility, the participation of both climate scientists and land managers is necessary during tool development. With the collaboration of Oregon and Idaho BLM sagebrush land managers and climate scientists, this study sought to assess land manager needs and define the criteria for useful and useable climate tools. Using an initial online survey, individual phone interviews with land managers, and a follow-up online survey, a series of land management activities and related climate variables were identified, and several web-based climate tools were assessed. Most managers perform vegetation management through a variety of means including seeding and herbicide application. Such activities are affected by the magnitude and timing of precipitation and temperature, as well as other variables, on seasonal and annual timeframes. For planning purposes land managers also need information on long-term 10-20 year climate trends. The act of listening to the needs of land managers uncovered communication barriers, and provided feedback on existing climate tools emphasizing accessibility, dependability and consistency, clear explanation of terminology, effective visualizations, and relevant spatial and temporal scales to the scope of management activities. We also identified a need for basic information and education on the location of existing climate tools and climate impacts, and a need for near-term forecasting tools that could bridge the gap between weather (≤ 6 months) and climate (≥ 30 years) projections. Title: Creating Useful and Usable Climate Tools for Sagebrush Land Management Through Scientist and Manager Collaboration Author: Brown, Melanie The sagebrush ecosystem, home to numerous plant and animal species including big sagebrush (Artemisia tridentata) and the endemic greater sage-grouse (Centrocercus urophasianus), has endured fragmentation and degradation of both quantity and quality due to the cumulative and synergistic relationships between an abundance of individual disturbances including grazing, invasive annuals and fire. Climate change may now be an additional threat that poses the greatest risk to these imperiled habitats. Natural resource agencies such as the Bureau of Land Management (BLM) seek to conserve sagelands through land management activities that ensure the survival of sage-grouse and continuity of the sagebrush biome. Web-based climate tools can help convey climate information that may be necessary for long-term land management, but these tools may not agree with the needs of land managers, may be too complex, or may be misinterpreted. To overcome barriers of user compatibility, the participation of both climate scientists and land managers is necessary during tool development. With the collaboration of Oregon and Idaho BLM sagebrush land managers and climate scientists, this study sought to assess land manager needs and define the criteria for useful and useable climate tools. Using an initial online survey, individual phone interviews with land managers, and a follow-up online survey, a series of land management activities and related climate variables were identified, and several web-based climate tools were assessed. Most managers perform vegetation management through a variety of means including seeding and herbicide application. Such activities are affected by the magnitude and timing of precipitation and temperature, as well as other variables, on seasonal and annual timeframes. For planning purposes land managers also need information on long-term 10-20 year climate trends. The act of listening to the needs of land managers uncovered communication barriers, and provided feedback on existing climate tools emphasizing accessibility, dependability and consistency, clear explanation of terminology, effective visualizations, and relevant spatial and temporal scales to the scope of management activities. We also identified a need for basic information and education on the location of existing climate tools and climate impacts, and a need for near-term forecasting tools that could bridge the gap between weather (≤ 6 months) and climate (≥ 30 years) projections. Close

• 39. [Article] Regional changes in landscape pattern and carbon stores in the interior of British Columbia as determined by satellite imagery

  The detection and mapping of large scale changes to forested landscapes is increasingly important in ecology and management. I used Landsat TM and MSS imagery to map forest cover in 1992 for a 4.2 million ...

  Citation × Citation Citation Abstract Copy Title: Regional changes in landscape pattern and carbon stores in the interior of British Columbia as determined by satellite imagery Author: Sachs, Donald The detection and mapping of large scale changes to forested landscapes is increasingly important in ecology and management. I used Landsat TM and MSS imagery to map forest cover in 1992 for a 4.2 million ha area of the interior of British Columbia with an overall classification accuracy of 79%. A combination of unsupervised and supervised classification allowed mapping of forested pixels into closed conifer, semi-open conifer, deciduous, and mixed deciduous and coniferous forest classes. The closed conifer class was further subdivided into old (> 140 years), mature (60 - 140 years), and young (< 60 years) age classes. Unsupervised classification of a combined image containing the Tasseled Cap indices from 1975 and 1992 imagery allowed accurate mapping of disturbances during the period. I examined changes in landscape pattern from 1975 - 1992 by calculating indices that describe overall landscape pattern and that of each cover class. The B.C. biogeoclimatic ecosystem classification map was used as an overlay to calculate landscape pattern and changes by biogeoclimatic zone. Analysis showed that 11.4% of the forested area outside provincial parks was disturbed during the 17 - year period. Disturbed areas were consistently much smaller than conifer patches in all biogeoclimatic zones and had a lower percentage of interior area. Conifer patch shape complexity varied between zones, but the size and shape of disturbed areas were similar in all zones. Results indicated the early stages of fragmentation of this landscape. Models of stand level carbon storage and carbon stores in forest products were used in conjunction with British Columbia Ministry of Forests inventory data to calculate a carbon budget for the Engelmann spruce - subalpine fir forests of the study area. Based on inventory data, the net flux of carbon from these forests to the atmosphere averaged 0.14 Mg ha⁻¹year⁻¹ between 1975 and 1992. Assuming no harvesting during this period, these forests would have been a net carbon sink averaging 0.39 Mg ha⁻¹year⁻¹. Calculating the carbon budget using satellite data showed a slight net carbon sink of 0.15 Mg ha⁻¹year⁻¹ for 1975 - 1992. The major difference between satellite- and inventory-based carbon budgets was due to differences in the simulation of the detrital carbon pool and timing of harvests. The satellite-based estimate failed to account for recovering areas harvested before 1975, and assumed a constant harvest rate. Title: Regional changes in landscape pattern and carbon stores in the interior of British Columbia as determined by satellite imagery Author: Sachs, Donald The detection and mapping of large scale changes to forested landscapes is increasingly important in ecology and management. I used Landsat TM and MSS imagery to map forest cover in 1992 for a 4.2 million ha area of the interior of British Columbia with an overall classification accuracy of 79%. A combination of unsupervised and supervised classification allowed mapping of forested pixels into closed conifer, semi-open conifer, deciduous, and mixed deciduous and coniferous forest classes. The closed conifer class was further subdivided into old (> 140 years), mature (60 - 140 years), and young (< 60 years) age classes. Unsupervised classification of a combined image containing the Tasseled Cap indices from 1975 and 1992 imagery allowed accurate mapping of disturbances during the period. I examined changes in landscape pattern from 1975 - 1992 by calculating indices that describe overall landscape pattern and that of each cover class. The B.C. biogeoclimatic ecosystem classification map was used as an overlay to calculate landscape pattern and changes by biogeoclimatic zone. Analysis showed that 11.4% of the forested area outside provincial parks was disturbed during the 17 - year period. Disturbed areas were consistently much smaller than conifer patches in all biogeoclimatic zones and had a lower percentage of interior area. Conifer patch shape complexity varied between zones, but the size and shape of disturbed areas were similar in all zones. Results indicated the early stages of fragmentation of this landscape. Models of stand level carbon storage and carbon stores in forest products were used in conjunction with British Columbia Ministry of Forests inventory data to calculate a carbon budget for the Engelmann spruce - subalpine fir forests of the study area. Based on inventory data, the net flux of carbon from these forests to the atmosphere averaged 0.14 Mg ha⁻¹year⁻¹ between 1975 and 1992. Assuming no harvesting during this period, these forests would have been a net carbon sink averaging 0.39 Mg ha⁻¹year⁻¹. Calculating the carbon budget using satellite data showed a slight net carbon sink of 0.15 Mg ha⁻¹year⁻¹ for 1975 - 1992. The major difference between satellite- and inventory-based carbon budgets was due to differences in the simulation of the detrital carbon pool and timing of harvests. The satellite-based estimate failed to account for recovering areas harvested before 1975, and assumed a constant harvest rate. Close

• 40. [Article] Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon

  Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western ...

  Citation × Citation Citation Abstract Copy Title: Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon Author: Jennings, Tara Nicolle Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western United States have increased in frequency, prompting the need to evaluate the effect of post-fire treatments on forest ecosystem recovery. This study examined whether compaction and subsoiling after post-fire salvage logging impacted the structure, metabolism, and function of soil bacterial communities, which were assessed using terminal restriction fragment length polymorphism (T-RFLP) and Biolog Ecoplates. Supporting data for these salvage logging effects included soil biological activities, soil chemistry, and physical soil properties in a mixed conifer forest in central Oregon. Post-fire salvage logging treatments had little effect on soil bacterial community richness, suggesting that soil bacteria in these post-fire landscapes are both tolerant of the occurrence of fires and resilient to disturbance. However, even though a statistically significant difference in bacterial species richness was not detected among treatments, a greater cumulative mean number of species was found across six sampling seasons in the compacted soil treatment compared to the fire-only and subsoiled treatments. This trend may be due to less predation on the soil bacteria by microbivores in the soil pores reduced in size by compaction. Additionally, there was a significant decline in the mean number of species after the spring 2007 sampling. A NMS ordination of the mean number of species suggested that the bacterial community composition changed after spring 2007. Furthermore, the lack of difference in mean number of species among treatments suggests that time since fire had a stronger effect on the structure of the soil bacterial community than did logging disturbance. Plant-available phosphorus and nitrogen concentrations were lower in the mechanically disturbed treatments than in the fire-only treatment. Soil respiration and soil phosphatase rates both were higher in the fire-only treatment. Mechanical disturbance may have long-lasting effects in an already nutrient limited system. No other differences among treatments for soil chemical properties were detected. Soil bulk density was lowest in the subsoiled treatment. Microbial community responses to burning and compaction caused by harvesting can be negative, neutral, or positive. While many factors, in addition to soil chemical and physical properties, affect the microbial community richness and functional diversity, our results support other recent studies showing that soil bacteria are resilient in disturbed environments. Title: Impacts of post-fire salvage logging on soil chemistry, physical properties and bacterial community composition in a mixed-conifer forest in central Oregon Author: Jennings, Tara Nicolle Land managers, scientists, and the interested public are confronted with uncertainty about the impacts of salvage logging on soil productivity. In recent years, stand-replacing wildfires in the western United States have increased in frequency, prompting the need to evaluate the effect of post-fire treatments on forest ecosystem recovery. This study examined whether compaction and subsoiling after post-fire salvage logging impacted the structure, metabolism, and function of soil bacterial communities, which were assessed using terminal restriction fragment length polymorphism (T-RFLP) and Biolog Ecoplates. Supporting data for these salvage logging effects included soil biological activities, soil chemistry, and physical soil properties in a mixed conifer forest in central Oregon. Post-fire salvage logging treatments had little effect on soil bacterial community richness, suggesting that soil bacteria in these post-fire landscapes are both tolerant of the occurrence of fires and resilient to disturbance. However, even though a statistically significant difference in bacterial species richness was not detected among treatments, a greater cumulative mean number of species was found across six sampling seasons in the compacted soil treatment compared to the fire-only and subsoiled treatments. This trend may be due to less predation on the soil bacteria by microbivores in the soil pores reduced in size by compaction. Additionally, there was a significant decline in the mean number of species after the spring 2007 sampling. A NMS ordination of the mean number of species suggested that the bacterial community composition changed after spring 2007. Furthermore, the lack of difference in mean number of species among treatments suggests that time since fire had a stronger effect on the structure of the soil bacterial community than did logging disturbance. Plant-available phosphorus and nitrogen concentrations were lower in the mechanically disturbed treatments than in the fire-only treatment. Soil respiration and soil phosphatase rates both were higher in the fire-only treatment. Mechanical disturbance may have long-lasting effects in an already nutrient limited system. No other differences among treatments for soil chemical properties were detected. Soil bulk density was lowest in the subsoiled treatment. Microbial community responses to burning and compaction caused by harvesting can be negative, neutral, or positive. While many factors, in addition to soil chemical and physical properties, affect the microbial community richness and functional diversity, our results support other recent studies showing that soil bacteria are resilient in disturbed environments. Close