Keywords

1 Introduction

1.1 Wetlands and Deltaic Sustainability

The Pearl River Delta (PRD) is formed by a network of several large rivers, the West, North and East River. It is a highly flood-prone region with about 85% urbanisation. It has a classical subtropical monsoon climate and suffers from excess water due to heavy precipitation from April to September every year. Over the past 40 years, the natural wetlandFootnote 1 area of the PRD has decreased dramatically; large areas of mudflats have been replaced by modern buildings and sealed surfaces (Zhao et al. 2016). The remaining urban wetlands are severely fragmented and often polluted, wildlife habitats have been damaged, and the ecological restoration function has declined. After losing the “sponge” that detains and stores stormwater, there have been more summer floods in the PRD in recent years. In this context, wetland parks (WPs), i.e. designed sustainable ecosystems with human and ecological value (Day et al. 2016), could be an appropriate basis for sustainable delta management and contribute to the remaining wetland ecosystem (Zhang et al. 2012).

1.2 Ecosystem Services

Ecosystem services (ESs) are understood as the benefits that humans get from the ecosystem and its conditions and processes (Costanza et al. 2017; Daily et al. 1997; Millennium Ecosystem Assessment 2003). ESs can link healthy biophysical ecosystems to human well-being. It is well established that ESs assessment could support biodiversity conservation, decision making, site management and spatial planning (Daily et al. 1997). In addition, the 14th Five-Year Plan of Guangzhou also emphasises the need to establish an Ecological Product Value (EPV, i.e. ESs) Realisation Mechanism, to better understand the wider values of natural/semi-natural ecosystems, such as wetlands and the need to protect them. Thus, we believe that a reasonable estimate of the ESs, especially the perceived value of the public, is the first step to embed them more fundamentally into future landscape designs.

2 Wetlands and Their ESs in Transition, Guangzhou

Located in the centre of the PRD between approximately 112°57′–114°3′E and 22°26′–23°56′N, Guangzhou covers an area of 7434.4 km2. The land slopes gradually from the north to the south. In the mountainous north, water catchments are depicted largely by lakes and streams, but are dominated by wider rivers and coastal wetlands in the south.

Most places of Guangzhou were still coastal or seascapes until the Ming and Qing dynasties (about six hundred years ago), when the current landscape pattern of Guangzhou began to take shape (Li 1983). It was also during this period that mulberry-dyke-fishpond began to develop as an efficient agricultural system for fish and silk production (Liu 2016). Until 1954, the built-up area of Guangzhou was still small, with a large area of surrounding wetlands (e.g. rice paddy, rivers, dyke-ponds, and coastal wetlands), orchards, and woods (U.S. Army Map Service 1954).

From the 1950s, Guangzhou began its economic development and the population has grown: there are 18.7 million permanent residents, nearly ten times the population in 1953 (Guangzhou Statistics Bureau 2021). The rise in population and urbanisation has resulted in a significant loss of wetlands, including paddy fields, aquaculture ponds, shallow marine water and rivers (Zhao et al. 2016). Meanwhile, highly intensive aquaculture replaced the traditional and ecological dyke-pond system (Hehl-Lange and Lange 2019). Moreover, many river branches (e.g. Liwan River and Donghao River) have been covered over and/or polluted since the 1950s.

New wetland parks (WP) have been designed and constructed recently, in response to more frequent flood disasters in the city and the increasing demand for recreational space. These landscapes are believed to be an effective nature-based solution to provide a compromise between wildlife protection and human utilisation. The development of WPs in Guangzhou covers the following four stages:

2.1 Spouting (1958–2003)

Four lake parks (LPs) were built in 1958. Labour was organised to excavate four artificial lakes, i.e. Liwan Lake (17 ha), Liuhua Lake (32 ha), Lu Lake (21 ha) and Dongshan Lake (23 ha) and to create parks that could maintain ecological balance, retain floods and provide cultural services (Li et al. 2018; Wu 2013; Wu and Lin 2018).

On joining the Ramsar Convention in 1992, the Chinese government agencies have gained relevant experience of legal, technical and management aspects associated with wetlands from cases abroad and thus laid the foundations for developing a new generation of WPs (Ma 2016).

2.2 Forming (2004–2012)

Recognising the local and regional environmental significance of wetlands, from 2004 to 2005, the State Council issued a series of documents to strengthen wetland protection and point out the development direction of WPs (Ma 2016, p. 6). After Xixi National WP in Hangzhou, the first national WP in China was opened in 2005 and the number of WPs accelerated rapidly (Ma 2016, p. 7).

At the end of 2006, construction of Baiyun Lake Park started as part of the Pearl River West Channel Water Diversion Project and became the largest artificial lake in Guangzhou (with 106 ha of waterbody) (Yu et al. 2018). In 2008, Haizhu National WP (with an area of 1100 ha) was created by turning some orchard-dyke-fishponds into larger lakes and reserving other dyke-ponds as ecological conservation areas (PPCCHD 2013).

Riverine wetlands were also transformed into WPs in this period. Remediation projects of the submerged and heavily polluted Lizhi River and Donghao River were implemented in 2009. Nowadays, these water systems possess clear water and have become popular places for recreation.

2.3 Maturing (2012–2019)

In the following years, many more artificial lakes or wetlands were created. Improved knowledge and advanced technology about constructed wetlands was utilised in the development of these wetlands, making WPs more mature in terms of habitat structure and ecological complexity.

Currently within Guangzhou, there are 12 large lakes and eight artificial wetlands for stormwater storage (Guangzhou Water Authority 2020) as a nucleus for WPs.

2.4 Developing and Upgrading (2020 Onwards)

More WPs are still under construction, and some existing WPs are currently being renewed or re-designed. For example, renewal of the Haizhu National WP includes expanding the water area, expanding the size of the area of floral displays, adding food courts, adding a museum etc., to improve recreation and aesthetic experience supporting natural education.

Considering the abundant river resources in Guangzhou (with 30 large rivers and 1338 river branches, with a total length of 5000 kms), the Ecological Belt programme along rivers was proposed for urban water treatment, ecological restoration and recreational and aesthetics services (Guangzhou Water Authority 2020). The 14th five-year plan (2021–2025) of Guangzhou emphasised the importance of the Ecological Belt and pointed out the necessity to upgrade three WPs (i.e. Baiyun WP, Haizhu National WP and Nansha WP) by strengthening the landscape and recreational facilities while protecting ecological resources. From a historical perspective, the ESs provided by the early wetlands in Guangzhou under human intervention changed from water supply services to regulation services. Then more emphasis was placed on cultural services and support services while ensuring regulation services, indicating the transitions within wetland and human needs. In the future, WPs will play an essential role in the development of Guangzhou.

3 Wetland Park and Their ESs in Guangzhou

WPs in Guangzhou (Fig. 15.1) vary considerably in area and width, and they usually originated in three ways:

Fig. 15.1
A map of Guangzhou locates 17 wetland parks with their year of construction. Before 2004, 4. After 2014, 10. Undergoing construction, 3. The parks built after 2014 have larger area.

Image Xuezhu Zhai

Wetland parks in Guangzhou.

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  • Designation of existing park space for wetlands management.

  • Transfer of natural wetlands for use as new park space because they contain wetland characteristics worthy of protection and restoration in a more public setting.

  • Creation of park space with constructed wetlands for surrounding run-offs retention or water quality improvement.

Some ESs associated with WPs in the PRD have been evaluated through multiple methods by local experts. WPs in Guangzhou can provide ESs, including wildlife habitat, flood regulation, air regulation, water purification, recreation, aesthetics and natural-based education (Table 15.1).

Table 15.1 ESs associated with WPs in Guangzhou
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3.1 Habitat

Wetland parks provide habitat for wildlife. Several studies have evaluated habitat services of WPs for plants and birds. Imported and invasive plant species account for a large proportion of WPs in Guangzhou. For example, there are a total of 625 species of vascular plants recorded in the Haizhu Wetland, including 320 species (51.2%) of introduced plants, 268 species (42.88%) of native plants and 37 species of invasive alien plants (5.92%) (Huang et al. 2018). It is estimated that the habitat service value is 2.1 million CNY per year, accounting for 1.83% of the total ESs value of this WP using the Benchmarking Method according to unit value of wetland wildlife habitat of global ESs assessment (Xie and Guo 2018, p. 30). In the Tianhe Daguan WP, the 2017 survey showed that there are 66 plant species, and that there is a slight increase in the number of plant species compared to before the WP was created (Wang 2019). Mangroves are mainly distributed in two coastal WPs in Nansha, and there is also a small area in Haizhu National WP.

WPs provide habitats for many birds in Guangzhou: there have been 392 species of birds recorded in Guangzhou in recent years, of which 258 have been recorded in WPs (Joint Action Platform of Chinese Bird Watching Organisation 2021). Among the 258 species, 24 are National Secondary Protected species, including five near-threatened species, two vulnerable species, two endangered species (i.e. black-faced spoonbill (Platalea minor) and great knot (Calidris tenuirostris)) and two critically endangered species (i.e. Baer’s pochard (Aythya baeri) and yellow-breasted bunting (Emberiza aureola) (defined by IUCN)). Nansha WP plays a vital role in providing habitat for migrating waterfowl, especially endangered species such as black-faced spoonbill and great knot.

3.2 Water Purification

Wetlands can filter nutrients and pollutants from surface water and upstream water. After sedimentation and filtration of the Pearl River water flowing into the Haizhu National WP, the water quality improves and reaches the standard for recreation. The value of the water purification is estimated to be 17.7 million CNY per year, accounting for 15.47% of the total ESs value (Xie and Guo 2018, pp. 29–30). The water quality at Daguan improved after it became a WP, with almost all sampling points reaching water quality standards for recreation, with water purification correlating with increased vegetation coverage in the water (Wang et al. 2019).

3.3 Flood Regulation

Low-lying wetland areas work as sinks that retain flood water. However, the actual flood regulation performance and storage capacity of WPs has not been studied yet in detail.

3.4 Air Regulation

Theoretically, vegetation in WPs could regulate the atmospheric CO2 and O2 balance and absorb air pollutants. However, there is no quantitative survey on air regulating service in WPs in Guangzhou. According to vegetation type and area, the annual atmospheric regulation value of the Haizhu Wetland is estimated to be about 6.5 million CNY (Liu 2019).

3.5 Recreation

The Haizhu National WP attracts approximately 10 million visitors. It is estimated that the recreation value of Haizhu National WP is about 507 million yuan per year (Liu et al. 2019). About 14.5 million people used Liwan LP in 2009, for taking walks, sitting, exercising and watching Cantonese Opera (Zhang and Huang 2015).

3.6 Environmental Education

Information is provided to visitors through signs which convey information about wetland functions and wetland habitats in WPs. Several well-known WPs with high quality habitats also hold some nature-based education activities. Haizhu Wetland Nature School offers popular courses and activities, e.g. for family groups at weekends (Fan et al. 2017). Environmental education companies provide fee-based nature study tours and wildlife watching activities in Haizhu National WP and Nansha WP, allowing participants to learn about plants, birds and insects in the daytime and amphibians at night. Most of these activities are only aimed at children, and there are few specific activities for adults; however, the willingness of adults to participate in nature observing activities is not low. From June 2019, Guangzhou Nature Observation Association organised a half-year wild bird observation and education activity in three WPs (i.e. Haizhu National WP, Lu LP and Liuhua LP); in June alone, more than 5,000 participants (mostly adults) were involved (Luo 2019).

4 Public Perception of Ecosystem Services Delivered in Wetland Parks

Generally, all ecosystems deliver ESs. People from urban environments are often not aware of their existence. If explained, it is easy for people to understand their importance, but they may still question their value (see Daily 1997). The disparity between actual ecosystem service value and perceived value may be significant (Daily 1997). Therefore, not only understanding the actual value of ESs in WPs is of importance; it is also vital to explore the citizens’ perceived value.

Previous research has shown that recreation, aesthetics and habitat services are the three most frequently perceived services in WPs in Guangzhou (Zhai and Lange 2020). An online survey during the peak of COVID-19 found that the public generally believes that visiting WP is beneficial to physical and mental health. The benefits for mental health are perceived to be higher than for physical health. In addition, the results emphasise that wildlife habitat services are considered an essential ecosystem service that promotes perceived health benefits (Zhai and Lange 2021).

4.1 The Case of Tianhe Daguan Wetland Park

Building on these studies, an in-depth survey of public perception on ESs delivered in WPs was conducted, using Tianhe Daguan WP as a case study. Tianhe Daguan WP was built in 2015 and is in the Tianhe District, where many high-tech companies are located. It is a linear park approximately 120 m wide and with a total area of 46.8 hectares. It consists of 23 cascade ponds and a reservoir to collect and purify stormwater. The water flows from north to south and then flows into a river (Fig. 15.2).

Fig. 15.2
A Google Earth map presents a narrow strip of land extending from the northeast to the southwest. 9 wetlands are marked 1 to 9 with 2 culverts, 1 each between 1 and 2, and 4 and 5. Wetland 7, in the mid-south, is the largest.

Wetland system of Tianhe Daguan WP (based on signs on-site and Wang 2019; Map Google earth adapted by Xuezhu Zhai)

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Since the perception of the environment is multisensory, a questionnaire and semi-structured interview were conducted on-site to obtain their users’ perceptions. Questions were asked about motivations for the visit, overall perception of the WP and the perception of the ESs that the WP delivered. Data was collected between 26 December 2020 and 5 February 2021. The study was approved by The University of Sheffield ethics committee.

Seventy respondents were involved in the questionnaire and 45 took part in the whole interview. This chapter is focussed on the key results from the qualitative data gathered in the interview. There were slightly more female respondents (55.6%) than male-respondents (44.4%). 70% of respondents have a college degree or higher. 68.9% of respondents were younger than 35 years old. Seventy percent of the respondents were visiting this WP for the first time.

4.2 Perceived ESs

4.2.1 Flood Regulation and Water Purification

Although flood regulation and water purification are the primary purposes for creating this WP, no one mentioned the flood regulation service. Only two respondents mentioned water purification services in the interview. Both respondents thought the water purification service is essential. One respondent thought water purification is more important than having more ornamental plants. Another respondent believed the water quality had improved since his last visit, thus allowing his child to play with the water.

As visitors typically avoid times of heavy rain, this pattern might help to explain why flood regulating services are not obvious for the visitors during normal visitation times.

4.2.2 Air Purification

Good air quality was the primary motivation of visits for a large proportion of respondents. Most respondents agreed that the air is clean in this WP, and the air quality in this WP is better than in the vicinity with the primary road and its many vehicles. Their judgements were mainly linked to the number of trees, i.e. many trees equating good air quality or sparse woods for poor air quality.

4.2.3 Wildlife Habitat

Most respondents agreed that there are abundant and diverse plants in this WP, but nearly half (42.31%) of the respondents had difficulties estimating the number of plants. Around one-third of respondents thought there were less than 100 plant species in this WP, while 11.5% believed there were 101–200 plant species. Only about 10% of respondents thought there were more than 200 species. Compared with a field survey conducted by the authors in October 2020 (144 species, with 58 quadrats) and a study in August 2017 (66 species, with 25 quadrats) (Wang 2019), the estimation by 17% of respondents was close to the actual circumstance.

Most respondents thought that diversity of birdlife in this WP is low. 36.5% of respondents did not pay attention or had difficulties estimating the number of bird species. Respondents who usually pay attention to wild animals found that they only encountered less than five bird species. 40.38% of respondents thought there were less than 20 bird species in this WP; among them. 15 respondents thought there were less than ten bird species. Only two respondents thought there are more than 100 bird species. In reality, 66 species (including 23 common species, which appears in more than 10% of records) have been recorded from April 2020 to May 2021 by citizen scientists. For each visit, on average, ten species were witnessed (ranging from one to twenty). In general, the bird habitat service was underestimated by the visitors. This might be explained by their visitation period and because most birds in this WP are small and difficult to see (e.g. the long-tailed shrike Lanius schach). Some birds are usually “only heard but not seen” (e.g. Asian Kole, Eudynamys scolopaceus), and it is difficult for people with a lack of basic knowledge to distinguish some birds. Also, there are bird species that look relatively similar (e.g. little egret (Egretta garzetta) and Chinese pond heron (Ardeola bacchus)).

4.2.4 Aesthetics

When talking about scenic beauty, some respondents mentioned “uniqueness”. Interestingly, several respondents noted that scenery of this WP reminded them of their hometown, so they thought it was beautiful. These stimuli vary from visual to olfactory experiences and from the fallen leaves and fish in the lake to the swamp and ponds.

The cypress forest is regarded as the most attractive place in this WP, especially the cypress forest next to ponds. Because of its attractiveness, many people leave the trail and enter the forest to take pictures (Fig. 15.3 top-left corner), which in turn might negatively impact the habitat. The reservoir, the lake (Fig. 15.3 bottom-right corner and ponds (Fig. 15.3 top-right corner) are also attractive due to the preference of water. A large area of diverse emergent aquatic plants (except water lilies) covering the water surface (Fig. 15.3 bottom-left corner) was considered messy.

Fig. 15.3
4 photos capture rows of tall coniferous trees with soft feathery leaves in different ecosystems.

Photos Xuezhu Zhai

Attractive places in Tianhe Daguan Wetland Park.

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4.2.5 Recreation

The most common activities visitors perform in this WP were taking walks, sitting and photography. Cat or dog-walking (on-leash), jogging, lying down and resting, bird watching, having picnics and pursuing nature observations were activities that respondents conducted in this WP. None of the respondents picked wild vegetables and fruits. Respondents did at least one activity and up to seven activities in their WP visit. On average, each respondent did three activities per visit in this WP.

Many respondents appreciate this WP as they can get close to nature pursuing activities such as picnics on the grassland, fishing or catching butterflies. While adults were having picnics on the lawn, they were also able to watch their children playing by the ponds.

For most respondents, thermal comfort was the main reason for choosing a place to stay. When there is direct sunlight and temperatures are high in summer, and even on sunny days in winter, respondents prefer to do activities in the shade. Other criteria include quiet locations with few people around, beautiful scenery (especially when there is a possibility to see animals) and a comfortable place for sitting.

4.2.6 Environmental Education

Overall, there are 75 signs about environmental education in the north part of this WP (with an area of 10 ha), from knowledge about Sponge City and the water purification of this WP to information on the plants and animal species in this WP. However, respondents mentioned the lack of signs and complained about the complex contents or the mismatch of the content and nearby plants. Several respondents said they did not pay attention to the signage because they are not interested in it, or they have no knowledge or background which would help them to understand it. Environmental education services that do not rely on signage have also been highlighted, mainly by respondents who came with young children.

5 Conclusions

By exploring the transition and status quo of wetlands and their ecosystem services and the perceived ESs by the public, this study summarises the characteristics of the ecosystem services of WPs in Guangzhou and the problems in the delivery of ecosystem services to propose suggestions for the future planning and design of WPs. Future research to widen the theoretical basis for WPs in adaptive transformation could be extended to include children and teenagers’ perception as well as the seasonal variation in ecosystem services in WPs. Depending on the individual, visitor perceptions of the ESs will vary to some degree. Results indicate that only a few members of the public understood the value of these locations in terms of water and flood management. Yet, from a policy perspective, this is one of the key drivers for WP creation. There is strong potential for signage and other media to help inform about the need and value of such landscapes. In contrast, the public made stronger links with recreation and leisure, and to a moderate degree with the value for wildlife and as a place to attain some relief from poor quality air and noise. Based on anecdotal information, WPs are perceived as being beneficial to health. Further empirical research is required to deliver “hard” facts to inform the public and guide policy makers in future planning.