Design and evaluation of a sustainable urban green wall system using native plant species

Thesis Abstract

The rapid urbanization experienced globally has underscored the pressing need for sustainable solutions to mitigate environmental challenges in cities, such as air pollution, urban heat island effects, and diminished biodiversity. Green wall systems have emerged as a promising strategy to address these issues; however, there is limited empirical evidence on their optimal design, sustainability, and the specific benefits of native plant species within urban contexts. This study aims to design, implement, and evaluate a sustainable urban green wall system utilizing native plant species to enhance ecological performance and aesthetic integration within city environments. The specific objectives include identifying suitable native plant species for green wall applications, developing a sustainable system design that promotes biodiversity and energy efficiency, and assessing the environmental, aesthetic, and social impacts of the system through rigorous evaluation. The study employs a mixed-methods research design encompassing both qualitative and quantitative approaches. A comprehensive literature review and environmental assessment guided the selection of native plant species, focusing on their adaptability, ecological benefits, and potential for sustainability. The target population comprises urban residents, city planners, and green infrastructure professionals within a metropolitan area with a population of approximately five million residents. A purposive sampling technique was used to select 150 residents for household surveys, complemented by 20 semi-structured interviews with urban planners and landscape architects. The sample size was determined using Cochran’s formula to ensure statistical validity and representation. Data collection involved structured questionnaires to measure residents’ perceptions of green walls’ environmental and aesthetic benefits, plant health assessment reports to track plant vitality, and ecological surveys to evaluate biodiversity improvements. Instruments were validated through expert panels and pilot testing, with reliability confirmed via Cronbach’s alpha coefficient exceeding 0. Eighty monitoring points were established on the green wall prototype for biophysical measurements, such as temperature, humidity, and pollutant levels, collected using digital sensors over a 12-month period. Data analysis employed descriptive statistics, inferential techniques such as ANOVA and multiple regression analysis to examine the relationship between plant species selection, environmental parameters, and system performance, and thematic analysis for qualitative interview data. Expected findings indicate that native plant species exhibit higher survival rates, lower maintenance requirements, and greater ecological benefits, such as increased urban biodiversity, compared to non-native counterparts. The green wall system is projected to significantly reduce surface and ambient temperatures, improve air quality by filtering pollutants, and foster community engagement with green infrastructure. The analysis is expected to reveal statistically significant correlations between plant selection, environmental impact metrics, and social acceptance. These outcomes will substantiate the ecological and social merits of native-species-based green walls in urban sustainability initiatives. This research contributes novel insights into sustainable green wall design, emphasizing the ecological advantages of native flora while integrating aspects of urban resilience and social acceptability. It extends current theoretical frameworks, including the Biophilia Hypothesis and the Ecosystem Services Theory, by empirically demonstrating how native plant-based green infrastructure enhances urban ecosystems and promotes environmental stewardship. The findings will inform policymakers, urban planners, and green infrastructure developers on best practices for incorporating native plant species into urban greening projects, fostering adaptive, low-maintenance, and ecologically resilient systems. The study concludes that well-designed, native plant-based green walls can serve as vital components of urban sustainability strategies, with significant environmental, aesthetic, and social benefits. Recommendations include adopting native species selection guides, developing maintenance protocols aligned with ecological principles, and promoting community participation in green wall projects. Future research should explore long-term performance, scalability in different climatic zones, and integration with other green infrastructure solutions to optimize urban ecological resilience. This research underscores the importance of native biodiversity in advancing sustainable urban development and provides a scientific basis for its widespread adoption.