title: Ecological and environmental transition across the forested-to-open bog ecotone in a west Siberian peatland

authors: Ratcliffe, Joshua Lee

subjects: Science & Technology

abstract: Climate change may cause increasing tree cover in boreal peatlands, and the impacts of this encroachment will be noted first at forested-to-open bog ecotones. We investigate key metrics of ecosystem function in five such ecotones at a peatland complex in Western Siberia. Stratigraphic analysis of three cores from one of these transects shows that the ecotone has been dynamic over time with evidence for recent expansion of forested peatland. We observed that the two alternative states for northern boreal peatlands (forested/open) clearly support distinct plant and microbial communities. These in turn drive and respond to a number of feedback mechanisms. This has led to steep ecological gradients across the ecotones. Tree cover was associated with lower water tables and pH, along with higher bulk density, aquatic carbon concentrations, and electrical conductivity. We propose that the conditions found in the forested peatland of Western Siberia make the carbon sink more vulnerable to warmer and drier conditions.

text: Ecological and environmental transition across the forested-to-open bog ecotone in a west Siberian peatland Climate change may cause increasing tree cover in boreal peatlands, and the impacts of this encroachment will be noted first at forested-to-open bog ecotones. We investigate key metrics of ecosystem function in five such ecotones at a peatland complex in Western Siberia. Stratigraphic analysis of three cores from one of these transects shows that the ecotone has been dynamic over time with evidence for recent expansion of forested peatland. We observed that the two alternative states for northern boreal peatlands (forested/open) clearly support distinct plant and microbial communities. These in turn drive and respond to a number of feedback mechanisms. This has led to steep ecological gradients across the ecotones. Tree cover was associated with lower water tables and pH, along with higher bulk density, aquatic carbon concentrations, and electrical conductivity. We propose that the conditions found in the forested peatland of Western Siberia make the carbon sink more vulnerable to warmer and drier conditions.

year: 2017

title: A comparison of demand for two different feeds with horses (Equus callabus)

authors: Armistead, Mary Jennie

subjects: operant

abstract: There are few studies with horses that examine either their food preferences or the use of increasing work requirements to assess their demand for food. The first experiment used Multiple-Stimulus-Without-Replacement procedure to measure six horses' preferences for four different feeds. From these, a high- (Yearling mix) and a low- (Rice) preference feed were selected. The horses were then exposed to two series of increasing fixed ratio (FR) schedules with each of two feeds, in fixed-length sessions. The overall response rates were bitonic, running response rates decreased and average post-reinforcement pauses increased with increases in fixed-ratio value, typical of previous research. Yearling mix maintained faster responding to higher fixed-ratio values for most horses than did Rice. The demand functions (i.e., the numbers of reinforcers obtained in a session as functions of the ratio size on double logarithmic coordinates) showed mixed elasticity for both Yearling mix and Rice (where there were enough data that a function could be sensibly fitted). There were lower levels of demand (i.e., number of reinforcers obtained) for Rice than Yearling mix at small fixed ratio values, the reverse of the findings reported previously for reinforcer size and preference value. It is suggested that this difference could have been the result of the open economic conditions of this study. However, the equation suggested by Hursh and Silberberg (2008) provided a good description of the data in this study, with Rice having a lower essential value that Yearling mix.

text: A comparison of demand for two different feeds with horses (Equus callabus) There are few studies with horses that examine either their food preferences or the use of increasing work requirements to assess their demand for food. The first experiment used Multiple-Stimulus-Without-Replacement procedure to measure six horses' preferences for four different feeds. From these, a high- (Yearling mix) and a low- (Rice) preference feed were selected. The horses were then exposed to two series of increasing fixed ratio (FR) schedules with each of two feeds, in fixed-length sessions. The overall response rates were bitonic, running response rates decreased and average post-reinforcement pauses increased with increases in fixed-ratio value, typical of previous research. Yearling mix maintained faster responding to higher fixed-ratio values for most horses than did Rice. The demand functions (i.e., the numbers of reinforcers obtained in a session as functions of the ratio size on double logarithmic coordinates) showed mixed elasticity for both Yearling mix and Rice (where there were enough data that a function could be sensibly fitted). There were lower levels of demand (i.e., number of reinforcers obtained) for Rice than Yearling mix at small fixed ratio values, the reverse of the findings reported previously for reinforcer size and preference value. It is suggested that this difference could have been the result of the open economic conditions of this study. However, the equation suggested by Hursh and Silberberg (2008) provided a good description of the data in this study, with Rice having a lower essential value that Yearling mix.

year: 2009

title: Toi tu te whenua, toi tu te tangata: A holistic Māori approach to flood management in Pawarenga

authors: Proctor, Elizabeth-Mary

subjects: flood management

abstract: This thesis is a study of how tikanga Māori principles could be used in practice in the management of natural hazards and in particular flooding in a rural area, Pawarenga. The aim was to investigate and document Te Uri O Tai Hapū preferred strategies for reducing flood risk in Pawarenga and to consider opportunities to use tikanga Māori principles and values in emergency response. The identification of key concepts and principles of tikanga Māori customs and their connections to whānau and hapū of Te Uri O Tai is key to this study. I used kaupapa Māori research methodologies as a guiding framework since researching in my own community required me to manage accountability both to its members and to the university. In particular it was important to obtain permission from the community before beginning, to ensure my research processes were acceptable, and to return my findings to the community. Qualitative data was gathered from a series of hui and interviews with local community members. Data was analysed inductively and organised into thematic networks. Two major organising themes were identified: resilience and vulnerability. Participants described a broad range of strengths inherent in the community that enabled them to respond to crises such as flood events. A number of cultural, social, physical, economic and political vulnerabilities were also identified; most of these were fundamental aspects of people‘s daily lives and did not prevent them from responding positively when floods occurred, but may have limited the scope of their responses. Tikanga was not a subject that participants felt comfortable talking about, but from the descriptions of how people actually responded during floods I was able to see examples of how tikanga was used. The resilience of the Pawarenga community is taken for granted by residents. When disasters such as floods occur, their resiliencies and strengths are brought into play to ensure the safety of all in the community. Tikanga Māori is an inherent part of this resiliency, and marae structures and protocols already in place provide a vital framework for flood response. I conclude that tikanga already has enormous value in flood response, and for Māori communities is an obvious choice as a foundation for a flood emergency management strategy. Furthermore, the value of tikanga as a flood emergency management strategy should be more explicitly recognised and supported by all authorities involved in disaster response and management. It was also clear that multiple dimensions of vulnerability (physical, cultural, social, economic and political) affect the Pawarenga community, and to some extent limit their capacity to respond. In particular political processes that exclude them from participating in decision-making and planning around environmental management generally have left people feeling marginalised, since they are unable to fulfil their kaitiaki role. With civil defence emergency management policies explicitly focused around resilience, participation of Te Uri O Tai Hapū in planning for emergency management should allow for their existing resilience, which stems from the upholding of tikanga, to be recognised and strengthened. However, this will only happen if relationships with the various authorities involved in emergency and natural hazard response are fostered, full participation in decision-making and in responding to natural hazard events is facilitated, and resources are available to support the community with their endeavours.

text: Toi tu te whenua, toi tu te tangata: A holistic Māori approach to flood management in Pawarenga This thesis is a study of how tikanga Māori principles could be used in practice in the management of natural hazards and in particular flooding in a rural area, Pawarenga. The aim was to investigate and document Te Uri O Tai Hapū preferred strategies for reducing flood risk in Pawarenga and to consider opportunities to use tikanga Māori principles and values in emergency response. The identification of key concepts and principles of tikanga Māori customs and their connections to whānau and hapū of Te Uri O Tai is key to this study. I used kaupapa Māori research methodologies as a guiding framework since researching in my own community required me to manage accountability both to its members and to the university. In particular it was important to obtain permission from the community before beginning, to ensure my research processes were acceptable, and to return my findings to the community. Qualitative data was gathered from a series of hui and interviews with local community members. Data was analysed inductively and organised into thematic networks. Two major organising themes were identified: resilience and vulnerability. Participants described a broad range of strengths inherent in the community that enabled them to respond to crises such as flood events. A number of cultural, social, physical, economic and political vulnerabilities were also identified; most of these were fundamental aspects of people‘s daily lives and did not prevent them from responding positively when floods occurred, but may have limited the scope of their responses. Tikanga was not a subject that participants felt comfortable talking about, but from the descriptions of how people actually responded during floods I was able to see examples of how tikanga was used. The resilience of the Pawarenga community is taken for granted by residents. When disasters such as floods occur, their resiliencies and strengths are brought into play to ensure the safety of all in the community. Tikanga Māori is an inherent part of this resiliency, and marae structures and protocols already in place provide a vital framework for flood response. I conclude that tikanga already has enormous value in flood response, and for Māori communities is an obvious choice as a foundation for a flood emergency management strategy. Furthermore, the value of tikanga as a flood emergency management strategy should be more explicitly recognised and supported by all authorities involved in disaster response and management. It was also clear that multiple dimensions of vulnerability (physical, cultural, social, economic and political) affect the Pawarenga community, and to some extent limit their capacity to respond. In particular political processes that exclude them from participating in decision-making and planning around environmental management generally have left people feeling marginalised, since they are unable to fulfil their kaitiaki role. With civil defence emergency management policies explicitly focused around resilience, participation of Te Uri O Tai Hapū in planning for emergency management should allow for their existing resilience, which stems from the upholding of tikanga, to be recognised and strengthened. However, this will only happen if relationships with the various authorities involved in emergency and natural hazard response are fostered, full participation in decision-making and in responding to natural hazard events is facilitated, and resources are available to support the community with their endeavours.

year: 2010