title: Conservative leaf economic traits correlate with fast growth of genotypes of a foundation riparian species near the thermal maximum extent of its geographic range

authors: Grady, Kevin C.

subjects: assisted migration

abstract: Plant functional traits involved in carbon and water acquisition are likely to be adaptive across the range of a species if the availability of these resources varies across this range and are limiting to growth or fitness. At the interspecific level, leaf economic traits associated with rapid resource capture are correlated with fast growth rates. However, relationships between leaf traits and growth are poorly understood at the intraspecific level.
We examined two hypotheses: (i) leaf traits vary genotypically among Populus fremontii populations from different thermal environments; and (ii) leaf traits are related to growth rate of these P. fremontii populations. We used a common garden at the warm edge of P. fremontii distribution that included individuals transplanted from 11 provenances. Provenances varied in mean annual maximum temperature by 5·9 °C, reflecting a range of expected increases in temperature over the next 80 years.
Conservative leaf traits (e.g. low specific leaf area, N content, stomatal conductance, net photosynthetic rate and high leaf water-use efficiency) were positively related to growth rates of genotypes and populations, a pattern opposite of that widely reported among species in other studies.
Provenance temperature explained 75% of the variation in multivariate leaf traits with the warmest provenances having the most conservative traits and highest growth rates. Clinal genetic variation suggests that P. fremontii may be adapted to thermal environments.
Leaf area-to-sapwood area ratio was positively associated with growth rate, while leaf area-based net photosynthetic rate was negatively associated with growth rate; these results suggest that hydraulic architecture was more important than leaf-level photosynthetic rate in determining growth rate.
Synthesis. Our results suggest that conservative leaf traits promote rapid growth of P. fremontii genotypes in extremely hot environments. Thus, relationships between leaf economic traits among species do not necessarily apply to the range of variation among genotypes within species. The generality of this pattern should be examined for other species that will be exposed to climate warming. Moreover, our research shows that common garden provenance trials are useful for identifying genotypes best suited to a predicted warmer climate and for improving understanding of the physiological basis for adaptation to warm environments.

text: Conservative leaf economic traits correlate with fast growth of genotypes of a foundation riparian species near the thermal maximum extent of its geographic range Plant functional traits involved in carbon and water acquisition are likely to be adaptive across the range of a species if the availability of these resources varies across this range and are limiting to growth or fitness. At the interspecific level, leaf economic traits associated with rapid resource capture are correlated with fast growth rates. However, relationships between leaf traits and growth are poorly understood at the intraspecific level.
We examined two hypotheses: (i) leaf traits vary genotypically among Populus fremontii populations from different thermal environments; and (ii) leaf traits are related to growth rate of these P. fremontii populations. We used a common garden at the warm edge of P. fremontii distribution that included individuals transplanted from 11 provenances. Provenances varied in mean annual maximum temperature by 5·9 °C, reflecting a range of expected increases in temperature over the next 80 years.
Conservative leaf traits (e.g. low specific leaf area, N content, stomatal conductance, net photosynthetic rate and high leaf water-use efficiency) were positively related to growth rates of genotypes and populations, a pattern opposite of that widely reported among species in other studies.
Provenance temperature explained 75% of the variation in multivariate leaf traits with the warmest provenances having the most conservative traits and highest growth rates. Clinal genetic variation suggests that P. fremontii may be adapted to thermal environments.
Leaf area-to-sapwood area ratio was positively associated with growth rate, while leaf area-based net photosynthetic rate was negatively associated with growth rate; these results suggest that hydraulic architecture was more important than leaf-level photosynthetic rate in determining growth rate.
Synthesis. Our results suggest that conservative leaf traits promote rapid growth of P. fremontii genotypes in extremely hot environments. Thus, relationships between leaf economic traits among species do not necessarily apply to the range of variation among genotypes within species. The generality of this pattern should be examined for other species that will be exposed to climate warming. Moreover, our research shows that common garden provenance trials are useful for identifying genotypes best suited to a predicted warmer climate and for improving understanding of the physiological basis for adaptation to warm environments.

year: 2013

title: Threshold cointegration and the short-run dynamics of twin deficit behaviour

authors: Holmes, Mark J.

subjects: current account balance

abstract: This paper examines the relationship between the current account and budget balances by means of a threshold cointegration approach advocated by Hansen and Seo (2002). Using US data covering 1947–2009, a long-run positive cointegrating relationship is confirmed. This supports the notion of a Keynesian twin deficits relationship. The short-run dynamics are investigated through an estimated threshold vector error correction model. Depending on the regime present, it is either the external or internal balance that is responsible for error correction. This has important implications for the use of fiscal policy to control the external balance.

text: Threshold cointegration and the short-run dynamics of twin deficit behaviour This paper examines the relationship between the current account and budget balances by means of a threshold cointegration approach advocated by Hansen and Seo (2002). Using US data covering 1947–2009, a long-run positive cointegrating relationship is confirmed. This supports the notion of a Keynesian twin deficits relationship. The short-run dynamics are investigated through an estimated threshold vector error correction model. Depending on the regime present, it is either the external or internal balance that is responsible for error correction. This has important implications for the use of fiscal policy to control the external balance.

year: 2010

title: Iwi, institutes, societies & community led initiatives

authors: Whaanga, Hēmi

abstract: With the rapid evolution, innovation and incredible growth of ICT, the avenues to exchange, access, manage, create, disseminate, display and research Indigenous data and Mātauranga Māori have increased at astounding rates. This generation, often referred to as ‘digital natives', ‘homo zappiëns’, ‘Net generation’, ‘millennials’, ‘i-generation’ (see, for example Akçayır, Dündar, & Akçayır, 2016; Kirschner & De Bruyckere, 2017; Prensky, 2001; Yong & Gates, 2014), have been raised, immersed and exposed to a myriad of digital technologies, video games, computers, digital music players and cellular phones during their brief lifetimes. Technologies have dramatically transformed how each generation access, communicate, share knowledge, distribute and view information. Social networks like Facebook, YouTube, Instagram, Twitter, Reddit, Pinterest, Tumblr and social networking apps such as Messenger, WhatsApp, WeChat, QQ Chat, QZone, Viber, LINE, and Snapchat, with billons of active users per month, are as familiar to this generation as was the radio, television and landline telephones to the Baby Boomers who grew up with pre-cellphone mobile technology.

text: Iwi, institutes, societies & community led initiatives With the rapid evolution, innovation and incredible growth of ICT, the avenues to exchange, access, manage, create, disseminate, display and research Indigenous data and Mātauranga Māori have increased at astounding rates. This generation, often referred to as ‘digital natives', ‘homo zappiëns’, ‘Net generation’, ‘millennials’, ‘i-generation’ (see, for example Akçayır, Dündar, & Akçayır, 2016; Kirschner & De Bruyckere, 2017; Prensky, 2001; Yong & Gates, 2014), have been raised, immersed and exposed to a myriad of digital technologies, video games, computers, digital music players and cellular phones during their brief lifetimes. Technologies have dramatically transformed how each generation access, communicate, share knowledge, distribute and view information. Social networks like Facebook, YouTube, Instagram, Twitter, Reddit, Pinterest, Tumblr and social networking apps such as Messenger, WhatsApp, WeChat, QQ Chat, QZone, Viber, LINE, and Snapchat, with billons of active users per month, are as familiar to this generation as was the radio, television and landline telephones to the Baby Boomers who grew up with pre-cellphone mobile technology.

year: 2017