title: Vertical distributions of chlorophyll in deep, warm monomictic lakes

authors: Hamilton, David P.

subjects: phytoplankton

abstract: The factors affecting vertical distributions of chlorophyll fluorescence were examined in four temperate, warm monomictic lakes. Each of the lakes (maximum depth >80 m) was sampled over 2 years at intervals from monthly to seasonal. Profiles were taken of chlorophyll fluorescence (as a proxy for algal biomass), temperature and irradiance, as well as integrated samples from the surface mixed layer for chlorophyll a (chl a) and nutrient concentrations in each lake. Depth profiles of chlorophyll fluorescence were also made along transects of the longest axis of each lake. Chlorophyll fluorescence maxima occurred at depths closely correlated with euphotic depth (r ² = 0.67, P < 0.01), which varied with nutrient status of the lakes. While seasonal thermal density stratification is a prerequisite for the existence of a deep chlorophyll maximum (DCM), our study provides evidence that the depth of light penetration largely dictates the DCM depth during stratification. Reduction in water clarity through eutrophication can cause a shift in phytoplankton distributions from a DCM in spring or summer to a surface chlorophyll maximum within the surface mixed layer when the depth of the euphotic zone (z eu) is consistently shallower than the depth of the surface mixed layer (z SML). Trophic status has a key role in determining vertical distributions of chlorophyll in the four lakes, but does not appear to disrupt the annual cycle of maximum chlorophyll in winter.

text: Vertical distributions of chlorophyll in deep, warm monomictic lakes The factors affecting vertical distributions of chlorophyll fluorescence were examined in four temperate, warm monomictic lakes. Each of the lakes (maximum depth >80 m) was sampled over 2 years at intervals from monthly to seasonal. Profiles were taken of chlorophyll fluorescence (as a proxy for algal biomass), temperature and irradiance, as well as integrated samples from the surface mixed layer for chlorophyll a (chl a) and nutrient concentrations in each lake. Depth profiles of chlorophyll fluorescence were also made along transects of the longest axis of each lake. Chlorophyll fluorescence maxima occurred at depths closely correlated with euphotic depth (r ² = 0.67, P < 0.01), which varied with nutrient status of the lakes. While seasonal thermal density stratification is a prerequisite for the existence of a deep chlorophyll maximum (DCM), our study provides evidence that the depth of light penetration largely dictates the DCM depth during stratification. Reduction in water clarity through eutrophication can cause a shift in phytoplankton distributions from a DCM in spring or summer to a surface chlorophyll maximum within the surface mixed layer when the depth of the euphotic zone (z eu) is consistently shallower than the depth of the surface mixed layer (z SML). Trophic status has a key role in determining vertical distributions of chlorophyll in the four lakes, but does not appear to disrupt the annual cycle of maximum chlorophyll in winter.

year: 2010

title: Social capital and regional social infrastructure investment: Evidence from New Zealand

authors: Roskruge, Matthew James

subjects: social capital

abstract: In this article, we link unique data on local social infrastructure expenditure with microlevel individual survey data of self-reported social capital measures of trust and participation in community activities. We use both probit and tobit models to estimate the impact of social infrastructure expenditure on social capital formation. Our results imply that the links between social capital, demographic characteristics, human capital, geography, and public social infrastructure investment are rather more subtle and complex than much of the literature implies. While we find evidence in support of many of the hypothesized relationships discussed in the social capital literature, our results also suggest that the impact of public social infrastructure investment is affected by both selection effects and free rider processes.

text: Social capital and regional social infrastructure investment: Evidence from New Zealand In this article, we link unique data on local social infrastructure expenditure with microlevel individual survey data of self-reported social capital measures of trust and participation in community activities. We use both probit and tobit models to estimate the impact of social infrastructure expenditure on social capital formation. Our results imply that the links between social capital, demographic characteristics, human capital, geography, and public social infrastructure investment are rather more subtle and complex than much of the literature implies. While we find evidence in support of many of the hypothesized relationships discussed in the social capital literature, our results also suggest that the impact of public social infrastructure investment is affected by both selection effects and free rider processes.

year: 2012

title: Kaupapa Māori framework and literature review of key prinicples

authors: Kennedy, Nathan

subjects: New Zealand

abstract: The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

text: Kaupapa Māori framework and literature review of key prinicples The literature review in this report was the starting point for the development of a Māori research strand within the Planning Under Co-operative Mandates (PUCM) research programme. The original purpose of this report Kaupapa Māori Framework and Literature Review of Key Principles was to establish definitions of environmentally significant concepts of kaupapa and tikanga Māori. In  addition,  the  review  sought  to  identify  and  briefly  describe  significant  variations between  understandings of the key concepts without attempting to reconcile these. As the purpose of the review in 2005 was to inform the development of a kaupapa Māori methodology for the identification and development of Māori environmental outcomes and indicators, we paid particular regard to Māori perceptions of the environment and the relevance of each concept in environmental terms.

year: 2009-06-30