Design and evaluate a native shrub planting scheme for urban biodiversity enhancement

Thesis Abstract

Urban biodiversity loss resulting from habitat fragmentation and limited native vegetation coverage poses significant challenges to ecological sustainability and human well-being. This study addresses the urgent need for effective ecological interventions by designing and empirically evaluating a native shrub planting scheme aimed at enhancing urban biodiversity. The primary objective is to develop a contextually appropriate shrub planting model, assess its ecological impacts, and determine its suitability for widespread implementation within city parks and green spaces. Specific objectives include identifying native shrub species that attract key pollinators and avian species, designing an optimal planting configuration, and evaluating biodiversity outcomes pre- and post-implementation. Employing a mixed-method research design, the study combines quantitative ecological surveys with qualitative stakeholder interviews. The population encompasses urban green spaces within a metropolitan area, with a stratified random sample of 10 sites selected to represent varying habitat types and levels of prior native vegetation. A sample of 150 native shrub plants, representing five candidate species, was propagated and planted across the selected sites. Data collection instruments included biodiversity assessment protocols (e.g., point counts, transect surveys), species richness and abundance indices, and semi-structured interview guides targeting local stakeholders, including city planners, landscape architects, and community members. The reliability of survey methods was verified through repeatability tests, and stakeholder interview transcripts were subjected to thematic analysis. Data analysis involved hierarchical cluster analysis to classify plant communities, repeated-measures ANOVA to compare biodiversity metrics before and after planting, and regression modeling to explore relationships between shrub density and observed biodiversity levels. Additionally, a modified version of the Ecological Niche Theory was employed to interpret plant-animal interactions within the planted schemes, alongside the Pollination and Habitat Selection theories to underpin the selection of shrub species. The anticipated findings are that the native shrub planting scheme significantly increases species richness and abundance of key pollinators and bird species within the study sites, with variation observed based on shrub configuration and management practices. The analysis is expected to reveal positive correlations between shrub density and biodiversity indices, supporting the ecological efficacy of the design. Qualitative insights will elucidate stakeholder perceptions of the scheme’s practicality, aesthetic value, and ecological benefits. This research contributes to knowledge by providing a replicable model for native shrub-based habitat enhancement in urban environments, integrating ecological data with stakeholder perspectives. It offers empirical evidence supporting native shrub planting as a sustainable strategy for urban biodiversity conservation, operationalized through an evidence-based design framework. The study concludes that targeted native shrub planting can serve as an effective, low-cost, and ecologically meaningful intervention to restore urban habitats and support biodiversity. It recommends the adoption of the scheme in urban planning policies, routine maintenance practices tailored to native species, and further research to refine species selection and spatial arrangements for different urban contexts. The findings also suggest avenues for future longitudinal studies assessing the long-term ecological resilience and socio-economic impacts of native shrub planting interventions in urban landscapes.