title: Quantifying relationships between land-use gradients and structural and functional indicators of stream ecological integrity

authors: Clapcott, Joanne E.

subjects: boosted regression

abstract: 1. Modification of natural landscapes and land-use intensification are global phenomena that can result in a range of differing pressures on lotic ecosystems. We analysed national-scale databases to quantify the relationship between three land uses (indigenous vegetation, urbanisation and agriculture) and indicators of stream ecological integrity. Boosted regression tree modelling was used to test the response of 14 indicators belonging to four groups – water quality (at 578 sites), benthic invertebrates (at 2666 sites), fish (at 6858 sites) and ecosystem processes (at 156 sites). Our aims were to characterise the ecological response curves of selected functional and structural metrics in relation to three land uses, examine the environmental moderators of these relationships and quantify the relative utility of metrics as indicators of stream ecological integrity.
2. The strongest indicators of land-use effects were nitrate + nitrite, delta-15 nitrogen value (δ15N) of primary consumers and the Macroinvertebrate Community Index (a biotic index of organic pollution), while the weakest overall indicators were gross primary productivity, benthic invertebrate richness and fish richness. All indicators declined in response to removal of indigenous vegetation and urbanisation, while variable responses to agricultural intensity were observed for some indicators.
3. The response curves for several indicators suggested distinct thresholds in response to urbanisation and agriculture, specifically at 10% impervious cover and at 0.1 g m−3 nitrogen concentration, respectively.
4. Water quality and ecosystem process indicators were influenced by a combination of temperature, slope and flow variables, whereas for macroinvertebrate indicators, catchment rainfall, segment slope and temperature were significant environmental predictor variables. Downstream variables (e.g. distance to the coast) were significant in explaining residual variation in fish indicators, not surprisingly given the preponderance of diadromous fish species in New Zealand waterways. The inclusion of continuous environmental variables used to develop a stream typology improved model performance more than the inclusion of stream type alone.
5. Our results reaffirm the importance of accounting for underlying spatial variation in the environment when quantifying relationships between land use and the ecological integrity of streams. Of distinctive interest, however, were the contrasting and complementary responses of different indicators of stream integrity to land use, suggesting that multiple indicators are required to identify land-use impact thresholds, develop environmental standards and assign ecological scores for reporting purposes.

text: Quantifying relationships between land-use gradients and structural and functional indicators of stream ecological integrity 1. Modification of natural landscapes and land-use intensification are global phenomena that can result in a range of differing pressures on lotic ecosystems. We analysed national-scale databases to quantify the relationship between three land uses (indigenous vegetation, urbanisation and agriculture) and indicators of stream ecological integrity. Boosted regression tree modelling was used to test the response of 14 indicators belonging to four groups – water quality (at 578 sites), benthic invertebrates (at 2666 sites), fish (at 6858 sites) and ecosystem processes (at 156 sites). Our aims were to characterise the ecological response curves of selected functional and structural metrics in relation to three land uses, examine the environmental moderators of these relationships and quantify the relative utility of metrics as indicators of stream ecological integrity.
2. The strongest indicators of land-use effects were nitrate + nitrite, delta-15 nitrogen value (δ15N) of primary consumers and the Macroinvertebrate Community Index (a biotic index of organic pollution), while the weakest overall indicators were gross primary productivity, benthic invertebrate richness and fish richness. All indicators declined in response to removal of indigenous vegetation and urbanisation, while variable responses to agricultural intensity were observed for some indicators.
3. The response curves for several indicators suggested distinct thresholds in response to urbanisation and agriculture, specifically at 10% impervious cover and at 0.1 g m−3 nitrogen concentration, respectively.
4. Water quality and ecosystem process indicators were influenced by a combination of temperature, slope and flow variables, whereas for macroinvertebrate indicators, catchment rainfall, segment slope and temperature were significant environmental predictor variables. Downstream variables (e.g. distance to the coast) were significant in explaining residual variation in fish indicators, not surprisingly given the preponderance of diadromous fish species in New Zealand waterways. The inclusion of continuous environmental variables used to develop a stream typology improved model performance more than the inclusion of stream type alone.
5. Our results reaffirm the importance of accounting for underlying spatial variation in the environment when quantifying relationships between land use and the ecological integrity of streams. Of distinctive interest, however, were the contrasting and complementary responses of different indicators of stream integrity to land use, suggesting that multiple indicators are required to identify land-use impact thresholds, develop environmental standards and assign ecological scores for reporting purposes.

year: 2012

title: Processing mathematics through digital technologies: A reorganisation of student thinking?

authors: Calder, Nigel Stuart

subjects: mathematical thinking

abstract: This article reports on aspects of an ongoing study examining the use of digital media in mathematics education. In particular, it is concerned with how understanding evolves when mathematical tasks are engaged through digital pedagogical media in primary school settings. While there has been a growing body of research into software and other digital media that enhances geometric, algebraic, and statistical thinking in secondary schools, research of these aspects in primary school mathematics is still limited, and emerging intermittently. The affordances of digital technology that allow dynamic, visual interaction with mathematical tasks, the rapid manipulation of large amounts of data, and instant feedback to input, have already been identified as ways mathematical ideas can be engaged in alternative ways. How might these, and other opportunities digital media afford, transform the learning experience and the ways mathematical ideas are understood? Using an interpretive methodology, the researcher examined how mathematical thinking can be seen as a function of the pedagogical media through which the mathematics is encountered. The article gives an account of how working in a spreadsheet environment framed learners' patterns of social interaction, and how this interaction, in conjunction with other influences, mediated the understanding of mathematical ideas, through framing the students' learning pathways and facilitating risk taking.

text: Processing mathematics through digital technologies: A reorganisation of student thinking? This article reports on aspects of an ongoing study examining the use of digital media in mathematics education. In particular, it is concerned with how understanding evolves when mathematical tasks are engaged through digital pedagogical media in primary school settings. While there has been a growing body of research into software and other digital media that enhances geometric, algebraic, and statistical thinking in secondary schools, research of these aspects in primary school mathematics is still limited, and emerging intermittently. The affordances of digital technology that allow dynamic, visual interaction with mathematical tasks, the rapid manipulation of large amounts of data, and instant feedback to input, have already been identified as ways mathematical ideas can be engaged in alternative ways. How might these, and other opportunities digital media afford, transform the learning experience and the ways mathematical ideas are understood? Using an interpretive methodology, the researcher examined how mathematical thinking can be seen as a function of the pedagogical media through which the mathematics is encountered. The article gives an account of how working in a spreadsheet environment framed learners' patterns of social interaction, and how this interaction, in conjunction with other influences, mediated the understanding of mathematical ideas, through framing the students' learning pathways and facilitating risk taking.

year: 2011

title: Anti-racism Allyship Amongst Psychologists and Students in Psychology Training in Aotearoa New Zealand

authors: Tan, Kyle K. H.

abstract: Racism is a well-established social determinant of health, impacting Māori, Pacific, and Asian communities in Aotearoa New Zealand. However, few scholarly studies have focused on racial justice allyship in Aotearoa, particularly within the psychology discipline. This study examines demographic and attitudinal factors associated with anti-racism allyship among psychologists and students in psychology training amidst escalating racist rhetoric and opposition to Māori self-determination in Aotearoa. Drawing data from an online anonymous survey (n = 280), we assessed participants’ responses on three scales: 1) Attitudes towards aspects of Māori (taha Māori); 2) Attitudes towards acknowledging the existence of racism and settler colonialism 3) Anti-racist allyship. Certain demographic groups (Pākehā, Asian, older-aged, male, or those who entered training decades ago) scored lower on these scales, indicating the need for targeted training. Regression analyses showed both ‘Attitudes towards taha Māori’ and ‘Attitudes towards racism and colonisation’ scales were significantly correlated with anti-racist allyship. Our findings call for a sustained investment in training anti-racist psychologists who are competent in providing culturally safe care and capable of challenging racial injustices. Future research is required on the development of a racial justice allyship model across all institutions that train, employ and regulate psychologists in Aotearoa that is informed by Te Tiriti o Waitangi.

text: Anti-racism Allyship Amongst Psychologists and Students in Psychology Training in Aotearoa New Zealand Racism is a well-established social determinant of health, impacting Māori, Pacific, and Asian communities in Aotearoa New Zealand. However, few scholarly studies have focused on racial justice allyship in Aotearoa, particularly within the psychology discipline. This study examines demographic and attitudinal factors associated with anti-racism allyship among psychologists and students in psychology training amidst escalating racist rhetoric and opposition to Māori self-determination in Aotearoa. Drawing data from an online anonymous survey (n = 280), we assessed participants’ responses on three scales: 1) Attitudes towards aspects of Māori (taha Māori); 2) Attitudes towards acknowledging the existence of racism and settler colonialism 3) Anti-racist allyship. Certain demographic groups (Pākehā, Asian, older-aged, male, or those who entered training decades ago) scored lower on these scales, indicating the need for targeted training. Regression analyses showed both ‘Attitudes towards taha Māori’ and ‘Attitudes towards racism and colonisation’ scales were significantly correlated with anti-racist allyship. Our findings call for a sustained investment in training anti-racist psychologists who are competent in providing culturally safe care and capable of challenging racial injustices. Future research is required on the development of a racial justice allyship model across all institutions that train, employ and regulate psychologists in Aotearoa that is informed by Te Tiriti o Waitangi.

year: 2025