title: Development of mechatronic dibbling machine for improving the quality of forestry seedlings

authors: Duke, Mike

subjects: forestry

abstract: A forestry nursery in Tokoroa, New Zealand grows approximately 3 million Radiata pine seedlings per annum of which about 65% (2 million) are of suitable quality for forestry plantations. The high rejection rate of 35% was attributed to poorly trained, seasonal workers and unsophisticated equipment. It was estimated that about 22% of seedling rejection (approximately 220,000 per year) was due to poorly dibbled holes that caused bends in the stems. The bends occurred when planters pinched the stems of the seedlings in an attempt to make them vertical. A research and development project was undertaken to develop a mechatronic dibbling machine that could produce vertical holes of specified depth. The machine also had to produce 120,000 holes per day and be flexible with regard to spacing and size. The completed mechatronic dibbling machine was tested at the Tokoroa nursery and produced 98% of the holes at the required angle and 100% of useable depth. Harvesting, the following season, showed that the unwanted stem bends had been eliminated with a subsequent reduction in rejects. Furthermore, it was found that worker productivity increased by approximately 10% as they did not have to spend time setting seedlings vertically.

text: Development of mechatronic dibbling machine for improving the quality of forestry seedlings A forestry nursery in Tokoroa, New Zealand grows approximately 3 million Radiata pine seedlings per annum of which about 65% (2 million) are of suitable quality for forestry plantations. The high rejection rate of 35% was attributed to poorly trained, seasonal workers and unsophisticated equipment. It was estimated that about 22% of seedling rejection (approximately 220,000 per year) was due to poorly dibbled holes that caused bends in the stems. The bends occurred when planters pinched the stems of the seedlings in an attempt to make them vertical. A research and development project was undertaken to develop a mechatronic dibbling machine that could produce vertical holes of specified depth. The machine also had to produce 120,000 holes per day and be flexible with regard to spacing and size. The completed mechatronic dibbling machine was tested at the Tokoroa nursery and produced 98% of the holes at the required angle and 100% of useable depth. Harvesting, the following season, showed that the unwanted stem bends had been eliminated with a subsequent reduction in rejects. Furthermore, it was found that worker productivity increased by approximately 10% as they did not have to spend time setting seedlings vertically.

year: 2016

title: Global relationships in tree functional traits.

authors: Maynard, D.S.

subjects: Biodiversity

abstract: Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.

text: Global relationships in tree functional traits. Due to massive energetic investments in woody support structures, trees are subject to unique physiological, mechanical, and ecological pressures not experienced by herbaceous plants. Despite a wealth of studies exploring trait relationships across the entire plant kingdom, the dominant traits underpinning these unique aspects of tree form and function remain unclear. Here, by considering 18 functional traits, encompassing leaf, seed, bark, wood, crown, and root characteristics, we quantify the multidimensional relationships in tree trait expression. We find that nearly half of trait variation is captured by two axes: one reflecting leaf economics, the other reflecting tree size and competition for light. Yet these orthogonal axes reveal strong environmental convergence, exhibiting correlated responses to temperature, moisture, and elevation. By subsequently exploring multidimensional trait relationships, we show that the full dimensionality of trait space is captured by eight distinct clusters, each reflecting a unique aspect of tree form and function. Collectively, this work identifies a core set of traits needed to quantify global patterns in functional biodiversity, and it contributes to our fundamental understanding of the functioning of forests worldwide.

year: 2022-06-08

title: Indigenous people in Aotearoa New Zealand are overrepresented in cannabis convictions

authors: Rapana, Wetini

subjects: Cannabis

abstract: Background: Previous work has demonstrated that cannabis laws have had a disproportionate impact on Māori, the Indigenous people of Aotearoa New Zealand. In 2019, the New Zealand Government amended cannabis laws, providing police with the power to determine whether a therapeutic or health-centred approach would be more beneficial than a conviction. In the current study, we use population level data to assess whether this law change has ameliorated the bias in cannabis convictions for Māori. Methods: Data were drawn from the Integrated Data Infrastructure (IDI), a large government database hosted by Aotearoa New Zealand’s national statistics office. In the IDI, we selected individuals who (1) were between 18 and 65, (2) were Māori or Pākehā (New Zealanders of European descent) and, (3) had any cannabis charges that proceeded to the courts. Results: Māori ethnicity was a significant predictor of the odds of receiving a cannabis conviction for Māori males (Odds: 1.56), with a marginally significant effect for Māori females (Odds: 1.57). Further, for Māori, there was no reduction in the number of cannabis charges before vs. after the amendment to cannabis laws. Conclusion: The current study demonstrates that the bias in cannabis convictions for Māori remain. Given this, the New Zealand Government must follow other countries around the world and move forward on cannabis law reform.

text: Indigenous people in Aotearoa New Zealand are overrepresented in cannabis convictions Background: Previous work has demonstrated that cannabis laws have had a disproportionate impact on Māori, the Indigenous people of Aotearoa New Zealand. In 2019, the New Zealand Government amended cannabis laws, providing police with the power to determine whether a therapeutic or health-centred approach would be more beneficial than a conviction. In the current study, we use population level data to assess whether this law change has ameliorated the bias in cannabis convictions for Māori. Methods: Data were drawn from the Integrated Data Infrastructure (IDI), a large government database hosted by Aotearoa New Zealand’s national statistics office. In the IDI, we selected individuals who (1) were between 18 and 65, (2) were Māori or Pākehā (New Zealanders of European descent) and, (3) had any cannabis charges that proceeded to the courts. Results: Māori ethnicity was a significant predictor of the odds of receiving a cannabis conviction for Māori males (Odds: 1.56), with a marginally significant effect for Māori females (Odds: 1.57). Further, for Māori, there was no reduction in the number of cannabis charges before vs. after the amendment to cannabis laws. Conclusion: The current study demonstrates that the bias in cannabis convictions for Māori remain. Given this, the New Zealand Government must follow other countries around the world and move forward on cannabis law reform.

year: 2022