title: Pittosporum kirkii: Autecology of an endemic shrub epiphyte

authors: Myron, Kirsty Jane

subjects: Pittosporum kirkii

abstract: This research investigated the autecology of the New Zealand endemic shrub epiphyte Pittosporum kirkii (Pittosporaceae). Pittosporum kirkii most frequently displays an epiphytic lifestyle, perched amongst nest epiphytes in the canopies of emergent or canopy trees in old-growth forest. The main objective of this research was to enhance the understanding of Pittosporum kirkii, with a focus on ecological, morphological and physiological characteristics. 

Ecological characteristics were investigated in field surveys of five key Pittosporum kirkii populations that encompass its known latitudinal extent. Survey results showed that P. kirkii is late successional epiphyte commonly found in the inner crown of large canopy and emergent hosts amongst nest epiphytes, it has a short flowering season and shows clinal patterns in leaf length with increasing latitude. Pittosporum kirkii meets the definition of a facultative epiphyte as it grows in rupestral, terrestrial and epiphytic lifestyles. The most common host species for P. kirkii is Dacrydium cupressinum.

Flowering was concentrated between November and December and individuals in the populations examined were functionally dioecious with a preponderance of males; flower pollinators and seed dispersers are uncertain.

Field data and supplementary data sets (e.g. herbarium records) were combined to develop a predicted environmental distribution map. Pittosporum kirkii has an abrupt distribution with strong habitat preferences restricting it to the upper North Island, in upper lowland and lower montane old-growth forest ecosystems. High vapour pressure deficits (>0.39 kPa) and low annual rainfall (<1172 mm) restrict environmental distribution. 

Investigations into the physiological and morphological characteristics of Pittosporum kirkii were focussed on water relations because water availability is speculated to be the most limiting factor across all of the habitats that P. kirkii occupies. In a glasshouse experiment P. kirkii seedlings were subjected to three levels of desiccation stress alongside epiphytic congener P. cornifolium. In the context of international literature, the stress strategies of each species were identified from analysis of morphological adaptations and physiological responses. Pittosporum kirkii has small relative leaf area, thick coriaceous upper leaf cuticles, substantial hypodermal tissue, and under desiccation stress, exhibited rapid reductions in stomatal conductance and photosynthetic activity with stress (ceased function at mean pre-dawn water potentials of -0.8 MPa). This evidence aligns P. kirkii with a desiccation postponement strategy. In contrast P. cornifolium has thinner cuticle hypodermal tissue, larger relative leaf area and maintains photosynthetic function under greater stress (ceased function at mean pre-dawn water potentials of -1.7 MPa), and as a result, lost water potential faster than P. kirkii. Therefore P. cornifolium is concluded to align with a desiccation tolerance stress strategy. Both species recovered within 3 days after re-watering, an important response for the drought-prone epiphytic, terrestrial and rupestral environments that both species inhabit.

Under the current threat classification Pittosporum kirkii is listed as in decline and is considered to be a data poor species. The threats to this species are uncertain; although possum browsing and forest clearance have been proposed, all available evidence is anecdotal and circumstantial. The abundant presence of P. kirkii on possum-free Great Barrier Island suggests relief from possum browse but other browsers are also restricted. Regenerative failures were not evident in mainland or offshore island populations and possum herbivory was not detected in mainland populations, likely because numbers were controlled. However, there may be other factors that may be potentially causing the decline of P. kirkii which could be identified with further research into pollinators, seed dispersal and sexual expression.

Pittosporum kirkii then is a distinctive member of New Zealand’s small guild of endemic shrub epiphytes but overall has the narrowest distribution, narrowest environmental profile, greatest habitat specificity and is the least abundant.

To present the key findings of this research alongside existing information, one chapter is presented in the format of the New Zealand Journal of Botany Biological Flora Series.

text: Pittosporum kirkii: Autecology of an endemic shrub epiphyte This research investigated the autecology of the New Zealand endemic shrub epiphyte Pittosporum kirkii (Pittosporaceae). Pittosporum kirkii most frequently displays an epiphytic lifestyle, perched amongst nest epiphytes in the canopies of emergent or canopy trees in old-growth forest. The main objective of this research was to enhance the understanding of Pittosporum kirkii, with a focus on ecological, morphological and physiological characteristics. 

Ecological characteristics were investigated in field surveys of five key Pittosporum kirkii populations that encompass its known latitudinal extent. Survey results showed that P. kirkii is late successional epiphyte commonly found in the inner crown of large canopy and emergent hosts amongst nest epiphytes, it has a short flowering season and shows clinal patterns in leaf length with increasing latitude. Pittosporum kirkii meets the definition of a facultative epiphyte as it grows in rupestral, terrestrial and epiphytic lifestyles. The most common host species for P. kirkii is Dacrydium cupressinum.

Flowering was concentrated between November and December and individuals in the populations examined were functionally dioecious with a preponderance of males; flower pollinators and seed dispersers are uncertain.

Field data and supplementary data sets (e.g. herbarium records) were combined to develop a predicted environmental distribution map. Pittosporum kirkii has an abrupt distribution with strong habitat preferences restricting it to the upper North Island, in upper lowland and lower montane old-growth forest ecosystems. High vapour pressure deficits (>0.39 kPa) and low annual rainfall (<1172 mm) restrict environmental distribution. 

Investigations into the physiological and morphological characteristics of Pittosporum kirkii were focussed on water relations because water availability is speculated to be the most limiting factor across all of the habitats that P. kirkii occupies. In a glasshouse experiment P. kirkii seedlings were subjected to three levels of desiccation stress alongside epiphytic congener P. cornifolium. In the context of international literature, the stress strategies of each species were identified from analysis of morphological adaptations and physiological responses. Pittosporum kirkii has small relative leaf area, thick coriaceous upper leaf cuticles, substantial hypodermal tissue, and under desiccation stress, exhibited rapid reductions in stomatal conductance and photosynthetic activity with stress (ceased function at mean pre-dawn water potentials of -0.8 MPa). This evidence aligns P. kirkii with a desiccation postponement strategy. In contrast P. cornifolium has thinner cuticle hypodermal tissue, larger relative leaf area and maintains photosynthetic function under greater stress (ceased function at mean pre-dawn water potentials of -1.7 MPa), and as a result, lost water potential faster than P. kirkii. Therefore P. cornifolium is concluded to align with a desiccation tolerance stress strategy. Both species recovered within 3 days after re-watering, an important response for the drought-prone epiphytic, terrestrial and rupestral environments that both species inhabit.

Under the current threat classification Pittosporum kirkii is listed as in decline and is considered to be a data poor species. The threats to this species are uncertain; although possum browsing and forest clearance have been proposed, all available evidence is anecdotal and circumstantial. The abundant presence of P. kirkii on possum-free Great Barrier Island suggests relief from possum browse but other browsers are also restricted. Regenerative failures were not evident in mainland or offshore island populations and possum herbivory was not detected in mainland populations, likely because numbers were controlled. However, there may be other factors that may be potentially causing the decline of P. kirkii which could be identified with further research into pollinators, seed dispersal and sexual expression.

Pittosporum kirkii then is a distinctive member of New Zealand’s small guild of endemic shrub epiphytes but overall has the narrowest distribution, narrowest environmental profile, greatest habitat specificity and is the least abundant.

To present the key findings of this research alongside existing information, one chapter is presented in the format of the New Zealand Journal of Botany Biological Flora Series.

year: 2012

title: Effects of coping style, social relationships and support on New Zealanders well-being during the COVID-19 pandemic

authors: Perry, Andrea

subjects: COVID-19

abstract: In early 2020 during the COVID-19 pandemic, the New Zealand Government implemented unprecedented measures such as lockdowns and social distancing. This research investigated the relationships between different coping styles, social support, social networks, social activity, and the impact on the mental health of adult New Zealanders during July and August 2020. At this point, New Zealand had successfully eliminated COVID-19 from the community (with the only cases being reported in quarantine facilities from arrivals to the country). 

Adult participants (18 years or above) were recruited in New Zealand through Facebook community groups and flyers placed in community locations such as medical centres, schools, and university campuses, to participate in an online survey between 13th July 2020 and 11th August 2020. The survey included: demographic questions, study-specific COVID-19 related questions, and seven standardised measures. We assessed three aspects of social support (perceived social support (Multidimensional Scale of Perceived Social Support (MPSS)), social network (Lubben Social Network Scale – revised (LSNR-R), social activities (Social Activity Log (SAL)), coping styles (Brief COPE), depression, anxiety, and stress (Depression, Anxiety and Stress Scale (DASS)), post-traumatic stress (The Abbreviated PCL-C - The Post-Traumatic Checklist), and post-traumatic growth (Post Traumatic Growth Inventory).

Our research investigated predictors of well-being and distress, including demographic variables (age group and gender), previous mental health diagnoses, coping styles, and social support. We hypothesised that higher scores in dysfunctional coping styles and lower scores on social support measures would be associated with higher distress and lower well-being. Our final sample contained 698 valid responses, consisting of 67% female (n=468), 31% male (n=217) and 2% other gender or did not specify (n=13). 

Our models significantly predicted variance in depression (55%), anxiety (48%), stress (52%), PTSD (56%), and post-traumatic growth (41%). Mean scores for depression, anxiety, stress, and dysfunctional coping styles were significantly higher for the youngest age group (18- to 24-year-olds) compared to older age groups. In addition, 18- to 24-year-olds experienced the biggest loss of perceived social support and size of social networks since the COVID-19 pandemic. However, in our regression models, the dysfunctional coping styles of behavioural disengagement and self-blame and a previous mental health diagnosis were consistently among the most common predictors for depression, anxiety, stress, and PTSD. Higher perceived social support was associated with lower levels of depression and PTSD, and higher social activity was associated with lower depression and stress scores. 

Furthermore, significant common predictors of distress included reduced perceived social support since the COVID-19 pandemic (for anxiety and stress) and social networks (for depression and PTSD). Social activity and adaptive coping styles (active coping, positive reframing, religion, emotional support) were significant predictors of post-traumatic growth. Overall, coping styles accounted for more variance (across all mental health outcomes) than age group, gender, previous mental health diagnoses or social support variables.

This research highlighted the disproportional effect that the COVID-19 pandemic was having on younger adults in New Zealand and stressed the need for strong social support and education on adaptive coping styles to reduce distress and improve well-being.

text: Effects of coping style, social relationships and support on New Zealanders well-being during the COVID-19 pandemic In early 2020 during the COVID-19 pandemic, the New Zealand Government implemented unprecedented measures such as lockdowns and social distancing. This research investigated the relationships between different coping styles, social support, social networks, social activity, and the impact on the mental health of adult New Zealanders during July and August 2020. At this point, New Zealand had successfully eliminated COVID-19 from the community (with the only cases being reported in quarantine facilities from arrivals to the country). 

Adult participants (18 years or above) were recruited in New Zealand through Facebook community groups and flyers placed in community locations such as medical centres, schools, and university campuses, to participate in an online survey between 13th July 2020 and 11th August 2020. The survey included: demographic questions, study-specific COVID-19 related questions, and seven standardised measures. We assessed three aspects of social support (perceived social support (Multidimensional Scale of Perceived Social Support (MPSS)), social network (Lubben Social Network Scale – revised (LSNR-R), social activities (Social Activity Log (SAL)), coping styles (Brief COPE), depression, anxiety, and stress (Depression, Anxiety and Stress Scale (DASS)), post-traumatic stress (The Abbreviated PCL-C - The Post-Traumatic Checklist), and post-traumatic growth (Post Traumatic Growth Inventory).

Our research investigated predictors of well-being and distress, including demographic variables (age group and gender), previous mental health diagnoses, coping styles, and social support. We hypothesised that higher scores in dysfunctional coping styles and lower scores on social support measures would be associated with higher distress and lower well-being. Our final sample contained 698 valid responses, consisting of 67% female (n=468), 31% male (n=217) and 2% other gender or did not specify (n=13). 

Our models significantly predicted variance in depression (55%), anxiety (48%), stress (52%), PTSD (56%), and post-traumatic growth (41%). Mean scores for depression, anxiety, stress, and dysfunctional coping styles were significantly higher for the youngest age group (18- to 24-year-olds) compared to older age groups. In addition, 18- to 24-year-olds experienced the biggest loss of perceived social support and size of social networks since the COVID-19 pandemic. However, in our regression models, the dysfunctional coping styles of behavioural disengagement and self-blame and a previous mental health diagnosis were consistently among the most common predictors for depression, anxiety, stress, and PTSD. Higher perceived social support was associated with lower levels of depression and PTSD, and higher social activity was associated with lower depression and stress scores. 

Furthermore, significant common predictors of distress included reduced perceived social support since the COVID-19 pandemic (for anxiety and stress) and social networks (for depression and PTSD). Social activity and adaptive coping styles (active coping, positive reframing, religion, emotional support) were significant predictors of post-traumatic growth. Overall, coping styles accounted for more variance (across all mental health outcomes) than age group, gender, previous mental health diagnoses or social support variables.

This research highlighted the disproportional effect that the COVID-19 pandemic was having on younger adults in New Zealand and stressed the need for strong social support and education on adaptive coping styles to reduce distress and improve well-being.

year: 2022

title: Improving prediction of potential for treatment completion at Tai Aroha

authors: Astridge Clarke,  Abigail Darcy

subjects: Treatment

abstract: Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

text: Improving prediction of potential for treatment completion at Tai Aroha Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

year: 2023