title: Consistent predator-prey biomass scaling in complex food webs

authors: Perkins, Daniel M.

subjects: Animals

abstract: The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure. Here, we address this shortcoming by characterising the biomass structure of 141 freshwater, marine and terrestrial food webs, spanning a broad gradient in community biomass. We test whether sub-linear scaling between predator and prey biomass (a potential signal of density-dependent processes) emerges within ecosystem types and across levels of biological organisation. We find a consistent, sub-linear scaling pattern whereby predator biomass scales with the total biomass of their prey with a near ¾-power exponent within food webs - i.e. more prey biomass supports proportionally less predator biomass. Across food webs, a similar sub-linear scaling pattern emerges between total predator biomass and the combined biomass of all prey within a food web. These general patterns in trophic structure are compatible with a systematic form of density dependence that holds among complex feeding interactions across levels of organization, irrespective of ecosystem type.

text: Consistent predator-prey biomass scaling in complex food webs The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure. Here, we address this shortcoming by characterising the biomass structure of 141 freshwater, marine and terrestrial food webs, spanning a broad gradient in community biomass. We test whether sub-linear scaling between predator and prey biomass (a potential signal of density-dependent processes) emerges within ecosystem types and across levels of biological organisation. We find a consistent, sub-linear scaling pattern whereby predator biomass scales with the total biomass of their prey with a near ¾-power exponent within food webs - i.e. more prey biomass supports proportionally less predator biomass. Across food webs, a similar sub-linear scaling pattern emerges between total predator biomass and the combined biomass of all prey within a food web. These general patterns in trophic structure are compatible with a systematic form of density dependence that holds among complex feeding interactions across levels of organization, irrespective of ecosystem type.

year: 2022-08-25

title: Conceptions, language, culture and mathematics and the New Zealand curriculum.

authors: Bailey, Judy

subjects: conceptions of mathematics

abstract: In this paper we explore two conceptions of mathematics that are evident in literature. Mathematics as a static body of knowledge is one conception, and another is of mathematics being an endeavour that is constructive and creative. With the release of The New Zealand Curriculum (Ministry of Education, 2007), we formalised our ongoing debates about these conceptions by constructing and using metaphors to explore and refine our ideas. In some parts of the curriculum document, there is juxtaposition with a conception of mathematics being social, constructive and creative. However, other aspects of the document appear to reflect the conception of mathematics as a body of knowledge. We express a concern that this latter conception of mathematics may become privileged over other possibilities. We therefore explore what constructive, creative mathematics might look like in a classroom.

text: Conceptions, language, culture and mathematics and the New Zealand curriculum. In this paper we explore two conceptions of mathematics that are evident in literature. Mathematics as a static body of knowledge is one conception, and another is of mathematics being an endeavour that is constructive and creative. With the release of The New Zealand Curriculum (Ministry of Education, 2007), we formalised our ongoing debates about these conceptions by constructing and using metaphors to explore and refine our ideas. In some parts of the curriculum document, there is juxtaposition with a conception of mathematics being social, constructive and creative. However, other aspects of the document appear to reflect the conception of mathematics as a body of knowledge. We express a concern that this latter conception of mathematics may become privileged over other possibilities. We therefore explore what constructive, creative mathematics might look like in a classroom.

year: 2010

title: Language switching in a digital library: Does it make a difference if the default language is set to Maori?

authors: Keegan, Te Taka Adrian Gregory

abstract: In this paper we investigate the effect of default interface language on usage patterns of the Niupepa digital library (a collection of historic Māori language newspapers), by switching the default interface language between Māori and English in alternate weeks.
Transaction analysis of the Niupepa collection logs indicates that changing default language affects the length of user
sessions and the number of actions within sessions, and that the English language interface was used most frequently.

text: Language switching in a digital library: Does it make a difference if the default language is set to Maori? In this paper we investigate the effect of default interface language on usage patterns of the Niupepa digital library (a collection of historic Māori language newspapers), by switching the default interface language between Māori and English in alternate weeks.
Transaction analysis of the Niupepa collection logs indicates that changing default language affects the length of user
sessions and the number of actions within sessions, and that the English language interface was used most frequently.

year: 2004-01-01