Below are my views on other environmental sustainability issues I am concerned with personally for Ministry of Sustainability and the Environment (MSE)’s reference.
Increasing local food production to ensure food security should go beyond importing food from more countries and relying on agrotechnology (or high-tech farms).
We should learn from indigenous traditions that rely on Nature-based practices, such as chemical-free soil-based permaculture, aka food forests. This is to ensure that if global supply chains are disrupted or if a global energy crisis occurs, we can still be self-sustainable without relying on food imports or resource-intensive industrial farms. Food forests also serve to protect biodiversity, cool the urban heat island effect, relieve stress and anxiety through forest therapy/bathing, and ensure that we get the necessary nutrition from organic foods instead of mere calories from nutrient-depleted foods, in order to maintain a strong immune system. We can learn from world history that shows how indigenous communities have been successfully surviving and thriving through self-sustaining, regenerative, low-consumption, high-nutrition lifestyles in tropical rainforests (such as the Amazon, Congo Basin and Southeast Asia) over thousands of years, while many empires with advanced technology of their days, such as the Mayan, Babylonian, Greek and Roman empires, could not last more than a few centuries, despite having been prosperous materially and outwardly, because of their self-destructive mindsets and unsustainable lifestyles.
In Singapore’s context, that means having a fusion of traditional soil-based farms (or food forests) and high-tech farms in Lim Chu Kang and Kranji countryside, as well as secondary forests, such as Tengah forest, Bukit Batok nature corridor and Khatib nature corridor, where there are already traditional farms being managed by the older local folks who grew up in kampongs. It would be unwise to force them out of the forests and let their expertise and experience go to waste while they also become prone to senility or dementia from being cooped up in a highly concretised environment. Having said that, I support having more urban farms in housing estates and on multistory carpark rooftops for added food security, although these should not be seen as substitutes for the need to conserve and restore our forests.
According to National Climate Change Secretariat (NCCS): “The Centre for Climate Research Singapore has projected that Singapore could experience an increase in daily mean temperature of 1.4C to 4.6C towards end of this century, more intense and frequent heavy rainfall events, and mean sea level rise of up to 1 metre by 2100.”
(to be continued, as it takes time to research and write based on the latest available information to ensure accuracy and relevance to our national conversation)
Earlier today, I noticed that parts of Bukit Batok South Hill area (next to Bukit Batok hillside park) have been denuded of trees and shrubs, and the heavy monsoon rain has washed the exposed topsoil away, causing soil erosion.
Heavy monsoon rain causing soil erosion and tree fall at Bukit Batok south hill next to Bukit Batok hillside park area on 13 August 2022 morning
On a steep slope along Bukit Batok West Ave 9 opposite Block 467B, the clearing of vegetation appeared to have resulted in a tree losing its stability and falling onto the pavement.
Tree fall in a steep slope where shrubs and other plants have been removed
These hazards suggest that we have crossed the ecological threshold through rapid deforestation and urbanisation – please see here for reference on a recent slope failure at Bukit Batok Hillside Park.
Moreover, along Bukit Batok West Ave 5 opposite Bukit Batok Hillside Park area, the cleared land along the perimeter of the marshy grassland may have caused the pavement to be flooded more easily during wet weather.
The removal of vegetation along the perimeter of the marshy grassland reduces soil permeability and increases surface runoff during rain.
Even if the clearance of vegetation has been done to prevent overgrowth onto the pavement, it appears to have been done aggressively to the point where there is less tree and shrub cover to absorb the rainwater.
As this low-lying area was formerly a depression or valley between Bukit Batok South Hill and Bukit Batok Hillside Park before a road (aka Bukit Batok West Ave 5) was built to divide the two hills in 2018, it remains a freshwater marsh on both sides (which support a fairly rich biodiversity) and is also prone to flash floods.
May I urge the relevant authorities and agencies to keep any trimming or pruning of vegetation to a bare minimum in this area please?
This is to ensure that it will not affect the habitats of the wildlife (which include uncommon forest-dependent species such as red-legged crakes and copper-cheeked frogs, as recorded in the Environmental Impact Studies report) and it will also minimise incidences of flash floods, considering the fact that climate change is causing more frequent and more severe storms as reported in the news?
“As for rainfall, the IPCC said that in general, bouts of rain could become more intense and frequent with each additional degree of warming.”
From “IPCC report indicates Singapore could take bigger hits from climate change” (TheStraits Times, 9 August 2021)
The excess water pooling on the pavement during and after rain causes the surface to be wet and slippery, posing a hazard for people
Incidentally, I reported a case via One Service recently, in which the slippery pavement along Bukit Batok West Avenue 5 has caused me to almost slip and fall down while travelling along the pavement. The puddles and flash floods in this area during wet weather may pose a hazard to other pedestrians, joggers, cyclists and food delivery riders who use the pavements.
Tree fall along Bukit Batok West Avenue 5, a likely result of edge effects and habitat fragmentation, where trees along forest edges experience increased wind exposure and other microclimatic changes
Last but not least, I learnt that NParks is currently covering several green areas (including Bukit Batok south hill and Bukit Batok hillside park area) and future parks in an environmental impact assessment (EIA) along Bukit Batok nature corridor, in line with its efforts to reduce fragmentation of habitats in Singapore.
“Mr Lee said that based on findings from the exercise, future environmental studies are expected to consider the ecological connectivity of the development site to other adjacent habitats.
Enhancement works in the nature corridor’s two parks will mainly consist of habitat restoration and other works that will help improve ecological connectivity, he added.”
From “Environmental impact assessment covering 122ha in Bukit Batok to start at end of year” (The Straits Times, 15 November 2021)
It would thus be inappropriate (and even unethical) to remove any trees along this critical part of the ecological corridor, which links Tengah nature way to Bukit Batok nature park and Bukit Timah nature reserve, especially while the EIA and ecological profiling exercise are still ongoing, as it would invariably affect the liveability of the environment and the biodiversity that depends on it.
Illustrations of biodiversity and ecological connectivity in Bukit Batok hillside park area hill 1 and 2
Otherwise, the findings and results of the EIA may be skewed at the expense of the wildlife residents who live and move around here, as well as the human residents in Bukit Batok who have come to enjoy and appreciate the wild nature, the cool ambience, and the mental health and immune boosting benefits provided freely by the forests along Bukit Batok nature corridor, both now and for many generations to come.
Thank you for your attention.
Yours sincerely, Jimmy Tan San Tek
P.S. My feedback was submitted through One Service bot in Telegram via the blog weblink due to space constraints, as I wasn’t able to submit it via One Service app due to technical issues.
Approximate locations of tree falls along Bukit Batok West Ave 5 and Ave 9 on 13 August 2022. (Source of base maps: One Service app, National Parks Board and Straits Times Graphics)
Indeed, climate change is a result of many parents, especially those in positions of influence and privilege, particularly in corporations and governments, who choose to live an unsustainable lifestyle or make decisions and policies that conform to the capitalistic economic system at the expense of our environment. As a result, our actions cause harm to the environment and affect the future of today’s children.
Come to think of it, if we see parenthood in a broader context, perhaps each of us can be a parent or mentor or guide to our younger generations, whether physically or spiritually.
Will our children and youths inherit a safe, diverse, inclusive and habitable world from us?
Will we also be teachable enough to learn (or relearn) the values of respecting and caring for Nature and sustainable living from them?
Aerial view of Pang Sua woodland and river canal, which are flanked between the built-up areas of Choa Chu Kang (background) and Bukit Panjang (foreground) housing estates (Photo by Jimmy Tan)
Here is my feedback on Housing and Development Board (HDB)’s Environmental Baseline Study (EBS) report for Choa Chu Kang N1, which includes Pang Sua woodland and river canal, in Singapore.
I understand that this forest patch is one of the few sizeable natural habitats (which include Kranji woodland, Clementi forest and Alexandra woods) located along the long and narrow 24-km Green Rail Corridor.
These core forest habitats are vital for native wildlife, such as critically endangered Sunda pangolins, common palm civets and wild boars, to rest, roost, forage and take refuge from apex predators, human disturbance and noisy motor traffic, otherwise they will be exposed to danger in open spaces and may also end up wandering into urban spaces and becoming roadkills or getting involved in human-wildlife conflicts.
(The above video records a sighting of a wild boar (whose species is invaluable for tree seed dispersal and regeneration of tropical forests) along the Green Rail Corridor between Pang Sua woodland and Kranji woods in February 2021. As noted in my feedback to NParks, wild boars are sensitive to disturbances of their natural habitat, which may force them to wander into residential areas. In 2017, a wild boar was involved in a conflict with a human being before it got into a fatal road accident in Hillview, about 2 km south of Pang Sua woodland.)
The EBS report noted that the “original vegetation at the Study Area was likely to be a mangrove swamp forest which was subsequently cleared for rubber plantations”. Since mixed vegetation, comprising mainly mature trees and shrubs, currently occupies around 15 ha of the study area, we should conserve and restore the forest to what it originally was as closely as possible, by naturalising Pang Sua canal and rewilding the woodland and Green Rail Corridor, in order to recreate a mix of lowland secondary forest and freshwater swamp forest (since the water in the canal is no longer saline after Kranji river has been dammed to form a reservoir).
This is because besides providing climate resilience and ecological connectivity, Pang Sua woodland is also a sanctuary for human residents and visitors to seek relief from the heat and stress of urban living that affects physical health and mental well-being.
Pang Sua woodland receives strong support from Nature groups, such as Nature Society (Singapore), Cicada Tree Eco-Place and Lepak in SG, as well as Nature enthusiasts, to be conserved for ourselves and our future generations.
Taking into consideration the official responses to public feedback on the Environmental Impact Assessment (EIA) reports regarding recent planned housing development projects in greenfield sites, such as Bukit Batok hillside park area and Dover-Ulu Pandan forest in 2020-2021, I would like to address possible objections or questions concerning the conservation and restoration of Pang Sua woodland, which is proposed by Nature groups and Nature enthusiasts, including me.
1. Is Pang Sua woodland still worth conserving since it isn’t near any nature reserve in Singapore?
As shown in the map below, Pang Sua woodland is a core habitat located at the Green Rail Corridor (as also noted in the EBS report). It is connected to Tengah forest and Western water catchment via Hillview and Bukit Gombak within 2-3 km in the south. It is also connected to Kranji woods and Sungei Buloh wetlands reserve, Kranji coastal nature park and Mandai mangrove mudflats in the north. To the northeast, it is linked to Bukit Mandai (within 2-3 km) and Central catchment nature reserve.
Pang Sua woodland functions as a critical ecological corridor to ensure safe movements of native wildlife species, including critically endangered Sunda pangolins and straw-headed bulbuls, between Western water catchment and Central catchment nature reserve. Without such ecological connectivity, having rare and endangered species (such as mousedeer, Sambar deer and Raffles banded langurs, which may one day use these green corridors too) confined to Central catchment nature reserve is like putting all the eggs in one basket, where the threatened species risk experiencing population decline and extinction, due to factors such as inbreeding, climate changeaccelerating tree mortality, lack of healthy genetic exchange, etc. (Photos by Jimmy Tan)
2. Should Pang Sua woodland be conserved fully as it doesn’t seem to have very much biodiversity?
Critically endangered pangolins have been seen using Pang Sua canal and woodland as an ecological corridor, which may also be used by straw-headed bulbuls as a stepping stone. It is a vital conduit to ensure their safe movements and healthy genetic exchange so as to sustain their existence in the long term. Even the common species, such as rain trees (Samanea Saman), serve as shelter and provide food for less common species.
Although rain trees are common non-native species, they support the growth of epiphytes and provide food and shelter for wildlife. As also noted in Tengah North Environmental Impact Studies (EIS) report (page 185), “it is important to recognize that both common and rare species contribute ecological functions in an ecosystem.” (Photo by Jimmy Tan)
Incidentally, the pangolin is one of the six indicator species identified in NParks’ island-wide ecological profiling exercise, which were selected “as they are sensitive forest dwellers that may venture out to forest edges, provided suitable habitat is created for them there”.
Even as Singapore’s strict enforcement of the ban of international trade of pangolins is commendable and should be applauded, it seems contradictory that our local pangolin population continues to face the risk of habitat loss, degradation and fragmentation, as well as roadkills, due to ongoing urban encroachment which threatens their existence and safe movements in core habitats and wildlife corridors, such as Tengah forest and Pang Sua woodland.
The Singapore Pangolin Working Group noted that “Sunda pangolins are mammals native to Singapore and are classified as Critically Endangered in the Singapore Red Data Book 2008 as well as the IUCN Red List of Threatened Species. Their main threats in Singapore are habitat loss and alteration, as well as road traffic accidents — this contrasts with the major threats that this species is facing regionally, which include poaching and the illegal wildlife trade.Singapore is not losing its forests as fast as its neighbours, but the slow creep of urbanisation continues to shrink the patches of forest pangolins depend on for food and shelter.” (Photo by Jimmy Tan for illustration)
3. Isn’t there a strong demand for public housing, and shouldn’t human needs come first instead of nature conservation?
Regardless of the reasons for a strong demand for public housing, brownfield sites (such as old or underutilised industrial sites, abandoned schools, open car parks, golf courses whose leases are expiring soon, old HDB flats nearing their 99-year lease that can undergo Selective En Bloc Redevelopment Scheme (SERS) or Voluntary Early Redevelopment Scheme (VERS) as early as possible, etc) should be prioritised over greenfield sites for housing development or redevelopment projects. For example, the heavy vehicle carpark and defunct bus terminal near Pang Sua woodland can be recycled to build tall Build-To-Order (BTO) flats. Also, human needs aren’t restricted to just housing, but also physical health and mental well-being. Since Singapore is already heating up twice as fast as the rest of the world, it would be detrimental to one’s health and well-being in the long run when one lives in a highly built-up area in hot sweltering conditions, even if it is within 10 minutes’ walk to small pocket parks, as they can hardly cool the urban heat island effect in the surroundings.
According to studies, a large forest of an area of 10 ha or more (such as Pang Sua woodland) can cool the surroundings by 1-2 degrees Celsius up to a distance of 350 metres, whereas plants on building facades can only cool up to 4 metres. The denser the foliage, the greater the transpiration and cooling effect of the forest (and the more it can help residents reduce electricity bills by relying less on artificial air-conditioning). (Photo by Jimmy Tan)
4. Hasn’t the Urban Redevelopment Authority (URA) master plan 2019 already designated Pang Sua woodland for housing developmentmany years ago?
Much as we appreciate the efforts made by urban planners, we also need to acknowledge the fact that urban planning 10 or 20 years ago was different from today’s context. Back then, urban planners weren’t required to take a course on basic ecology and the EIA process, so they might not have taken habitat fragmentation and climate crisis into consideration adequately. The Climate Action Tracker has considered Singapore’s climate policies and actions to be highly insufficient as of July 2020. The Intergovernmental Panel on Climate Change (IPCC) has also declared Code Red for the climate emergency in 2021. We cannot afford to adhere rigidly to the master plan if we want to be responsive to be more climate resilient and prevent biodiversity collapse.
Climate resilience and biodiversity protection are urgent needs in the post-pandemic era we live in. Lama El-Hatow, an environmental and social consultant, showed an illustration “where future crises were represented in tsunami waves, each bigger than the one before it. She explained that once COVID-19 (the first wave) comes to an end, economic recession, climate change, and biodiversity collapse will follow”. (Illustration from The Cairo Review)
5. Should we not consider this issue as a zero-sum game, but rather consider how conservation and development can be done in tandem to have a certain balance, such as by replacing forest loss with replanted trees?
We can achieve that balance by prioritising the recycling of previously developed lands. It takes decades for newly planted trees to grow and mature to be able to provide the same level of ecosystem services and biodiversity support as the existing mature trees, so forest conservation needs to take precedence over tree planting, inasmuch as the latter is also important.
For example, Pang Sua woodland functions as a natural “rain garden” to absorb rain and purify surface runoff and groundwater flow that goes into Pang Sua river.
The river flows into Kranji reservoir, where the water will be treated before it is transported to residential and industrial areas.
The healthy riverine ecosystem downstream of Pang Sua river canal testifies to the water purifying and life-giving effect of Pang Sua woodland, which serves as a natural rain garden. (Photos by Jimmy Tan)
Such essential ecosystem services are provided by Pang Sua woodland free of charge.
Hence, conserving the forest would be a cost-effective and self-sustaining nature-based solution to ensure water security, rather than removing the forest and replacing it with man-maderain gardens which will cost a lot of time and resources.
Then again, that might well be a pipe dream that would only come true in an ideal or enlightened world.
This is because if we continue to subscribe to the environmentally destructive capitalistic economic system that prioritises Gross Domestic Product (GDP) growth over ecological health, then we will be tempted to justify clearing the trees to sell the land to developers, and give more business to architects, landscaping companies and property agencies.
After all, these companies look to the government for new development projects in order to earn profits too.
(A case in point: property agencies were quick to chime in after the government announced their response to public feedback on the Environmental Baseline Study for Dover-Ulu Pandan forest in end July 2021.)
We will also be tempted to justify using public funds to plant a man-made rain garden to replace the existing woodland and then credit it to our national efforts to transform Singapore into a “City in Nature”.
Surely by creating (preventable) problems through incessant deforestation and urbanisation in order to solve them using expensive technology, we can then profess to achieve our Key Performance Indicators (KPI) and present Singapore as a smart and sustainable nation?
Or should we be working towards the implementation of a less resource-intensive and more sustainable and equitable economic model that actually respects ecological boundaries and connectivity, instead of finding ourselves gravitating towards greenwashing while heading towards self-destruction?
Spiders, frogs, geckos and dragonflies are some of the natural predators of mosquitoes. Once a forest is cleared to make way for concrete buildings and roads, the warmer microclimate and loss of natural predators tend to allow mosquitoes to breed profusely and spread dengue virus. Aedes mosquitoes thrive in highly disturbed greenery, construction sites and urban areas, where they lay eggs in warm stagnant water uninhabited by their natural predators. Fogging or fumigation has shown to be not very effective in controlling the mosquito population, and instead tends to make them more resistant and harder to kill. There is currently a rise in dengue fever cases, and it is imperative that we conserve and restore our natural ecosystems, in order to experience good ecological health and mitigate the disease outbreak effectively. (Illustration from Philippe Birker)
6. Isn’t it a fact that Singapore is a small island-state and doesn’t have a large hinterland like bigger countries?
Yes, it is precisely because Singapore is a small tropical island that it should be respected for originally having tropical rainforests and mangrove forests that are best suited to the hot, wet and humid equatorial climate, instead of being dominated by the increasing number of buildings and roads that are worsening the urban heat island effect virtually every year.
As rightly declared by the Singapore Parliament in February 2021, climate change is an existential crisis. Public housing is not, even though it is a hot-button issue (despite Singapore’s low birth rate, slow or zero population growth and high public housing occupancy rates). Have we been getting our priorities right in our long-term planning review?
For example, the Singapore Green Plan 2030 mentions about our ambition to be transformed “from mudflats to metropolis”. Yet I have come to realise something about the science of mangrove mudflats:
The very thing that we seemed to be ashamed of in the past is now helping us deal with the very crisis that we have brought upon ourselves because of our disrespect for and over-exploitation of Nature in the name of (unsustainable) economic development.
If we compare our post-independence narrative of the 57-year-old city-state with the natural history scientific narrative of our thousands-of-years old rainforest and mangrove forest heritage of a tropical island located at the Equator, I wonder how much we are actually force-fitting the concept of “eternal” economic growth and increasing population growth and density without further risking our climate, ecological and mental health thresholds.
Maybe we need to consider adapting the doughnut economic model for better sustainability and rethink the ambition to go “from mudflats to metropolis” because the mangrove mudflats (and forests) have been shown to help boost climate resilience, mitigate urban heat island effect and floods, and protect biodiversity and mental health of our population.
Mangroves can absorb up to five times more carbon dioxide by area than tropical upland forests due to strong carbon storage in the soil, but are being lost at an alarming rate. Both types of tropical forests play an important role in combating climate crisis and supporting biodiversity. (Illustration by IUCN)
Thus, conserving and restoring our forests, including Pang Sua woodland, is a scientifically proven, cost-effective, nature-based solution to deal with the danger of declining quality of life and deteriorating health and well-being for the populace (especially those who are most vulnerable to the impacts of climate change, such as the very young, the elderly, those with pre-existing health conditions, those who work outdoors and those who lack access to adequate air-cooling devices or facilities) in a metropolis that isn’t suited to a hot humid tropical climate in the first place.
Summary of my proposal
I agree with the general recommendations on pages 71-72 of the EBS report, such as greening Pang Sua canal, establishing eco-links and planting trees intensively with shrubby undergrowth.
May I also propose the following scientific nature-based conservation and mitigation measures to further enhance the environment in Choa Chu Kang N1 study area, for the sake of better climate resilience, biodiversity support and public health protection in the long term?
(1) Avoid using chemical pesticides, including fumigation, in the vicinity, and instead leverage the help of natural predators of pest insects by ensuring the environment is conducive for frogs, toads, spiders, geckos, dragonflies, damselflies, etc to thrive (instead of concretising the ground surface and using harmful chemical sprays). As mentioned earlier, fogging is not very effective and tends to make dengue-carrying mosquitoes more resistant and harder to kill. It also harms benign insects and microorganisms, which are vital to a healthy functioning of the ecosystem. Even the use of Wolbachia-Aedes technology may have unknown or undesirable side effects such as the mutation of mosquitoes. Hence, we should use ecologically friendly mosquito control measures, such as making the environment habitable to mosquitoes’ natural predators, such as frogs, spiders and dragonflies, in Pang Sua woodland (as well as all residential areas in Singapore), in order to prevent dengue outbreaks successfully.
(2) Avoid or minimise the use of petrol-powered leaf blowers and lawn mowers, not only in Pang Sua woodland, but also in all housing estates, because they cause air and noise pollution (thus affecting people’s health and well-being), and harm microorganisms and invertebrates (which include pollinators, such as bees, wasps, moths, beetles and butterflies). For more than a decade, members of the public have been calling for these pollutive machines to be banned, as noted in my recent Youtube video about this issue. Otherwise, we are merely paying lip service to the importance of biodiversity when we cause harm to the various organisms (by mowing them down, compacting the soil, and destroying the weeds and wild flowers) instead of protecting them for giving us food security and maintaining a healthy functioning ecosystem.
Gas-powered leaf blowers, grass-cutting machines and lawn mowers create air and noise pollution, which is detrimental to human health and the environment. They contribute to greenhouse gas emissions and planetary warming, and should have no place in a country that considers itself “green and sustainable”. (Photos by Jimmy Tan)
(3) Observe holistically the United Nations’ Sustainable Development Goals, such as SDG12 “Responsible consumption and production”, by changing the way we produce and consume goods and resources, in order to reduce our ecological footprint, and SDG15 “Life on land”, by conserving and restoring the use of terrestrial ecosystems such as forests and wetlands, halting deforestation to mitigate the impact of climate change, and reducing the loss of natural habitats and biodiversity which are part of our natural heritage.
The UN Sustainable Development Goal 15 includes the goal to “promote the implementation of sustainable management of all types of forests, halt deforestation, restore degraded forests and substantially increase afforestation and reforestation globally“. This should apply to Singapore’s forests, regardless of whether we have a “forestry sector”, because the forests are considered renewable resources (in view of the economic value of their ecosystem services) and are part of the terrestrial ecosystems, which support biodiversity and provide ecosystem services to mitigate the impact of climate change. Otherwise, it would be inappropriate for us to claim that we are achieving sustainable development in this area. (Illustration by Margreet De Heer)
For example, if we do not practise responsible consumption and production, and even if we commit the grievous error of destroying Pang Sua woodland and all the other remaining forests in Singapore to build more BTO flats, there will still be a strong demand for public housing, since we have not addressed the insatiable human desire to keep wanting to consume more and more resources at the expense of the environment (and ultimately our quality of life and our very survival).
Imagine the wildlife, such as pangolins, wild boars and palm civets, losing their forest habitats forever, while some humans occupy their former spaces just for a few years before moving or upgrading to another housing elsewhere.
The first scenario is largely a matter of life and death, while the second is largely a matter of lifestyle choice, comfort and convenience.
Ethically speaking, is it worth destroying forests (which are also natural habitats and wildlife corridors) just to cater to this kind of frivolous demand for public housing in greenfield sites (when we can choose instead to educate the public about environmental stewardship and sustainability and redirect such demand for housing towards renting flats/rooms, buying resale flats or new flats in previously developed lands, etc)?
Ecologically speaking, is it wise to replace forests with buildings and parks where newly planted trees take decades to grow, mature and provide the same level of ecosystem services as the existing large trees to combat climate emergency (in which we are racing against time “to avoid the worst ravages of climate breakdown“)?
Economically speaking, does it make sense to ignore the socioeconomic and health costs of losing forests while spending huge amounts of public funds to mitigate floods, dengue and zoonotic outbreaks, mental health crisis, etc?
“It has also been demonstrated that urbanicity could represent a possible risk factor for the spillover phenomenon, facilitating the virus transition from animals to humans via intermediate hosts. Particularly, deforestation policies may facilitate this process, resulting in the destruction of natural habitats of numerous species and reduction of biodiversity, as well as in greater interaction between wildlife and human activity.”
Therefore, as Pang Sua woodland and canal are an integral part of the Green Rail Corridor, which provides “unique, highly accessible green spaces island-wide“, let us all keep in mind Minister Desmond Lee’s words:
“Community involvement and stewardship will be a key strategy in realising our vision for the Rail Corridor as a vibrant, inclusive, and shared community space. Our community spaces can only become more vibrant when they are designed, programmed and cherished in partnership with the people who treasure, care for and use them.”
Indeed, it is only by treasuring and caring for our community spaces, such as Pang Sua woodland and Green Rail Corridor, will we be able to ensure that they become vibrant and inclusive, not only for ourselves but also the flora and fauna which co-exist with us.
In a nutshell, Pang Sua woodland provides food, shelter, fresh air, cool ambienceand immune booster for wildlife and human visitors who travel along the Green Rail Corridor.
All are welcome to visit, regardless of race, language, religion, gender, social status or vaccination status.
No payment is needed.
The complimentary ecosystem services, which are of immeasurable value, are provided by Nature 24/7, 365 days a year.
(Photos of zebra dove, collared kingfishers, changeable lizard, monitor lizard and plantain squirrel taken by Jimmy Tan at Pang Sua woodland on 26 April 2022)
I wish to thank Housing and Development Board (HDB) for inviting the public to provide our feedback on the Environmental Impact Studies (EIS) report for the Tengah North area.
I also wish to commend the EIS team for putting together a comprehensive EIS report covering the geomorphology, soil, hydrogeology, surface hydrology, water quality, ecology and biodiversity, airborne noise, ambient air quality, visual and landscape, waste management, and Environmental Management and Monitoring Plan (EMMP) at Tengah forest.
Given the tight window of review between 5 November and 3 December 2021 and my busy work schedule, I regret that my feedback may not be as detailed as I would like it to be.
Because of time constraints as well as space constraints in the online feedback form (which does not allow attachments of photos or documents), I will have to write my feedback in the form of a blog and post its link in the form. (This will also enable me to update my feedback as and when necessary to ensure it is as accurate and up-to-date as possible.)
Below is my feedback concerning four main aspects of the EIS report:
Environmental Impact Study (EIS) Requirement for the Project
Ecology and Biodiversity
Environmental Management and Monitoring Plan
Land Use
1. Environmental Impact Study (EIS) Requirement for the Project
According to page 23 of the report, “Tengah Town is planned to be integrated with the area’s surrounding greenery and biodiversity. One major attraction will be the creation of an approximately 100 m wide and 5 kilometres (km) long Forest Corridor, in collaboration with NParks, is envisioned to form part of the larger network of greenery that connects the Western Water Catchment Area and the Central Catchment Nature Reserve (CCNR).”
Since Tengah forest serves to connect the Western Water Catchment Area and the Central Catchment Nature Reserve, we should ensure that it can facilitate the movements of endangered species, such as Raffles’ banded langur, leopard cat, Sambar deer and Sunda pangolin, for healthy genetic exchange and long-term survival. (Photo sources (L to R): Andie Ang, Marcus Chua, Charles J. Sharp, Piekfrosch)
I am heartened to know that Tengah forest is recognised as an important conduit of wild greenery between the two main water catchment areas in Singapore because we can use it to boost the chances of long-term survival of our critically endangered species, such as Raffles’ banded langur, leopard cat, Sambar deer and Sunda pangolin, besides other keynote species that are important for our ecosystems, as all organisms are interdependent and interconnected parts of Nature.
For example, there are about 60 Raffles’ banded langur individuals in Bukit Timah nature reserve (BTNR) and CCNR, whereas they used to be found in other places such as Tuas and Changi until the 1920s. Since Raffles’ banded langurs are endemic only to southern Peninsular Malaysia and Singapore, we cannot afford to be complacent, lest their population declines due to inbreeding and inadequate forested space.
Having such critically endangered species confined to only BTNR and CCNR is like putting all the eggs in one basket, which is risky and unwise because climate change can affect forests adversely, such as resulting in many trees dying from prolonged dry spells (or droughts) and becoming less resilient to pests and pathogens.
By helping their populations to expand to Western water catchment area via Tengah forest (and other ecological corridors in Bukit Batok and Bukit Gombak), as well as to Upper Thomson forest and Sembawang Woods in the east side of Thomson Nature Park, to Bukit Brown heritage park and Botanic Gardens in the south side of MacRitchie forest, and to Clementi forest and Dover-Ulu Pandan forest in the south side of BTNR, we can improve the chances of their long-term survival as a result of healthy genetic exchange.
If pushed past a certain tipping point, ecosystems may collapse and be unable to recover.Thus, we cannot guarantee that CCNR will be immune to the effects of climate change in the long term. (Source: theweirdandwild)
Similarly, there are only about 20 leopard cats estimated to live in the Western water catchment and CCNR today. Ever since tigers and leopards have become extinct by mid 19th century, the leopard cat is the only native wild cat left in Singapore. Thus, Tengah forest can be its crucial lifeline for long-term survival through ecological connectivity and healthy genetic exchange. As a signatory of United Nations Biological Diversity Convention since 1992, Singapore has a responsibility to conserve our biodiversity, especially our rare native species.
Like the leopard cats, the population of Sambar deer was estimated to be around 20. They were found only in CCNR, and may venture as far south as Bukit Brown heritage park. Since some of them live around Mandai area, one possible route they could take to move to Western catchment area is via Bukit Mandai, Green Rail corridor, Bukit Gombak and Tengah forest.
Last but not least, Sunda pangolins are estimated to number around 100 in the wild in Singapore. As some of them have been discovered and recorded in the EIS report for Tengah North, it is likely that the pangolins use Tengah forest as a core habitat for feeding and breeding, as well as an ecological corridor to move between Western water catchment and CCNR.
As suggested by Nature Society, eco-links are needed to help wildlife move between the eastern side of Tengah forest and the forests in Bukit Batok and Bukit Gombak. The eco-links may take the form of rope bridges (which are ideal for squirrels, macaques, langurs, etc), underground culverts (which are ideal for snakes, pangolins, etc) and/or some other means, so that certain mammals and reptiles can use them to cross the roads safely. (Photo by Jimmy Tan)
(Update on 17 May 2022)
As I regret that my original feedback was incomplete due to insufficient time to submit a more comprehensive response in view of the tight one-month public feedback period and my other commitments, I am wondering if the following proposals can be taken into consideration in your Environmental Monitoring and Management Plan for Tengah (which I mentioned in my recent feedback to HDB regarding the EBS report on Choa Chu Kang N1 and EIS report on Keppel Club site)?
For ease of reference, I have copied and pasted the relevant portions as follows:
(1) Avoid using chemical pesticides, including fumigation, in the vicinity, and instead leverage the help of natural predators of pest insects by ensuring the environment is conducive for frogs, toads, spiders, geckos, dragonflies, damselflies, etc to thrive (instead of concretising the ground surface and using harmful chemical sprays).
(2) Avoid or minimise the use of petrol-powered leaf blowers and lawn mowers, not only in (Tengah forest), but also in all housing estates, because they cause air and noise pollution (thus affecting people’s health and well-being), and harm microorganisms and invertebrates (which include pollinators, such as bees, wasps, moths, beetles and butterflies).
(3) Observe holistically the United Nations’ Sustainable Development Goals, such as SDG12 “Responsible consumption and production”, by changing the way we produce and consume goods and resources, in order to reduce our ecological footprint, and SDG15 “Life on land”, by conserving and restoring the use of terrestrial ecosystems such as forests and wetlands, halting deforestation to mitigate the impact of climate change, and reducing the loss of natural habitats and biodiversity which are part of our natural heritage.
Kindly refer to the weblinks below for more details of the proposals in the entire context:
P.S. In my feedback to NParks on 21 March 2022, I have also written the following:
Even if 140 ha of Tengah forest has been set aside for green spaces, it is uncertain if they refer to dense forests or open wooded parks, and it constitutes only 20% of the total area, which I am concerned may not be enough, in view of the relatively narrow designated nature way without much buffer space. As proposed in the petition to preserve 30-50% of Tengah forest to protect biodiversity and tackle climate emergency, we need to “preserve at least 30 to 50 percent of Tengah forest’s original 700-ha size (or 210 to 350 ha) for purifying the air, cleaning the soil, removing pollutants, cooling the urban heat island effect, supporting biodiversity, preventing/mitigating risk of floods, zoonotic viruses and dengue diseases (as well as roadkills and human-wildlife conflicts), reducing electricity usage for air-conditioning, enhancing our physical and mental health etc, thereby potentially saving billions of dollars of public funds and personal/household expenses, in terms of healthcare, socioeconomic and environmental costs.”
Multiply this effect over time and space, and we will get more extreme weather changes, such as more intense and/or prolonged storms, heat waves, droughts, etc in different parts of the world.
In the longer run, we describe the phenomena collectively as “climate change”.
When measured in terms of the average time span of 35 years, climate may be observed as predictable meteorological patterns, which are fairly constant.
Weather is less predictable, as it changes daily, or even hourly.
Of course, in a much longer term, such as thousands or millions of years, climate changes significantly.
That’s how we get ice ages in between long periods of global warming.
But in the Anthropocene that we live in, climate changes faster than ever before, due to unprecedented emissions of carbon from human activities, such as:
🌳 Deforestation to make way for urbanisation 🌳 Burning of fossil fuels for energy, transport, etc
This is where we are.
On a global scale, winds are influenced by the Coriolis effect, which has to do with Earth’s rotation. 🌏
It causes prevailing winds to rotate clockwise or anti-clockwise, depending on whether they are in the Northern or Southern hemispheres.
That’s how we get monsoons, cyclones, typhoons and hurricanes in different regions of the world, which are being made more extreme by climate change.
These severe weather events may result in natural disasters, such as flash floods, landslides, mudslides, slope failures, etc, which in turn may cause property damage, injuries and/or deaths of people who are affected.
Sumatra squall in Singapore, caused by the southwest monsoon.
Note: This post is meant to provide only a simplified explanation of climate change. Besides wind, temperature and rain, other weather elements, such as humidity and cloud cover, have a part to play in climate too. Local weather cycles affect global weather cycles, and vice versa. To make things more complicated, deep ocean currents also affect the climate on continents.
The much publicised “Tengah Forest Town” development that is planned to clear 90% or more of the original forest has become a controversy. For a start, Tengah forest (aka Bulim forest) has a very impressive record of 262 fauna species, of which 60 are regarded as forest-dependent wildlife species and at least 44 species are nationally threatened, according to HDB’s baseline report dated 2017. The forest also has at least 33 species of plant life with “conservation significance”, as well as 159 significant large trees, of which 90% belong to the fig family (Moraceae). (Photos by Jimmy Tan)
This diagrammatic map illustrates that Tengah forest is a vital conduit and habitat supporting biodiversity and ecological connectivity between Western catchment area and Central catchment area, which are Singapore’s main terrestrial “green lungs”. They provide essential ecosystem services, including removing pollutants, purifying the air, absorbing carbon emissions, cleaning the soil, preventing flash floods, cooling the urban heat island effect, and providing food and shelter for living organisms. Thus, they potentially save billions of dollars’ worth of social, health and environmental costs that would be incurred if the forests were removed or reduced. (Satellite image dated May 2021 by Akihiko Hoshide)
It has been about two years since Housing and Development Board (HDB) has started development works in the 700-ha Tengah forest in early 2019 after fencing up its perimeter. It has resulted in the clearance of about 30% or more (or 210 ha or more) of the forest so far, in a bid to build a “forest town” in Singapore, which would be about the same size of Bishan housing estate.
To date, HDB has launched thousands of new BTO (Build-To-Order) apartment flats in parts of Tengah area in November 2018, May 2019, November 2019, August 2020, November 2020 and February 2021. In May 2021, another 782 HDB BTO flat residential units were launched in Tengah.
However, although an environmental baseline study (EBS) was done in Tengah forest in 2017, we urgently need to reconsider the ramifications of Tengah forest town development because concerns about rapid deforestation and urbanisation in Singapore have been raised by Nature groups and members of the public, especially in recent years.
Since the early 2010s, more and more people in Singapore have been voicing their concerns about the loss of wild green spaces and biodiversity resulting from the destruction of regenerating secondary rainforests, such as Lentor-Tagore forest, Bidadari forest,Tengah forest, Pasir Ris forest, Kranji woodlands, Jurong Eco Garden nature trails, and Bukit Batok Hillside Park area forest. These forests have been sacrificed to varying degrees for development, despite comprehensive descriptions of wildlife sightings having been recorded (and alternative sites for development having been proposed in the cases of Tengah forest and Bukit Batok Hillside Park area).
Deforestation in Lentor forest in August 2016 (Photo by Jimmy Tan)
Deforestation in Bidadari forest in July 2017 (Photo by Jimmy Tan)
Deforestation in Tengah forest in November 2020 (Photo by Jimmy Tan)
Deforestation in Pasir Ris Park in December 2020 (Photo by Jimmy Tan)
Deforestation in Jurong Eco Garden around nature trail in January 2021 (Photo by Jimmy Tan)
Deforestation in Kranji woodlands in February 2021 (Photo by Jimmy Tan)
Deforestation in Bukit Batok Hillside Park area forest in April 2021 (Photo by Jimmy Tan)
More recently, three petitions for conserving Bukit Batok Hillside Park area, Clementi forest and Dover-Ulu Pandan forest have been started in Singapore since last year, garnering over 13,000 signatures, 19,000 signatures and 50,000 signatures respectively as of May 2021.
These petitions have highlighted various negative consequences of continual deforestation, such as increased urban heat island effect contributing to climate change, endangerment of forest-dependent species and biodiversity loss, and threat to our physical and mental well-being as well as our very existence.
As the fate of Tengah forest is still hanging in the balance, this blog post serves to provide examples of its rich biodiversity and its indispensable function as an important ecological corridor connecting Western catchment area and Central catchment area. It also aims to highlight the fact that Tengah forest in its current state is crucial for dealing with climate emergency and biodiversity loss as well as improving our quality of life.
In view of the importance of Tengah forest (which we will read about below), we urgently need to preserve the rest of its remaining area as much as possible, or at least 30 to 50 percent of its original 700-ha size (or 210 to 350 ha). In order to do so, we need to:
heed Covid-19 pandemic (and resurgence of community cases) and other warning signs seriously and halt or minimise deforestation in Singapore, including in Tengah forest
treat climate emergency as it really is because we are running against time to deal with its existential threat to our survival, and Tengah forest is big enough to have a significant impact on our microclimate
protect our biodiversity in Tengah forest (and its connecting corridors and core nature areas) from further loss and endangerment of species
establish sizeable wildlife corridors and core habitats areas in Tengah forest in order to maintain a healthy ecosystem that benefits humans, flora and fauna
focus on redeveloping alternative sites or brownfield sites such as underutilised lands and abandoned schools etc in order to achieve a better and more sustainable future for ourselves and our future generations.
1. We need to heed Covid-19 pandemic (and resurgence of community cases) and other warning signs seriously and halt or minimise deforestation in Singapore, including in Tengah forest.
One of the natural streams running through the verdant landscape of Tengah forest. If the forest is cleared, it may lead to a spike in infectious diseases. According to a study done by Harvard University, “cleared forests lead to ecological changes that increase the risk of disease outbreaks, particularly those carried by mosquitoes — and the mosquito populations that thrive in deforested areas tend to be more dangerous for humans.”Even if we rely on fogging or chemical fumigation, it is not very effective in controlling dengue-carrying mosquitoes’ populations because not only does it cause them to become more resistant but also it harms their natural predators such as frogs, spiders and dragonflies. Thus, it is better to curb deforestation and practise reforestation for dealing with dengue and other such diseases at the root, instead of merely treating the symptoms of the problem. (Photo by Jimmy Tan)
In view of the possibility that the coronavirus has made the jump from animals to humans in China since late 2019, the Covid-19 resurgence in local community cases in Singapore in late May this year is a cause of concern, especially in the wake of continual deforestation and urbanisation.
On 4 June 2021, scientists behind a new independent taskforce, which is hosted by Harvard University and will report to the coalition on Preventing Pandemics at the Source, said that ending the destruction of nature to stop outbreaks at their source is more effective and cheaper than responding to them.
“Recent research estimated the annual cost of preventing further pandemics over the next decade to be $26bn (£18bn), just 2% of the financial damage caused by Covid-19. The measures would include protecting forests, shutting down risky trade in wildlife, better protecting farm animals from infection and rapid disease detection in wildlife markets.”
Incidentally, earlier this year, we have been talking about adopting science-based approach and nature-based solutions in dealing with wildlife management and environmental issues. In the case of Tengah forest, National Development Minister Desmond Lee said:
“we recognised that the forests at the future Bukit Batok Hillside Nature Park and Bukit Batok Central Nature Park are important stepping stones between the Bukit Timah Nature Reserve, and the future Tengah Forest Corridor. That is why we dedicated these nature parks as part of the Bukit Batok Nature Corridor – they will be kept lushly forested, so that they can strengthen not just the area’s green network, but also ecological connectivity between the Nature Reserve and Tengah.”
While it is good that we are taking the science-based approach towards wildlife management and forest conservation, we will be ignoring the scientists’ warnings about pandemics and environmental destruction at our peril. In other words, the conservation of Tengah forest (and other secondary forests) is a non-negotiable measure that we must take in order to deal with the urgent public health and environmental crises facing us.
Aerial view of Tengah forest where deforestation has already begun since 2019. Scientists have asserted that forest conservation is a necessary antidote in dealing with the pandemic because natural prevention of zoonotic viruses is better and more cost-effective than vaccination and other measures. (Photo by Jimmy Tan, 10 November 2020)
2. We need to treat climate emergency as it really is because we are running against time to deal with its existential threat to our survival, and Tengah forest is big enough to have a significant impact on our microclimate.
On 1 February 2021, in response to the petitions and the questions raised by various Members of Parliaments (MPs) on behalf of concerned residents and citizens, the Singapore Parliament has rightly declared the issue of climate change a global emergency, recognising it as a “threat to mankind” that requires a concerted effort to “deepen and accelerate efforts to mitigate and adapt to climate change, and to embrace sustainability in the development of Singapore”.
Singapore’s continuous temperature records since 1948 show that the island has warmed, notably in the mid-1970s when rapid urbanisation took place. The upward trend is approximately double the trend in global temperatures. Eight of the ten warmest years on record in Singapore have occurred in the 21st century and all the ten warmest years are since 1997. (Source: www.weather.gov.sg)
While the Green Plan includes the one-million tree planting programme, which is laudable, botanist Shawn Lum cautioned that “tree planting is beautifully complementary to, and not a substitute for, the care and protection of existing forest habitats.”
In fact, one of the most effective (and cost-effective) nature-based solutions to combat climate change, as also proposed by conservation scientist Professor Koh Lian Pin, is to “protect Singapore’s remaining forests and avoid further emissions from deforestation“.
Moreover, replanting trees, or reforestation, takes decades for the trees to grow and mature under the right conditions, and cannot replace our need for forest conservation, since planting trees does virtually nothing to protect the local biodiversity and ecosystems fully. Also, if we plant trees of similar species for aesthetic landscaping to create manicured parks and gardens, it is like developing monocultures that are incapable of recreating plant diversity as per their existence in the wild.
Although the SG Green Plan may envision Singapore becoming a metropolis like London or New York, we need to bear in mind that unlike these cities in cool temperate countries, Singapore is a small tropical island-state. Since we experience hot, wet and humid tropical climate at the Equator, we cannot keep removing our default natural vegetation, which includes tropical rainforests, freshwater swamp forests and mangrove forests, without facing dire consequences on our health, safety and well-being as well as our flora and fauna.
Being located at the Equator, Singapore receives the maximum intensity of direct sun rays and experiences high temperatures throughout the year. Humans, flora and fauna in this tropical island are much more vulnerable to the effect of climate change, such as heat stress and droughts, than those in cool temperate regions. (Source: National Geographic)
According to the Meteorological Service Singapore’s Centre for Climate Research Singapore, last year’s annual mean temperature of 28 degrees Celsius was half a degree higher than the long-term average, making 2020 the eighth warmest year on record. Singapore’s official meteorological agency also noted a recent sharp rise in temperatures and warned that maximum daily temperatures could reach 40 degrees Celsius by as early as 2045.
The urban heat island effect in Singapore at 2.00 am (April 2016) | Cooling Singapore, 2018. We can see that Tengah forest is cooler than highly built-up urban environments, such as Jurong town and Jurong industrial estate in the southwest. (Base map: coolingsingapore.sg)
Singaporean climate change scientist and professor Winston Chow attributed the rising temperatures to a phenomenon known as the “Urban Heat Island Effect,” which occurs when cities replace natural land cover with dense concentrations of concrete, pavement, buildings, and other surfaces that absorb and retain massive amounts of heat. He added:
“Singapore has definitely been getting hotter and every degree counts. The hot weather we’ve been experiencing recently is not only a clear indicator of climate change but also the effect of how rapidly urbanization alters local climates.”
Now that Singapore is heating up twice as fast as the planet due to rapid deforestation and urbanisation, if we continue to remove our few remaining secondary rainforests, such as Tengah Forest, we may soon reach a tipping point at which heat stress affects both human health (through greater risks of dehydration, heat strokes, etc) and carbon dioxide uptake by trees (due to damage to leaf tissue and declining tree health).
“Climate change increases the risk of illness through increasing temperature, more frequent heavy rains and runoff, and the effects of storms. Health impacts may include gastrointestinal illness like diarrhea, effects on the body’s nervous and respiratory systems, or liver and kidney damage.”
In terms of economic and financial implications, it is likely that we will be spending billions of dollars improving healthcare infrastructure and access as well as covering increased medical bills when we see a rise in cases of heat waves affecting the human body and more severe storms and more frequent floods resulting in water-borne illnesses. There are also intangible costs, such as loss of reputation, lost recreation and the psychological impact on people, all of which feed back to the economy, as noted by Nanyang Technological University (NTU)’s head of economics, Euston Quah.
Similar concerns about climate change on the environment have also been raised by scientists around the world. For example, according to Professor Daniel Murdiyarso, principal scientist at the Center for International Forestry Research (CIFOR), based in Bogor, Indonesia:
“Deforestation or removal of rainforests has certainly reduced the landscape capacity to absorb atmospheric carbon dioxide. Combined with the effect of climate change, it has caused the ecosystem to be more vulnerable to extensive droughts and wildfires. Rainforests are very fragile. Large-scale disturbance like deforestation or fires will not give them the chance to renew themselves.”
“Forests are needed to absorb carbon, but the overheating planet might soon flip a critical switch” (CNA, updated 4 May 2021)
Already, scientists are concerned that as much as 40% of the Amazon rainforest, which is more than 3,000 times the size of Singapore, may reach a tipping point in 50 years’ time, whereby it may collapse and morph into arid savannahs as a result of climate change.
So we cannot guarantee that we will not be spared from such an ecological catastrophe too, especially since our protected nature reserves occupy less than 5% of our total land area, while we continue to lose our spontaneous vegetation, which includes secondary forests, shrublands and scrublands, and which occupies only about 20% of our total land area.
(In contrast, Mauritius, also a tropical island like Singapore with a high human development index, has 47% of its total area occupied by forests. So, it may very well be a myth that we must keep on sacrificing our forests for economic development in order to enjoy a high standard of living and good quality of life.)
Thus, it is imperative for us to treat climate change as a real emergency and re-emphasise the importance of Tengah forest (as well as other secondary forests) for dealing with climate emergency and biodiversity loss as well as improving our quality of life.
We need dense rainforests, such as Tengah forest, to cool the urban heat island effect through mass transpiration. They function like natural air conditioners of the environment. Imagine how much cost Singapore can save by conserving forests and using less artificial air-conditioning for homes, offices, shopping malls and so on. Studies have shown that mature trees in dense forests have greater cooling power and sequester more carbon than young trees in fragmented parks and gardens too. (Photo taken by Jimmy Tan on 16 June 2021, which shows mist in the morning due to evapotranspiration from the dense trees and natural streams in Tengah forest)
3. We need to protect our biodiversity in Tengah forest (and its connecting corridors and core nature areas) in order to prevent further loss and endangerment of species.
Firstly, an environmental baseline study (EBS) had been initially done for Tengah forest by HDB. Given the findings of this baseline study, the vice-president of the Nature Society (Singapore) (NSS), Dr Ho Hua Chew has pointed out that Tengah forest harbours a rich biodiversity.
Yellow flat butterfly (rare) – photo by M Saniroz Sunda pangolin (critically endangered) – photo by Steven Chong Straw-headed bulbul (critically endangered) – photo by Jimmy Tan Changeable hawk-eagle (endangered) – photo by Jimmy TanLong-tailed parakeet (near threatened) – photo by Jimmy Tan Baya weavers’ nesting trees (resident) – photo by Jimmy Tan Grey-headed fish eagle (near threatened) – photo by Jimmy TanSmooth-coated otter (critically endangered) – photo by Jimmy TanContrary to a misconception that Tengah forest is “of low conservation value”, diverse species of native wildlife have actually been found in Tengah forest, including rare, endangered and critically endangered species. These species include yellow flat butterflies, Sunda pangolins, straw-headed bulbuls, changeable hawk-eagles, grey-headed fish eagles, smooth-coated otters and long-tailed parakeets. As a signatory of the United Nations Convention on Biological Diversity, Singapore has a global responsibility to conserve these species.
An academic paper on updating the classification system for secondary forests in Singapore has noted that rare, threatened or endangered species may be found in regenerating forests. Hence, nature groups and members of the public should be consulted as early as possible on urban planning before any environmental impact assessment (EIA) is carried out and before any developer is awarded a construction project contract tender for any forest patch.
Like Dr Andie Ang from the Wildlife Reserves Singapore Conservation Fund also noted, even if delays were to occur, it is better off to consult green groups and residents at the review stages of the URA Master plan. This is so that we can “ensure a higher quality of urban planning, which can minimise the impact on the environment and improve the overall quality of life for residents. Feedback at an early stage would also help planners to understand what residents want and to build accordingly”.
As it were, the general public were apparently not consulted in advance to gauge if there was a significant demand for housing in Tengah forest before HDB conducted EIA in the forest several years ago. Notably in February 2021, one day after the latest batch of BTO flats were launched in Toa Payoh/Bidadari, Whampoa/Kallang, Tengah and Bukit Batok, the latter two appeared to be not quite popular for home buyers. As the Straits Times noted:
“Those who wish to live in the non-mature estates of Bukit Batok and Tengah may have better luck as application rates were relatively low yesterday evening.”
Thus, in view of the rich biodiversity in Tengah forest and the relatively low initial demand for housing in Tengah, we need to seriously reconsider the need to develop the rest of Tengah forest as originally planned. We should also focus on redeveloping brownfield sites within reasonable distance from existing town amenities and infrastructure, such as vacant lands, underutilised lands, abandoned schools, etc, as well as building taller apartment blocks where possible in order to make up for any shortfall of planned flat units.
Secondly, according to a Straits Times article dated 23 February 2021, National Development Minister Desmond Lee said that “a more comprehensive picture of Singapore’s nature areas and how they connect to one another will be developed. The idea is to map out the islandwide ecosystem and connectivity to better consider how specific sites connect to nature areas, buffers and corridors.”
Indeed, we do need to take into account the big picture of biodiversity on a national scale instead of treating the development of Tengah Forest Town merely as a localised or discrete project. Hence, we need to acknowledge that in view of the rich biodiversity in the regenerating secondary forests between the Western catchment area and Central catchment area (which include Tengah forest, Bukit Batok Hillside Park ridges, Bukit Gombak forest (aka Little Guilin or Bukit Batok Town Park), Bukit Batok Nature Park and Bukit Timah Nature Reserve, etc), it is paramount to preserve the remaining parts of Tengah forest as much as possible (which in fact is one of the largest contiguous patches of green space in Singapore, bigger than even the 163-ha Bukit Timah Nature Reserve).
The big picture: How Tengah forest ecosystem connects with other nature areas, buffers and corridors, such as Green Rail Corridor, Gombak forest, Bukit Batok Hillside Park area, Bukit Timah nature reserve, and so on. According to NParks, these corridors facilitate the movement of native wildlife (including insects, birds, amphibians, reptiles and mammals) and exchange of genetic material between Western catchment area and Central catchment area, leading to healthier populations.
This will ensure that the native wildlife, such as Sunda pangolins, Sunda colugos (or flying lemurs), palm civets, Malayan box turtles, green crested lizards and greater bamboo bats, have sufficient space to live, move, feed, reproduce and carry out pollination and seed dispersal, without ending up as animal roadkills or getting into conflicts with humans in residential areas, which may lead to injuries or even deaths.
During my recces in Tengah forest in 2017-2019, I was fortunate to see a number of resident animals such as a smooth-coated otter, a grey-headed fish eagle, baya weavers and wild boars. It is saddening to see that the forest is losing important habitat niches for these native wildlife species due to forest clearance and human disturbances from the ongoing construction works.
As a testament to the rich biodiversity in Tengah forest, at least a dozen baya weavers’ nests have been found in the northeastern part of Tengah forest. This sighting, together with other wildlife sightings mentioned in this blog, suggests that there is abundant natural food supply and complex food webs of interconnected flora and fauna that already exist in the ecosystem.
From my understanding, HDB is currently doing a new Environmental Impact Study (EIS) in the north of Tengah, including the baya weavers’ nesting area that I have highlighted to them via OneService app. I was told that their EIS consultant will take into consideration my feedback when assessing the potential impacts from the development plans with mitigating measures to be recommended and implemented by the future contractor.
(It must be noted that the new EIS is being done in a smaller area within the original Tengah forest, which is already cleared in some parts. Hence, the results of the EIS may reflect lower biodiversity than before any construction work began in 2019, due to disturbances being caused to the flora and fauna by edge effects, light pollution, noise pollution, etc as a result of the forest clearances. In other words, this new EIS is unlikely to capture the full conservation value of the original Tengah forest, hence our review of the EIS report must take this reality into consideration.)
The baya weaver nests are located at the edge of a scrubland surrounded by the lush forests near the track leading to Jalan Lam Sam. It is about half an hour’s walk from the canal near Brickland Road in the northeast part of Tengah forest. The photos shown in the map were taken in April 2019 when the forest wasn’t fenced up (Source: Google Maps; photos by Jimmy Tan)
As for the beautiful flat yellow butterfly, it is described as rare in the forested plains of Singapore and Malaya, with only a few sightings in parts of Singapore, including Tengah forest. Moreover, according to Delvinder Kaur, junior animal care officer, Zoology, Wildlife Reserves Singapore, “insects are responsible for approximately 80% of the pollination out there. Pollination is needed for our crops, and that gives us food security”. Given Tengah forest’s close proximity to Kranji countryside where farms are plentiful in Lim Chu Kang and Neo Tiew areas, the proliferation of insects, such as bees and butterflies, in Tengah forest is crucial for pollination of crops in the nearby farms to ensure food security for us. This also means that we shouldn’t just focus on protecting rare, endangered and/or endemic species (as crucial as they are), but we should also seek to accommodate common species because they also contribute uniquely to functional diversity, and both rare and common species are all interrelated and interdependent in the ecosystem.
A critically endangered Sunda pangolin was found dead by the roadside along Dunearn Road near Bukit Timah nature reserve in July 2015. It is likely a victim of a road accident. Conservation of rainforest habitats, including a substantial portion of Tengah forest, is necessary for preventing such endangered wildlife from becoming extinct because every individual pangolin’s life matters and counts towards the collective success of their conservation. (Photo by Jimmy Tan)
Both Sunda pangolins and straw-headed bulbuls are globally critically endangered, and their populations are also threatened by poachers for illegal wildlife pet trade. NSS has reported that the confirmed presence of the Sunda pangolin with a young in Tengah forest “reveals that Tengah forest is not just a foraging ground for the species but most notably a breeding ground as well”.
As for the straw-headed bulbuls, they have become extinct in Thailand and parts of Indonesia and are facing a decline in Malaysia. It is estimated that at least 202 individual straw-headed bulbuls are distributed over multiple forest patches, including Tengah forest, in Singapore, which has become a crucial global stronghold for preventing them from becoming extinct in the wild. It would be tragic if such critically endangered species were to disappear altogether in the wild right under our nose due to our neglect to take care of ecological connectivity (just like how the large forest gecko and cream-coloured giant squirrel became extinct after Bukit Timah expressway (BKE) was built in the 1980s) when we have the knowledge and the means to protect them and their natural habitats.
This video has recorded the songs of the critically endangered straw-headed bulbuls in the eastern part of Tengah forest next to Brickland Road. It also shows a baya weavers’ nesting tree next to a trail within the vicinity.
Notably, the presence of eagles (also known as raptors or birds of prey), which are apex predators at the top of a food chain, indicates a healthy, thriving ecosystem in Tengah forest, where there exists a complex food web consisting of plant producers, microorganisms, herbivores, carnivores and omnivores. Also, the endangered changeable hawk-eagles, near-threatened grey-headed fish eagles and near-threatened long-tailed parakeets are forest-dependent native wildlife, hence their populations may be adversely affected if we continue to destroy our secondary rainforests, such as Tengah forest, and replace their natural feeding and breeding grounds with parks, gardens and roadside trees around concrete buildings.
Like Mr Lim Liang Jim, Group Director of National Biodiversity Centre who oversees NParks’ Nature Conservation Masterplan, said:
“We really don’t know at this point in time how species interrelate. So, it could even be a butterfly effect. If you lose one small species, you will never know what it will result in the long term to the health of the forestry.”
(Note: The aforementioned insects, birds and mammals are just some examples of the numerous important native wildlife in Tengah forest. Do refer to Nature Society Singapore (NSS)’s Position Paper on HDB’s Tengah Forest Plan here for more details on its flora and fauna.)
4. We need sizeable wildlife corridors and core habitat areas in Tengah forest in order to maintain a healthy ecosystem that benefits humans, flora and fauna.
As of early May 2021, about 30% or more of Tengah forest (or about 210 ha or more) is estimated to have been cleared so far. It is hoped that at least 30% to 50% of the original forest will be preserved for its indispensable ecosystem services. (Source: Global Forest Watch)
Firstly, while it is somewhat encouraging that the town planners have set aside 50 ha out of 700 ha to create a wildlife corridor of 100 m wide in the Tengah forest town development plan to facilitate animals’ movements as a connector, NSS feels that its effectiveness in helping the wildlife adapt to the change with this corridor is questionable.
According to NSS, the 100 m width will not be enough to mitigate disturbances for wildlife because 50 m is the standard buffer for a forest habitat on all flanks and there will not be any interior space. This will be tragic for the rich wildlife currently inhabiting the area.
Secondly, it is worrying that under the HDB’s plan, only up to 10% of Tengah’s original forest is retained. This means that half of the species there could be wiped out, based on an ecological rule of thumb, the NSS said. Even though HDB said that some 20% of the land in Tengah will be set aside for “green spaces”, the replanted young trees and crops in man-made parks and community gardens and farms cannot substitute the regenerating secondary forest in terms of ecosystem services and biodiversity support.
Based on current estimates, Bukit Batok is rightfully Singapore’s unofficial “forest town”, with the largest percentage of forest cover at 17%. While it is an admirable goal for Tengah to become Singapore’s first smart and sustainable town, it is not appropriate to project Tengah as Singapore’s first “forest town” when only 50 ha out of 700 ha (or a mere 7%) forest cover will be preserved, which is much less than the forest cover in Bukit Batok. (Base map: NParks)
Thirdly, if we were to consider the percentage of forest cover found in housing estates in Singapore, Bukit Batok actually tops the list. It is estimated that Bukit Batok has 17% forest cover, because about 190 ha out of a total area of 1,113 ha is occupied by the forests in Bukit Batok Town Park (77 ha), Bukit Batok Nature Park (36 ha), Bukit Batok Hillside Park area Hill 1 and Hill 2 (30 ha), Bukit Batok East Forest (30 ha) and Bukit Batok Central Nature Park (17 ha).
Thus, it would be incongruous to proclaim Tengah as Singapore’s first “forest town” when its planned forest cover of a paltry 50 ha pales in comparison to that of its neighbouring town Bukit Batok. At this point, credit must be given to the town planners for having set aside 190 ha of the total area of Bukit Batok for the forests. Bukit Batok is a role model for other towns to emulate for its wild green spaces that provide essential ecosystem services and support biodiversity. It is also hoped that no further deforestation should be carried out in Bukit Batok after the unfortunate clearing of part of Bukit Batok Hillside Park area in February 2021 for housing development because the forests there are vital for ecological connectivity.
At the same time, we need to ask ourselves: “Will the word “forest” in the name “Tengah forest town” be merely used as a form of tokenism? Or will it be prioritised to honour the native species whose previous generations have existed and used the forest as a habitat and ecological corridor long before our forefathers arrived on this island?” If it is the latter, then we need to ensure that Tengah “forest town” lives up to its billing by preserving at least 30% to 50% of the original forest cover. May we refer to the map showing the two core areas for wildlife as proposed by NSS below?
Tengah Forest core habitat areas with eco-links for optimal connectivity between Western catchment area and Central catchment area, as proposed by NSS. The approximate locations of some native wildlife sightings from around 2017 onwards are based on various sources such as NParks, NSS, Saniroz and Jimmy. Altogether, the core areas and Tengah Nature Way should take up at least 200 to 300+ ha of the total area of 700 ha, in order for Tengah forest to continue to provide optimal ecosystem services and support biodiversity for ourselves and our future generations. (Base map: Nature Society (Singapore), Photo of pangolin is from Wikimedia, all other photos by Jimmy Tan)
As proposed by NSS’s position paper on Tengah Forest, “the eco-links/bridges that should be created as the essential part of the Tengah Nature Way (TNW) need to be set up first — prior to the further clearing of the forest after Phase 1. This will at least allow the wildlife to disperse to whatever available green refuges outside the Tengah development zone. Otherwise, the problem of wildlife roadkills will be re-enacted as in the tourism development at the Mandai Lake Road recently. Most importantly, some core areas must be designated and left untouched for the future survival of the wildlife within the Tengah Forest itself — so that some, if not all, of the forest-affiliated species recorded there will still have a home for their long-term survival”.
“The Tengah Nature Way is the culmination of the first ever large-scale scheme to promote ecological connectivity, guided with ecological principles, in our town planning processes and we are certainly heartened by this bold plan, but given the rich biodiversity that exists at Tengah Forest, more should be done in terms of biodiversity protection for both resident and migratory species through the setting aside of some parts of the forest as core habitats.”
Given that the proposed Tengah Nature Way is only 100 metres wide, it is worrying that the TNW is designated to be placed next to the busy, noisy Kranji Expressway, as also noted in “NSS Position Paper on Tengah Forest”. Incidentally, a sign in Bukit Timah nature reserve warns visitors that “loud noises drive animals away“. Based on personal experience, traffic noise from the expressway can still be heard 100 metres away, which may harm the well-being and reproductive ability/frequency of wildlife moving along TNW. In addition, as the corridor is long and narrow, the trees will be prone to edge effects and light pollution, and the animals may also be vulnerable to human-wildlife conflicts when they venture out of the forest corridor into urban spaces. (Photo by Jimmy Tan; map extract from ViewRanger).
5. We need to focus on redeveloping alternative sites or brownfield sites such as underutilised lands and abandoned schools etc, in order to achieve a better and more sustainable future for ourselves and our future generations
As mentioned earlier, we should also focus on redeveloping brownfield sites within reasonable distance from existing town amenities and infrastructure, such as vacant lands (such as mowed lawns in Bukit Batok, Jurong, Choa Chu Kang, etc), underutilised lands (such as open carparks), abandoned schools (such as the now defunct Jurong Junior College), etc, as well as building taller apartment blocks (within the vicinity and/or elsewhere in Singapore) where possible in order to make up for any shortfall of planned flat units.
Instead of clearing the remaining parts of Tengah forest, we should focus on redeveloping underutilised lands in other parts of Singapore. The graph shows an overview of the utilisation rate of State land in aggregate form. (Source: data.gov.sg)
Just as the SG Green Plan 2030 advocates that “Reduce, Reuse and Recycle” will become a norm for citizens and businesses, with a national strategy to address e-waste, packaging waste and food waste, we should apply the same 3R principle for recycling our existing built-up lands in order to conserve Tengah forest (and other secondary forests such as Clementi forest, Dover-Ulu Pandan forest, Bukit Brown forest, Pang Sua woodlands, Kranji forest, Sembawang woods, etc) as much as possible. This will ensure that sustainable development will be a living reality for us all. In fact, the following statement released by the Ministry of National Development also supports the move to recycle existing built-up lands.
“In the past, we could build new homes on swathes of undeveloped open land. Now, after 55 years of building and development, there are far fewer of these, and it has become more challenging to balance competing uses for land. In order to continue providing good homes for Singaporeans, we will have to recycle previously developed land.”
Besides abandoned schools and other underutilised lands around the vicinity, alternative sites for development may include the mowed lawns (or vacant cleared lands) along Pan-Island Expressway west of Tengah forest, the mowed lawns along Brickland Road east of Tengah forest, as well as the empty plots of land opposite Bukit Batok Hillside Park area. The empty plot of land between Dulwich College and a cluster of BTO flats along Bukit Batok Road may also be considered as an alternative site. NSS has also suggested in their position paper on Tengah forest to consider the area that will be made available at Paya Lebar Air Base for development in about a decade’s time. Granted that some of these plots of land might have been reserved for other uses such as schools, commercial work spaces and places of worship, the post-Covid era, in which school mergers (amid falling birth rates), home-based learning, online shopping, remote working and live-streaming religious services, classes, prayers and festivals have become the new normal, may render such traditional land uses redundant, or at least, less important. (Map by Global Forest Watch; photos by Jimmy Tan)
Last but not least, it appears that the upcoming Tengah forest town is designed not so much to accommodate genuine home buyers who may be facing prospects of homelessness, but rather to appeal to property investors. The article “Residential hotspots: Districts shaping up to be interesting investment bets” (1 April 2021) reveals such intent with key words like “investors”, “home upgrading”, “property market”, etc. For example, it states “Home-owners in Tengah are likely to look towards the nearest growth centre, JLD (Jurong Lake District), for home upgrading opportunities after serving out their minimum occupation periods (MOPs). While there are no current launches in the JLD, projects such as Parc Clematis and Clavon have seen positive reception from the market as investors buy into the growth potential of the JLD.”
This trend of home upgrading and property investment shows that public housing today is a far cry from what it used to be in the 1960s when many people had lacked safe housing with proper sanitation. Hence, is it justifiable that we continue to sacrifice our few remaining secondary forests to build more BTO flats instead of redeveloping underutilised lands? We are talking about existential threats to our native flora and fauna because it is a matter of life and death for them, whereas for many of us, it is just a matter of material comfort and convenience rather than basic survival or a real housing crisis.
In other words, the proposed development of Tengah forest town seems to be a case of “induced demand” for public housing. There seems to be a growing trend that many people buy BTO flats not because they have no place to live or have a genuine need to move out of existing homes, but rather because more supply of flats invites people to buy property for upgrading and investment.
In the context of climate emergency and biodiversity loss, even if there are people who have a genuine need for new housing or if they want to upgrade and invest in property, it should be better for them to consider resale flats, private property, etc, or at the very least, choose locations where BTO flats are built on existing built-up lands such as mature housing estates, rather than our precious few remaining greenfield sites, such as secondary forests like Tengah forest, Dover forest, etc.
Summary
In view of the sheer importance of Tengah forest for dealing with climate emergency and biodiversity loss as well as improving our quality of life, it would be very much appreciated if the authorities could:
preserve the rest of Tengah forest as much as possible, or at least 30 to 50 percent of its original 700-ha size (or 210 to 350 ha) for purifying the air, cleaning the soil, removing pollutants, cooling the urban heat island effect, supporting biodiversity, preventing/mitigating the risk of floods, zoonotic viruses, dengue diseases, saving electricity usage for air-conditioning, enhancing our physical and mental health etc, thereby potentially saving billions of dollars of public funds and personal/household expenses, in terms of healthcare, socioeconomic and environmental costs.
allocate the aforementioned two core habitat areas within Tengah forest to serve as essential resting/feeding/breeding spaces for wildlife, as proposed by NSS
designate eco-links in both the western and eastern parts of Tengah forest to facilitate safer and easier movement of wildlife along the ecological corridors and nature areas between Western catchment areas and Central catchment areas
ensure that the wildlife moving along the long, narrow Tengah Nature Way are protected from traffic noise from the expressway and potential human disturbances from the surrounding new/upcoming residential areas as much as possible
release the latest EIS report on the north of Tengah to Nature groups and members of the public for our feedback and review when it is ready for early engagement in the planning and development process, before any further development work starts and before any developer is awarded the tender for any construction project done in Tengah forest.
The last point is in line with the key changes made to the existing environmental impact assessment (EIA) framework in 2020, which include the following:
“The third change to the framework will see the planning process – and not just the development work itself – become more sensitive to Singapore’s natural environment. This will be done through earlier engagement with nature groups in the planning and development process, and through the introduction of a course on basic ecology and the EIA process for planners from development agencies.”
“Development works in Singapore to be more sensitive to wildlife under changes to EIA framework” (25 October 2020)
It is noteworthy that fig trees make up 90% of the 159 significant large trees recorded in Tengah forest. They are nutritious food sources for humans and animals, and they are also known to restore forests and biodiversity. It is worth reiterating that planting trees in place of a destroyed forest is not the same and will not achieve the same results. The root fungal network that a forest has is ecologically important for natural regeneration, according to researchers such as forest ecologist Suzanne Simard. (Photo by Jimmy Tan)
“We have to look at forests as a whole and not in compartments. You cannot talk about intact forests without talking about the wildlife that lives in the forest. So even if you preserve a green corridor or a strip of greenery, but if it’s an inadequate space for wildlife to really thrive in, that’s not fully protecting our biodiversity.”
P.S. May I invite you to click on the petition link here to support the preservation of at least 30 to 50 percent of Tengah forest for protecting our biodiversity and tackling climate emergency?
Imagine a zombie apocalypse scenario where there is hardly any human being seen in the city.
Where have all the human beings gone to?
The shiny skyscrapers and grand sculptures are left empty like giant whitewashed tombstones.
Are these buildings monuments of humankind’s glorious achievements?
Or are they stark reminders of a decadent dystopia?
In the hot sweltering oven of the sun-baked tropical desert, the air feels hostile and oppressive.
Seedlings of trees all across the island have stories to share.
Those who had the privilege and “good fortune” to be planted in the Gardens by the Bay are under protection by default.
Those who were “unlucky” to grow up in forests such as Bukit Batok Hillside Park live in fear that their days are numbered.
They have heard horror stories of how their tree relatives in Punggol, Tampines, Lentor, Bidadari and Tengah forest woke up one fine morning and heard the dreadful noise of the excavators that came rumbling in to clear their habitats.
Meanwhile, as the island reaches a boiling point, one wonders how long more humans continue the onslaught without destroying themselves.
Already, the city is simmering under the unrelenting heat today (which currently feels like 35 degrees Celsius at 9.50 pm).
How long more can we endure the urban heat island effect and still pay lip service to sustainable development?
P.S. If you do not wish to see our city becoming a post-apocalyptic desert, please sign the petition to support nature conservation and sustainable development.
Yesterday I posted on Facebook about the shift from southwest monsoon to southeast monsoon in Singapore originating from Sumatra, Indonesia. The transition from southwest monsoon in June-July to northeast monsoon in December-January appears to happen around September.
This morning, torrential rain brought by prevailing winds from Sumatra (otherwise known as Sumatra squall) came visiting Singapore again. Though the wind directions in Singapore shown in the weather app by National Environment Agency appear haphazard, the rain seems to be moving from southeast to northwest, as shown below.
How will this knowledge help us?
For me, it can help me plan my route if I want to cycle from the western towards the central or eastern part of Singapore during this time. I can ask myself: Which route shall I take to avoid the brunt of the storm as much as possible? When would be the best time to start my journey?
As evening approached on 18 June 2017, Sunday, a late developer of Sumatra squall made its presence felt in Singapore.
Strong winds blowing from southwest brought heavy rain coupled with thunder and lightning, which lasted over an hour.
“Squall-lines usually occur during pre-dawn and early morning, and are most frequent between the months of April and November. However, squall-lines can occasionally form in the afternoons and move landwards along with the prevailing winds.” (From Stormy shores: the Sumatras)
Nature and Us 