Ecosystem services in urban green and blue space: vegetation, perception, and implementation.

We are in a time of increasing global inequality, climate change, and biodiversity and
habitat loss. Urban areas are a nexus of conflicting environmental, social, and political
pressures. One promising avenue to mitigate these pressures is the development of urban blue green space using nature-based solutions and integrated ecosystem service
planning. However, this field of research is relatively new and there are still key questions
to be addressed in good practice for equitable and efficient use of urban green blue space. Particularly as ecosystem service delivery through specific interventions or habitat
creation may have yet unresolved trade-offs and conflicts.

This thesis takes an interdisciplinary and evidence-based approach to the evaluation of
multiple ecosystem services provided by urban aquatic and terrestrial plants, addressed
via the following methods. The chapters are prepared as manuscripts and as such utilised
“we” to describe the authors of this research. Chapter 2 is a literature review that
highlights trends in our understanding of blue green space and the ecosystem services that they provide. This chapters asks what the gaps in our understanding of ecosystem services and identifies future research directions. The results show that there are key geographic disparities, a lack of long-term experimental datasets and a neglect of aquatic ecosystem service recognition. We also found there was a reliance on remote sensing for ecosystem service assessment and suggests key research priorities to address questions related to these findings.

There is a fundamental need to understand how aquatic plants are distributed in urban
areas. To answer this question, Chapter 3 uses a national data set of pond plant
communities to identify trends in distributions and community composition between non
urban and urban ponds. We found that urban plant communities were significantly more
species-poor, homogeneous, and exhibited significant spatial autocorrelation at distance
classes <50km when compared to their non-urban counterparts. We recommend key
management and research objectives to enhance and improve urban pond habitats.
Using a Before-After, Control-Impact, experimental design paired with a green space user
survey, Chapter 4 identifies the fundamental dynamics of floating ecosystems as a novel
nature-based solution in blue space. This work highlighted that floating ecosystems
enhance urban plant diversity but have limited impact on invertebrate family richness,
water quality metrics, or additional social, aesthetic, or wellness value.

This work recommends carefully considering management when installing floating ecosystems, as broader landscape factors are likely to be more influential in impacting water quality, perceptions, and local biodiversity benefits. Further work should be undertaken to identify how current floating ecosystem technology should be configured, differently managed, or enhanced to meet local management needs.

Finally, chapter five focuses on the social dimensions of enhancing urban green and blue
space. Utilising a survey of the British public, generalized linear mixed models, and
thematic discussion we identify current perceptions, barriers, and uncertainties in the
public’s understanding of ecosystem services within urban green spaces and examine
predictors and willingness to pay for urban green and blue space enhancement. We found that people had an overall preference for the creation of more ecologically valuable habitats against more traditionally managed habitats, generally ecosystem service recognition was strong, and people did not associated vegetation with providing
disservice, except for a few select examples. Overall people were generally willing to pay
for the development of more diversity green blue spaces, predictors of willingness to pay
and positive ecosystem service recognition was in line with previously established
predictors of positive environmental attitudes. We suggest that there is public support to
develop ecosystem service delivery with the development of more ecologically valuable
vegetation types.

Overall, these results provide valuable evidence for the use of nature-based solutions in
urban green spaces. Importantly, this work highlights key research priorities to address
uncertainties in our understanding of the perceptions of ecosystem services, provides
robust evidence for increasing natural vegetation cover to enhance ecosystem service
provision in urban green blue spaces, and highlights important caveats to consider in the
management of urban freshwater habitats for habitat creation and conservation.