Biological, Earth and Environmental Sciences - Masters by Research Theses

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Urban trees and biodiversity in Cork city
(University College Cork, 2022) Marron, Caoimhe; Lettice, Eoin; Doyle Prestwich, Barbara
Biodiversity is poorly quantified in urban landscapes and is not effectively incorporated into urban planning and policymaking. Land-use change (e.g., urbanisation) is one of the key drivers of biodiversity loss. Furthermore, urbanisation is expected to increase from 50 to 70% by 2050. The CSO reported a 0.6% decrease of residents living in highly rural areas of Ireland (2011-2016), including a 5.5% increase in residents living in independent urban towns. Urban trees have a broad range of ecosystem services; it is likely that many of these services will become increasingly important due to climate change pressures (e.g., changing climatic conditions, extreme natural occurrences). This thesis examines the role of urban trees/green spaces in supporting the biodiversity of other taxa (lichens, invertebrates, birds, and ground vegetation) in Cork city. There was a total of 102 individual trees studied across 6 Cork city sites, including the UCC arboretum (n=26); Cork city Marina (n=12); the Atlantic Pond (n=17); Kennedy Park (n=11); The Lee Fields (n=18); Fitzgerald’s Park (n=18). A full survey of all 4 taxa was conducted per tree, including the use of sticky traps for invertebrates; quadrat sampling for both vegetation and lichens; and observational point-counts for birds. There were no significant differences/associations between the species richness of the various taxa and the species of tree. This could be due to a limited number of replicate trees, which can be expected with an observational-based approach. However, community-level analyses have shown significant variations in the taxa communities among the 6 sites (p<0.001 for all taxa). These data suggest that the type of urban site is significantly associated with biotic community composition. Additionally, the research investigates the relationship that microclimate (light intensity and temperature) and canopy openness have with urban tree species. Microclimate data loggers were deployed at the base of all trees for each experiment and hemispherical canopy images were taken to determine canopy openness in Fitzgerald’s Park. In general, there were no, or little associations found between microclimate data, canopy openness and biodiversity. Thus, the assessment of the hypothesis that microclimate conditions impact taxa communities was inconclusive. Overall, the study supported the hypothesis that urban trees and green spaces support a large variety of individuals from other taxa and provides a baseline for biodiversity in Cork city, specifically regarding future studies and urban planning.
The ecology and phylogeography of the common lizard (Zootoca vivipara) in Ireland
(University College Cork, 2023) Lyne, Linda; Butler, Fidelma; Ramsay, Ruth; European Regional Development Fund
Ireland has only one native terrestrial reptile, the common lizard Zootoca vivipara. Many people are unaware of its presence in Ireland and little research has been conducted on the species here. However, understanding the ecology of the common lizard in Ireland could greatly help with the conservation of our only native lizard. Here we show that records of common lizards in Ireland are predominantly from coastal areas and that it occupies smaller microhabitats, such as banks or stone walls, which potentially have microclimates that offer advantages for thermoregulation. Using records of Z. vivipara sightings from the National Biodiversity Data Centre, this research identified data gaps within the distribution of Z. vivipara in Ireland, but it is uncertain if these gaps are explained by unsuitable habitat type or low sampling effort. In addition, distribution of records were found to be centred around coastal areas and sites popular with human outdoor recreation. Recorder bias, habitat suitability, and coastal sunshine hours were identified as potential factors influencing the distribution of records. A focused study on the Iveragh Peninsula, in the south-west of Ireland, observed Z. vivipara from habitat types such as upland peatland/heath (23%), gardens (17%) and old stone walls/ruins (16%). Wind speed, air temperature, and relative humidity were environmental parameters examined in this research to investigate the influence of microclimates within the microhabitats which lizards occupy. Wind speed was found to be significantly lower at ground level (P<0.05) compared to 2m height, and thus, wind may have an influence on where lizards are found within habitats. In addition, through genetic analysis, we confirm for the first time, that Irish Z. vivipara belong to the Western viviparous clade. This brings Irish phylogeographic research on the species up to date with similar research in other parts of the species’ range. We also identify that unique haplotypes are present in Ireland and that unique lineages also exist within geographically disparate populations here. Additional genetic sampling is recommended to fully understand how Z. vivipara colonised Ireland post-glacially. It is recommended that a long-term study is established to perform focused surveys for lizard presence/absence in areas where data gaps occur in sightings records of the species in Ireland. This focused study should also identify reasons for data gaps, such as habitat suitability or recorder effort. A population dynamics and behavioural study is needed to examine how environmental parameters influence Z. vivipara presence/absence in certain habitats. Finally, additional samples for genetic sequencing would greatly benefit the research into the different haplotypes identified in this study. A more geographically widespread range of samples, including from off-shore islands, would aid in understanding how Z. vivipara arrived and dispersed in Ireland.
Biodiversity, people, and logistics: the balancing act of urban park management
(University College Cork, 2023) Horan, Sadhbh; Harrison, Simon; Lettice, Eoin
In a time when global populations are moving to urban centres, the need for adequate green spaces in towns and cities for the health of both people and nature is paramount. The management of such spaces in Ireland is idiosyncratic and requires investigation. Multiple studies have tried to quantify the key influences to take into consideration when managing an urban park and for this thesis it was determined that the intersection of biodiversity, people and logistics encompassed theses influences. The aim of this study was to determine how best to manage parks in terms of habitat, amenity and management choice, based on the three selected influences. Diversity of vascular plants and fungi were assessed at six parks in Cork city. In addition, park user questionnaires and SOPARC (System for Observing Play and Recreation in Communities) observations were made to quantify people’s park use and opinions. Finally, in order to determine what systems were already in place, structured interviews were undertaken with individuals and organisations who manage urban parks in Ireland. Results show that dry meadow is the optimal choice of habitat for Irish parks due to it high level of biodiversity, its popularity among park visitors, and its compatibility with park amenities however the choice of habitat needs to take abiotic and social factors into account also. Basic amenities such as footpaths and litter bins were preferred over elaborate ones such as outdoor exercise equipment, while overall, recreational facilities were more popular than sports facilities. Logistically, in urban centres where a park management sector was present, it was often underfunded and understaffed, and so while the progress made by these groups is commendable, they are simply not rigorous enough to sustain the growing number and need for urban parks in Ireland. Urban green spaces require a complex understanding of each of the three influences highlighted in this study both across urban centres and within individual parks and cities in order for optimal management to take place.
New insights into the summer distribution of basking sharks (Cetorhinus maximus) in the northeast Atlantic
(University College Cork, 2022) Stasiuleviciute, Edita; Rogan, Emer; Jessopp, Mark John; Department of Communication, Climate Action and Environment; Department for Culture, Heritage and the Gaeltacht, Ireland; Sustainable Energy Authority of Ireland
Basking sharks, Cetorhinus maximus, have undergone widespread historic exploitation in the northeast Atlantic and are of conservation concern. A greater knowledge on their spatial and temporal habitat use in response to environmental conditions is required to better inform subsequent monitoring and management strategies. Several efforts to describe the occurrence and distribution of basking sharks have been already made, however nothing at large spatial scales. Sighting information on basking sharks was derived from three aerial survey programmes which covered extensive inshore and offshore waters within the northeast Atlantic. The occurrence of basking sharks in the area was highly seasonal, with individuals predominately observed during the summer months (May-August). Hotspots of occurrence were within the coastal waters off the south and west of Ireland, whereas areas such as southwest of England and west of Scotland, previously considered to be hotpots for basking sharks, were not aggregation sites during summer months, suggesting a seasonal change in distribution. Based on satellite-derived environmental variables and climate indices, this study revealed that distribution of basking sharks was associated with (1) lower chl-a concentrations (< 2.27 mg/m³), (2) shallow coastal waters which are most likely important summer feeding grounds; and (3) positive North Atlantic Oscillation (NAO) winter index, most likely through association with prey species. Sea surface temperature (SST) had no significant effect on the distribution of basking sharks. This study provided new insights into the seasonal occurrence of basking sharks on a large scale within the northeast Atlantic. The results produced here could be incorporated into future management frameworks for assessing the threat and conservation needs for this regionally protected species, as well as providing guidance for future research efforts.
The carbon sequestration potential of the Irish uplands
(University College Cork, 2022-09-01) Swan, Sophia; Harrison, Simon; Sullivan, Timothy
The Irish uplands, which cover much of the western half of the country, have long been known as a bare, treeless landscape, used for grazing livestock. They are characterised by thin, peaty unproductive soils, and tend to provide poor economic returns to those farming them. A land use shift is currently occurring across the uplands, with many farmers ceasing actively to exploit the land and leaving the industry, a process exacerbated by isolation, poor incomes, and a lack of successors willing to continue farming the family landholdings. This comes at a time when Ireland is urgently seeking novel approaches to sequester carbon from the atmosphere, and offset GHG emissions from intensive agriculture. Expanding woodland cover onto degraded agricultural land is one of several potential methods being explored worldwide to increase terrestrial carbon sequestration and storage. This study aims to determine the future carbon sequestration potential of the Irish uplands, through the potential regeneration of native woodland, in the event that their land use shifts away from livestock grazing and the associated vegetation management of burning. We chose the Iveragh peninsular, Co. Kerry, SW Ireland as our study site. This is an area of extensive upland landscape, with a long history of extensive cattle and sheep grazing on the unenclosed land, including a considerable area of upland commonage. We used two approaches to estimate the potential carbon sequestration potential of regenerating woodland in the uplands. Firstly, we wished to determine the environmental and anthropogenic factors associated with woodland regeneration currently observed within the study site, so as to better predict the location and extent of any future woodland regrowth. This was achieved using a combination of online GIS mapping techniques, coupled with ground-truthing of the extent of tree regrowth. Secondly, we wished to establish the realistic nature of any potential future natural woodland cover, in terms of species composition, density and growth form of trees and in the soil composition underneath such woodland. We surveyed the woodland cover of a number of small, uninhabited and unexploited islands within lakes of the southwestern uplands. These islands were ascertained to have been ungrazed since at least the middle 19th century and likely for much longer, owing to their small size and inaccessibility to grazing animals. The vegetation and soil data were then used to calculate the potential carbon storage of any future woodland regeneration. GIS analysis revealed that slope, elevation, soil type, controlled burning practises and proximity to woodland seed source all influenced the current extent of tree regeneration in the study site. Significant differences were observed between the vegetative composition of the islands and adjacent mainland sites, with dense woodland cover consisting primarily of holly, rowan and birch observed across islands. This island vegetation sequestered ten times more carbon per hectare than adjacent mainland sites, which predominantly consisted of Molinia grassland, with no woodland growth noted. Soils in mainland sampling areas were consistently wetter and less carbon rich than those sampled on islands. Based on these factors, it was determined that within 40 years, 0.6% of the Irish uplands could show natural woodland regeneration, should barriers to re-growth (sheep grazing and vegetation burning) be removed. A higher percentage woodland regeneration could be achieved with additional proactive tree planting programme, which is likely necessary to establish woodland growth in areas remote from existing trees and which have been treeless for many centuries. Despite such a small, predicted increase in percentage tree cover via natural means, this still provides the potential to store over 600,000 tonnes of carbon, thus providing Ireland with valuable ways to offset carbon emissions, along with increasing biodiversity and reduce flood risk over the coming years.

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