title: Vegetational change along an altitudinal gradient, Mount Egmont, New Zealand

authors: Clarkson, Bruce D.

subjects: Botany

abstract: A direct gradient analysis was conducted on Mt Egmont, New Zealand, firstly to examine quantitatively changes in composition, physiognomy and structure of the vegetation along the altitudinal gradient in order to investigate the accepted notions of vegetation zonation, and secondly to relate such an analysis to other New Zealand gradient analyses and to the two views on vegetation description and analysis, the continuum view and the discrete community (association) view. 
Vegetation data was collected at altitudinally defined sites on five major ridges on Mt Egmont; North Egmont (Blundell’s Track, Ngatoro Track and the Razorback), York Road Track Ridge, Stratford (Summit Road), Dawson Falls (Summit Track), and Lake Dive Track Ridge. The data collected on the York Road Track Ridge provided the basis for describing altitudinal change while the remainder was used to examine in detail the tree-shrub and shrub-tussock interfaces. 
Sample size (quadrat and line transect) was determined after minimal area checks to ensure that a representative combination of species was sampled at each site. Data from a total of sixty plots was collected and preliminary analysis, including graphing of the major species distributions and calculation of similarity matrices to compare quadrats, revealed a tendency toward discontinuity in species distributions. This allowed a classificatory rather than ordinatory strategy of data analysis to be followed. Cluster analyses based on statistical tests of species association were used to determine "natural" groupings of positively associated species and qualitative and quantitative classifications of samples were used to define vegetation zones or groupings at specific similarity index levels. 
Tree-shrub interfaces and tussock-shrub interfaces were compared on the basis of species complement, the degree of floristic, physiognomic and structural discontinuity in the vegetation, and differences in species interaction at each of the locations. 
The effects of data amalgamation, altitudinal interval employed, altitudinal range encountered, and classificatory versus ordinatory techniques, on the conclusions drawn were examined. 
Graphing of species distributions, cluster analyses, and classifications supported in part previously described zonation patterns but enabled a refinement of the generally accepted notions of vegetation zonation on Mt Egmont. In contrast to previous research the vegetation zones identified have a quantitative and objective basis. 
Comparison of the results with those of other New Zealand gradient analyses enabled elucidation of several major species distributions and species interactions because of the unique species complement found on Mt Egmont. 
Comparison of different data collection and manipulation techniques indicated that decisions made may cause data to conform to one or other of the two major approaches (continuum or discrete community types) to vegetation description and analysis. 
The study of the tree-shrub interfaces and shrub-tussock inter­faces showed that the vegetation on Mt Egmont exhibits a spectrum of species distributions ranging from continua through to discontinuities at different locations and specific examples of each are described. Possible explanations advanced include differences in species complement and species interaction, the non-equivalence of the altitudinal gradient at different locations, and differences in environmental factors including slope and aspect.

text: Vegetational change along an altitudinal gradient, Mount Egmont, New Zealand A direct gradient analysis was conducted on Mt Egmont, New Zealand, firstly to examine quantitatively changes in composition, physiognomy and structure of the vegetation along the altitudinal gradient in order to investigate the accepted notions of vegetation zonation, and secondly to relate such an analysis to other New Zealand gradient analyses and to the two views on vegetation description and analysis, the continuum view and the discrete community (association) view. 
Vegetation data was collected at altitudinally defined sites on five major ridges on Mt Egmont; North Egmont (Blundell’s Track, Ngatoro Track and the Razorback), York Road Track Ridge, Stratford (Summit Road), Dawson Falls (Summit Track), and Lake Dive Track Ridge. The data collected on the York Road Track Ridge provided the basis for describing altitudinal change while the remainder was used to examine in detail the tree-shrub and shrub-tussock interfaces. 
Sample size (quadrat and line transect) was determined after minimal area checks to ensure that a representative combination of species was sampled at each site. Data from a total of sixty plots was collected and preliminary analysis, including graphing of the major species distributions and calculation of similarity matrices to compare quadrats, revealed a tendency toward discontinuity in species distributions. This allowed a classificatory rather than ordinatory strategy of data analysis to be followed. Cluster analyses based on statistical tests of species association were used to determine "natural" groupings of positively associated species and qualitative and quantitative classifications of samples were used to define vegetation zones or groupings at specific similarity index levels. 
Tree-shrub interfaces and tussock-shrub interfaces were compared on the basis of species complement, the degree of floristic, physiognomic and structural discontinuity in the vegetation, and differences in species interaction at each of the locations. 
The effects of data amalgamation, altitudinal interval employed, altitudinal range encountered, and classificatory versus ordinatory techniques, on the conclusions drawn were examined. 
Graphing of species distributions, cluster analyses, and classifications supported in part previously described zonation patterns but enabled a refinement of the generally accepted notions of vegetation zonation on Mt Egmont. In contrast to previous research the vegetation zones identified have a quantitative and objective basis. 
Comparison of the results with those of other New Zealand gradient analyses enabled elucidation of several major species distributions and species interactions because of the unique species complement found on Mt Egmont. 
Comparison of different data collection and manipulation techniques indicated that decisions made may cause data to conform to one or other of the two major approaches (continuum or discrete community types) to vegetation description and analysis. 
The study of the tree-shrub interfaces and shrub-tussock inter­faces showed that the vegetation on Mt Egmont exhibits a spectrum of species distributions ranging from continua through to discontinuities at different locations and specific examples of each are described. Possible explanations advanced include differences in species complement and species interaction, the non-equivalence of the altitudinal gradient at different locations, and differences in environmental factors including slope and aspect.

year: 1977

title: Detecting subtle shifts in ecosystem functioning in a dynamic estuarine environment

authors: Pratt, Daniel Robert

abstract: Identifying the effects of stressors before they impact ecosystem functioning can be challenging in dynamic, heterogeneous ‘real-world’ ecosystems. In aquatic systems, for example, reductions in water clarity can limit the light available for photosynthesis, with knock-on consequences for secondary consumers, though in naturally turbid wave-swept estuaries, detecting the effects of elevated turbidity can be difficult. The objective of this study was to investigate the effects of shading on ecosystem functions mediated by sandflat primary producers (microphytobenthos) and deep-dwelling surface-feeding macrofauna (Macomona liliana; Bivalvia, Veneroida, Tellinidae). Shade cloths (which reduced incident light intensity by ~80%) were deployed on an exposed, intertidal sandflat to experimentally stress the microphytobenthic community associated with the sediment surface. After 13 weeks, sediment properties, macrofauna and fluxes of oxygen and inorganic nutrients across the sediment-water interface were measured. A multivariate metric of ecosystem function (MF) was generated by combining flux-based response variables, and distance-based linear models were used to determine shifts in the drivers of ecosystem function between non-shaded and shaded plots. No significant differences in MF or in the constituent ecosystem function variables were detected between the shaded and non-shaded plots. However, shading reduced the total explained variation in MF (from 64% in non-shaded plots to 15% in shaded plots) and affected the relative influence of M. liliana and other explanatory variables on MF. This suggests that although shade stress may shift the drivers of ecosystem functioning (consistent with earlier investigations of shading effects on sandflat interaction networks), ecosystem functions appear to have a degree of resilience to those changes.

text: Detecting subtle shifts in ecosystem functioning in a dynamic estuarine environment Identifying the effects of stressors before they impact ecosystem functioning can be challenging in dynamic, heterogeneous ‘real-world’ ecosystems. In aquatic systems, for example, reductions in water clarity can limit the light available for photosynthesis, with knock-on consequences for secondary consumers, though in naturally turbid wave-swept estuaries, detecting the effects of elevated turbidity can be difficult. The objective of this study was to investigate the effects of shading on ecosystem functions mediated by sandflat primary producers (microphytobenthos) and deep-dwelling surface-feeding macrofauna (Macomona liliana; Bivalvia, Veneroida, Tellinidae). Shade cloths (which reduced incident light intensity by ~80%) were deployed on an exposed, intertidal sandflat to experimentally stress the microphytobenthic community associated with the sediment surface. After 13 weeks, sediment properties, macrofauna and fluxes of oxygen and inorganic nutrients across the sediment-water interface were measured. A multivariate metric of ecosystem function (MF) was generated by combining flux-based response variables, and distance-based linear models were used to determine shifts in the drivers of ecosystem function between non-shaded and shaded plots. No significant differences in MF or in the constituent ecosystem function variables were detected between the shaded and non-shaded plots. However, shading reduced the total explained variation in MF (from 64% in non-shaded plots to 15% in shaded plots) and affected the relative influence of M. liliana and other explanatory variables on MF. This suggests that although shade stress may shift the drivers of ecosystem functioning (consistent with earlier investigations of shading effects on sandflat interaction networks), ecosystem functions appear to have a degree of resilience to those changes.

year: 2015

title: Bilingual Education in Aotearoa/New Zealand

authors: Hill, Richard Kenneth

subjects: Maori medium

abstract: Bilingual education in the context of New Zealand is now over 30 years old. The two largest linguistic minority groups involved in this type of education – the Indigenous Māori and Pasifika peoples of Samoan, Tongan, Cook Islands and Niuean and Tokelauan backgrounds – have made many gains but have struggled in a national context where minority languages have low status. Māori bilingual programs are well established and have made a significant contribution towards reducing Māori language shift that in the 1970s looked to be beyond regeneration. Pasifika bilingual education by contrast is not widely available and not well resourced by the New Zealand government. Both forms continue to need support and a renewed focus at local and national levels.

This chapter provides an overview of past development of Māori and Pasifika bilingual education and present progress. For Māori, the issues relate primarily to how to boost language regeneration, particularly between the generations. Gaining greater support for immersion programs and further strengthening bilingual education pedagogies, particularly relating to achieving biliteracy objectives, are key. In the context of Pasifika, extending government and local support would not only safeguard the languages but has the potential to counteract long-established patterns of low Pasifika student achievement in mainstream/English-medium schooling contexts. Finally, the future of both forms of bilingual education can be safeguarded if they are encompassed within a national languages policy that ensures minority language development in the predominantly English monolingual national context of New Zealand.

text: Bilingual Education in Aotearoa/New Zealand Bilingual education in the context of New Zealand is now over 30 years old. The two largest linguistic minority groups involved in this type of education – the Indigenous Māori and Pasifika peoples of Samoan, Tongan, Cook Islands and Niuean and Tokelauan backgrounds – have made many gains but have struggled in a national context where minority languages have low status. Māori bilingual programs are well established and have made a significant contribution towards reducing Māori language shift that in the 1970s looked to be beyond regeneration. Pasifika bilingual education by contrast is not widely available and not well resourced by the New Zealand government. Both forms continue to need support and a renewed focus at local and national levels.

This chapter provides an overview of past development of Māori and Pasifika bilingual education and present progress. For Māori, the issues relate primarily to how to boost language regeneration, particularly between the generations. Gaining greater support for immersion programs and further strengthening bilingual education pedagogies, particularly relating to achieving biliteracy objectives, are key. In the context of Pasifika, extending government and local support would not only safeguard the languages but has the potential to counteract long-established patterns of low Pasifika student achievement in mainstream/English-medium schooling contexts. Finally, the future of both forms of bilingual education can be safeguarded if they are encompassed within a national languages policy that ensures minority language development in the predominantly English monolingual national context of New Zealand.

year: 2017