title: Catchment land use and trophic state impacts on phytoplankton composition: a case study from the Rotorua lakes’ district, New Zealand

authors: Paul, Wendy J.

subjects: bacillariophyta

abstract: Trophic state of lakes has been related to catchment land use, but direct links between phytoplankton taxa and land use are limited. Phytoplankton composition, represented by relative cell abundance of phyla, was measured over a period of 4 years in 11 lakes in the Rotorua region, New Zealand. The lakes differed in morphometry, trophic state and land use (as percentage catchment area). We tested whether relative proportion of land uses, indirectly representing relative nutrient loading, was the overarching driver of phytoplankton composition. Trophic state was correlated negatively with native forest and positively with pasture and urban area. Cyanoprokaryota were correlated negatively with native forest and positively with pasture and trophic state, Chlorophyta were correlated positively with native forest and urban land use and negatively with pasture and trophic state, and Bacillariophyta were positively correlated with dissolved reactive silica to dissolved inorganic nitrogen (Si:DIN) and Si to dissolved reactive phosphorus (Si:DRP) ratios. Lakes with higher nutrient loads had higher trophic state and Cyanoprokaryota dominance. Chlorophyta were negatively correlated with Cyanoprokaryota and Bacillariophyta, suggesting competition amongst these groups. Our results apply to lakes potentially subject to changes in catchment land use, which may have implications for trophic state, phytoplankton composition and Cyanoprokaryota blooms.

text: Catchment land use and trophic state impacts on phytoplankton composition: a case study from the Rotorua lakes’ district, New Zealand Trophic state of lakes has been related to catchment land use, but direct links between phytoplankton taxa and land use are limited. Phytoplankton composition, represented by relative cell abundance of phyla, was measured over a period of 4 years in 11 lakes in the Rotorua region, New Zealand. The lakes differed in morphometry, trophic state and land use (as percentage catchment area). We tested whether relative proportion of land uses, indirectly representing relative nutrient loading, was the overarching driver of phytoplankton composition. Trophic state was correlated negatively with native forest and positively with pasture and urban area. Cyanoprokaryota were correlated negatively with native forest and positively with pasture and trophic state, Chlorophyta were correlated positively with native forest and urban land use and negatively with pasture and trophic state, and Bacillariophyta were positively correlated with dissolved reactive silica to dissolved inorganic nitrogen (Si:DIN) and Si to dissolved reactive phosphorus (Si:DRP) ratios. Lakes with higher nutrient loads had higher trophic state and Cyanoprokaryota dominance. Chlorophyta were negatively correlated with Cyanoprokaryota and Bacillariophyta, suggesting competition amongst these groups. Our results apply to lakes potentially subject to changes in catchment land use, which may have implications for trophic state, phytoplankton composition and Cyanoprokaryota blooms.

year: 2012

title: Improved electrical efficiency by active cooling of building integrated photovoltaic panels

authors: Anderson, Timothy Nicholas

subjects: photovoltaics

abstract: The electrical efficiency of photovoltaic devices can be directly related to the temperature of the photovoltaic cells. The ability to actively cool building integrated photovoltaic solar panels allows their electrical efficiency to be maintained during periods of high solar radiation. Furthermore, the ability to capture and store heat from building integrated photovoltaic panels presents the opportunity for building integrated photovoltaic thermal (BIPVT) solar collectors. In this study a BIPVT solar collector was analysed and key parameters affecting its electrical efficiency were identified.

text: Improved electrical efficiency by active cooling of building integrated photovoltaic panels The electrical efficiency of photovoltaic devices can be directly related to the temperature of the photovoltaic cells. The ability to actively cool building integrated photovoltaic solar panels allows their electrical efficiency to be maintained during periods of high solar radiation. Furthermore, the ability to capture and store heat from building integrated photovoltaic panels presents the opportunity for building integrated photovoltaic thermal (BIPVT) solar collectors. In this study a BIPVT solar collector was analysed and key parameters affecting its electrical efficiency were identified.

year: 2007

title: Kai whakakitenga-nui te whakatōhea: Whenua planning for kai security

authors: Maxwell, Te Kahautu

abstract: To exercise Tino Rangatiratanga in our pursuit to define our local food systems through the traditional knowledge and practice of growing kai that will inspire and transform the health and well-being of all Whakatōhea, Whānau, Hapū, Iwi.

text: Kai whakakitenga-nui te whakatōhea: Whenua planning for kai security To exercise Tino Rangatiratanga in our pursuit to define our local food systems through the traditional knowledge and practice of growing kai that will inspire and transform the health and well-being of all Whakatōhea, Whānau, Hapū, Iwi.

year: 2025