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: Identification of the floral source of New Zealand honeys

authors: Petchell, Laura Eleanor

subjects: Honey

abstract: Depending on the nectar source, honey is either unifloral (derived mostly from one plant type), or polyfloral (derived from multiple plant types). Unifloral honey has characteristic sensory properties, and is therefore of greater commercial value. Currently, identification of floral source involves pollen counting, a specialised and labour intensive process. The current research was aimed at developing an alternative, rapid, chemistry-based method of floral identification. The aroma of honey depends on volatile compounds present; these may be derived from the plant from which nectar was taken. Therefore by identifying volatiles in honey it could be possible to identify floral source. Solid-phase microextraction (SPME) is a technique that is useful for the headspace analysis of volatile compounds; when coupled with GC-MS it provides a powerful tool for fingerprinting volatiles in honey. GC-MS chromatograms of ten New Zealand unifloral honey types were obtained after headspace SPME extraction. Statistical analysis of the GC-MS chromatographic data was used to discriminate between floral types. Probability plots were used to identify compounds indicative of floral source; this method discriminated between honey types with 90% success. Hierarchical cluster analysis and principal component analysis were used to study the structure of the data. Learning algorithms in Weka (machine-learning software) were used to build models of data to classify honey types. The logistic model tree algorithm classified 89.8% of samples correctly. Such a model has the potential to be used to classify future honey samples, once further samples have been tested to validate the model.

text: Identification of the floral source of New Zealand honeys Depending on the nectar source, honey is either unifloral (derived mostly from one plant type), or polyfloral (derived from multiple plant types). Unifloral honey has characteristic sensory properties, and is therefore of greater commercial value. Currently, identification of floral source involves pollen counting, a specialised and labour intensive process. The current research was aimed at developing an alternative, rapid, chemistry-based method of floral identification. The aroma of honey depends on volatile compounds present; these may be derived from the plant from which nectar was taken. Therefore by identifying volatiles in honey it could be possible to identify floral source. Solid-phase microextraction (SPME) is a technique that is useful for the headspace analysis of volatile compounds; when coupled with GC-MS it provides a powerful tool for fingerprinting volatiles in honey. GC-MS chromatograms of ten New Zealand unifloral honey types were obtained after headspace SPME extraction. Statistical analysis of the GC-MS chromatographic data was used to discriminate between floral types. Probability plots were used to identify compounds indicative of floral source; this method discriminated between honey types with 90% success. Hierarchical cluster analysis and principal component analysis were used to study the structure of the data. Learning algorithms in Weka (machine-learning software) were used to build models of data to classify honey types. The logistic model tree algorithm classified 89.8% of samples correctly. Such a model has the potential to be used to classify future honey samples, once further samples have been tested to validate the model.

year: 2009

title: Takuahi: Te oriori mō Tāmaunga-o-te-rangi - Mana atua, mana whenua, mana tangata

authors: Dewes, Mahue

subjects: Takuahi

abstract: E roa nei tātau te Māori nō ngā wā o Hawaiki e tito ana i te waiata, i te haka, i te oriori, i te mōteatea hei waka kawe i ngā kōrero tuku iho ki ngā whakatipuranga hou. He putuputu tonu ngā tūmomo karere, ka raua atu ki roto i wēnei momo titonga waiata a te Māori. Ka whārikihia e ngā tohunga kaitito ngā karere nei mā te reo kīwaha, mā te reo whakataukī, mā te reo auaha hei kura huna. Mei māmā te kimi, ka tohunga katoa ngā Māori. Kai te aroaro o te tuhingaroa nei, ka ketuketu i tētahi o ngā oriori o Ngāti Porou, otiā, nō Te Whānau-a-Hinerupe, ko te oriori mō Tāmaunga-o-te-rangi, nā Te Māperetahi. Mā konei ake e ruku atu ai ki te raparapa i ngā kura huna e whakatauira ana i te mana Atua, mana whenua, mana tangata hei mana ahi kā. Mā tēnā hoki e whakatauira te mana ahi kā, kai a Tama, otiā, hei tauira atu ki ngā uri o Te Whānau-a-Hinerupe i tō rātau ake ahi kā roa ki Te Kawakawa mai Tawhiti. Ko ngā kōrero kua kohingia, he kōrero nō ngā tāngata e mōhio ana ki ngā tūmomo mana, ā, ki ngā kōrero e pā ana ki te oriori nei. Ka iringia wēnei rau kōrero hei whakarākei tonu i te pae tapu o Te Whānau-a-Hinerupe.

text: Takuahi: Te oriori mō Tāmaunga-o-te-rangi - Mana atua, mana whenua, mana tangata E roa nei tātau te Māori nō ngā wā o Hawaiki e tito ana i te waiata, i te haka, i te oriori, i te mōteatea hei waka kawe i ngā kōrero tuku iho ki ngā whakatipuranga hou. He putuputu tonu ngā tūmomo karere, ka raua atu ki roto i wēnei momo titonga waiata a te Māori. Ka whārikihia e ngā tohunga kaitito ngā karere nei mā te reo kīwaha, mā te reo whakataukī, mā te reo auaha hei kura huna. Mei māmā te kimi, ka tohunga katoa ngā Māori. Kai te aroaro o te tuhingaroa nei, ka ketuketu i tētahi o ngā oriori o Ngāti Porou, otiā, nō Te Whānau-a-Hinerupe, ko te oriori mō Tāmaunga-o-te-rangi, nā Te Māperetahi. Mā konei ake e ruku atu ai ki te raparapa i ngā kura huna e whakatauira ana i te mana Atua, mana whenua, mana tangata hei mana ahi kā. Mā tēnā hoki e whakatauira te mana ahi kā, kai a Tama, otiā, hei tauira atu ki ngā uri o Te Whānau-a-Hinerupe i tō rātau ake ahi kā roa ki Te Kawakawa mai Tawhiti. Ko ngā kōrero kua kohingia, he kōrero nō ngā tāngata e mōhio ana ki ngā tūmomo mana, ā, ki ngā kōrero e pā ana ki te oriori nei. Ka iringia wēnei rau kōrero hei whakarākei tonu i te pae tapu o Te Whānau-a-Hinerupe.

year: 2016