Hongkongers’ Perceptions of Urban Green Space Plants and Biodiversity
| Dr. Caroline Law, Board Governor, Friends of the Earth (HK)
As the world talks about
biodiversity, the conservation of native species has become a major issue.
Native plants provide food and ideal habitats for various animals and
microorganisms; animals in turn disperse the seeds, creating a mutually
beneficial environment for future generations to flourish. Such habitats
support a wide variety of animal and plant species, provide a more stable
ecological environment, and avoid the problem of species homogenisation, thus
enhancing fauna and flora diversity in the vicinity. Native plants, also known
as indigenous plants, are resistant to local diseases and pests, and require
less watering, fertilising and pest control. If used for urban greening, they
would produce lower urban carbon footprint than exotic species. A recent study
published in the journal Nature suggests that a diverse forest can raise the
soil carbon storage and nitrogen storage for over a decade.
Earlier, I assessed plant
species diversity in Hong Kong's urban green space (UGS), and found that more
than 70% of the plants are exotic species, and only about 20% are native
Understanding how the public
evaluates UGS attributes and plant species characteristics can provide
reference for green space designs that meet public expectation. In another
study, I surveyed 827 adult Hong Kong residents to assess their perception of
UGS attributes and plant species.
The results revealed that most
people have different levels of misconceptions about native and exotic plants.
Most people thought "exotic plants can provide corresponding food source
for native wildlife", but the fact is, exotic plants cannot provide food
source that fully meets the needs of native wildlife. Some rare animals depend
on certain native plants for their survival, such as the red lacewing butterfly
and its host plant king snake creeper; the white dragontail and Illigera celebica; the golden birdwing
and India birthwort. If the host plants which the animals feed on disappear,
the survival of the animals will also be threatened.
The public's intention is vital
to the concept design of public green space. Therefore, this study was
conducted using Principal component analysis (PCA) and Cluster analysis (CA) to
allow for better generalisation.
Evaluation of UGS attributes
Based on the evaluation of UGS
attributes, respondents are categorised into three groups: Ecological group
(31%), Eclectic group (33%) and Pragmatic group (36%). The study shows that
among the many design considerations, safety, naturalness and environmental
friendliness of UGS are more important to the public, while the nurturing of
wildlife is less important.
Three variables (plant species
knowledge, gender, and education level) are statistically correlated with
respondents' ratings of UGS attributes. There were fewer women than men in the
ecological group, and women rated the pragmatic attributes (safety, space
design, and adequacy of facilities) higher. One possibility is that women are
more likely to take their children to parks and are therefore more concerned
about safety and facilities. It proves that people’s motivation for UGS use
affects their attitude towards its design. The ecological group has a better
plant species knowledge, whereas the pragmatic group is less knowledgeable in
this field. Plant species knowledge is positively correlated with the
assessment of green attributes (environmental conservation, natural scenery,
plant species diversity, nurturing of wildlife) and negatively correlated with
the assessment of pragmatic attributes. Meanwhile, respondents belonging to the
eclectic group (give high ratings on all attributes) are generally less
educated, but there is no significant difference in the ratings of green and pragmatic
attributes by education level.
Ecological group emphasised
natural scenery rather than artificial elements, and regards UGS as a place to
experience nature and nurture urban ecology. Ecological group expects plant
species in UGS to be of high conservation value, while pragmatic group expects
plant species to be "harmless”— safe (non-toxic/thornless), attracting no pests
and dangerous insects, and producing no nuisance. The results can be used as a
reference for UGS's plant selection strategy to fulfill different functions and
cater for target users.
Hongkongers’ Evaluation of Plant
Species Characteristics in UGS
Based on the evaluation of plant
species characteristics, respondents can be categorised into three groups:
Conservation supporters (23%), All-round perfectionists (43%) and Safety
defenders (34%). In terms of plant species characteristics, all-round
perfectionists account for over 40% of the respondents, and most of the
respondents considers all positive plant characteristics to be important.
However, it has been found that while the public hopes green plants could
provide food source for urban wildlife, plant characteristics of native plants
are also the least important consideration. Such contradiction reflects the public's
misperception, which ignores the importance of native plants in greening. Therefore,
we should actively promote the benefits of native plants and inculcate proper
knowledge of greening to the public, so as to achieve ecological harmony in the
All three categories of
respondents agree that "the selection of plant species for public green
space in Hong Kong lacks variety ". Respondents who emphasise the
conservation value of plant species (i.e. conservation supporters) are particularly
concerned about the selection of plant species, expressing dissatisfaction with
the current selection strategy.
For dense cities like Hong Kong,
landscape architects and greening managers may consider adopting dualistic
zonation with different attributes in large urban parks:
·Natural Ecology Zone: A naturalistic or ecologically
designed core area, where suitable native plants or plants with high ecological
and conservation values (such as fleshy-fruited, thorny plant species) are
planted with minimal horticultural input.
·Recreational Facilities Zone: Adopt a general
horticultural design and intensive horticultural management in areas with high
density of recreational and fitness facilities, catering for the fitness and
socialising needs of people of different ages, as well as the physical and
psychological security towards plant choices for people using the area.
The findings here can help improve the design and plant selection of
UGS. Equipping one park with diversified design features can meet different
expectations and needs of the residents, so that the general public can enjoy
the wildlife even without having to go to country parks.