title: Restoration of three indigenous forest types in Tauranga City, New Zealand

authors: Dean, Hamish Alston

subjects: restoration

abstract: This research examined the current state and developmental trajectory of forest restoration projects in Tauranga City with the aim of establishing whether they will eventually develop into functioning forest ecosystems similar to their natural counterparts. Three forest types historically present in Tauranga were studied: coastal Metrosideros excelsa forest, semi-coastal broadleaved forest, and semi-coastal Dacrycarpus dacrydioides swamp forest.

Forty-five variable-area plots were established in thirteen categories comprising at least two planted sites of different ages for each forest type, naturally regenerating sites within the city, and old-growth reference forests outside of the city. Vegetation parameters including tree diameters, numbers of saplings and seedlings, cover abundance and groundcover were measured or recorded. Site characteristics such as aspect and slope were also recorded. Soil samples were taken in each of the thirteen forest categories and microclimate conditions were recorded over a period of eight months using micro data loggers. Data were analysed by comparing species population structures along with diversity and naturalness in each forest category. Non-metric Multidimensional Scaling and Multi-Response Permutation Procedures were used to examine the relationships between restoration sites and reference sites in each forest type and across all three forest types.  Environmental data were compared using ANOVA and relationships between physical, environmental, and vegetation characteristics were examined using Spearman rank correlations.

Results from the planted restoration sites were compared with the naturally regenerating forests and the reference forests. Coastal forest restoration sites were found to be developing into Metrosideros excelsa forest but recruitment of mid- and late-successional species was failing, probably due to browse from exotic animals and isolation from seed sources.  This was the case even in mature Metrosideros excelsa forest on Mauao. 

Restricted regeneration of canopy species was evident in the semi-coastal broadleaved reference sites but the reason for this was not clear. Naturally regenerating sites were being invaded by Prunus campanulata which has the potential to dominate the vegetation. The understorey in the restoration sites was developing through regeneration and colonisation of species that had not been planted, indicating that the vital ecosystem function of seed dispersal has been restored. However, successional canopy species were failing to recruit. 
Old-growth Dacrycarpus dacrydioides forest at White Pine Bush was found to be on a trajectory towards Beilschmiedia tawa-dominated forest. Naturally regenerating swamp forest in Kopurererua Valley was dominated by Salix cinerea and had almost no regeneration of native species. Planted restoration sites in Kopurererua Valley and Te Maunga are likely to become Dacrycarpus-dominated stands but with lower stem densities than natural stands. The Dacrycarpus dacrydioides in the older restoration sites at Te Maunga were beginning to naturally regenerate but seedlings are only likely to survive where there is sufficient light and reduced competition.
Across all forest types the proportion of exotic species decreased from an average of 50% in the youngest restoration sites to just 1.5% in the reference forests. 
 
Microclimate conditions generally became more similar to reference forest conditions with increasing stand age. While younger sites had similar average temperatures and relative humidity to reference sites, the fluctuations in temperature and humidity significantly decreased with stand age from an average range of 28.6 °C and 76.7% RH in the youngest restoration sites, to an average range of 19.9 °C and 48.9% RH in the reference sites. 

Recommendations relevant to the management of existing and future restoration plantings in each of the three forest types are provided.

text: Restoration of three indigenous forest types in Tauranga City, New Zealand This research examined the current state and developmental trajectory of forest restoration projects in Tauranga City with the aim of establishing whether they will eventually develop into functioning forest ecosystems similar to their natural counterparts. Three forest types historically present in Tauranga were studied: coastal Metrosideros excelsa forest, semi-coastal broadleaved forest, and semi-coastal Dacrycarpus dacrydioides swamp forest.

Forty-five variable-area plots were established in thirteen categories comprising at least two planted sites of different ages for each forest type, naturally regenerating sites within the city, and old-growth reference forests outside of the city. Vegetation parameters including tree diameters, numbers of saplings and seedlings, cover abundance and groundcover were measured or recorded. Site characteristics such as aspect and slope were also recorded. Soil samples were taken in each of the thirteen forest categories and microclimate conditions were recorded over a period of eight months using micro data loggers. Data were analysed by comparing species population structures along with diversity and naturalness in each forest category. Non-metric Multidimensional Scaling and Multi-Response Permutation Procedures were used to examine the relationships between restoration sites and reference sites in each forest type and across all three forest types.  Environmental data were compared using ANOVA and relationships between physical, environmental, and vegetation characteristics were examined using Spearman rank correlations.

Results from the planted restoration sites were compared with the naturally regenerating forests and the reference forests. Coastal forest restoration sites were found to be developing into Metrosideros excelsa forest but recruitment of mid- and late-successional species was failing, probably due to browse from exotic animals and isolation from seed sources.  This was the case even in mature Metrosideros excelsa forest on Mauao. 

Restricted regeneration of canopy species was evident in the semi-coastal broadleaved reference sites but the reason for this was not clear. Naturally regenerating sites were being invaded by Prunus campanulata which has the potential to dominate the vegetation. The understorey in the restoration sites was developing through regeneration and colonisation of species that had not been planted, indicating that the vital ecosystem function of seed dispersal has been restored. However, successional canopy species were failing to recruit. 
Old-growth Dacrycarpus dacrydioides forest at White Pine Bush was found to be on a trajectory towards Beilschmiedia tawa-dominated forest. Naturally regenerating swamp forest in Kopurererua Valley was dominated by Salix cinerea and had almost no regeneration of native species. Planted restoration sites in Kopurererua Valley and Te Maunga are likely to become Dacrycarpus-dominated stands but with lower stem densities than natural stands. The Dacrycarpus dacrydioides in the older restoration sites at Te Maunga were beginning to naturally regenerate but seedlings are only likely to survive where there is sufficient light and reduced competition.
Across all forest types the proportion of exotic species decreased from an average of 50% in the youngest restoration sites to just 1.5% in the reference forests. 
 
Microclimate conditions generally became more similar to reference forest conditions with increasing stand age. While younger sites had similar average temperatures and relative humidity to reference sites, the fluctuations in temperature and humidity significantly decreased with stand age from an average range of 28.6 °C and 76.7% RH in the youngest restoration sites, to an average range of 19.9 °C and 48.9% RH in the reference sites. 

Recommendations relevant to the management of existing and future restoration plantings in each of the three forest types are provided.

year: 2013

title: Palaeolimnological studies on Lake Maratoto, North Island, New Zealand

authors: Green, John D.

abstract: The Middle Waikato (or Hamilton) Basin is a promising area for studies of the postglacial history of Northern New Zealand. The major geomorphological features of the basin were developed in the last 40,000 years, mainly by aggradation of the ancestral Waikato River (Mccraw 1967, Hume et al 1975) and in the process a number of peat bogs and small lakes were formed which now provide suitable locations for palaeoclimatic and palaeoecological investigations. Four pollen diagrams from peats in the area have been published (Harris 1963, McGlone et al 1978) which show similar features to diagrams from elsewhere in the North Island (McGlone and Topping 1979) but there have been no comparable studies of sediments from the lakes.

text: Palaeolimnological studies on Lake Maratoto, North Island, New Zealand The Middle Waikato (or Hamilton) Basin is a promising area for studies of the postglacial history of Northern New Zealand. The major geomorphological features of the basin were developed in the last 40,000 years, mainly by aggradation of the ancestral Waikato River (Mccraw 1967, Hume et al 1975) and in the process a number of peat bogs and small lakes were formed which now provide suitable locations for palaeoclimatic and palaeoecological investigations. Four pollen diagrams from peats in the area have been published (Harris 1963, McGlone et al 1978) which show similar features to diagrams from elsewhere in the North Island (McGlone and Topping 1979) but there have been no comparable studies of sediments from the lakes.

year: 1979

title: Civilisation, settlers and wanderers: Law, politics and mobility in nineteenth century New Zealand and Australia

authors: Seuffert, Nan

subjects: colonization

abstract: Mobility was constitutive of the 19th century British colonial period in the Pacific. The circulation of capital and commodities, technologies of transportation and communication, travelling ideologies and systems of governance and surveillance, as well as the movement of explorers, whalers, labourers, settlers, missionaries, colonial administrators, convicts, soldiers, sojourners, immigrants, and transnational and displaced indigenous peoples, all shaped the politics and the period (see Ballantyne 2009: 7-8; Seuffert 2006: 7-8; Arrighi 1994: 48-58). Highly mobile British and European immigrants with money or skills were termed 'settlers', with associated connotations of stabilising and civilising influences. Missionaries and colonial officials who were integral to colonisation were also often highly mobile, carrying policies and regulatory regimes with them, and their colonial roles as 'civilising' influences included 'settling' and advancing the position of indigenous and other colonised peoples. In contrast, the mobility of poor whites and racialised populations - such as 'Melanesian' indentured labourers (Banivanua-Mar 2007: 3-4)2, Indian workers, displaced indigenous peoples and 'sojourner' Chinese - attracted the attention of law (and policy) makers and institutional authorities and were subjected to various forms of surveillance, regulation and policing designed to constrain and contain them.

text: Civilisation, settlers and wanderers: Law, politics and mobility in nineteenth century New Zealand and Australia Mobility was constitutive of the 19th century British colonial period in the Pacific. The circulation of capital and commodities, technologies of transportation and communication, travelling ideologies and systems of governance and surveillance, as well as the movement of explorers, whalers, labourers, settlers, missionaries, colonial administrators, convicts, soldiers, sojourners, immigrants, and transnational and displaced indigenous peoples, all shaped the politics and the period (see Ballantyne 2009: 7-8; Seuffert 2006: 7-8; Arrighi 1994: 48-58). Highly mobile British and European immigrants with money or skills were termed 'settlers', with associated connotations of stabilising and civilising influences. Missionaries and colonial officials who were integral to colonisation were also often highly mobile, carrying policies and regulatory regimes with them, and their colonial roles as 'civilising' influences included 'settling' and advancing the position of indigenous and other colonised peoples. In contrast, the mobility of poor whites and racialised populations - such as 'Melanesian' indentured labourers (Banivanua-Mar 2007: 3-4)2, Indian workers, displaced indigenous peoples and 'sojourner' Chinese - attracted the attention of law (and policy) makers and institutional authorities and were subjected to various forms of surveillance, regulation and policing designed to constrain and contain them.

year: 2011