title: A stochastic sub-national population projection methodology with an application to the Waikato region of New Zealand

authors: Cameron, Michael Patrick

subjects: cohort-component model

abstract: In this paper we use a stochastic population projection methodology at the sub-national level as an alternative to the conventional deterministic cohort-component method. We briefly evaluate the accuracy of previous deterministic projections and find that there is a tendency for these to be conservative: under-projecting fast growing populations and over-projecting slow growing ones. We generate probabilistic population projections for five demographically distinct administrative areas within the Waikato region of New Zealand, namely Hamilton City, Franklin District, Thames-Coromandel District, Otorohanga District and South Waikato District. Although spatial interaction between the areas is not taken into account in the current version of the methodology, a consistent set of cross-regional assumptions is used. The results are compared to official sub-national deterministic projections. The accuracy of sub-national population projections is in New Zealand strongly affected by the instability of migration as a component of population change. Unlike the standard cohort-component methodology, in which net migration levels are projected, the key parameters of our stochastic methodology are age-gender-area specific net migration rates. The projected range of rates of population growth is wider for smaller regions and/or regions more strongly affected by net migration. Generally, the identified and modelled uncertainty makes the traditional ‘mid range’ scenario of sub-national population projections of limited use for policy analysis or planning beyond a relatively short projection horizon. Directions for further development of a stochastic sub-national projection methodology are suggested.

text: A stochastic sub-national population projection methodology with an application to the Waikato region of New Zealand In this paper we use a stochastic population projection methodology at the sub-national level as an alternative to the conventional deterministic cohort-component method. We briefly evaluate the accuracy of previous deterministic projections and find that there is a tendency for these to be conservative: under-projecting fast growing populations and over-projecting slow growing ones. We generate probabilistic population projections for five demographically distinct administrative areas within the Waikato region of New Zealand, namely Hamilton City, Franklin District, Thames-Coromandel District, Otorohanga District and South Waikato District. Although spatial interaction between the areas is not taken into account in the current version of the methodology, a consistent set of cross-regional assumptions is used. The results are compared to official sub-national deterministic projections. The accuracy of sub-national population projections is in New Zealand strongly affected by the instability of migration as a component of population change. Unlike the standard cohort-component methodology, in which net migration levels are projected, the key parameters of our stochastic methodology are age-gender-area specific net migration rates. The projected range of rates of population growth is wider for smaller regions and/or regions more strongly affected by net migration. Generally, the identified and modelled uncertainty makes the traditional ‘mid range’ scenario of sub-national population projections of limited use for policy analysis or planning beyond a relatively short projection horizon. Directions for further development of a stochastic sub-national projection methodology are suggested.

year: 2010-03

title: Thresholds for sustainable regeneration in urban restoration plantings in Hamilton City, New Zealand

authors: Overdyck, Elizabeth

subjects: forest restoration

abstract: Urban forest patches have unique environmental and landscape characteristics which may influence the restoration of native plant communities. Urbanisation can lead to a drier and warmer climate, a prevalence of exotic seed sources and isolation from remnant native forest seed sources. This research investigates how these factors influence native species presence in different aged urban forest patches and uses life history traits to identify vulnerable species groups which may require active reintroduction. Seed rain, soil seed banks and vegetation composition was recorded within urban forest restoration plantings (10-36 years old) in Hamilton City, New Zealand with comparison to naturally regenerating forest within the city and a nearby rural forest remnant. To address dispersal limitation for several key mid to late successional forest species an experiment was also undertaken to investigate broadcast seeding as a method to reintroduce trees with large seeds and fleshy fruits into established early successional vegetation.

Seed rain, soil seed banks (fern spores inclusive) and understorey vegetation in urban forest were found to have higher exotic species richness and lower native species density and richness than rural forest. Both understorey vegetation and soil seed banks of urban sites >20 years old had lower exotic species richness than younger (10–20 years) sites, indicating a developmental threshold that provided some resistance to exotic species establishment. A prevalence of exotic species in urban seed rain, however, will allow reinvasion through edge habitat and following any disturbance to canopy vegetation. Persistent soil seed banks from both urban and rural sites were dominated by exotic herbaceous species and native fern species, while few other native forest species were found to persist for >1 year in the seed bank.

Urban native seed rain was greater in quantity than exotic seed rain (reflecting immediately surrounding vegetation) although only when native canopy species had been planted suggesting a benefit of initial planting to encourage restoration of native communities. Novel species arriving in the seed rain, but not present in the immediate vegetation, were often not abundant in quantity but represented three quarters of the native species recorded in urban seed rain providing evidence for some long-distance dispersal (particularly for wind-dispersed species) and potential for new species to establish. Urban and rural seed rain contained a similar number of novel native species arriving, although compositionally dissimilar, whereas a greater number of novel exotic species arrived in urban seed rain. Establishment for some native species arriving in urban seed rain was limited, e.g. ferns, indicating a suitable forest microclimate is still to develop. 

It was found that the native forest flora in Hamilton City represented just over half (57%) of the species present in forests of the broader Hamilton Ecological District. This suggests limited natural colonisation from beyond the urban area and the absent species are suggested as priorities for urban reintroduction. In turn only 35% of the city forest flora was found to be represented in the seed supply (annual seed rain and soil seed bank) and understorey sampling in urban forest patches. An over representation of trees in the city forest flora may reflect some relictual long-lived species that are surviving but may no longer have viable populations. Forbs and parasitic plants, highly shade tolerant (i.e. late successional) species and those with biotic pollinators were under represented in the seed supply and understorey indicating some limitation for regeneration or colonisation in young urban forests. The richness of bird-dispersed native species in urban forest patches increased with proximity and size of good quality native vegetation but no other effects of dispersal mode on urban native species presence were found. 

To facilitate dispersal, broadcast seeding was found to be a viable method of improving regeneration of large-seeded late successional trees and may be a cost-effective alternative to planting saplings. Seedling establishment can be improved with fruit flesh removal and clay ball treatments, especially in the presence of mammalian seed predators.

text: Thresholds for sustainable regeneration in urban restoration plantings in Hamilton City, New Zealand Urban forest patches have unique environmental and landscape characteristics which may influence the restoration of native plant communities. Urbanisation can lead to a drier and warmer climate, a prevalence of exotic seed sources and isolation from remnant native forest seed sources. This research investigates how these factors influence native species presence in different aged urban forest patches and uses life history traits to identify vulnerable species groups which may require active reintroduction. Seed rain, soil seed banks and vegetation composition was recorded within urban forest restoration plantings (10-36 years old) in Hamilton City, New Zealand with comparison to naturally regenerating forest within the city and a nearby rural forest remnant. To address dispersal limitation for several key mid to late successional forest species an experiment was also undertaken to investigate broadcast seeding as a method to reintroduce trees with large seeds and fleshy fruits into established early successional vegetation.

Seed rain, soil seed banks (fern spores inclusive) and understorey vegetation in urban forest were found to have higher exotic species richness and lower native species density and richness than rural forest. Both understorey vegetation and soil seed banks of urban sites >20 years old had lower exotic species richness than younger (10–20 years) sites, indicating a developmental threshold that provided some resistance to exotic species establishment. A prevalence of exotic species in urban seed rain, however, will allow reinvasion through edge habitat and following any disturbance to canopy vegetation. Persistent soil seed banks from both urban and rural sites were dominated by exotic herbaceous species and native fern species, while few other native forest species were found to persist for >1 year in the seed bank.

Urban native seed rain was greater in quantity than exotic seed rain (reflecting immediately surrounding vegetation) although only when native canopy species had been planted suggesting a benefit of initial planting to encourage restoration of native communities. Novel species arriving in the seed rain, but not present in the immediate vegetation, were often not abundant in quantity but represented three quarters of the native species recorded in urban seed rain providing evidence for some long-distance dispersal (particularly for wind-dispersed species) and potential for new species to establish. Urban and rural seed rain contained a similar number of novel native species arriving, although compositionally dissimilar, whereas a greater number of novel exotic species arrived in urban seed rain. Establishment for some native species arriving in urban seed rain was limited, e.g. ferns, indicating a suitable forest microclimate is still to develop. 

It was found that the native forest flora in Hamilton City represented just over half (57%) of the species present in forests of the broader Hamilton Ecological District. This suggests limited natural colonisation from beyond the urban area and the absent species are suggested as priorities for urban reintroduction. In turn only 35% of the city forest flora was found to be represented in the seed supply (annual seed rain and soil seed bank) and understorey sampling in urban forest patches. An over representation of trees in the city forest flora may reflect some relictual long-lived species that are surviving but may no longer have viable populations. Forbs and parasitic plants, highly shade tolerant (i.e. late successional) species and those with biotic pollinators were under represented in the seed supply and understorey indicating some limitation for regeneration or colonisation in young urban forests. The richness of bird-dispersed native species in urban forest patches increased with proximity and size of good quality native vegetation but no other effects of dispersal mode on urban native species presence were found. 

To facilitate dispersal, broadcast seeding was found to be a viable method of improving regeneration of large-seeded late successional trees and may be a cost-effective alternative to planting saplings. Seedling establishment can be improved with fruit flesh removal and clay ball treatments, especially in the presence of mammalian seed predators.

year: 2014

title: How institutions frame mātauranga Māori (Commissioned by Waikato Regional Council)

authors: Whaanga, Hēmi

abstract: The primary questions for this report are:
1) How is Mātauranga Māori framed by Institutions?
2) How is Mātauranga Māori being operationalised by Institutions in New Zealand?
Mātauranga Māori is the intellectual capital generated by whānau, hapū and Iwi over multiple generations. It is a shared-community knowledge that is embedded in lived experience and carried in stories, song, place names, dance, ceremonies, genealogies, memories, visions, prophesies, teachings and original instructions, as and learnt through observation and copying of other community members.
It is a holistic system of orally passed knowledge, concepts, beliefs and practice. Mātauranga Māori, mātauranga ā-iwi, mātauranga ā-hapū, and mātauranga ā-whānau are dynamic, innovative, and generative systems of knowledge. Mātauranga Māori has been defined, framed, and operationalised with varying success by Institutions. Although the overall definitions vary somewhat, the general premise is that these government agencies acknowledge that mātauranga Māori is Māori-specific knowledge that is adaptive and regionally distinct. This recognition is important as it reinforces the notion that Māori are not a homogenous group, and that mātauranga Māori will differ across Iwi.
For the vast majority of institutions, improving their understanding of mātauranga Māori is an important strategic aim that can help guide their decision making, management, and monitoring procedures. Achieving this aim helps recognise the innovative potential of Māori knowledge, its contribution to council activities, and the usefulness of culturally appropriate data.
This report has identified seven factors that contribute towards a framework of understanding:
1) Acknowledging contemporary relevance and application: Iwi partners value mātauranga
Māori not only for its historic significance but its contemporary relevance in times of political change. Legislative requirements, iwi expectations, and a desire to build respectful relationships also contribute to current moves to understand and incorporate mātauranga Māori across regional council planning and decision-making activities.
2) Acknowledging cultural validity: Mātauranga Māori informs not only traditional practices but also Māori and iwi participation within Council activities.
3) Accepting epistemological difference: Eurocentric values and scientific disciplines tend to have primacy in a regional council context in part through historical tendencies and political representation. Mātauranga Māori brings a different value set and way of understanding phenomena to the table.
4) Acknowledging mana whenua responsibility for mātauranga Māori: The management and use of mātauranga represents a core responsibility of mana whenua. Relocating mātauranga and responsibility to act as a kaitiaki from a whānau, hapū or iwi to an institution, is a sensitive topic. Mātauranga is often vested with specific people (kaitiaki) or with local whānau and hapū to ensure the responsibilities for protecting the environment remain with those that live there.
5) Developing a more nuanced understanding of mātauranga Māori: Developing a more nuanced understanding of the different disciplines and content that exist under the broad definition of mātauranga Māori is necessary if Councils are to incorporate mātauranga Māori across a greater range of their work programmes.

text: How institutions frame mātauranga Māori (Commissioned by Waikato Regional Council) The primary questions for this report are:
1) How is Mātauranga Māori framed by Institutions?
2) How is Mātauranga Māori being operationalised by Institutions in New Zealand?
Mātauranga Māori is the intellectual capital generated by whānau, hapū and Iwi over multiple generations. It is a shared-community knowledge that is embedded in lived experience and carried in stories, song, place names, dance, ceremonies, genealogies, memories, visions, prophesies, teachings and original instructions, as and learnt through observation and copying of other community members.
It is a holistic system of orally passed knowledge, concepts, beliefs and practice. Mātauranga Māori, mātauranga ā-iwi, mātauranga ā-hapū, and mātauranga ā-whānau are dynamic, innovative, and generative systems of knowledge. Mātauranga Māori has been defined, framed, and operationalised with varying success by Institutions. Although the overall definitions vary somewhat, the general premise is that these government agencies acknowledge that mātauranga Māori is Māori-specific knowledge that is adaptive and regionally distinct. This recognition is important as it reinforces the notion that Māori are not a homogenous group, and that mātauranga Māori will differ across Iwi.
For the vast majority of institutions, improving their understanding of mātauranga Māori is an important strategic aim that can help guide their decision making, management, and monitoring procedures. Achieving this aim helps recognise the innovative potential of Māori knowledge, its contribution to council activities, and the usefulness of culturally appropriate data.
This report has identified seven factors that contribute towards a framework of understanding:
1) Acknowledging contemporary relevance and application: Iwi partners value mātauranga
Māori not only for its historic significance but its contemporary relevance in times of political change. Legislative requirements, iwi expectations, and a desire to build respectful relationships also contribute to current moves to understand and incorporate mātauranga Māori across regional council planning and decision-making activities.
2) Acknowledging cultural validity: Mātauranga Māori informs not only traditional practices but also Māori and iwi participation within Council activities.
3) Accepting epistemological difference: Eurocentric values and scientific disciplines tend to have primacy in a regional council context in part through historical tendencies and political representation. Mātauranga Māori brings a different value set and way of understanding phenomena to the table.
4) Acknowledging mana whenua responsibility for mātauranga Māori: The management and use of mātauranga represents a core responsibility of mana whenua. Relocating mātauranga and responsibility to act as a kaitiaki from a whānau, hapū or iwi to an institution, is a sensitive topic. Mātauranga is often vested with specific people (kaitiaki) or with local whānau and hapū to ensure the responsibilities for protecting the environment remain with those that live there.
5) Developing a more nuanced understanding of mātauranga Māori: Developing a more nuanced understanding of the different disciplines and content that exist under the broad definition of mātauranga Māori is necessary if Councils are to incorporate mātauranga Māori across a greater range of their work programmes.

year: 2017