title: The associations between physical-test performance and match performance in women’s rugby sevens players

authors: Sella, Francesco Stefano

abstract: Evaluating the relationships between physical-test and match performance in team sports could be useful for training prescription and athlete evaluation. Here we investigated these relationships in women’s Rugby Sevens. Thirty provincial-representative players performed Bronco-fitness, countermovement-jump, acceleration, speed, and strength tests within two weeks before a two-day tournament. Match-running and match-action performance measures were provided by GPS units and video analysis. Generalised and general linear mixed models were employed to estimate the effect of a two standard-deviation difference in physical test measures on match measures. Effect magnitudes were assessed via standardisation (using the between player SD) and, for effects on tries scored, also via match winning (based on simulating matches). Evidence for substantial and trivial true magnitudes was provided by one-sided interval-hypothesis tests and Bayesian analysis. There was good evidence of positive effects of many physical-test measures on match high-intensity running, with large effects for jump height and acceleration. There was some evidence of small-moderate positive effects of speed and Bronco, and of small-moderate negative effects of maximal strength and jump height, on match total running and high intensity changes in speed. The evidence was generally inadequate for associations between physical-test measures and match actions, but there was good evidence of small-large positive effects of back squat and jump height on tries scored. Enhancing players’ jump height and back-squat performance might therefore increase the likelihood of match success in women’s Rugby Sevens.

text: The associations between physical-test performance and match performance in women’s rugby sevens players Evaluating the relationships between physical-test and match performance in team sports could be useful for training prescription and athlete evaluation. Here we investigated these relationships in women’s Rugby Sevens. Thirty provincial-representative players performed Bronco-fitness, countermovement-jump, acceleration, speed, and strength tests within two weeks before a two-day tournament. Match-running and match-action performance measures were provided by GPS units and video analysis. Generalised and general linear mixed models were employed to estimate the effect of a two standard-deviation difference in physical test measures on match measures. Effect magnitudes were assessed via standardisation (using the between player SD) and, for effects on tries scored, also via match winning (based on simulating matches). Evidence for substantial and trivial true magnitudes was provided by one-sided interval-hypothesis tests and Bayesian analysis. There was good evidence of positive effects of many physical-test measures on match high-intensity running, with large effects for jump height and acceleration. There was some evidence of small-moderate positive effects of speed and Bronco, and of small-moderate negative effects of maximal strength and jump height, on match total running and high intensity changes in speed. The evidence was generally inadequate for associations between physical-test measures and match actions, but there was good evidence of small-large positive effects of back squat and jump height on tries scored. Enhancing players’ jump height and back-squat performance might therefore increase the likelihood of match success in women’s Rugby Sevens.

year: 2022-11-18

title: The ecological consequences of stream sedimentation for freshwater macroinvertebrates in the Te Awanui/Tauranga Harbour catchment

authors: Lea, Brooklyn

subjects: freshwater ecology

abstract: Sedimentation is a significant stressor in streams and rivers globally. The natural sediment regime 
paradigm posits that human activities have greatly altered the natural transport of sediment in river 
networks and that land-uses leading to increased bank erosion and surface runoff have resulted in 
large quantities of fine sediment being deposited in streams and rivers. In New Zealand, land 
conversion from native forest to pastoral agriculture has dramatically increased riverine sediment 
loads, making deposited fine sediment (DFS) a major stressor that negatively impacts stream 
ecosystem health. Consequently, DFS is an important attribute managed under the National Policy 
Statement for Freshwater Management 2020. However, uncertainties remain in how best to 
monitor the effects of DFS, and what impacts different land-use types have on stream ecosystems 
in addition to the adverse influence of sedimentation.  
In my study, I surveyed 24 stream sites allocated evenly to three land-use types (native forest, 
pastoral agriculture, and horticulture, e.g. kiwifruit orchards) in the Tauranga Harbour basin. I 
measured habitat attributes, including DFS, and sampled stream macroinvertebrate communities 
at each site. Using macroinvertebrate data, I calculated and compared taxonomic and trait-based 
metrics as indicators of ecosystem health across land-use types. I used a variety of metrics, 
including the Macroinvertebrate Community Index (MCI) and its quantitative equivalent, the 
QMCI, the Average Score Per Metric (ASPM) index, and community-weighted mean trait 
abundances, including facets of functional diversity to assess impacts on stream health.  
I found that human land uses negatively influenced stream health, indicated by greatly reduced 
MCI, QMCI, and ASPM scores. Although DFS explained most of the negative influences on 
macroinvertebrate communities in pastoral and horticultural streams, there were differences 
between native forest and horticultural streams not accounted for by DFS that contributed to 
declines in ecosystem health. I also found that sediment-specific macroinvertebrate metrics 
(sediment ‘decreasers’) were the best indicators of DFS impacts on stream health. Contrary to my 
predictions, I did not find that functional diversity was strongly reduced by land use or DFS, 
although several key traits responded to these stressors. Notably, life history trait modalities 
involving the number of reproductive cycles per year and oviposition site responded strongly to 
DFS and land use, indicating potential mechanisms contributing towards the impacts of these 
stressors on macroinvertebrate communities.  
ii 
My study points to the need to continuously manage the deposition of fine sediment in streams to 
help mitigate the adverse effects of human land use. Future research should further explore the 
role that fine sediment and other stressors associated with human land uses play in the degradation 
of streams ecosystems in the Tauranga Harbour basin. Quantifying land use and land cover 
(LULC) attributes using geospatial tools will help further explore the relationship between 
catchment properties and macroinvertebrate responses. Additionally, issues regarding trait 
syndromes, trade-offs, and database inconsistencies must be addressed to better understand the 
mechanistic links between specific macroinvertebrate traits and fine sediment.

text: The ecological consequences of stream sedimentation for freshwater macroinvertebrates in the Te Awanui/Tauranga Harbour catchment Sedimentation is a significant stressor in streams and rivers globally. The natural sediment regime 
paradigm posits that human activities have greatly altered the natural transport of sediment in river 
networks and that land-uses leading to increased bank erosion and surface runoff have resulted in 
large quantities of fine sediment being deposited in streams and rivers. In New Zealand, land 
conversion from native forest to pastoral agriculture has dramatically increased riverine sediment 
loads, making deposited fine sediment (DFS) a major stressor that negatively impacts stream 
ecosystem health. Consequently, DFS is an important attribute managed under the National Policy 
Statement for Freshwater Management 2020. However, uncertainties remain in how best to 
monitor the effects of DFS, and what impacts different land-use types have on stream ecosystems 
in addition to the adverse influence of sedimentation.  
In my study, I surveyed 24 stream sites allocated evenly to three land-use types (native forest, 
pastoral agriculture, and horticulture, e.g. kiwifruit orchards) in the Tauranga Harbour basin. I 
measured habitat attributes, including DFS, and sampled stream macroinvertebrate communities 
at each site. Using macroinvertebrate data, I calculated and compared taxonomic and trait-based 
metrics as indicators of ecosystem health across land-use types. I used a variety of metrics, 
including the Macroinvertebrate Community Index (MCI) and its quantitative equivalent, the 
QMCI, the Average Score Per Metric (ASPM) index, and community-weighted mean trait 
abundances, including facets of functional diversity to assess impacts on stream health.  
I found that human land uses negatively influenced stream health, indicated by greatly reduced 
MCI, QMCI, and ASPM scores. Although DFS explained most of the negative influences on 
macroinvertebrate communities in pastoral and horticultural streams, there were differences 
between native forest and horticultural streams not accounted for by DFS that contributed to 
declines in ecosystem health. I also found that sediment-specific macroinvertebrate metrics 
(sediment ‘decreasers’) were the best indicators of DFS impacts on stream health. Contrary to my 
predictions, I did not find that functional diversity was strongly reduced by land use or DFS, 
although several key traits responded to these stressors. Notably, life history trait modalities 
involving the number of reproductive cycles per year and oviposition site responded strongly to 
DFS and land use, indicating potential mechanisms contributing towards the impacts of these 
stressors on macroinvertebrate communities.  
ii 
My study points to the need to continuously manage the deposition of fine sediment in streams to 
help mitigate the adverse effects of human land use. Future research should further explore the 
role that fine sediment and other stressors associated with human land uses play in the degradation 
of streams ecosystems in the Tauranga Harbour basin. Quantifying land use and land cover 
(LULC) attributes using geospatial tools will help further explore the relationship between 
catchment properties and macroinvertebrate responses. Additionally, issues regarding trait 
syndromes, trade-offs, and database inconsistencies must be addressed to better understand the 
mechanistic links between specific macroinvertebrate traits and fine sediment.

year: 2024

title: Two-step human−environmental impact history for northern New Zealand linked to late-Holocene climate change

authors: Newnham, Rewi M.

subjects: New Zealand

abstract: Following resolution of a long-standing debate over the timing of the initial settlement of New Zealand from Polynesia (late 13th century), a prevailing paradigm has developed that invokes rapid transformation of the landscape, principally by fire, within a few decades of the first arrivals. This model has been constructed from evidence mostly from southern and eastern regions of New Zealand, but a more complicated pattern may apply in the more humid western and northern regions where forests are more resilient to burning. We present a new pollen record from Lake Pupuke, Auckland, northern New Zealand, that charts the changing vegetation cover over the last 1000 years, before and after the arrival of people. Previous results from this site concurred with the rapid transformation model, although sampling resolution, chronology and sediment disturbance make that interpretation equivocal. Our new record is dated principally by tephrochronology together with radiocarbon dating, and includes a cryptotephra deposit identified as Kaharoa tephra, a key marker for first settlement in northern New Zealand. Its discovery and stratigraphic position below two Rangitoto-derived tephras enables a clearer picture of environmental change to be drawn. The new pollen record shows an early phase (step 1) of minor, localised forest clearance around the time of Kaharoa tephra (c. 1314 AD) followed by a later, more extensive deforestation phase (step 2) commencing at around the time of deposition of the Rangitoto tephras (c. 1400‒1450 AD). This pattern, which needs to be corroborated from other well-resolved records from northern New Zealand, concurs with an emerging hypothesis that the ‘Little Ice Age’ had a significant impact on pre-European Māori with the onset of harsher conditions causing a consolidation of populations and later environmental impact in northern New Zealand.

text: Two-step human−environmental impact history for northern New Zealand linked to late-Holocene climate change Following resolution of a long-standing debate over the timing of the initial settlement of New Zealand from Polynesia (late 13th century), a prevailing paradigm has developed that invokes rapid transformation of the landscape, principally by fire, within a few decades of the first arrivals. This model has been constructed from evidence mostly from southern and eastern regions of New Zealand, but a more complicated pattern may apply in the more humid western and northern regions where forests are more resilient to burning. We present a new pollen record from Lake Pupuke, Auckland, northern New Zealand, that charts the changing vegetation cover over the last 1000 years, before and after the arrival of people. Previous results from this site concurred with the rapid transformation model, although sampling resolution, chronology and sediment disturbance make that interpretation equivocal. Our new record is dated principally by tephrochronology together with radiocarbon dating, and includes a cryptotephra deposit identified as Kaharoa tephra, a key marker for first settlement in northern New Zealand. Its discovery and stratigraphic position below two Rangitoto-derived tephras enables a clearer picture of environmental change to be drawn. The new pollen record shows an early phase (step 1) of minor, localised forest clearance around the time of Kaharoa tephra (c. 1314 AD) followed by a later, more extensive deforestation phase (step 2) commencing at around the time of deposition of the Rangitoto tephras (c. 1400‒1450 AD). This pattern, which needs to be corroborated from other well-resolved records from northern New Zealand, concurs with an emerging hypothesis that the ‘Little Ice Age’ had a significant impact on pre-European Māori with the onset of harsher conditions causing a consolidation of populations and later environmental impact in northern New Zealand.

year: 2018