Department of Pest Management and Conservation

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https://hdl.handle.net/10182/35

The Department of Pest Management and Conservation carries out research and teaching in the following specialist areas: Animal behavior; Conservation and biodiversity; Ecological restoration; Evolutionary biology; Fire ecology; Molecular ecology; Plant microbiology; Plant pathology; Remediation of degraded and contaminated land; Soil ecology; Sustainable agriculture and ecosystem services; Wildlife and pest management.

Now showing 1 - 5 of 809

Turning up the heat: Climate change consequences for Pinot Noir berry quality
(Winetitles, 2024-04) Moukarzel, Romy; Parker, Amber; Schelezki, Olaf; Gregan, S; Jordan, B
Temperature increase due to climate change affects grapevine productivity and berry quality. Studies have shown that higher temperatures lead to increased sugar concentrations at harvest, or earlier harvests to retain the same sugar targets. Temperature increases may also impact anthocyanins (colour) and amino acids crucial for fermentation. New Zealand researchers out to explore how microclimates influence anthocyanin, phenolic compounds and amino acids in Pinot Noir.
Osmotic stress responses, cell wall integrity, and conidiation are regulated by a histidine kinase sensor in Trichoderma atroviride
(MDPI, 2023-09) Calcáneo-Hernández, G; Landeros-Jaime, F; Cervantes-Chávez, JA; Mendoza - Mendoza, Artemio; Esquivel, E
Trichoderma atroviride responds to various environmental stressors through the mitogen-activated protein kinase (MAPK) Tmk3 and MAPK-kinase Pbs2 signaling pathways. In fungi, orthologues to Tmk3 are regulated by a histidine kinase (HK) sensor. However, the role of T. atroviride HKs remains unknown. In this regard, the function of the T. atroviride HK Nik1 was analyzed in response to stressors regulated by Tmk3. The growth of the Δnik1 mutant strains was compromised under hyperosmotic stress; mycelia were less resistant to lysing enzymes than the WT strain, while conidia of Δnik1 were more sensitive to Congo red; however, ∆pbs2 and ∆tmk3 strains showed a more drastic defect in cell wall stability. Light-regulated blu1 and grg2 gene expression was induced upon an osmotic shock through Pbs2-Tmk3 but was independent of Nik1. The encoding chitin synthases chs1 and chs2 genes were downregulated after an osmotic shock in the WT, but chs1 and chs3 expression were enhanced in ∆nik1, ∆pbs2, and ∆tmk3. The vegetative growth and conidiation by light decreased in ∆nik1, although Nik1 was unrequired to activate the light-responsive genes by Tmk3. Altogether, Nik1 regulates responses related to the Pbs2-Tmk3 pathway and suggests the participation of additional HKs to respond to stress.
Citizen science is a vital partnership for invasive alien species management and research
(Elsevier on behalf of Cell Press, 2024-01-19) Pocock, MJO; Adriaens, T; Bertolino, S; Eschen, R; Essl, F; Hulme, Philip; Jeschke, JM; Roy, HE; Teixeira, H; de Groot, M
Invasive alien species (IAS) adversely impact biodiversity, ecosystem functions, and socio-economics. Citizen science can be an effective tool for IAS surveillance, management, and research, providing large datasets over wide spatial extents and long time periods, with public participants generating knowledge that supports action. We demonstrate how citizen science has contributed knowledge across the biological invasion process, especially for early detection and distribution mapping. However, we recommend that citizen science could be used more for assessing impacts and evaluating the success of IAS management. Citizen science does have limitations, and we explore solutions to two key challenges: ensuring data accuracy and dealing with uneven spatial coverage of potential recorders (which limits the dataset's “fit for purpose”). Greater co-development of citizen science with public stakeholders will help us better realize its potential across the biological invasion process and across ecosystems globally while meeting the needs of participants, local communities, scientists, and decision-makers.
Evaluating the densities and distribution of root-lesion nematodes (Pratylenchus spp.) in wheat grown in Canterbury, New Zealand
(New Zealand Plant Protection Society (Inc.), 2023-05-18) Thiellier, MJ; Kularathna, Manjula
Species of root-lesion nematode (Pratylenchus spp.) are associated with significant reductions in wheat yield in wheat-growing regions around the world. Of these, Pratylenchus thornei and P. neglectus are known to cause the highest damage to the Australasian wheat industry. New Zealand is known to produce high wheat yields on a per-hectare basis yet little research has been conducted to date to determine the effects of Pratylenchus spp. on the production of wheat in New Zealand. Therefore, as the first step towards filling this knowledge gap, the current research focused on conducting surveys to determine the population densities and distribution of Pratylenchus spp. in wheat-growing regions in Canterbury, South Island, New Zealand. Surveys were conducted at ten selected sites that were geographically distinct from each other. At six of the ten sites, lesion nematode populations were reported to be above the recorded Australian threshold of 2000 nematodes per kg of soil. In Australia, it’s been recorded that around 50% yield reductions can occur in intolerant wheat varieties when population densities reaches this number. Differences in population density within each location was also observed indicating the uneven distribution of lesion nematodes within a field. Morphological measurements of the nematodes collected from multiple sites during this study confirmed the presence of P. thornei and P. neglectus in Canterbury wheat-producing areas indicating a potential threat to the New Zealand wheat industry by root-lesion nematodes. Further studies need to be conducted to fully understand the situation and to develop management strategies to mitigate threats from nematodes.
Soil carbon, erosion, and the stormflow mobilisation of sediment and nutrients in a high-country landscape : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University
(Lincoln University, 2023) Provost, Shyam Michael
This study was carried out at Mt. Grand Station, a high-country pastoral farm in the South Island of New Zealand. The landscape (400 - 1300 m altitude) supports a gradient and mosaic of native and endemic woody shrub and tussock grassland vegetation amongst more productive exotic pasture, the latter established through aerial seed top-dressing and fertilisation. In recent years several areas of the farm at higher altitudes have been converted to conservation management following Tenure Review, placing additional pressure on the remaining farmland to maximise productivity, a situation similarly faced by many other high-country farms. However, further intensification of pasture grassland would compromise existing less productive native vegetation. This research project investigated soil conservation and loss, and freshwater quality, aiming to advance existing knowledge relating to environmental sustainability of the high-country. Topsoil carbon stocks were quantified beneath various vegetation communities at different altitudes of the station to gain a better understanding of soil carbon and its dynamics. Two watershed catchments were targeted for high-frequency sampling during rainfall events, to investigate the likely significance of water flow on the mobilisation of sediment and nutrients, and to help improve the accuracy of existing run-off estimates. In addition, soil erosion was estimated from differences in residual soil 137Cs activity, which was generated from historic Pacific nuclear testing, between two of the dominant types of vegetation cover. The results revealed the potential for native vegetation to enhance soil carbon sequestration. At low - middle altitudes (450 - 850 m) of the farm, topsoil beneath a woody shrub (kānuka) vegetation cover had significantly higher carbon concentrations and carbon stocks than areas of adjacent pasture. At higher elevations (>1000 m) topsoil beneath dominant snow tussocks had significantly higher carbon, nitrogen and phosphorus concentrations, with higher carbon stocks than adjacent inter-tussock spaces. The total loads of suspended solids, nitrogen and phosphorus exported to catchment waterways were significantly larger during high-flow events in comparison to baseflow conditions, and large proportions of the high-flow loads were mobilised on the rising hydrograph following high rainfall. These findings draw attention to the significance of taking account of the early stages of rainfall events to improve accuracy when quantifying high-country catchment loads. Data for 137Cs were variable but these provisional results indicate that soil beneath kānuka is likely to have undergone lower rates of erosion over the previous 65 years in comparison to areas of adjacent pasture. The combined findings of the three parts of the experimental work in this study are interpreted as being indicative of the present and future potential for South Island high-country farming environments to make a significant contribution towards climate change mitigation through vegetation management, resultant soil building and prevention of soil erosion. It is argued that closer attention to ecological restoration is likely to have mutual benefits for conservation, the farming system and the environment. Maintenance and better-informed management of the mosaic of native and exotic vegetation can play a more important role in longer-term sustainability of this high-country land management system than is currently appreciated.

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