title: Vegetation recovery and management of kahikatea (Dacrycarpus dacrydioides)-dominated forest remnants in the Waikato Region

authors: Wilcox, Fiona Joyce

subjects: New Zealand

abstract: The principle aim of this study was to determine whether fencing alone is a sufficient management tool for facilitating the recovery and persistence of indigenous flora in kahikatea-dominated forest patches in the Waikato region. The floral composition of twenty-six kahikatea-dominated forest patches of varied fencing time, management regime and proximity to an urban area (Hamilton City) were sampled using a modified RECCE method in 10x10m quadrats between October 2007 and February 2008. Where woody weed species were present within a forest patch, their diameter at breast height (d.b.h) and reproductive status was noted (presence/absence of flowers and/or fruit). The results of the study demonstrate that, while fencing of a patch and time for native vegetation recovery are important factors in promoting native floral species recovery and ecosystem composition, the combination of patch size, distance of a patch from a main road, and patch location were better predictors of the observed variation in native species cover than fencing time alone; particularly in the layers most affected by grazing. This study indicates that patches less than seven hectares in area, regardless of location, will require continued human intervention to ensure their persistence; and patches in urban areas, irrespective of size, may never become self-sustaining. Furthermore, the results indicate that medium to low levels of management are the most effective in promoting native flora species recovery and reducing exotic species impacts. Fifteen to twenty years of fencing represents an important stage in the trajectory of a forest fragment where exotic species cover drops below 5%, and native species recruitment is steadily rising. However, the trajectory of floristic change will be different for each patch depending on the length of time since fragmentation, the length of time it has been grazed, how far it is from native seed sources and its surrounding landscape use.

text: Vegetation recovery and management of kahikatea (Dacrycarpus dacrydioides)-dominated forest remnants in the Waikato Region The principle aim of this study was to determine whether fencing alone is a sufficient management tool for facilitating the recovery and persistence of indigenous flora in kahikatea-dominated forest patches in the Waikato region. The floral composition of twenty-six kahikatea-dominated forest patches of varied fencing time, management regime and proximity to an urban area (Hamilton City) were sampled using a modified RECCE method in 10x10m quadrats between October 2007 and February 2008. Where woody weed species were present within a forest patch, their diameter at breast height (d.b.h) and reproductive status was noted (presence/absence of flowers and/or fruit). The results of the study demonstrate that, while fencing of a patch and time for native vegetation recovery are important factors in promoting native floral species recovery and ecosystem composition, the combination of patch size, distance of a patch from a main road, and patch location were better predictors of the observed variation in native species cover than fencing time alone; particularly in the layers most affected by grazing. This study indicates that patches less than seven hectares in area, regardless of location, will require continued human intervention to ensure their persistence; and patches in urban areas, irrespective of size, may never become self-sustaining. Furthermore, the results indicate that medium to low levels of management are the most effective in promoting native flora species recovery and reducing exotic species impacts. Fifteen to twenty years of fencing represents an important stage in the trajectory of a forest fragment where exotic species cover drops below 5%, and native species recruitment is steadily rising. However, the trajectory of floristic change will be different for each patch depending on the length of time since fragmentation, the length of time it has been grazed, how far it is from native seed sources and its surrounding landscape use.

year: 2010

title: Food preferences and demand in the brushtail possum (Trichosurus vulpecula)

authors: Cameron, Kristie Elizabeth

subjects: possum

abstract: The common brushtail possum (Trichosurus vulpecula) has been reported to eat vegetation, fruit, invertebrates, and occasionally fungi, eggs and meat in the wild. The relative preference between food types found in the wild, however, has not been investigated in a controlled laboratory study. In this series of experiments, single and paired preference assessments and demand procedures were conducted systematically under laboratory conditions to investigate the preference and demand for food types reportedly consumed by possums.
In Experiment 1, 20 possums were used in a single stimulus assessment where the consumption of individually presented food items was measured. The foods presented were berries, raw chicken, egg, fivefinger leaves, locusts and mushrooms. More than 75% of possums consumed berries, locusts and mushrooms but fewer than 50% of possums consumed fivefinger, raw chicken and eggs. In Experiment 2, 12 possums were used in a paired stimulus assessment to establish relative preference for the same foods. The results showed that no single food was preferred by all possums. Overall locusts were the most preferred food, followed in order of preference by berries, egg, mushrooms, chicken and foliage. The single stimulus preference assessment confirmed the palatability of foods. The paired stimulus assessment provided a rank order of food preferences.
In Experiments 3 and 4, the demand for these foods were measured under concurrent progressive-ratio (PR) and fixed-ratio (FR) schedules of reinforcement. In Experiment 3, the same six food types were used and every possible food pair (30 pairs in total) was presented to six possums in concurrent PR and FR 30 schedules. Exponential models of demand were applied to consumption rates and Pmax, break point and cross point values were generated. The rank orders for each parameter were compared. Overall, more responding was allocated to the PR schedule when a preferred food was available compared to the constant FR schedule. Cross points were larger for chicken, egg and locust, however, stable responding under the constant fixed-ratio schedule was not observed.
The aim of Experiment 4 was to investigate possible reasons for the lack of stable responding. The experimental procedure of Experiment 3 was replicated with four food pairs and the constant FR schedule was alternated between 30 and 10 responses across sessions. Responding under the constant FR schedule was similar to that in Experiment 3 but the demand for foods under the PR schedule was similar.
In Experiment 5, the same methodology in Experiments 3 and 4 was used except that each ratio requirement of the PR schedule was increased every five days, termed a PFR schedule. The same food pairs were used (berries and egg, and chicken and mushrooms). The same descriptions of demand were found in Experiment 5 as in Experiment 4, with higher demand for egg and chicken compared to berries and mushroom. A comparison of the linear (Hursh, Raslear, Shurtleff, Bauman, & Simmons, 1988) and exponential demand (Hursh & Silberberg, 2008) models showed that the exponential model provided better fits to the data. In addition, the cross price model (Hursh, Madden, Spiga, DeLeon, & Francisco, 2013) plotted with the exponential model of demand accounted for better cross points than the linear model.
In Experiment 6, the aim was to confirm the similarity in performance under concurrent schedules where the incrementing schedules increased within or across sessions. Twelve possums were exposed to schedules that increased within a session using the same procedure as Experiments 3 and 4; and schedules that increased across sessions in a semi-replication of Experiment 5 where each ratio requirement was in place for one day. The progression of the incrementing schedule was also varied between a geometric sequence (basis 2), and an arithmetic sequence (step 5) to ascertain if progression type affected the demand for foods. The food pairs of berries and egg, and two new foods of a barley and coco-pop® mix and rolled oats were tested. The same response rate patterns were observed under the geometric and arithmetic progressions. The parameters of the exponential and cross price demand models predicted estimates that differed in their description of demand across PR and PFR schedules, progression and food type. The break points and cross points were larger under PFR FR schedules and geometric progressions.
In conclusion, the preference assessments (Experiments 1 and 2) identified that locust was the most preferred food across possums but individual food choices were idiosyncratic. The demand procedures (Experiments 3 – 6) identified that possums are opportunistic in their food choice as they will respond for all foods at low ratio requirements and will respond at higher ratio requirements for more preferred foods even when another food is available for a lower cost. This series of experiments also highlighted that systematic studies are required to investigate what possums will eat and what they prefer to eat.

text: Food preferences and demand in the brushtail possum (Trichosurus vulpecula) The common brushtail possum (Trichosurus vulpecula) has been reported to eat vegetation, fruit, invertebrates, and occasionally fungi, eggs and meat in the wild. The relative preference between food types found in the wild, however, has not been investigated in a controlled laboratory study. In this series of experiments, single and paired preference assessments and demand procedures were conducted systematically under laboratory conditions to investigate the preference and demand for food types reportedly consumed by possums.
In Experiment 1, 20 possums were used in a single stimulus assessment where the consumption of individually presented food items was measured. The foods presented were berries, raw chicken, egg, fivefinger leaves, locusts and mushrooms. More than 75% of possums consumed berries, locusts and mushrooms but fewer than 50% of possums consumed fivefinger, raw chicken and eggs. In Experiment 2, 12 possums were used in a paired stimulus assessment to establish relative preference for the same foods. The results showed that no single food was preferred by all possums. Overall locusts were the most preferred food, followed in order of preference by berries, egg, mushrooms, chicken and foliage. The single stimulus preference assessment confirmed the palatability of foods. The paired stimulus assessment provided a rank order of food preferences.
In Experiments 3 and 4, the demand for these foods were measured under concurrent progressive-ratio (PR) and fixed-ratio (FR) schedules of reinforcement. In Experiment 3, the same six food types were used and every possible food pair (30 pairs in total) was presented to six possums in concurrent PR and FR 30 schedules. Exponential models of demand were applied to consumption rates and Pmax, break point and cross point values were generated. The rank orders for each parameter were compared. Overall, more responding was allocated to the PR schedule when a preferred food was available compared to the constant FR schedule. Cross points were larger for chicken, egg and locust, however, stable responding under the constant fixed-ratio schedule was not observed.
The aim of Experiment 4 was to investigate possible reasons for the lack of stable responding. The experimental procedure of Experiment 3 was replicated with four food pairs and the constant FR schedule was alternated between 30 and 10 responses across sessions. Responding under the constant FR schedule was similar to that in Experiment 3 but the demand for foods under the PR schedule was similar.
In Experiment 5, the same methodology in Experiments 3 and 4 was used except that each ratio requirement of the PR schedule was increased every five days, termed a PFR schedule. The same food pairs were used (berries and egg, and chicken and mushrooms). The same descriptions of demand were found in Experiment 5 as in Experiment 4, with higher demand for egg and chicken compared to berries and mushroom. A comparison of the linear (Hursh, Raslear, Shurtleff, Bauman, & Simmons, 1988) and exponential demand (Hursh & Silberberg, 2008) models showed that the exponential model provided better fits to the data. In addition, the cross price model (Hursh, Madden, Spiga, DeLeon, & Francisco, 2013) plotted with the exponential model of demand accounted for better cross points than the linear model.
In Experiment 6, the aim was to confirm the similarity in performance under concurrent schedules where the incrementing schedules increased within or across sessions. Twelve possums were exposed to schedules that increased within a session using the same procedure as Experiments 3 and 4; and schedules that increased across sessions in a semi-replication of Experiment 5 where each ratio requirement was in place for one day. The progression of the incrementing schedule was also varied between a geometric sequence (basis 2), and an arithmetic sequence (step 5) to ascertain if progression type affected the demand for foods. The food pairs of berries and egg, and two new foods of a barley and coco-pop® mix and rolled oats were tested. The same response rate patterns were observed under the geometric and arithmetic progressions. The parameters of the exponential and cross price demand models predicted estimates that differed in their description of demand across PR and PFR schedules, progression and food type. The break points and cross points were larger under PFR FR schedules and geometric progressions.
In conclusion, the preference assessments (Experiments 1 and 2) identified that locust was the most preferred food across possums but individual food choices were idiosyncratic. The demand procedures (Experiments 3 – 6) identified that possums are opportunistic in their food choice as they will respond for all foods at low ratio requirements and will respond at higher ratio requirements for more preferred foods even when another food is available for a lower cost. This series of experiments also highlighted that systematic studies are required to investigate what possums will eat and what they prefer to eat.

year: 2014

title: lnteragency collaboration in youth justice: Creating change through action research

authors: Atkinson, Melanie

abstract: This thesis describes a community psychology intervention in the Hamilton youth justice sector from September 2001 through to August 2004. I initiated the project with a Maori social service provider, Maatua Whangai, to address poor communication, gaps in service provision, and a lack of coordination and leadership in the sector. Drawing on an action research methodology the purpose of the project was to create better outcomes for youth offenders and their families by using an interagency approach to increase collaboration, coordination and the effectiveness of service delivery.
 My role became one of project manager and researcher. Representatives from the key agencies in the wider youth justice sector became participants and together we embarked on a journey of transformation. The group we formed, initially known as the 'Hamilton Youth Justice Collaboration', became the Hamilton Youth Offending Team (YOT), following the establishment of YOTs nationally by the Ministry of Justice in 2002. 
This thesis details the development of the Hamilton YOT, focusing on its purposes, methods, process, relationships and outcomes. The ten initiatives planned and implemented by the YOT are also discussed. Some of these initiatives addressed system-wide issues. Others targeted the way services were delivered by the statutory youth justice agencies. The final group of initiatives aimed to improve the knowledge of services for young people and also established services or programme to fill gaps in services. 
Collaborative initiatives tend to generate multiple purposes and goals aimed at multiple levels of the situation. Thus an ecological and systems approach was used to analyse the impact of the YOT's activities. This allowed for larger units of analysis at the instrumental, structural, relational and cultural dimensions of the environment. 
In the first instance this project created a group of agencies to provide oversight and leadership for the sector. This growth in capacity for analysing problems, devising solutions, and mobilising the required resources, allowed for the various initiatives to be implemented. YOT members spoke positively about the changes that had been made and there was a perception that the quality of service delivery had increased. The outcome evaluation that was conducted confirmed the assumption that improving communication and coordination of services, aligning service delivery with good practice, and increasing the capacity of services would equate to improved outcomes. In addition to the positive impacts on 'clients', the introduction of norms and practices that focused on cooperation and the increased opportunities for joint work, connectedness and mutual support, produced positive changes in the relational environment. 
While the extent to which interagency collaboration improved is considered, there is a strong focus on what was learned about the process of collaboration. The roles of the researcher and the participation by YOT members are also examined. The thesis ends with a reflection on the project as a whole, considering the major findings the study has made in the areas of action research, evaluation and collaboration.

text: lnteragency collaboration in youth justice: Creating change through action research This thesis describes a community psychology intervention in the Hamilton youth justice sector from September 2001 through to August 2004. I initiated the project with a Maori social service provider, Maatua Whangai, to address poor communication, gaps in service provision, and a lack of coordination and leadership in the sector. Drawing on an action research methodology the purpose of the project was to create better outcomes for youth offenders and their families by using an interagency approach to increase collaboration, coordination and the effectiveness of service delivery.
 My role became one of project manager and researcher. Representatives from the key agencies in the wider youth justice sector became participants and together we embarked on a journey of transformation. The group we formed, initially known as the 'Hamilton Youth Justice Collaboration', became the Hamilton Youth Offending Team (YOT), following the establishment of YOTs nationally by the Ministry of Justice in 2002. 
This thesis details the development of the Hamilton YOT, focusing on its purposes, methods, process, relationships and outcomes. The ten initiatives planned and implemented by the YOT are also discussed. Some of these initiatives addressed system-wide issues. Others targeted the way services were delivered by the statutory youth justice agencies. The final group of initiatives aimed to improve the knowledge of services for young people and also established services or programme to fill gaps in services. 
Collaborative initiatives tend to generate multiple purposes and goals aimed at multiple levels of the situation. Thus an ecological and systems approach was used to analyse the impact of the YOT's activities. This allowed for larger units of analysis at the instrumental, structural, relational and cultural dimensions of the environment. 
In the first instance this project created a group of agencies to provide oversight and leadership for the sector. This growth in capacity for analysing problems, devising solutions, and mobilising the required resources, allowed for the various initiatives to be implemented. YOT members spoke positively about the changes that had been made and there was a perception that the quality of service delivery had increased. The outcome evaluation that was conducted confirmed the assumption that improving communication and coordination of services, aligning service delivery with good practice, and increasing the capacity of services would equate to improved outcomes. In addition to the positive impacts on 'clients', the introduction of norms and practices that focused on cooperation and the increased opportunities for joint work, connectedness and mutual support, produced positive changes in the relational environment. 
While the extent to which interagency collaboration improved is considered, there is a strong focus on what was learned about the process of collaboration. The roles of the researcher and the participation by YOT members are also examined. The thesis ends with a reflection on the project as a whole, considering the major findings the study has made in the areas of action research, evaluation and collaboration.

year: 2006