An Assessment of urban greening challenges and opportunities associated with urban densification in the EThekwini Municipality

ABSTRACT

It is critical that urban densification is accepted as a planning strategy for enhanced, sustainable urban development, especially considering the compacting of urban areas, integrated land uses, reduced land take and the need to conserve urban green spaces. Nevertheless, its implementation has challenged the management of urban green spaces. Densification has created a dilemma in planning as planners battle to provide better green spaces, while simultaneously implementing urban densification projects. This study explores the persistent challenges and opportunities of urban densification in intermediate African cities, using a case study of Umhlanga in the eThekwini Municipality in KwaZulu-Natal, South Africa. The study used a mixed method approach, using questionnaires, unstructured interviews and field observations. The results indicated that urban growth in intermediate towns is dominated by horizontal expansion, despite introducing urban densification policies, which has proved detrimental to ecological conservation. Furthermore, embarking on growth that integrates various land uses is increasingly enhancing those towns’ resilience and slowing down urban sprawl. This study shows that transformation in urban planning is essential in integrating ecological conservation in densification projects. Urban densification should not be treated in isolation but involve multiple city stakeholders in several city departments to achieve a broad range of goals.

KEYWORDS:

• Densification
• sustainable development
• green spaces
• compact city
• urban sprawl

1. Introduction

Urbanization, as an aggregate of economic growth, population increase and land use change, is considered the main route to social development (Xiao et al., 2020). Accelerated urbanization implies great pressure on natural environments and creates changes in land use patterns, pushing most African cities to their conservation limits (Arku, 2009). Urbanization introduces many positive changes into urban systems such as energy generation strategies, comprehensive information built up, better transport facilities and green spaces’ structure and quality (Von Thaden et al., 2021). On its negative side, different forms of urbanization exacerbate land fragmentation, encouraging accelerated developments (Li et al., 2019). This strongly leads to significant loss of habitats, farming land and forests, reducing the provision of ecological services and climate regulation by green spaces (Puplampu & Boafo, 2021; Xiao et al., 2020).

Both population growth and urban development depend on ecosystem benefits that are fundamental in supporting quality human life (Lin & Zhu, 2018). Based on this, it is essential for urban areas to constantly maintain healthy ecosystems and supply of ecological services, essential for achieving sustainable development (Kowarik et al., 2020).

1.1. Review of literature

Many African cities are still grappling with the effects of rapid urbanization and strongly require effective planning and implementation of sustainable densification for balanced economic, social and environmental needs (Todes & Turok, 2018). Therefore, most urban green spaces (UGS) face a bleak future if cities continue on the current trajectory, where urbanization continues to lower biodiversity and encroach on critical UGS (Eigenbrod et al., 2011) without compensation measures.

According to Le-Roux and Arnold (Le-Roux et al., 2019), Africa’s urban population has grown from 15% of the total population in 1960 to approximately 40% by 2010. Predictions expect this to exceed 60% by 2050 (Puplampu & Boafo, 2021). South Africa is also expected to follow this high urban population growth trend. Such growth has caused an increased focus on sustainable urbanization strategies. The main concepts framing the sustainable urbanization process include compact development, mixed uses, and high density (Sim et al., 2016), which can easily promote the integration of ecological elements.

Despite the many studies on the effects of urbanization on ecosystems, there are still gaps in quantifying the challenges and opportunities of urban densification on UGS in intermediate African cities. For the past four decades, the concept of compact cities in developing countries has become a popular global paradigm of sustainable urban development, widely acknowledged in urban research and policy documents (Bibri et al., 2020; Swilling, 2005). This strategy has become the preferred development pattern appropriate to present and future urban developments (Pelczynski & Tomkowicz, 2019) due to its ability to regulate urban sprawl and increase the resilience of cities in ways that also address ecological conservation. However, despite densification gaining more acceptance, concerns and criticisms have surfaced concerning its ecological effects.

Urban densification also faces opposition in its implementation as a sustainable strategy for future urban development. Residents prefer spacious low-density living, which can lead to sprawling suburban areas; however, private businesses prefer to densify urban areas as a way of maximizing finances, as opposed to public interests of providing decent and affordable houses (Hardin, 1998; URBACT, 2019). Furthermore, Swilling (2005) described the densification challenge as a ‘tragedy of commons’, based on the understanding that the gains and costs are not enjoyed by the same stakeholders. The gains of densification are generally abstract and are found in the future, while its solid costs are felt in the present (Greene et al., 2017). This has become a universal challenge across many cities as stakeholders’ grapple with understanding the long-term benefits of densification against their immediate preferences (URBACT, 2019).

Successful densification strategies strongly require the influence of policy changes to save African cities from low-density sprawling (Adebayo, 2012). Well-planned cities, with compact and dense characteristics, benefit from urban agglomerations and, simultaneously, reduce the costs of providing infrastructural services (Berggren, 2017). Recent studies have revealed that an average African city is 20% more fragmented than Asian cities and 29% more expensive, with 37% less exposure to people and jobs (Lall et al., 2017). Sustainable densification may offer solutions to these issues.

Even if urban developments were to utilize infill land and brownfields, this would not be sufficient to accommodate the ever-increasing urban functions and population (URBACT, 2019). As land reserves are diminishing in big cities, attention is now being turned to greenbelts which have been protected for many years (Todes & Turok, 2018). Under these circumstances, urban densification is inevitable for sustainable urban development (Steuteville, 2020). Proponents of urban development have also noted that the implementation of densification has been challenged by the realization that it is not the only facet of sustainable development.

Urban development’s sustainability is considered a sum of three balanced economic, environmental and social pillars (Purvis et al., 2019). What should be prioritized in sustainable urban development is not only densification but a balanced relationship between these three pillars.

Failing land policies have left most of these cities trapped in low-density developments (Isidore et al., 2016; Kriticos, 2018). Other challenges facing urbanization include land regulations, building and zoning standards (Güneralp et al., 2017). These policies can negatively affect developers and relegate low-income residents to the urban outskirts with fewer density restrictions, forcing towns and cities to continue sprawling at low densities.

In the South African context, the perception of urban densification has become a prominent agenda of urban planning, strongly influenced by the United Nations Conference on Sustainable Development, Brazil, in 2012 (UN-Habitat, 2015). The crucial ambition of urban planning in South Africa is to build an environment where buildings and infrastructure promote quality living (Du Plessis, 2015; Thwala & Aigbavboa, 2016). However, an increase in urban population is simultaneously associated with scarcity of space, making it difficult to gratify the basic needs of sustainable urbanization. Therefore, vertical planning has become a key theme in modern urban planning, with urban planners cautiously keeping an eye on both the economic and environmental needs of the present and the future (UN-Habitat, 2019).

Serious environmental problems may occur, with the United Nations (UN) forecasting a rapid increase to 68% in the world’s urban population by 2050 (UN-Habitat, 2015), combined with the effects of climate change. The continued horizontal sprawling, characterizing many African cities (Adebayo, 2012), will cause municipalities to struggle in supplying, basic services such as water and energy, due to the exploding urban population. If this growth is not strategically planned for, haphazard developments may come to the fore, causing a serious threat to UGS and liveability (Holdsworth et al., 2019).

This research is based on the findings from Umhlanga in KwaZulu-Natal, South Africa. Umhlanga is a small, upmarket residential and commercial resort town located on the northern edge of the greater metropolitan city of Durban (eThekwini) (eThekwini Municipality, 2020). It is one of the fastest growing centres of the greater eThekwini Metropolitan Municipality with a population of about 50 000 in 2022 (SouthAfrica.com, 2022). Its main source of growth is estate and property development, aided by tourism and recreation. The greater parts of Umhlanga, like Umhlanga Ridge, started as a sugarcane farming area but residential properties have grown incredibly in this area, which is now characterized by sprawling gated communities and luxury estates (SouthAfrica.com, 2022). It has become a much sought-after retail office and residential area, as more businesses have relocated from central Durban into this area.

The main objective of this research was to explore and assess greening challenges and opportunities associated with densification in urban areas. This will assist most African cities to upgrade their urban development strategies and policies to levels that promote environmental sustainability and better living. Apart from adding more knowledge on the sustainable urbanization discourse, this study is also significant in exposing the dilemma of sustainable urbanization in African cities, emphasizing the tension between limited environmental capacity and the need for ecological conservation.

2. Materials and methods

2.1. Methodological outline

The research used a mixed method approach for this study, advantageously integrating the benefits of different methods. It assumed that by combining qualitative and quantitative research approaches, the researcher would obtain a complete understanding of the research problem. Based on the underpinnings of pragmatism, this design made use of multiple methods of collecting urban densification and urban greening information in Umhlanga. This was highly effective, as data from the two methods complimented each other in counteracting the weaknesses of each method.

The mixed methods approach assisted in gaining a complete image of the urban challenges associated with urban densification, instead of using a standalone quantitative or qualitative method (Edmonds & Kennedy, 2016). A case study design of Umhlanga’s commercial and residential nodes was used where data were collected through questionnaires, unstructured interviews and field observations. Through the triangulation of data from the different methods, the study managed to address many of the weaknesses of the different methods used in this study, such as being subjective, biased and lacking in rigour.

Simple random sampling was used to select the participants for the questionnaire survey. This method was selected due to its ability to reduce errors and bias. A harmonized list from the municipality’s Department of Housing and the ratepayer’s association was used for simple random sampling. A sample size of 800 participants was selected for the survey, of which 649 participants successfully completed it.

Purposive sampling was used to identify the participants for interviews and areas for field observations. This method was considered critical in the matching of the sample to the aim and objectives of the research, therefore refining the rigour of the study and the dependability of the data and results (Campbell et al., 2020; Mouton, 2011). Subjective judgement was aided by wide research and consultants on the possible participants and areas to improve representativeness.

The survey participants’ identities were protected through using abbreviations for names – thus, the views of GD, BN, TJ and HH were used in this study. Ridgeside, Cornubia, Umhlanga Village, Gateway and Prestondale were selected as areas for field observations as they exhibited concepts of densification and green space conservation.

The interviews were directed at the municipality officials responsible for development and environmental planning in addition to private sector personnel associated with urban development and management. The interview questions focused on the planning and implementation issues of densification and how they have impacted the town’s social, economic and environmental spheres, especially the challenges of integrating green spaces into densification projects. Furthermore, the questions also focused on the challenges and opportunities of urban densification in all the direct and indirect projects of the eThekwini Municipality.

Questionnaires were served to both residents and workers in the selected areas. The maps of Umhlanga’s built up areas were obtained from the eThekwini Municipality. Furthermore, the urban planning and green infrastructure strategy department assisted in calculating the floor space per land unit of subdivided areas of Umhlanga. These calculations assisted purposive sampling in identifying areas of high densification to visit for field observations and data collection.

To obtain a better picture of green space reduction, maps at 5-year intervals, from 2000 onwards, were analysed and calculations of green space losses were made per each divided zone of Umhlanga. For field observations, not every part of the study area exhibited densification and greening and, therefore, purposive sampling helped in selecting areas with appropriate characteristics. Field observation involved site visits to observe the levels of densification and any visible challenges associated with the effects on UGS. Written observations and aerial and ground photographs were used as part of the field observations.

After transcribing the interview data, a thematic analysis was adopted on the combined interview and field observation data. Data collected through questionnaires were coded and uploaded to the Statistical Package for the Social Sciences (SPSS) for analysis. The results were presented graphically to convey themes. This enabled accurate conclusions on the effects of densification on ecological conservation in Umhlanga. The five broad themes derived from the qualitative and quantitative analyses include: loss of green spaces in core and urban fringe zones; loss of farming land to housing development; loss of green open spaces due to infill developments; fragmentation of UGS due to urban development; and opportunities created by urban densification.

2.2. Study area

The eThekwini Metropolitan Municipality, including the city Durban and its surrounds, is situated on the south-eastern coast of South Africa, covering an estimated area of 2,300 km² (Marx & Charlton, 2003). Its population in 2015 was approximately 3,48 million, with a growth rate of about 1.3% per annum (eThekwini Municipality, 2015). Rapid urban growth and climate change have had a major impact on eThekwini’s environmental assets, such as urban forests, open spaces and municipal parks, leading to a fragmented pattern of growth whose impact threatens the area’s long-term sustainability. Furthermore, its undulating relief has resulted in fragmented growth as some steep slopes are difficult to settle, opening a gap for informal settlement. All these factors threaten the natural ecosystem of the municipality.

EThekwini has a rich mix of natural resources, making it a microcosm of one of the 35 biodiversity hotspots in the world and a home to a high proportion of endemic plant and animal species (UN-Habitat, 2019). Its assortment of three terrestrial biomes includes ‘savanna, forest, and grassland and supports over 2,000 plant species, 97 km of coast, 18 rivers, 16 estuaries, and 4,000 km of river shoreline’ (World Bank, 2022).

Umhlanga is a town situated on the northeast coast of Durban and stretches from La Lucia in the south to Harewood Park and Woodlands in the north, bounded by the N2 highway on the left and the Indian Ocean on the right. Currently, its northern expansion now includes the commercial, residential and industrial areas of Cornubia.

Umhlanga was formerly dominated by sugar cane farming, which has gradually retreated, giving way to one of the biggest business hubs in eThekwini, where the newest developments are built on green fields. Umhlanga is the fastest growing town in the eThekwini Municipality, housing the Gateway Shopping Mall, one of the biggest shopping complexes in the southern hemisphere, with the second tallest building (Pearl Sky) in South Africa (eThekwini Municipality, 2015) [62], showing the increase in vertical expansion. Although the town has been expanding horizontally with low densities, vertical growth now dominates most core areas.

3. Results

Sustainable urbanization in many African cities is confronted with the dilemma of limited environmental capacity and overwhelming pressure to conserve the ecological environment in the face of rapid urban population growth (Yang et al., 2020). Competition for urban land has seen green spaces being relegated to the lower echelons of the urban development agenda, where their contribution to sustainable urbanization and development is viewed as very low, if not insignificant. Similar challenges are experienced in Umhlanga, along with many other challenges and opportunities associated with urban densification and green space conservation.

3.1. Challenges and opportunities

As stated earlier, the challenges and opportunities may be grouped into five categories: 1) loss of green spaces in core and urban fringe zones; 2) loss of farming land due to housing development; 3) loss of green open spaces due to infill developments; 4) fragmentation of UGS due to urban development; and 5) opportunities created by urban densification. The challenges per category will be presented and discussed as follows.

3.1.1. Loss of green spaces in core and urban fringe zones

Aerial and ground photographs from field observations revealed that more green spaces are being lost on the urban outskirts of Umhlanga as the town’s growth continues to be dominated by low-density horizontal sprawl. The lost land includes spaces with natural vegetation providing ecological functions and promoting biodiversity. Figure 1.2 and Figure 1.4 indicate how green spaces are being lost in Umhlanga due to urban growth. Umhlanga is a planned new town and, therefore, most of its development land has come from green fields.

Interviews with members of the Department of Development Planning, Environment and Management confirmed that most of the vegetation species lost to urban development and compaction are not on the list of endangered species or the Durban Metropolitan Open Space System (DMOSS). A system of green corridors in the city of Durban is earmarked for significant conservation. However, ecologists argue that all natural vegetation has ecological functions critical to the ecosystem balance (Blondel, 2006). More positively, the Biodiversity and Impact Assessment Branch in 2020 confirmed that the eThekwini Municipality has a policy of compensating for cleared protected vegetation by planting the vegetation elsewhere in the city. This is a good way to compensate the city for lost vegetation but its implementation has been shrouded with challenges of low turnover which has diminished its ecological advantages (Hordijk et al., Hordijk & Sara, 2014).

3.1.2. Loss of farming land to housing development

The loss of farming land due to housing developments was identified as the dominant challenge, with 39% of the survey participants agreeing with this opinion, as evident in Figure 2. The photographs in Figures 3 and 4 show the loss of farming land due to urban expansion and mostly densification. Furthermore, Figure 1 clearly shows the northwards expansion of Umhlanga town that has engulfed the farming land.

Figure 1. Northwards urban expansion onto agricultural land in Umhlanga. Source (Barger, 2016).

The mixed-use development in Ridgeside and the extension of Umhlanga town centre to the Cornubia Shopping Mall and Cornubia low-income housing projects have also caused more natural and farming land to vanish (Figure 2 and 4). Despite the introduction of densification and mixed-use functions, more ecological spaces continue to be lost, reinforcing the need for effective integration of urban greening into urban development projects in such urban areas.

Figure 2. Ridgeside mixed-use mega development node. Source (SA Property Insider, 2018).

The process of densification also acts as a subtle challenge behind transforming UGS into built up areas (Colding et al., 2020). To cut service costs, provision planners have resorted to multifunctional land use, interweaving, intensifying and combining different functions on available urban land (Coleman, 2016). This, in turn, has absorbed peri-urban green spaces, mostly under sugarcane farming. The new residential and commercial areas of Cornubia (Figure 1.3 and Figure 1.4) and Prestondale have resulted in built up land spilling over onto fertile lands and sugarcane farmland, resulting in a permanent loss of arable land, which was a source of urban green space.

3.1.3. Loss of green open spaces due to infill developments

The loss of open green spaces due to infill urban development programmes was also identified as the second biggest challenge, with a 31% frequency in the survey (Figure 2). Due to the adoption of urban densification policies, the eThekwini Municipality has encouraged infill development to reduce urban sprawl and encroachment on green spaces on the outskirt zones. This has seen high rise buildings emerge in the commercial areas of Umhlanga. As beneficial as it may seem, the process has also been responsible for destroying the few pockets of vegetation left in core areas. However, as the town has grown denser, it has also augmented its efforts of urban gardening, such as vegetation being planted in parks, on reclaimed dunes and along roadsides (personal communication with Umhlanga Rocks Urban Improvement Precinct, 2020).

The World Health Organization (WHO) identifies parks, sports fields, woods, natural open spaces, wetlands, residential gardens and street trees as fundamental elements of a dense urban ecosystem (Puplampu & Boafo, 2021). The rapid urbanization of South African towns and cities is increasingly responsible for degrading environmental assets. Conserving ecological assets can increase the productivity and liveability of these urban areas and promote resilience to extreme weather events.

3.1.4. Fragmentation of UGS due to urban development

The loss of UGS due to infrastructure upgrades was selected by 16% of the surveyed residents (Figure 2). In comparison, the challenge of green space fragmentation was also identified and approved by 14% of the participants as a problem affecting the conservation of UGS in the face of urban densification and urban sprawl.

Umhlanga is one of the fastest growing towns in the eThekwini Municipality. As such, many infrastructure constructions and upgrades are constantly being in all parts of the town, especially on the northern periphery of the town in Prestondale and Cornubia. Although power lines, water pipes and sewage pipes allow vegetation re-growth, they partially reduce vegetation density, especially big trees, leading to impairment and environmental degradation. Conversely, road and bridge construction directly contributes to a high fragmentation of UGS, resulting in numerous environmental problems, such as reduced biodiversity and a reduction in ecological services, such as carbon dioxide sequestration.

3.1.5. Opportunities presented by urban densification

The data from the interviews revealed that densification, supported by appropriate infrastructure and services development, remains essential to strategic planning policies, enabling the successful provision of amenities. Integrated planning and designing can bring together aspects of densification and greening for the town’s good. Increased densification in Umhlanga has increased property investment, access to world-class amenities, social lifestyle facilities, and better accessibility (personal communication with BN and TJ, October, 2020). Furthermore, it emerged that urban densification had brought more development in some areas but at the expense of increased destruction of ecological spaces. However, all municipal personnel confirmed that the existence of natural forests and man-made green spaces in Umhlanga indicates the town’s strong observance of urban planning and ecological conservation regulations.

The private sector participants also confirmed that densification was the right undertaking for the town, but the continuous implementation of such projects, in a fragmented manner, with few projects dedicated to ecological improvements, is not good for conserving UGS (personal communication with HH and GD, 2020). Overall, the current form of densification reduces green spaces, with few ecological enhancements in many development projects. Thus, a more holistic approach is needed, in which all urban stakeholders spearhead integrated densification and greening projects.

3.2. Perception of urban challenges associated with densification

This section presents the results of the field observations (Figures 1, 2, 3, 4, 5) and the survey conducted in selected areas of Umhlanga to identify the different challenges associated with the conservation of UGS as the town grew, experiencing urban sprawl and densification (Figure 2). The survey objective was to gather residents’ perceptions of the urban greening challenges associated with the urban densification and horizontal sprawling of the town supplemented by field observations. The four groups of challenges were surveyed.

Figure 3. Cornubia location within the sugarcane estates of Tongaat Hulett in northern Umhlanga. Source: municipality photograph (September, 2016).

Figure 4. Clearance of land for the development of the Cornubia shopping mall. Source: municipality photograph (September, 2016).

Figure 5. Perceptions of Umhlanga residents on challenges affecting UGS conservation in Umhlanga due to urbanisation.

3.3. Possible ways to promote adequate UGS in areas of densification

The quantitative survey, shown in Table 1, attempted to glean UGS conservation strategies from assessing residents’ perceptions of possible strategies for green space conservation. Collaboration between various stakeholders was the most popular perception. Its effectiveness is supported by the work of Umhlanga Rocks Urban Improvement Precinct Umhlanga, which coordinates the private sector’s efforts in collaboration with the municipality. This has increased community members’ indirect influence in managing urban growth. Targeting specific user groups can be effective, especially concerning disadvantaged groups and areas in ecological services. However, in this case, this was not applicable, as Umhlanga has few instances of social polarization. The retention of native vegetation and increasing understorey cover and native plantings in UGS were low rated, as exotic vegetation is increasingly being used.

Table 1. Residents’ perception how to promote or ensure adequate UGS in Umhlanga.

Perception	Target specific user groups and create health and social benefits from green spaces.	Community participation in the planning, designing and maintenance of UGS	Collaboration with stakeholders and other sectors	Increasing understorey cover and native plantings in UGS	Retention of native vegetation during urbanization to promote urban biodiversity
Participants	86	196	277	35	55
% of participants	13	30	43	5	9

Despite lagging behind in integrating UGS into the architecture of high-rise buildings, there are attempts to integrate UGS into horizontal developments. For example, the Hawaan Forest Estate (Figure 6) has been sited on the edge of a forest with strong ecological considerations that are friendly to nature (personal communication with BN, GD, and TJ, October, 2020).

Figure 6. The Hawaan forest Estate on the edge of the Hawaan forest.

Source: Unknown, The Hawaan Forest Estate in Estate Living, 2019, Durban.

Figure 7. Integrating green spaces into urban development.

The estate has prioritized the careful planting of indigenous plants in the residential properties adjacent to the forest in its planning and design. Homeowners preferring to do their gardening are strictly allowed to choose from a list of about 600 indigenous plant species found in the adjacent forest (personal communication with BN, GD, and TJ, October, 2020). This design allows the forest to extend into the estate gardens and grounds and colonize the whole residential development.

4. Discussion

The study explored the emerging greening challenges and opportunities facing the town of Umhlanga in the eThekwini Metropolitan Municipality due to rapid urbanization. Introducing urban densification has been considered the more appropriate strategy for sustainable urbanization within urban spatial development. Traditional plans have considered densification as a planning initiative for core areas; however, current urban developments like those witnessed in Umhlanga are increasingly advancing the idea that densification beyond central business centres is a change worth fighting for in an attempt to reduce urban sprawl (Olanrewaju & Adegun, 2021). These areas are characterized by low people and building densities, with diverse services offering better densification chances of reducing urban sprawl and ecological fragmentation (URBACT, 2019). However, this does not happen cheaply. In Umhlanga, densification away from core areas has come with negative externalities, including loss of green spaces and the need for large financial sponsorship.

4.1. Loss of green spaces in core and urban fringe zones

The growing need for commercial and residential land in and around the town has reduced the size and quality of green spaces in the town. Densification through urban consolidation has posed a great threat to the viability of UGS in Umhlanga. These findings are not similar to studies carried out in Australia (Lin et al., 2015), New Zealand (Matthews et al., 2015) and the United Kingdom (Loram et al., 2007), where it was discovered that residential land uses had become the biggest factor in preserving and increasing UGS and associated services.

As towns and cities undergo rapid densification in terms of infrastructure, they also need to undergo environmental revival as the new norm that fosters a more sustainable ecological future. Therefore, cities need to change their ecological inculcation if green spaces are to survive in urban densification environments. The analysis of the current distribution of green spaces in Umhlanga’s residential and commercial areas shows a negative balance between urban densification and the number of green spaces, which indicates that more green spaces need to be developed.

As building density increases, the amount of urban vegetation cover decreases. This outcome strongly resembles the findings of McPherson et al. (2011), who discovered that Los Angeles’ tree canopy cover decreased as density and land use increased. Intermediate towns like Umhlanga can save existing green spaces if urban development processes like urban densification and urban greening can be integrated into the urban environment at an early stage.

Lowering cities’ ecological footprint may not be enough given the rapid growth in urbanization; developing towns and cities that are environmentally sustainable is a necessity (Lin et al., Lin et al., 2015). This calls for the increased integration of different forms of green spaces into built up areas. As Umhlanga develops at an unprecedented rate, the fragmentation and loss of natural and semi-natural ecosystems may be the biggest challenge to achieving sustainable urbanization. One of the biggest consequence is the loss of beneficial UGS and the threat to the conservation of urban ecosystems. Overall, this lowers the liveability of urban areas, with increased pollution regulation and runoff, and lowered carbon sequestration and storage.

According to the World Health Organization (WHO) (WHO, 2022), green spaces like parks, watercourses, green walkways and urban forests are critical solutions to urban health. Nature in urban areas benefits people’s mental, physical and emotional wellbeing, thereby enhancing the building of healthier and more connected societies (Sugiyama et al., 2008). The standard recommendations from WHO is that these UGS should be located within a five-minute walk from people’s homes (Shitta, 2022). However, the loss of green spaces in Umhlanga shows that most intermediate towns and cities are not able to satisfy this.

Increased stress and health ailments associated with respiration shows the validity of UGS as the ‘lungs’ of a city (Jones & History, Jones, 2018). Researchers from Barcelona Institute for Global Health (ISGlobal)’s Urban Planning, Environment and Health Initiative concluded that about 43 000 premature deaths in Europe could be prevented annually if UGS were increased, as the 62% of the population surveyed live in less greener areas than those recommended by the WHO (El-lipse, 2021).

The loss of UGS in Umhlanga will lead to the acceleration of urban heat and flooding, which are amplified by climate change, threatening urban residents’ well-being and health. In contrast, exposure to UGS offers various social, physical, and mental benefits leading to sustainable urbanization and ecosystem balance.

Beautifying disused open and neglected spots with attractive vegetation can positively contribute to useful UGS that can withstand destruction and pollution encroachment compared to their old versions (Matthews et al., 2015). As unlikely as it may be, river valleys, brownfields, disused transport routes and cemeteries can be integrated into UGS.

4.2. Fragmentation of green areas

Fragmentation does not only lead to the loss of green spaces but causes habitat loss and disorder. Urban growth in Umhlanga has not occurred uniformly from one centre but from different nodes across the town, amounting to increased fragmentation of ecological spaces. This results in an incremental loss and a series of declines of green spaces.

Densification brings several advantages to a town, such as proximity of services, better renewal and more vibrancy. However, if these advantages are at the expense of green spaces due to fragmentation, then sustainability will be compromised. Continued loss of UGS from generation to generation triggers a baseline shift, in which each current state of ecology is taken as the new norm, disregarding the previous states (Le-Roux et al., 2019).

This study believes that municipalities should take a bold stance and do away with day-to-day planning in favour of long-term planning that can meet an ever-increasing and unpredictable future (Colding et al., 2020). The case of Umhlanga also revealed that urban expansion and densification occur exclusively at the expense of farmland located on the urban fringe zone (Gren & Andersson, 2018). Vertical urbanization should be prioritized for inland reclaimed grey land, consolidated land or renewing already built areas rather than on buildings that replace existing green spaces.

The potential consequences of fragmented ecological spaces are the loss of ecological functions, lowering the quality of urban life overall. Green spaces are vital in the socio-economic and environmental activities of urban areas. These include purifying soil water bodies, maintaining carbon and oxygen balance, alleviating urban heat island effect and beautifying the environment (Calderón-Contreras & Quiroz-Rosas, 2017; Li et al., 2019). Without UGS, residents will not be able to enjoy the daily leisure and entertainment functions expected in urban areas (Huang et al., 2019).

Broader urban planning states that cities are not just buildings and people; liveable cities also comprise of open green spaces (Haaland & Konijnendijk, 2015). This study acknowledges that the eThekwini Municipality is increasingly prioritizing green space development and conservation in its urbanization process. Furthermore, this study’s findings on the importance of sustainable densification concurs with the broader views of compact cities as experienced in big cities such as Amsterdam and Copenhagen (Gilles et al., Gilles & Buizer, 2015). In this regard, compact cities prioritize densified occupation and mixed-use developments, which lowers infrastructure spending and promotes community cohesion. Umhlanga exhibits some of these characteristics although they are at times minimal.

4.3. Challenges of urban intensification

The intensification of urban functions has also been a subtle driver behind UGS loss as developers seek to cut costs and conserve energy (Märit, 2015). From a planning point of view, multifunctional land use includes interweaving, intensifying, layering and timing (Williams et al., 2010).

Intensifying is advantageous for increasing the effectiveness and efficiency of specified land use on the same piece of land, while layering functions vertically, where possible. Timing uses the same building for multiple functions at changed moments and interweaving conglomerates’ different functions on the same piece of land (Westerink et al., 2013; Wim, 2017). Interweaving and intensifying can apply to green space conservation as observed in parts of Umhlanga, where high-rise blocks and horizontally dense housing units co-existed with green spaces. However, caution should be exercised in implementing intensification projects in ecological areas, as events in Stockholm, Europe’s fastest growing city, revealed. In Stockholm, planners had to grapple with a sudden population boom, culminating in the need for new homes (Colding et al., 2020). To deal with growing urban densification and population growth, multi-functionality in the use of public parklands became a quick solution to the growing challenge. However, such a strategy reduced existing UGS. Moreover, it ran contrary to planners’ aspirations of developing cities that are more resilient to the different effects of climate change, while promoting biodiversity based on green spaces with certain ecological qualities (Erlwein & Pauleit, 2021).

4.4. Perceptions of residents on loss of UGS

An analysis of residents’ perceptions revealed that the quantity and quality of UGS tend to increase with the increase in socio-economic advantages or affluence in an area. This observation is compatible with earlier European and American findings, which revealed that the quality and quantity of UGS are often related to social status in an area (Hoffimann et al., 2017). High affluence in Umhlanga has made it possible for several green spots to remain intact and even improve in the face of densification. The main drivers of ecological change are residents based on their interaction with ecological elements (Grêt-Regamey et al., 2020).

Through dedicated urban planning, re-inventing towns and cities with nature can be a reality. Using technology and creativity, designers can transform concrete jungles into nature-friendly cities, if given the opportunity and necessary support. City planners can now integrate nature into cities, just as seriously as they used to make industrial objects in the past. Unfortunately, plausible as it is, most greening plans have remained unfulfilled. Many nature-based urban designs remain only plans that will never leave the drawing boards due to lack of funds and infrastructural support (eThekwini Municipality, 2017), a fate that has crippled many African cities.

4.5. Integration of UGS into urban planning development

Umhlanga should adopt a green infrastructure strategy in the city’s planning and renewal systems and should maintain ecosystem services, which are significant for sustainable urbanization (Liu & Russo, 2021). A fundamental feature of a green infrastructure strategy involves integrating different economic, social and ecological benefits of urbanization to contribute to sustainable growth. This can be achieved through ecosystem-based programmes adapted into climate change, research and innovation policies. The substantial benefits of a green infrastructure strategy can be achieved by including assessment tools like the Environmental Impact Assessments and Strategic Environmental Assessments for different densification projects to infuse compatibility of urban development strategies with UGS conservation (Fataar, 2018; Liu & Jensen, 2018). Green infrastructure needs to be integrated into many national and local government funding streams to make it more effective. For many African cities, this is a drawback due to insufficient funding for green infrastructure development.

The municipality should, therefore, make it mandatory in all its planning strategies to include a green infrastructure strategy implementation, if the future of urban greening is to be sustained in the wake of accelerated urban population growth. European Union policy objectives in Europe have seen green infrastructure being integrated into many funding streams such as the European Regional Development Fund (ERDF), European Social Fund (ESF) and the Natural Capital Financing Facility (NCFF) (European-Commission, 2014). This has given cities a strong footing in conserving UGS.

As difficult as it is to extrapolate ecological results from a specific location to other parts of the world, or even to urban areas in the same country, examples from international cases can strongly assist towns and cities in developing countries in assimilating new strategies that integrate ecological conservation into urban densification strategies (Engelberg et al., 2016).

Identifying green urban development opportunities like integrated urban densification are a win-win situation for the urban area and its people. Such approaches are critical to African cities because they are more cost effective while remaining friendly to the ecological environment (Madureira & Monteiro, 2021; Mensah, 2014). Restoring urban vegetation, rehabilitating brownfields, road sides, river systems and reclaimed lands by integrating them into urban densification strategies could go a long way in reducing urban flooding and urban decay, while rejuvenating the economic and social benefits by reversing environmental degradation (World Bank, 2022).

Towns and cities undergoing densification require complimentary policies to implement strategies to achieve sustainable urbanization. Policy changes and initiatives, such as open streets or slow streets, can help promote the interaction of urban activities with ecological functions. This in a way raises awareness of the importance of ecological spaces in dense areas which can translate into better conservation measures. This involves the closure of certain streets to vehicles to allow pedestrian activities for a given time period. Additionally, central streets with more plants, can be prioritized, thereby promoting access to ecological services.

It is overdue that the policy frameworks of most intermediate towns and cities embrace the creation of environments for all users (Dannenberg, 2011). Urban development plans should be reviewed to ensure that local design guidelines and zoning codes promote the provision of greenscapes, green streets and green walkways (Duan et al., 2019). Policies can also guide progressive monitoring and evaluation to promote sustainable urbanization. In this way municipalities will be able to identify any unintended consequences that may derail progress (Embarak, 2021).

4.6. Integrating urban development with greening strategies

The greening challenges observed in Umhlanga due to rapid urbanization and densification should be addressed holistically, in which greening strategies and urban development processes are fully integrated. Figure 7 shows greening strategies and urban development processes to promote sustainable urbanization. Figure 7 Integrating green spaces into urban development

The model in Figure 7 highlights that the processes of urban development need to be integrated with greening strategies, while constant monitoring ensures that the designed objectives are met to ensure sustainable implementation of urban densification and greening. Urban planning should be at the core of promoting opportunities for advancing sustainable development while lowering negative externalities (European Commission, 2020; Gren & Andersson, 2018). It should be complemented with high ecological awareness among leaders, planners and residents in urban developments. All processes should constantly be exposed to monitoring processes to ensure the alignment and achievement of objectives, culminating in the successful implementation of urban densification and greening.

Implementing such a model should be done early because once towns and cities are fully established, they become costly to alter and integrate resilient strategies (Dogan & Stupar, 2017). It is therefore crucial for young towns such as Umhlanga to get their urbanization process correct from the beginning, to bypass unsustainable patterns of infrastructure development (UN-Habitat, 2019).

5. Conclusions

The rapid rate of Africa’s urbanization poses a great conservation risk to its exceptionally rich biodiversity. This leaves conservation and urban planning policies in need of sustainable responses to deal with the direct and indirect urbanization trends regarding UGS.

This research explored the persistent difficulties and prospects of urban densification on ecological conservation, as urban areas grapple with urban sprawl in parts of the eThekwini Municipality. Despite the concentration of urban functions and population in high-density nodes, the physical expansion of urban areas in growing African cities and towns continues to encroach on critical UGS. The results of this study suggest that Umhlanga is undergoing urban transformation through horizontal and vertical expansion as residential and commercial developments compete for development land with ecological green spaces.

The implementation of urban densification has increasingly been acknowledged as inevitable in lowering total land take. This has been the case with Umhlanga as the eThekwini Municipality works to balance its demographic change, economic pressure and the demand of large transport infrastructure projects.

The main findings of this research reveals that urbanization, as a form of social and economic development, is increasing in many African cities, as shown in the case of Umhlanga, South Africa. The implementation of urban densification is associated with promoting urban compaction, easy access to services and lowering urban land take. However, the implementation of densification has created conflict with environmental needs, such as the conservation of green spaces.

It emerged from this study that the horizontal expansion of built up urban areas leads to a loss of agricultural land and green spaces (Foley et al., 2005). While densification is considered positive, its responsible for squeezing out critical UGS. In addition, Umhlanga has experienced continuous loss of agricultural land directly due to land take and indirectly through recreational activities necessitated by the growing urban area. This has put pressure on sugarcane farms, making it difficult to maintain farming at productive levels. It was also highlighted that competition for land to develop dense and compact facilities has not only reduced Umhlanga’s green spaces but has caused the fragmentation of natural spaces, making it difficult to maintain ecological and ecosystem functions. Once an area is fragmented, it becomes difficult to provide ecosystem services.

It is therefore recommended that urban planners and policy makers should mix land uses, allowing the blending of residential, economic and environmental functions. This compaction is essential for improving accessibility of services by bringing them within walking distances. Based on these findings, the research advances the view that urban planners and urban authorities must be active in the challenges and complexities of urban densification strategies in modern urban environments. The research clearly shows that by increasing urban densification many economic, environmental and social benefits can be realized. However, increasing density alone risks exacerbating the actual problems that urban densification intends to ease.

Densification should therefore be cautiously considered and be partnered with quality designs, mixed land uses, better connectivity and increased accessibility of services. In order to conserve critical UGS, municipality planners should desist from uniform densities in ecologically sensitive areas. Better planning for quality green spaces through tree planting activities can benefit the ecology of urban areas undergoing densification.

Acknowledgments

The authors acknowledge the support given by the eThekwini Metropolitan Municipality, especially the Department of Development, Planning, Environment and Management for facilitating the data collection and providing several clarifications on municipality processes in the study area. We also acknowledge the financial assistance given by the University of Zululand and support provided by the School of Geography and Environmental Studies.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the University of Zululand [Grant].