title: Contrasting responses to catchment modification among a range of functional and structural indicators of river ecosystem health

authors: Young, Roger G.

subjects: biotic indices

abstract: 1. The value of measuring ecosystem functions in regular monitoring programs is increasingly being recognised as a potent tool for assessing river health. We measured the response of ecosystem metabolism, organic matter decomposition and strength loss, and invertebrate community composition across a gradient of catchment impairment defined by upstream landuse stress in two New Zealand streams. This was performed to determine if there were consistent responses among contrasting functional and structural indicators.
2. Rates of gross primary production (GPP) and ecosystem respiration (ER) ranged from 0.1 to 7.0 gO2 m−2 day−1 and from 0.34 to 16.5 gO2 m−2 day−1 respectively. Rates of GPP were variable across the landuse stress gradient, whereas ER increased linearly with the highest rates at the most impacted sites. Production/respiration (P/R) and net ecosystem metabolism (NEM) indicated that sites at the low and high ends of the stress gradient were heterotrophic with respiration rates presumably relying on organic matter from upstream sources, adjacent land or point sources. Sites with moderate impairment were predominantly autotrophic.
3. Declines in the tensile strength of the cotton strips showed no response across part of the gradient, but a strong response among the most impaired sites. The rate of mass loss of wooden sticks (Betula platyphylla Sukaczev) changed from a linear response to a U-shaped response across the impairment gradient after water temperature compensation, whereas leaf breakdown at a subset of sites suggested a linear loss in mass per degree-day. Three macroinvertebrate metrics describing the composition of the invertebrate community and its sensitivity to pollution showed similar linear inverse responses to the landuse stress gradient.
4. The first axis of a redundancy analysis indicated an association between landuse stress and various measures of water quality, and wooden stick mass loss, the invertebrate metric % EPT [percentage of macroinvertebrate taxa belonging to the Ephemeroptera, Plecoptera and Trichoptera (excluding Hydroptilidae] taxa, P/R and NEM, supporting the utility of these structural and functional metrics for assessing degree of landuse stress. The second axis was more strongly associated with catchment size, ER and GPP which suggests that these indicators were responding to differences in stream size.
5. Our results suggest that nonlinear responses to catchment impairment need to be considered when interpreting measurements of ecosystem function. Functional indicators could be useful for detecting relatively subtle changes where the slope of the response curve is maximised and measurements at the low and high ends of the impairment gradient are roughly equivalent. Such responses may be particularly valuable for detecting early signs of degradation at high quality sites, allowing management responses to be initiated before the degradation becomes too advanced, or for detecting initial moves away from degraded states during the early stages of restoration. Close links between structural and functional indices of river health across an impairment gradient are not necessarily expected or desirable if the aim is to minimise redundancy among ecological indicators.

text: Contrasting responses to catchment modification among a range of functional and structural indicators of river ecosystem health 1. The value of measuring ecosystem functions in regular monitoring programs is increasingly being recognised as a potent tool for assessing river health. We measured the response of ecosystem metabolism, organic matter decomposition and strength loss, and invertebrate community composition across a gradient of catchment impairment defined by upstream landuse stress in two New Zealand streams. This was performed to determine if there were consistent responses among contrasting functional and structural indicators.
2. Rates of gross primary production (GPP) and ecosystem respiration (ER) ranged from 0.1 to 7.0 gO2 m−2 day−1 and from 0.34 to 16.5 gO2 m−2 day−1 respectively. Rates of GPP were variable across the landuse stress gradient, whereas ER increased linearly with the highest rates at the most impacted sites. Production/respiration (P/R) and net ecosystem metabolism (NEM) indicated that sites at the low and high ends of the stress gradient were heterotrophic with respiration rates presumably relying on organic matter from upstream sources, adjacent land or point sources. Sites with moderate impairment were predominantly autotrophic.
3. Declines in the tensile strength of the cotton strips showed no response across part of the gradient, but a strong response among the most impaired sites. The rate of mass loss of wooden sticks (Betula platyphylla Sukaczev) changed from a linear response to a U-shaped response across the impairment gradient after water temperature compensation, whereas leaf breakdown at a subset of sites suggested a linear loss in mass per degree-day. Three macroinvertebrate metrics describing the composition of the invertebrate community and its sensitivity to pollution showed similar linear inverse responses to the landuse stress gradient.
4. The first axis of a redundancy analysis indicated an association between landuse stress and various measures of water quality, and wooden stick mass loss, the invertebrate metric % EPT [percentage of macroinvertebrate taxa belonging to the Ephemeroptera, Plecoptera and Trichoptera (excluding Hydroptilidae] taxa, P/R and NEM, supporting the utility of these structural and functional metrics for assessing degree of landuse stress. The second axis was more strongly associated with catchment size, ER and GPP which suggests that these indicators were responding to differences in stream size.
5. Our results suggest that nonlinear responses to catchment impairment need to be considered when interpreting measurements of ecosystem function. Functional indicators could be useful for detecting relatively subtle changes where the slope of the response curve is maximised and measurements at the low and high ends of the impairment gradient are roughly equivalent. Such responses may be particularly valuable for detecting early signs of degradation at high quality sites, allowing management responses to be initiated before the degradation becomes too advanced, or for detecting initial moves away from degraded states during the early stages of restoration. Close links between structural and functional indices of river health across an impairment gradient are not necessarily expected or desirable if the aim is to minimise redundancy among ecological indicators.

year: 2009

title: Heterogeneity and Female-Headed Households in Sri Lanka: Vulnerability and Resilience in a Transitional Development Society

authors: Adikaram Boyagoda, Adikaram Mudiyanselage Kumudika Suramya

subjects: Female headed households

abstract: Since the 1970s, female-headed households (FHHs) in developing countries have often been used in development literature as a proxy for poverty and vulnerability. In reality the profile of women-headed households is diverse; they include, at the least, rich and poor women, aged widows as well as young single mothers and wives of migrant workers, educated professionals and semi-literate manual labourers. This diversity of characteristics, with its attendant diversity of experience and vulnerability unfolds a picture of heterogeneity, rather than homogeneity.  Yet, despite ample evidence that FHHs are, in fact, heterogeneous and not homogeneous, contemporary research and practice remains caught dominantly within the ‘poverty-vulnerability’ nexus. The heterogeneity of female headship is undermined by conventional notions of homogeneity. It is this gap that the present research addresses. Drawing on interdisciplinary perspectives especially from demography, gender studies; particularly gender and development, risk and vulnerability studies, as well as scholarship on social capital, this thesis employs a ‘heterogeneity’ lens to specifically examine the complexities of household formation, economic conditions and social relations of FHHs in Sri Lanka, in an attempt to explore their vulnerabilities and resilience.

The choice of Sri Lanka as the context for this study is grounded in the demographic reality of a relatively high, and consistently increasing, proportion of households headed by women since the 1970s. By 2009/10, FHHs accounted for nearly one-quarter of all households, throughout the country. In order to capture the geographical and social diversity of FHHs, empirical research was conducted in three contrasting types of district in Sri Lanka, encompassing urban, rural, and estate sectors.   Two main data collection strategies were employed in a mixed methods approach: a sample survey of a cross-section of 534 FHHs, and in-depth interviews with 32 female heads purposively selected from among the survey participants. The findings and discussions include quantitative statistical and qualitative thematic analyses based on primary data, combined with secondary data from censuses, national survey reports and micro-studies of FHHs in Sri Lanka. 

The key findings show the diversity in profile of FHHs in the sample: they range from single person to large extended households. While some households consist of only the woman head and her young children, others comprise aged parents and a woman head. Households were also constituted of ‘working-age’ household members, including the female heads who were totally reliant on others for income and other resources. The study also revealed novel findings that challenge the emphasis of most conventional perceptions of poverty and female headship. From an economic perspective, the results show women from rich households can be personally poor, lacking, among others, in skills to manage household economies, while women in low-income brackets may be resilient, enterprising and satisfied with their needs, despite their apparent poverty. Finally, the thesis highlights the significant role of social capital, a relatively under-researched area in relation to FHHs. The findings reveal that many female heads in Sri Lanka are rich in social capital, a resource in its own right for these women. However, social capital itself needs to be disaggregated into ‘support networks’ and ‘leverage networks’ to understand the role it plays in providing long-term security and resilience. The results show that the majority of FHHs in the sample had access to support networks that provide day-to-day subsistence, but which did not offer them prospects to leverage out of their current situation.

text: Heterogeneity and Female-Headed Households in Sri Lanka: Vulnerability and Resilience in a Transitional Development Society Since the 1970s, female-headed households (FHHs) in developing countries have often been used in development literature as a proxy for poverty and vulnerability. In reality the profile of women-headed households is diverse; they include, at the least, rich and poor women, aged widows as well as young single mothers and wives of migrant workers, educated professionals and semi-literate manual labourers. This diversity of characteristics, with its attendant diversity of experience and vulnerability unfolds a picture of heterogeneity, rather than homogeneity.  Yet, despite ample evidence that FHHs are, in fact, heterogeneous and not homogeneous, contemporary research and practice remains caught dominantly within the ‘poverty-vulnerability’ nexus. The heterogeneity of female headship is undermined by conventional notions of homogeneity. It is this gap that the present research addresses. Drawing on interdisciplinary perspectives especially from demography, gender studies; particularly gender and development, risk and vulnerability studies, as well as scholarship on social capital, this thesis employs a ‘heterogeneity’ lens to specifically examine the complexities of household formation, economic conditions and social relations of FHHs in Sri Lanka, in an attempt to explore their vulnerabilities and resilience.

The choice of Sri Lanka as the context for this study is grounded in the demographic reality of a relatively high, and consistently increasing, proportion of households headed by women since the 1970s. By 2009/10, FHHs accounted for nearly one-quarter of all households, throughout the country. In order to capture the geographical and social diversity of FHHs, empirical research was conducted in three contrasting types of district in Sri Lanka, encompassing urban, rural, and estate sectors.   Two main data collection strategies were employed in a mixed methods approach: a sample survey of a cross-section of 534 FHHs, and in-depth interviews with 32 female heads purposively selected from among the survey participants. The findings and discussions include quantitative statistical and qualitative thematic analyses based on primary data, combined with secondary data from censuses, national survey reports and micro-studies of FHHs in Sri Lanka. 

The key findings show the diversity in profile of FHHs in the sample: they range from single person to large extended households. While some households consist of only the woman head and her young children, others comprise aged parents and a woman head. Households were also constituted of ‘working-age’ household members, including the female heads who were totally reliant on others for income and other resources. The study also revealed novel findings that challenge the emphasis of most conventional perceptions of poverty and female headship. From an economic perspective, the results show women from rich households can be personally poor, lacking, among others, in skills to manage household economies, while women in low-income brackets may be resilient, enterprising and satisfied with their needs, despite their apparent poverty. Finally, the thesis highlights the significant role of social capital, a relatively under-researched area in relation to FHHs. The findings reveal that many female heads in Sri Lanka are rich in social capital, a resource in its own right for these women. However, social capital itself needs to be disaggregated into ‘support networks’ and ‘leverage networks’ to understand the role it plays in providing long-term security and resilience. The results show that the majority of FHHs in the sample had access to support networks that provide day-to-day subsistence, but which did not offer them prospects to leverage out of their current situation.

year: 2014

title: Weaving the mat of Māori and Pacific learner success

authors: Tiakiwai, Sarah-Jane

subjects: Supporting learners, Pacific learner success, Māori learner success, higher education

abstract: The mat we are trying to weave at the University of Waikato to address educational outcomes, disparities and inequities in education for Māori and Pacific learners will weave rich data, stories and experience. Our goal is to use data to be better informed about what works for Māori and Pacific learners and what does not. Data is useful in building a more complete picture of what is happening to students, but student voice and previous research that has already captured the voices of Māori and Pacific experts, educators, students, families and communities can tell us more about why we are getting these outcomes. As we harness data to improve our knowledge, we must not forget the stories already in the mat and the stories being woven in the mat, for the stories are the gold.

This report details our work on this data-informed rather than data-driven project. It discusses how improved data and data analytic capability enhanced our understanding of the literature on Māori and Pacific learner success and the experience of Māori and Pacific learners at UoW. Our research and the report, however, also unapologetically privilege case studies through literature and Māori and Pacific student voices. We lay out the various materials – data, literature and voice – that will form our mat with this in mind, weaving them together in order to achieve better outcomes for Māori and Pacific learners at our university. These learners are the why of this mahi. Their success will create a beautiful pattern in the
weave.

text: Weaving the mat of Māori and Pacific learner success The mat we are trying to weave at the University of Waikato to address educational outcomes, disparities and inequities in education for Māori and Pacific learners will weave rich data, stories and experience. Our goal is to use data to be better informed about what works for Māori and Pacific learners and what does not. Data is useful in building a more complete picture of what is happening to students, but student voice and previous research that has already captured the voices of Māori and Pacific experts, educators, students, families and communities can tell us more about why we are getting these outcomes. As we harness data to improve our knowledge, we must not forget the stories already in the mat and the stories being woven in the mat, for the stories are the gold.

This report details our work on this data-informed rather than data-driven project. It discusses how improved data and data analytic capability enhanced our understanding of the literature on Māori and Pacific learner success and the experience of Māori and Pacific learners at UoW. Our research and the report, however, also unapologetically privilege case studies through literature and Māori and Pacific student voices. We lay out the various materials – data, literature and voice – that will form our mat with this in mind, weaving them together in order to achieve better outcomes for Māori and Pacific learners at our university. These learners are the why of this mahi. Their success will create a beautiful pattern in the
weave.

year: 2022-06