title: Biodiversity enhances the multitrophic control of arthropod herbivory

authors: Barnes, Andrew D.

subjects: Science & Technology

abstract: Arthropod herbivores cause substantial economic costs that drive an increasing need to develop environmentally sustainable approaches to herbivore control. Increasing plant diversity is expected to limit herbivory by altering plant-herbivore and predator-herbivore interactions, but the simultaneous influence of these interactions on herbivore impacts remains unexplored. We compiled 487 arthropod food webs in two long-running grassland biodiversity experiments in Europe and North America to investigate whether and how increasing plant diversity can reduce the impacts of herbivores on plants. We show that plants lose just under half as much energy to arthropod herbivores when in high-diversity mixtures versus monocultures and reveal that plant diversity decreases effects of herbivores on plants by simultaneously benefiting predators and reducing average herbivore food quality. These findings demonstrate that conserving plant diversity is crucial for maintaining interactions in food webs that provide natural control of herbivore pests.

text: Biodiversity enhances the multitrophic control of arthropod herbivory Arthropod herbivores cause substantial economic costs that drive an increasing need to develop environmentally sustainable approaches to herbivore control. Increasing plant diversity is expected to limit herbivory by altering plant-herbivore and predator-herbivore interactions, but the simultaneous influence of these interactions on herbivore impacts remains unexplored. We compiled 487 arthropod food webs in two long-running grassland biodiversity experiments in Europe and North America to investigate whether and how increasing plant diversity can reduce the impacts of herbivores on plants. We show that plants lose just under half as much energy to arthropod herbivores when in high-diversity mixtures versus monocultures and reveal that plant diversity decreases effects of herbivores on plants by simultaneously benefiting predators and reducing average herbivore food quality. These findings demonstrate that conserving plant diversity is crucial for maintaining interactions in food webs that provide natural control of herbivore pests.

year: 2020-11-01

title: The post-antibiotic effect of manuka honey on gastrointestinal pathogens

authors: Lin, Shih-Min (Sam)

subjects: biology

abstract: An increasing number of studies have shown that honey has substantial antimicrobial activity [1]. This has mostly been demonstrated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests in which microorganisms are exposed to a constant level of honey for a long period. However, the efficacy of honey taken orally would be greatly affected by dilution in large amounts of body fluids and water from food and drink as well as by a short period of contact with bacterial cells owing to rapid peristalsis in the gastrointestinal tract. We therefore investigated how long it would take manuka honey to eliminate microorganisms and whether or not honey has a post-antibiotic effect (PAE) similar to other common drugs.

text: The post-antibiotic effect of manuka honey on gastrointestinal pathogens An increasing number of studies have shown that honey has substantial antimicrobial activity [1]. This has mostly been demonstrated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests in which microorganisms are exposed to a constant level of honey for a long period. However, the efficacy of honey taken orally would be greatly affected by dilution in large amounts of body fluids and water from food and drink as well as by a short period of contact with bacterial cells owing to rapid peristalsis in the gastrointestinal tract. We therefore investigated how long it would take manuka honey to eliminate microorganisms and whether or not honey has a post-antibiotic effect (PAE) similar to other common drugs.

year: 2010

title: Mātauranga Māori to inform understanding of population dynamics and health of pipi in Waihī Estuary, Bay of Plenty.

authors: Kettle, Tyla

abstract: Estuaries are among the most productive ecosystems on earth. They hold significant value to Māori as they connect the whenua (land), awa (river) and moana (ocean), and are an important source of kaimoana (seafood) including shellfish. However, due to increased anthropogenic pressures, many estuaries are degraded, affecting taonga (Māori treasure) species such as pipi (Paphies australis). My thesis uses kaupapa Māori methodology and is co-developed with Ngāti Whakahemo, tangata whenua (people of the land) of Waihī Estuary. This project fundamentally draws upon mātauranga Māori (traditional Māori knowledge), combined with western science to map the historic and current distribution, abundance and health of pipi in Waihī Estuary; as well as explore the perceptions of threats to pipi and estuary ecology from tangata whenua and the regional authority. 
Participatory mapping was used via kōrero/interviews with kaumātua to identify sites of significance for pipi, which were then sampled in November 2020. Mātauranga ā iwi from Ngāti Whakahemo informed the sampling locations. Previous pipi sampling methodology and protocols undertaken by the Ministry for Primary Industries (MPI) were used to facilitate temporal comparisons of pipi distribution and abundance. Environmental factors including sediment grain size, organic content, total nitrogen (TN) and total phosphorus (TP) were also measured to help understand what drives the population dynamics of pipi. Perceptions of tangata whenua and staff members of the Bay of Plenty Regional Council (BOPRC) were also explored following methods similar to Klain et al. (2018) and implementing a dread risk tool via participatory mapping.
Results show that culturally significant sites identified by kaumātua support high pipi abundances of large size (40mm+), with low abundances of pipi in the upper reaches of the estuary. The inclusion of sites identified by MPI allowed for more comprehensive survey on pipi population dynamics by utilising a stratified survey design. Pipi size and abundance was significantly correlated with environmental factors with high pipi densities associated with medium grain size fractions and low levels of TN, TP and organic content. Over harvesting was perceived by kaumātua and BOPRC staff members as the dominant threat to pipi abundance and Waihī Estuary. Nutrients related to sewage inputs and runoff were rated as the second highest perceived threat and diseased shellfish ranked third by kaumātua and BOPRC staff members. 
This study demonstrates that the sharing of mātauranga ā iwi can fundamentally inform western science methods and can be used as an approach to research in the marine science realm. The research space was shared by researchers and kaumātua, was honourable of the mātauranga, iwi voices were heard and a co-developed field survey plan/research plan was produced. Iwi concerns were made a priority throughout, and incorporated into the monitoring, mapping and management frameworks. Thus, I had a Māori-centred agenda which is important as Ngāti Whakahemo are looking to utilise the results from my research to inform their iwi environmental management plan. This approach will help to strengthen current marine management practices and in turn Aotearoa New Zealand’s ecosystems due to iwi environmental management plans being informed by such results.

text: Mātauranga Māori to inform understanding of population dynamics and health of pipi in Waihī Estuary, Bay of Plenty. Estuaries are among the most productive ecosystems on earth. They hold significant value to Māori as they connect the whenua (land), awa (river) and moana (ocean), and are an important source of kaimoana (seafood) including shellfish. However, due to increased anthropogenic pressures, many estuaries are degraded, affecting taonga (Māori treasure) species such as pipi (Paphies australis). My thesis uses kaupapa Māori methodology and is co-developed with Ngāti Whakahemo, tangata whenua (people of the land) of Waihī Estuary. This project fundamentally draws upon mātauranga Māori (traditional Māori knowledge), combined with western science to map the historic and current distribution, abundance and health of pipi in Waihī Estuary; as well as explore the perceptions of threats to pipi and estuary ecology from tangata whenua and the regional authority. 
Participatory mapping was used via kōrero/interviews with kaumātua to identify sites of significance for pipi, which were then sampled in November 2020. Mātauranga ā iwi from Ngāti Whakahemo informed the sampling locations. Previous pipi sampling methodology and protocols undertaken by the Ministry for Primary Industries (MPI) were used to facilitate temporal comparisons of pipi distribution and abundance. Environmental factors including sediment grain size, organic content, total nitrogen (TN) and total phosphorus (TP) were also measured to help understand what drives the population dynamics of pipi. Perceptions of tangata whenua and staff members of the Bay of Plenty Regional Council (BOPRC) were also explored following methods similar to Klain et al. (2018) and implementing a dread risk tool via participatory mapping.
Results show that culturally significant sites identified by kaumātua support high pipi abundances of large size (40mm+), with low abundances of pipi in the upper reaches of the estuary. The inclusion of sites identified by MPI allowed for more comprehensive survey on pipi population dynamics by utilising a stratified survey design. Pipi size and abundance was significantly correlated with environmental factors with high pipi densities associated with medium grain size fractions and low levels of TN, TP and organic content. Over harvesting was perceived by kaumātua and BOPRC staff members as the dominant threat to pipi abundance and Waihī Estuary. Nutrients related to sewage inputs and runoff were rated as the second highest perceived threat and diseased shellfish ranked third by kaumātua and BOPRC staff members. 
This study demonstrates that the sharing of mātauranga ā iwi can fundamentally inform western science methods and can be used as an approach to research in the marine science realm. The research space was shared by researchers and kaumātua, was honourable of the mātauranga, iwi voices were heard and a co-developed field survey plan/research plan was produced. Iwi concerns were made a priority throughout, and incorporated into the monitoring, mapping and management frameworks. Thus, I had a Māori-centred agenda which is important as Ngāti Whakahemo are looking to utilise the results from my research to inform their iwi environmental management plan. This approach will help to strengthen current marine management practices and in turn Aotearoa New Zealand’s ecosystems due to iwi environmental management plans being informed by such results.

year: 2021