title: Light requirements of Australian tropical vs. cool-temperate rainforest tree species show different relationships with seedling growth and functional traits

authors: Lusk, Christopher H.

subjects: Conduit diameter

abstract: Background and Aims A trade-off between shade tolerance and growth in high light is thought to underlie the temporal dynamics of humid forests. On the other hand, it has been suggested that tree species sorting on temperature gradients involves a trade-off between growth rate and cold resistance. Little is known about how these two major trade-offs interact.
Methods Seedlings of Australian tropical and cool-temperate rainforest trees were grown in glasshouse environments to compare growth versus shade-tolerance trade-offs in these two assemblages. Biomass distribution, photosynthetic capacity and vessel diameters were measured in order to examine the functional correlates of species differences in light requirements and growth rate. Species light requirements were assessed by ﬁeld estimation of the light compensation point for stem growth.
Results Light-demanding and shade-tolerant tropical species differed markedly in relative growth rates (RGR), but this trend was less evident among temperate species. This pattern was paralleled by biomass distribution data: speciﬁc leaf area (SLA) and leaf area ratio (LAR) of tropical species were signiﬁcantly positively correlated with compensation points, but not those of cool-temperate species. The relatively slow growth and small SLA and LAR of Tasmanian light-demanders were associated with narrow vessels and low potential sapwood conductivity.
Conclusions The conservative xylem traits, small LAR and modest RGR of Tasmanian light-demanders are consistent with selection for resistance to freeze–thaw embolism, at the expense of growth rate. Whereas competition for light favours rapid growth in light-demanding trees native to environments with warm, frost-free growing seasons, frost resistance may be an equally important determinant of the ﬁtness of light-demanders in cool-temperate rainforest, as seedlings establishing in large openings are exposed to sub-zero temperatures that can occur throughout most of the year.

text: Light requirements of Australian tropical vs. cool-temperate rainforest tree species show different relationships with seedling growth and functional traits Background and Aims A trade-off between shade tolerance and growth in high light is thought to underlie the temporal dynamics of humid forests. On the other hand, it has been suggested that tree species sorting on temperature gradients involves a trade-off between growth rate and cold resistance. Little is known about how these two major trade-offs interact.
Methods Seedlings of Australian tropical and cool-temperate rainforest trees were grown in glasshouse environments to compare growth versus shade-tolerance trade-offs in these two assemblages. Biomass distribution, photosynthetic capacity and vessel diameters were measured in order to examine the functional correlates of species differences in light requirements and growth rate. Species light requirements were assessed by ﬁeld estimation of the light compensation point for stem growth.
Results Light-demanding and shade-tolerant tropical species differed markedly in relative growth rates (RGR), but this trend was less evident among temperate species. This pattern was paralleled by biomass distribution data: speciﬁc leaf area (SLA) and leaf area ratio (LAR) of tropical species were signiﬁcantly positively correlated with compensation points, but not those of cool-temperate species. The relatively slow growth and small SLA and LAR of Tasmanian light-demanders were associated with narrow vessels and low potential sapwood conductivity.
Conclusions The conservative xylem traits, small LAR and modest RGR of Tasmanian light-demanders are consistent with selection for resistance to freeze–thaw embolism, at the expense of growth rate. Whereas competition for light favours rapid growth in light-demanding trees native to environments with warm, frost-free growing seasons, frost resistance may be an equally important determinant of the ﬁtness of light-demanders in cool-temperate rainforest, as seedlings establishing in large openings are exposed to sub-zero temperatures that can occur throughout most of the year.

year: 2013

title: Democracy vs. populism: the transformation of politics in Nigeria?

authors: Adeakin, Ibikunle

subjects: neo-liberal military-directed populism

abstract: Since the return of electoral democracy to Nigeria in 1999, two of the four elected presidents have been former military dictators who have stressed anti-corruption and national security policies in populist campaigns. As military dictators in previous years, they had instigated regimes that had practiced stern military discipline; as populists they have leaned toward these two policies. Reactions to civilian corruption and threats to national security have represented the primary military rationales for mil-itary intervention in the past. A popular vote in 2015 for former military dictator Gen- eral Muhammadu Buhari seems to have represented a continuing preference for popu- lism over democracy. We will examine the new populism in Nigeria, complicated as it is by questions of ethnicity, religion and military identity, with a view to explaining the like- ly outcome of the first peaceful transference of power from one political party to anoth- er in Africa’s most populous country.

text: Democracy vs. populism: the transformation of politics in Nigeria? Since the return of electoral democracy to Nigeria in 1999, two of the four elected presidents have been former military dictators who have stressed anti-corruption and national security policies in populist campaigns. As military dictators in previous years, they had instigated regimes that had practiced stern military discipline; as populists they have leaned toward these two policies. Reactions to civilian corruption and threats to national security have represented the primary military rationales for mil-itary intervention in the past. A popular vote in 2015 for former military dictator Gen- eral Muhammadu Buhari seems to have represented a continuing preference for popu- lism over democracy. We will examine the new populism in Nigeria, complicated as it is by questions of ethnicity, religion and military identity, with a view to explaining the like- ly outcome of the first peaceful transference of power from one political party to anoth- er in Africa’s most populous country.

year: 2017

title: Māori & Psychology Research Unit Annual Report 2012

authors: Waitoki, Waikaremoana

abstract: Annual report of the Māori and Psychology Research Unit (MPRU) 2012. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

text: Māori & Psychology Research Unit Annual Report 2012 Annual report of the Māori and Psychology Research Unit (MPRU) 2012. The unit was established in August of 1997. The unit is designed to provide a catalyst and support network for enhancing research concerning the psychological needs, aspirations, and priorities of Maori people. The MPRU is well situated to draw together skilled and experienced interdisciplinary research groups by networking and establishing working relationships with staff and students within the Faculty of Arts and Social Sciences, the University, and the wider community.

year: 2012