As this semester draws to a close, I think it is timely to reflect on my learning experience. Although I was already interested in this field right from the start, learning and blogging about environmental issues have improved my knowledge and understanding about them. Reading the posts from my peers has also given me greater insights on the myriad of environmental and sustainability issues we face today.

Personally, the main takeaway would be the fact that there is no perfect solution to many of the environmental issues we face given their complexities and interconnectedness to global trends and demands. They include issues I had previously blogged about, such as the trade in wild orchids fueled by collectors worldwide [1] as well as destructive sand mining activities in the region [2].

Beyond blogging, the interactive classroom activities on oil exploration and bats have also demonstrated the difficulties in coming up with a solution that can completely satisfy all the stakeholders involved.

Perhaps, tackling complex environmental issues could start with placing more emphasis on education. Italy plans to incorporate environmental education into its curriculum in 2020, thus becoming the first nation in the world to do so [3]. It cited concerns that humanity may not have time to wait for the next generation to take action [3].

I would like to end this blog post off with a quote by Wendell Berry.

“Earth is what we all have in common”

The onus is on us human beings to stop this destructive downward spiral, and to find ways to live sustainably and in harmony with our surrounding environment.

Till next time!




[1]: Phelps, J.(2015)A Blooming Trade: Illegal Trade of Ornamental Orchids in mainland Southeast Asia (Thailand, Lao PDR, Myanmar). TRAFFIC. Petaling Jaya, Selangor, Malaysia.

[2]: The mining of sand, a non-renewable resource. Retrieved from https://www.greenfacts.org/en/sand-extraction/l-2/index.htm#0

[3]: Italy to start climate change lessons for students in every grade. (2019, November 6). Retrieved from https://www.straitstimes.com/world/italy-to-start-climate-change-lessons-for-students-in-every-grade.


Although mangrove forests are quite well known given the attention which has been placed on them, have you ever wondered what exists further upriver? In some undisturbed riverine habitats, the mangrove forest would eventually transition to freshwater swamp forests, beyond the tidal reach of the sea [1].


Where do they occur?

Freshwater swamp forests exist throughout tropical Southeast Asia, in the catchment area of river systems [2]. This forest type used to be quite extant in Singapore but has largely been lost to development, with Nee Soon Swamp Forest being the only vestige of a once larger system [3].


How are they different from other forests?

Compared to other dryland forests, freshwater swamp forests grow in permanently swampy, low-lying areas which are fed by a network of freshwater streams.  Some of the trees have developed stilt and pencil-like roots to cope with waterlogged conditions [4].

Fig 1. Stilt roots of unknown tree species at Sime Road Swamp near MacRitchie. Source: Me


Fig 2. Buttress roots of an unidentified tree, possibly Alstonia spatulata. Sime Road Swamp near MacRitchie. Source: Me


What are the drivers of its destruction?

In Singapore, losses of freshwater swamps started in the 19th century, starting with land clearance by villagers for the planting of food crops like fruits and vegetables [3]. Later on, freshwater swamps in Jurong and Mandai were cleared for a pineapple estate and reservoir construction respectively [5].

Fig 3. Stump of Melanorrhoea wallichii after the clearance of swamp forest for a pineapple estate. Jurong, Singapore, 1933. Source: The freshwater swamp-forest of South Johore and Singapore


The Sedili wetlands in Johor, Malaysia are one of the few riverine sites which showcase the unique transition in vegetation from mangrove to freshwater swamp forests [1]. Even so, much of it has been logged [6]

In Sumatra, much of its freshwater swamp forests have been turned into plantations through slash and burn. The leftover forests cover less than 20% of its historic area [7].

As such, it can be seen that the main driver of forest loss is agricultural activity.


What is being done to protect them?

Nee Soon Swamp Forest is part of the Central Catchment Nature Reserve and is protected [3]. At the Singapore Botanic Gardens, Keppel Discovery Wetlands was created to emulate a natural swamp forest which once grew on that site through the use of native swamp forest plants [8]. The trails also serve to educate members of the public about swamp forest plants and animals [8].

Image result for keppel discovery wetlands
Fig 4. Keppel Discovery Wetlands, Singapore Botanic Gardens. Source: Little Day Out

In Malaysia, about 40% of the South-East Pahang Peat Swamp Forest is protected by 4 nature reserves [9]. Tasek Bera, an important freshwater lake is also a Ramsar site [10].



More attention needs to be given to the conservation of freshwater swamps even though they may not be well known due to the inaccessibility of the soft, muddy areas. For a start, public education could begin with what people commonly see. For instance, not many people may know that the commonly seen sealing wax palm actually originated from freshwater swamp forests in the region [11].

Image result for sealing wax palm singapore
Fig 5. Sealing Wax Palm, Cyrtostachys renda. Source: Dave’s Garden

Many fish species common to the aquarium trade such as Boraras maculatus also hail from these forests [12]. Perhaps, people can better recognize the value of such habitats if they can associate it with something they are familiar with.

Adult pair, male at top. © Peter Macguire
Fig 6. Boraras Maculatus. Source: Seriously Fish


Habitat enhancement work can also be done on suitable areas, such as the Sime Road Swamp as outlined in the Nature Society Report [3].

Hopefully, as more people recognise the value of freshwater swamps, there will be a greater impetus to conserve them.

Till next time.




[1]:  Nather Khan, I., Firuza, B. M., & Abdul Aziz, A. S. (2013). Ecology and conservation values of Sedili Kecil wetland, Malaysia.  Ecology, Environment and Conservation 19(3), 19–26. Retrieved from https://www.researchgate.net/publication/288239182_Ecology_and_conservation_values_of_Sedili_Kecil_wetland_Malaysia


[2]: Bada, O. (2018, May 31). Freshwater Swamp Forests – Forest Types Around the World. Retrieved from https://www.worldatlas.com/articles/what-is-a-freshwater-swamp-forest.html.


[3]: O’Dempsey, T., & Chew, P. T. (2011). THE FRESHWATER SWAMP FORESTS OF SUNGEI SELETAR CATCHMENT: A STATUS REPORT, 1–46. Retrieved from https://www.nss.org.sg/documents/Pages 121 – 166 Tony OD & Chew PT THE FRESHWATER SWAMP FORESTS OF SUNGEI SELETAR CATCHMENT.pdf


[4]: https://www.nparks.gov.sg/biodiversity/our-ecosystems/terrestrial


[5]: Corner, E. J. H. (1978). The freshwater swamp-forest of South Johore and Singapore. Singapore: Botanic Parks & Recreation Department.


[6]: http://mnsjohor.blogspot.com/2008/09/sg-lukah-freshwater-wetlands-ulu-sedili.html


[7]: Sumatran freshwater swamp forests. (n.d.). Retrieved from https://www.worldwildlife.org/ecoregions/im0157.


[8]: Keppel Discovery Wetlands Media Factsheet. (n.d.). Retrieved from https://www.nparks.gov.sg/-/media/nparks-real-content/news/2016/keppel-discovery-wetlands/factsheet–keppel-discovery-wetlands_updated-25-aug.pdf?la=en&hash=BB4B3BC0C7E25F64DFB850B19D1AF98CCE64C3BD.


[9]: MALAYSIA’S CONSERVATION AND SUSTAINABLE USE PEAT SWAMP FORESTS. (2006). Retrieved from https://www.my.undp.org/content/malaysia/en/home/library/environment_energy/EEPub_PeatSwamp.html


[10]: Conserving Freshwater Habitats. (n.d.). Retrieved from http://www.wwf.org.my/about_wwf/what_we_do/freshwater_main/freshwater_conserving_freshwater_habitats/.


[11]: FLORA & FAUNA WEB. (n.d.). Retrieved from https://www.nparks.gov.sg/florafaunaweb/flora/2/6/2618


[12]: http://animal-world.com/encyclo/fresh/cyprinids/DwarfRasbora.php

Biophilic City

In the last few blog posts, I have talked about some of the drivers of environmental degradation and their negative impacts on the environment in Singapore and the region. Today, we shall analyse what Singapore has done to enhance its natural and urban habitats in the face of ongoing development.


Issues faced by Singapore

Through the years of relentless development, much of Singapore’s natural heritage has been destroyed. Habitat fragmentation is one of the concerns, of which the most iconic case would be the separation of Bukit Timah Nature Reserve (BTNR) from the rest of the Central Catchment Nature Reserve (CCNR) [1].

Moreover, there has also been ongoing loss of fringe forest areas which are adjacent to but not part of the CCNR, such as the Lentor forest [2].


What is being done and how effective have they been?

While the Park Connector Network (PCN) is perhaps quite well known, fewer people may have heard of nature ways. This is one method which the National Parks Board has been using to enhance the movement of wildlife between the various nature areas and to attract them into urban areas [3]. Through mixed plantings to simulate the layered structure of a natural forest, more varied habitats are created, hereby encouraging species which occupy different forest layers to use the nature ways [4].

Nature Ways - layers
Fig 1. Illustration of layered streetscapes. Source: National Parks Board


While it is encouraging that NParks intends to extend the total length of nature ways from the current 100km to 180km by 2030 [3], I think more can be done to improve on the existing PCNs. At a total length of 300km, PCNs are more extensively connected to urban areas compared to nature ways [5], as seen in the figures below.


Image result for park connector network
Fig 1. Park connector Networks in Singapore. Source: The New Paper


Fig 2. Nature ways in Singapore. Source: National Parks Board


Many of the PCNs I have observed only consisted of trees planted in rows and interspaced by grass patches, which may not provide sufficient cover and habitats for the dispersal of fauna. Furthermore, the continuity of PCNs are broken by roads which may impede the movement of wildlife.


Fig 3. Large gaps between trees at Jalan Pelikat Park Connector. Source: Me


Fig 4. A roadway breaking the connectivity of Jalan Pelikat Park Connector. Source: Me

Another initiative was the creation of nature parks. These forested sites are mainly located on the fringes of the CCNR and BTNR and cover a total area of roughly 302 hectares [5]. While they are not nature reserves, they serve to protect core areas of the reserve from excessive disturbance at the fringes. They also draw visitors away from the main nature reserves, helping to offset the impacts of excessive visitorship [5]. Besides, habitat enhancement work has been undertaken in the nature parks, such as the replanting of native species and removal of weedy, exotic species [6]. For the nature parks which I had visited, many had also retained their natural streams. They are highly valuable, given the loss of freshwater habitats over the years due to development [7].

Fig 5. Native orchids replanted at Thomson Nature Park, including Grammatophyllum speciosum and Bulbophyllum blumei. Source: Me


Fig 5. Natural stream at Windsor Nature Park, with aquatic plants in the stream, possibly Cryptocoryne griffithii. Source: Me



Although it is laudable that Singapore has been actively trying to improve urban biodiversity through the methods described above, we should not think of them as a silver bullet to the ongoing forest clearance. Ultimately, the most ideal scenario would be the continued improvement and expansion of the green corridors and buffer areas while retaining as many forested areas as possible.

Till next time!





[1]: Eco-Link@BKE – Reconnecting Our Biodiversity. (2014). Retrieved from https://www.nparks.gov.sg/mygreenspace/issue-20-vol-1-2014/conservation/eco-link-bke–reconnecting-our-biodiversity.


[2]: 16B-Banner URA Contract 1 – Site Clearance, Earthworks, Construction of Drains, Sewers & Related Ancillary Works at Yio Chu Kang Road / Lentor Drive Area Client Urban Redevelopment Authority Project Completion Feb 2018 Contract 1 – Site Clearance, Earthworks, Construction of Drains, Sewers and Related Ancillary Works at Yio Chu Kang Road / Lentor Drive Area. (n.d.). Retrieved from https://www.samwoh.com.sg/success-stories/case-studies/engineering-projects/880-ura-contract-1-site-clearance-earthworks-construction-of-drains-sewers-related-ancillary-works-at-yio-chu-kang-road-lentor-drive-area.html.


[3]: Nature Ways. (2019). Retrieved from https://www.nparks.gov.sg/gardens-parks-and-nature/nature-ways.


[4]: Community gathers to celebrate 25 years of the Park Connector Network. (2015, September 20). Retrieved from https://www.nparks.gov.sg/news/2015/9/community-gathers-to-celebrate-25-years-of-the-park-connector-network.


[5]: Nature Parks as Buffer Parks . (2017, April). Retrieved from https://www.nparks.gov.sg/-/media/nparks-real-content/news/2017/windsor-nature-park/buffer-parks.pdf.


[6]: NParks’ habitat enhancement efforts. (2018, July 9). Retrieved from https://www.nparks.gov.sg/news/2015/11/28-nov-fs-nparks-habitat-enhancement-efforts.


[7]: Lim, K. K. P., & Ng, P. K. L. (n.d.). A Guide To The Freshwater Fishes of Singapore. Retrieved from http://habitatnews.nus.edu.sg/guidebooks/freshfish/text/103.htm.


Green Turfs


In the entire Southeast Asia, there are about 1120 golf courses, with Thailand being the nation with the highest number of golf courses at a staggering 315 [1]. However, while golf courses can be rather picturesque with their verdant landscape against the backdrop of rolling hills, it belies the fact that they can be harmful to the environment.

Image result for sicc golf course
Fig 1. Singapore Island Country Club. Source: My Guide Singapore

Where are they being built?

Construction of new golf courses is happening mainly in Thailand, where numbers have increased from 240 in 2017 [9] to 315 in 2019 [1]. In other nations such as Malaysia and Vietnam, the number of golf courses has also risen significantly in a span of 2 years [1].



In Southeast Asia, the negative environmental impacts of constructing new golf courses can be quite significant as forests are often cleared to make way for them [2]. Most recently, in the neighbouring state of Johor, new golf courses and resorts have encroached into mangrove forests in Sungai Pulai which is listed under RAMSAR as a wetland of significant importance, with over 800 hectares of forests being affected [3].

Image result for sungai pulai land clearance
Fig 2. Sungai Pulai wetlands. Source: FMT News

For the grass to grow optimally, fertilisers have to be applied regularly [4]. However, during periods of rainstorms, runoff from the golf courses would contain high levels of nutrients from the fertilisers such as nitrates and phosphates as a result [4]. This could lead to eutrophication of water bodies nearby and the death of aquatic organisms [4].

Golf courses can also contribute to habitat fragmentation, as is the case in Singapore. For instance, golf courses in the Central Catchment Nature Reserve (CCNR) break up forest tracts into patches, inhibiting the dispersal of plants and animals [5]. Forest fragmentation as a result of golf courses is one of the reasons implicated in the poor genetic diversity of the Short-tailed Babbler in Singapore by limiting their dispersal [6].

Fig 3. Golf courses outlined in red. Note the forest patch south of Macritchie Reservoir (in yellow) separated from the rest of CCNR. Source: Google Maps


Short-tailed Babbler
Fig 4. Short-tailed babbler at Mandai. Source: Oriental Bird Images



Given that the number of golf courses in Southeast Asia increased from 898 in 2017 [1] to 1120 in 2019 [7], the trends show no sign of abatement. As such, it may not be possible to completely phase out the development of new golf courses. However, some steps can be taken to minimise the environmental impacts of golf courses.

One way would be to avoid building golf courses on or near ecologically sensitive areas such as forested areas. Instead, they could be built on land which had already been disturbed by human activities such as ex-plantation areas [8].

Moreover, golf courses with their water bodies and groves of trees can serve as precious habitats for wildlife in a sea of ongoing development [8]. In Singapore, the previous Transview golf course (current University Town) was home to 42 species of local and migratory birds [9]. Serapong golf course on Sentosa also serves as a refuge for Rhizophora stylosa, a mangrove tree species [10]. Perhaps, habitats in golf courses can be further enhanced by using native plants in landscaping works, similar to habitat enhancement works done in some of our nature areas [11].

I hope this has given you an insight into golfing and its impacts! Till next time!





[1]: Golf around the world 2019. (2019), 1–24. Retrieved from https://www.randa.org/~/media/files/golfdevelopment/gaw-2019-edition-3-hi.ashx


[2]: Wheeler, K., & Nauright, J. (2006). A Global Perspective on the Environmental Impact of Golf. Sport in Society9(3), 427–443. doi: 10.1080/17430430600673449


[3]: Pillai, V. (2019, April 2). Putrajaya told to intervene to stop more golf courses on Johor mangrove reserve. Retrieved from https://www.freemalaysiatoday.com/category/nation/2019/04/02/putrajaya-told-to-intervene-to-stop-more-golf-courses-on-johor-mangrove-reserve/.


[4]: Rice, P. J., & Horgan, B. P. (2011). Nutrient loss with runoff from fairway turf: An evaluation of core cultivation practices and their environmental impact. Environmental Toxicology and Chemistry30(11), 2473–2480. doi: 10.1002/etc.659


[5]: It is FRAGMENTED. (n.d.). Retrieved from http://www.chopefornature.org/our-nature-reserves/it-is-fragmented/.


[6]: Sadanandan, K. R., & Rheindt, F. E. (2015). Genetic diversity of a tropical rainforest understory bird in an urban fragmented landscape. The Condor117(3), 447–459. doi: 10.1650/condor-14-199.1


[7]:  Golf around the world 2017. (2017), 1–24. Retrieved from https://www.randa.org/~/media/files/downloadsandpublications/golf-around-the-world-2017.ashx




[8]: Colding, J., & Folke, C. (2008). The Role of Golf Courses in Biodiversity Conservation and Ecosystem Management. Ecosystems12(2), 191–206. doi: 10.1007/s10021-008-9217-1


[9]: https://www.nss.org.sg/conservationsingapore/


[10]: Bakau pasir. (2013, January). Retrieved from http://www.wildsingapore.com/wildfacts/plants/mangrove/rhizophora/stylosa.htm.


[11]: Hong, J. (2018, December 3). Native plants to replace alien trees in Rail Corridor stretch. Retrieved from https://www.straitstimes.com/singapore/native-plants-to-replace-alien-trees-in-rail-corridor-stretch.



Orchids under threat

Rhino horns, tiger tooth or pangolin scales – these are the things that come to people’s minds when they think of illegal wildlife trade. However, there is another kind of illegal trade which has not gotten as much attention. Welcome to the world of orchids. The trade in illegally harvested wild orchids in Southeast Asia goes on unnoticed despite them being accorded strong protection under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) [1].


Where is this occurring?

Illegal collection occurs throughout Southeast Asia. In Thailand and the surrounding nations, orchids collected from the wild are sold at plant markets such as Chatuchak [1]. In Malaysia, this is especially prevalent in Cameron Highlands, where orchids are sold at roadside stalls by Orang Asli aborigines [2] or collected from the jungles by plant hunters from Thailand and Singapore [3].

Fig 1. Orchids on sale in a stall at Chatuchak, Thailand. Source: Botanical garden photography



Fig 2. Unidentified orchid, possibly a Coelogyne species, Cameron Highlands, Malaysia. Source: Me


What are the drivers of illegal harvesting?

The demand for wild orchids is mainly fuelled by collectors of rare plants from the wild rather than casual hobbyists who are more inclined to grow hardy, farm-raised orchid species and hybrids with large, beautiful flowers such as those from the Phalaenopsis family [4].

Fig 3. Large flowered Phalaenopsis orchid hybrid. Source: Honolulu Orchid Society


How are they evading the regulations?

The proliferation of online marketplaces and groups has enabled the growth in trade of wild orchids [4]. Moreover, many orchid sellers online tend to mix wild plants with legitimate, nursery cultivated specimens, making it difficult to pinpoint which plants are illegally collected [4].

On E-commerce platform Carousell, I chanced upon an account selling orchids, some of which looked like wild plants. Upon questioning the provenance of an orchid from the genus Oberonia, the seller mentioned that it came from West Java. When probed further on whether it came from the forest, he claimed that he had forgotten as it was from a friend, which sounded rather suspicious and could be a way of shunning responsibility.


Fig 4. An orchid from the Oberonia genus on sale. Source: Carousell


Other listings showed large Rhynchostylis retusa (fig. 5) plants with small, broken root systems, tell-tale signs of orchids having been ripped off the trees they were growing on [5]. I also observed that the Hymenorchis javanica (fig. 6) still seems to be attached to a tree branch, meaning that branch could have been sawed off a tree to harvest the orchid growing on it.

Fig 5. Rhynchostylis retusa orchids with tiny root systems. Note the spelling error in the listing. Source: Carousell



Fig 6. Hymenorchis javanica orchid, seemingly attached to the original tree branch it was growing on. Source: Carousell


Impacts of illegal harvesting

Many wild orchids species have limited distributions [1]. Plant collectors in Thailand have commented on decreasing abundance of orchids in the wild, with populations in certain localities completely wiped out due to over-collection [1]. In Vietnam, populations of Paphiopedilum canhii plunged by 99.5% within half a year of its discovery in 2010 due to illegal harvesting [6].

Fig 7. Paphiopedilum Canhii, newly discovered slipper orchid species. Source: Orchid Species



Being quite of an orchid enthusiast myself, this is an issue close to my heart. In my opinion, it is not worth degrading habitats just to satisfy human desires. Hobbyists interested in growing orchid species and hybrids should purchase those that are artificially propagated in nurseries. Here are some tips on how to recognise and avoid buying illegally harvested wild orchids [5].

  • Only buy orchids from well-known nurseries.
  • Always find out about the provenance of the plant.
  • Ensure that a CITES certificate is present when bringing in orchids purchased from foreign countries.
  • Tell-tale signs of illegally harvested orchids include torn leaves, lack of healthy roots and plants still attached to the original tree bark.

Till next time!



[1]: Phelps, J.(2015)A Blooming Trade: Illegal Trade of Ornamental Orchids in mainland Southeast Asia (Thailand, Lao PDR, Myanmar). TRAFFIC. Petaling Jaya, Selangor, Malaysia.

[2]: Illegal Orchid Poaching: Stealing from the Forest. (2011). Retrieved from https://www.facebook.com/notes/traffic-southeast-asia/illegal-orchid-poaching-stealing-from-the-forest/302954379735413/.

[3]: Hakim, A. (2015, January 26). Smuggling the bane of Cameron Highlands’ exotic and rare orchids. Retrieved from https://www.therakyatpost.com/2015/01/26/smuggling-bane-cameron-highlands-exotic-rare-orchids/.

[4]: Hinsley, A. (2018). THE ROLE OF ONLINE PLATFORMS IN THE ILLEGAL ORCHID TRADE FROM SOUTH EAST ASIA. The Global Initiative Against Transnational Organized Crime, 1–18. Retrieved from https://globalinitiative.net/wp-content/uploads/2018/09/TGIATOC-OrchidTrade-A4-Web.pdf

[5]: Khew, C. (2015, September 11). S-E Asia’s blooming black market trade in wild orchids. Retrieved from https://www.straitstimes.com/singapore/s-e-asias-blooming-black-market-trade-in-wild-orchids.

[6]: Averyanov, L. V., Pham, V. T., Loc, P. K., Hiep, N. T., Canh, C. X., Vinh, N. T., & Hieu, N. Q. (2014). FIELD SURVEY OF PAPHIOPEDILUM CANHII: FROM DISCOVERY TO EXTINCTION . Retrieved from https://www.rufford.org/files/www.slipperorchid.org__0.pdf


Limestone Towers….Or Concrete Towers?

While driving to Cameron Highlands in Malaysia this June, I was awed by the scenic limestone outcrops dotting the landscape around the winding road from Simpang Pulai to Tanah Rata up in the highlands. However, as I approached them, I was alarmed by the large-scale limestone mining activities which were eating away at these majestic landforms. This post also serves as a continuation of my previous post on sand mining. 

What are some types of limestone landforms?

Regionally, the tropical climate means that tower karsts are one of the most common visible limestone landforms [1]. They are formed due to erosional processes leaving more resistant portions of the limestone bed intact as outcrops, thus forming limestone towers interspaced by flat land [2]. 

Fig 1. Limestone outcrop at Maya Bay, Thailand. Source: Me

Mining of limestone

Limestone is highly versatile with many functions, including cement production, raw material for animal feed and the purification of molten metal [3]. 

However, mining the limestone can have adverse impacts on the environment. Groundwater flow patterns through the subterranean karst formation could be disrupted, along with the pollution of water bodies on the surface [4]. Moreover, dust clouds and loud sounds from blast mining could affect the surrounding environment through pollution [4].

Image result for limestone mining malaysia
Fig 2. Limestone mine. Source: GCCP Resources Limited

Threats to endemic species

In Southeast Asia, many plant and animal species from limestone areas are also found nowhere else, having adapted to a landscape very unlike any other [5]. Thus, they may have difficulty spreading to other habitats [5].  For instance, Vatica najibiana, a tree species was recently discovered in Peninsular Malaysia and can only be found on 2 limestone hills, one of which has been earmarked for mining [6]. 

Fig 3. Vatica najibiana in situ. Source: Species New To Science

Bukit Charas in Pahang, Malaysia was where I did my geographical fieldwork on limestone landforms back in school. A few kilometres away, limestone mining on Bukit Pancing [7] had completely ravaged and flattened the limestone hill, resulting in the global extinction of a snail species, Plectostoma sciaphilum [7] found only on that hill. 



Image result for extinct snails malaysia limestone
Fig 4. Plectostoma sciaphilum. Source: The Star
Fig 5. Limestone cave in Bukit Charas, Pahang, Malaysia. Source: Me



In a short survey I conducted to gauge people’s awareness of limestone landforms, 50% of respondents were unaware of them. 56.3% of respondents did not know about the existence of limestone habitats as well. Perhaps, the lack of awareness of limestone landforms and habitats could be due to Singapore’s geographic distance from karstic areas, with the nearest localities being a few hours by car in neighbouring Malaysia. 

Limestone areas also have great tourism potential due to the scenic landscape [5]. In the same survey, 93.8% of respondents would visit limestone areas, further highlighting its tourism value. If the value of tourism outweighs that of mining, it could be an incentive for locals to turn to eco-tourism.  

Fig 6. Karst towers and tourists at James Bond Island, Phang Nga Bay, Thailand. Source: Me

Moreover, there have been efforts to alter cement production methods to use lesser quantities of limestone as a feedstock [8]. This method involves combining fly ash from coal fired power stations with other minerals to create the new cement. The new cement attained the same strength as concrete made with ordinary cement after one week [8]. Thus, reducing the usage of limestone would result in more limestone landforms and habitats being saved. 

In a nutshell, limestone habitats deserve more recognition and protection. Short term gains from the over-exploitation of limestone would result in irreversible damage to this unique ecosystem. 

I hope this post has piqued your interest in limestone landforms! 

Till next time!

Ke Yao



[1]: Gillieson, D. (2005). Karst in Southeast Asia. The Physical Geography of Southeast Asia, 157–175. Retrieved from https://www.researchgate.net/publication/292603085_Karst_in_Southeast_Asia


[2]: Karst Topography. (n.d.). Retrieved from https://www.britannica.com/science/cave/Karst-topography#ref499902.


[3]: King, H. M. (n.d.). What Is Limestone and How Is It Used? Retrieved from https://geology.com/rocks/limestone.shtml.


[4]: Csanyi, C. (2016, September 29). Environmental Hazards of Limestone Mining. Retrieved from https://education.seattlepi.com/environmental-hazards-limestone-mining-5608.html.


[5]: Reuben Clements, Navjot S. Sodhi, Menno Schilthuizen, Peter K. L. Ng, Limestone Karsts of Southeast Asia: Imperiled Arks of Biodiversity, BioScience, Volume 56, Issue 9, September 2006, Pages 733–742, https://doi.org/10.1641/0006-3568(2006)56[733:LKOSAI]2.0.CO;2


[6]: Ummul-Nazrah AR, Mohd Hairul MA, Imin K, Kiew R, Ong PT (2018) Vatica najibiana (Dipterocarpaceae), a new species from limestone in Peninsular Malaysia. PhytoKeys 98: 99–106. https://doi.org/10.3897/phytokeys.98.23903


[7]: Kugan, J. (2014, December 22). Going, going, gone: Malaysia’s wildlife loses battle against extinction Read more at https://www.thestar.com.my/lifestyle/features/2014/12/22/going-going-gone-malaysias-wildlife-loses-battle-against-extinction#QaalbsgV3PpOivWw.99. Retrieved from https://www.thestar.com.my/lifestyle/features/2014/12/22/going-going-gone-malaysias-wildlife-loses-battle-against-extinction.


[8]: Patel, P. (2018, June 26). Engineers have created a cement alternative to reduce concrete’s carbon footprint. Retrieved from https://qz.com/1314754/engineers-have-created-a-cement-alternative-to-reduce-concretes-carbon-footprint/.

Sandy shores of doom?

If you have been to East Coast Park or Sentosa, you would probably have spent some time on their sandy beaches. However, have you ever thought about where all the sand comes from? Although sand is something that seems rather innocuous, it is one of the most harvested resources on the planet [1]. Unlawful mining of this important resource [1] often occurs in the region, with severe impacts on the environment [1]. 


What are the issues with sand mining in the region?

Sand mining usually takes place along the coasts and in river systems [2] where deposits of sand are known to exist [2]. However, the uncontrolled harvesting of sand has led to problems such as increased erosion [3] and the destruction of riverine and marine habitats [3]. 

For instance, in Cambodia, the dredging of sand deposits in the Mekong River [4] near its confluence with the Tonle Sap could alter the river dynamics, possibly changing the flow patterns of the seasonal reversal between the Mekong and Tonle Sap and impacting local wildlife [4].

Fig 1. Seasonal changes in flow patterns of the Tonle Sap. Source: EurekAlert!


Nearer to home, sand mining in the Malaysian state of Johor has fueled discontent among the Orang Asli [5]. They claimed that 2 rivers, Sungai Linggiu and Sungai Sayong, have dried up due to the ongoing extraction of sand [5] and it has affected their livelihoods as fish stocks plunged [5].

Fig 2. Dried up portion of the rivers. Source: Malay Mail


The role of Singapore

Singapore is the largest importer of sand in the region [6], mainly to fuel our large-scale land reclamation projects [6]. which has enabled us to grow to a size of 724.2 k㎡ [7]. Although Singapore claims to only import sand from sustainable sources [8], the Ministry of National Development (MND) remained mum when asked about where the sand was coming from [8]. 

Fig 3. Changes in Singapore’s landmass through time. Source: The Straits Times.

Moreover, trade records show that Singapore’s sand imports from Cambodia were worth USD$752 million from 2007 to 2016 [9] while data released by the Cambodian government showed just USD$5 million [9] , implying that some of the sand imported could have come from illegal sources as well. 


My thoughts

I think that Singapore has a significant role to play in the ongoing sand mining crisis. The secrecy around discussing our sand sources could point to our reluctance in addressing this inconvenient truth, especially when we need large quantities of sand for development [6].

However, not all is lost. In a bid to reduce our use of sand, an attempt has been made at using empoldering [10] instead of conventional land reclamation on Pulau Tekong [10], thus cutting sand consumption.

Fig 4. Conceptual graphic on poldering. Source: The Straits Times

Another exciting field is the conversion of marine clay into a porous material similar to sand [11], after which it can be used for reclamation [11]. This could reduce Singapore’s sand imports as marine clay is abundant [11] in Singapore.

While these potential solutions are not a panacea to the ongoing sand crisis, I think it is a step in the right direction. Hopefully, in the near future, we can take it one step further and minimise further land reclamation once the current projects are completed. 

Till next time!

Ke Yao



[1]: Sand mining ‘mafias’ destroying environment, livelihoods: UN. (2019, May 8). Retrieved from https://www.eco-business.com/news/sand-mining-mafias-destroying-environment-livelihoods-un/


[2]: The mining of sand, a non-renewable resource. Retrieved from https://www.greenfacts.org/en/sand-extraction/l-2/index.htm#0


[3]: Nag, O. S. (2018, November 13). What Are The Negative Effects Of Sand Mining? Retrieved from https://www.worldatlas.com/articles/what-are-the-ill-effects-of-sand-mining.html


[4]: Koehnken, L., & Rintoul, M. (2018). Impacts Of Sand Mining On Ecosystem Structure, Process & Biodiversity In Rivers. IMPACTS OF SAND MINING ON ECOSYSTEM STRUCTURE, PROCESS & BIODIVERSITY IN RIVERS. WWF. Retrieved from http://d2ouvy59p0dg6k.cloudfront.net/downloads/sand_mining_impacts_on_world_rivers__final_.pdf


[5]: Tan, B. (2018, November 4). Two rivers dry up in Johor, allegedly from sand-mining: Malay Mail. Retrieved from https://www.malaymail.com/news/malaysia/2018/11/04/two-rivers-dry-up-in-johor-allegedly-from-sand-mining/1689811


[6]: Ismail, M. (2018, November 26). Feeding Singapore’s hunger for sand. Retrieved from https://theaseanpost.com/article/feeding-singapores-hunger-sand


[7]: https://data.gov.sg/dataset/total-land-area-of-singapore


[8]: Low, Y. (2019, March 25). Explainer: Why sand is so highly valued and the controversy surrounding cross-border trade. Retrieved from https://www.todayonline.com/singapore/explainer-why-sand-so-highly-valued-and-consequences-overmining


[9]: Hasnan, L. (2019, August 12). Sand mining in Malaysia. Retrieved from https://theaseanpost.com/article/sand-mining-malaysia


[10]: Yeo, S. J. (2016, November 17). Pulau Tekong to get extra land the size of two Toa Payoh towns using new reclamation method. Retrieved from https://www.straitstimes.com/singapore/singapore-to-use-new-land-reclamation-method-in-pulau-tekong


[11]: Lee, M. (2017, November 14). New Soil seeks to break new ground in land reclamation. Retrieved from https://www.straitstimes.com/business/companies-markets/new-soil-seeks-to-break-new-ground-in-land-reclamation

An oasis on our southern seas?

Our lovely landfill 

Landfills and beach resorts are not often associated with one another. What about, a bit of both? Last Saturday, we embarked on a fieldtrip to Semakau Landfill located off Singapore. For a start, I already knew that Semakau was not a run-of-the-mill landfill overflowing with trash. However, what I saw left me pleasantly surprised. No dust and loose ash were seen drifting about. With its Casuarina lined roads and coconut palms swaying in the wind, it was reminiscent of a seaside resort. 


History of Semakau Landfill

In 1995, development work for Semakau Landfill commenced and it began receiving incineration ash on 1 April 1999 [1]. During the construction period, Pulau Semakau and Pulau Seking were merged via land reclamation and surrounded by a 7km rock bund [1] to contain the ashes. A receiving station was also built to receive incineration ash from Tuas Marine Transfer Station [2]. 

Fig 1. Semakau Landfill [3]. Source: The Straits Times
What has been done to reduce the environmental impacts?

Rock bund

When Semakau Landfill was being built, rock bunds were constructed to contain the ashes from incineration. However, due to the ever present threat of leachate entering the sea, the rock bund was designed with special considerations. Besides the use of marine clay, it was also inlaid with rocks and impermeable membranes [4] to prevent leachate from leaking into the sea and harming the marine environment. 

Fig 2. Impermeable membrane layer in the rock bund circled in red. Source: Me

Wastewater treatment

With Phase 1 almost fully filled, NEA completed work on the Phase 2 cell in 2015 [5], along with the closure of a 160m gap which previously allowed for tidal exchange. However, due to precipitation and the displacement of water from ash being unloaded into the cell, potentially polluted water could overflow into the sea. The floating wastewater treatment plant which occupies an area of 2500㎡ [5] was built to handle this. When water levels in the cell reach a predetermined level, the plant automatically processes the water to meet Trade Effluent Discharge standards [5] before pumping it into the sea. With treatment capacity at 180000㎥ per day [5], it helps to minimise the impact of pollution on marine biodiversity. 


Mangrove replanting

Back during the construction phase, 13ha [6] of mangroves were cleared on Pulau Semakau to create an anchor point for the rock bund. However, 2 plots of land were planted with Rhizophora species [6] in the north and south of the island to compensate for this loss. The dense network of stilt roots from the replanted trees help to dissipate wave energy [6] acting on the rock bund.  Besides providing suitable habitats for wildlife, the mangrove forests also serve as bioindicators in case of any leakages from the landfill [6].  

Fig 3. Replanted mangroves on the northern patch in front of the rock bund. Source: Me
Fig 4. Replanted areas in red. Original mangroves removed for construction in yellow. Source: Google Maps



I feel that Semakau Landfill is a good showcase of how the environmental impacts of waste disposal can be minimised through proper planning. As a testament to this, habitats on and around Semakau are thriving [7], with species such as the globally endangered plant Caesalpinia bonduc [7] being found on the island. Throughout the region however, improper waste disposal is still a major problem, with recent cases like the Sungai Kim Kim incident in neighbouring Johor [8] highlighting issues with poor waste management. Hopefully, as time passes, more progress will be made in this area to reduce its impacts on our environment. 


Fig 4. Grey Heron perched on the rock bund. Source: Me

Till next time!

Ke Yao




[1]: http://eresources.nlb.gov.sg/infopedia/articles/SIP_1008_2010-03-22.html


[2]: https://www.nea.gov.sg/our-services/waste-management/waste-management-infrastructure/tuas-marine-transfer-station


[3]: https://www.straitstimes.com/singapore/environment/spore-aims-to-send-one-third-less-waste-to-semakau-landfill-by-2030-amy-khor


[4]: Chua, G. (2016). Growing the “Garbage of Eden”. Retrieved from https://www.clc.gov.sg/docs/default-source/urban-solutions/urb-sol-iss-8-pdfs/case-study-singapore-pulau-semakau.pdf


[5]: Semakau Landfill Phase II. (n.d.). Retrieved from https://www.capam.org/knowledge/articles/2017/semakau_landfill_phase_ii.html


[6]: Yang, S., Lim, R. L. F., Sheue, C.-R., & Yong, J. W. H. (2011). THE CURRENT STATUS OF MANGROVE FORESTS IN SINGAPORE, 111–114. Retrieved from https://nss.org.sg/documents/Pages 99-120. Yang et al., 2013. Singapore Mangroves (updated).pdf


[7]: Teo, S., Yeo, R. K. H., Chong, K. Y., Chung, Y. F., Neo, L., & Tan, H. T. W. (2011). THE FLORA OF PULAU SEMAKAU: A PROJECT SEMAKAU CHECKLIST, 265–266. Retrieved from https://www.researchgate.net/publication/256094058_THE_FLORA_OF_PULAU_SEMAKAU_A_PROJECT_SEMAKAU_CHECKLIST/link/58268e3208ae5c0137ebad20/download


[8]: Sukaimi, S. A. (2019, June 24). Authorities confirm: Latest Pasir Gudang pollution caused by Sg Kim Kim toxic waste. Retrieved from https://www.nst.com.my/news/nation/2019/06/498799/authorities-confirm-latest-pasir-gudang-pollution-caused-sg-kim-kim-toxic


Eco developments in Singapore??

“Eco Developments”

Recently, there has been a lot of talk about upcoming ecologically friendly developments in Singapore. One of the more prominent cases would be that of the Mandai Project. When I first heard this project in Mandai, I was thrilled, thinking the area would be developed into something along the lines of a nature park. According to its website, one of its development guidelines was to be a “sustainability showcase for the next generation” [1]. However, it has also drawn flak for its supposed impacts on the surrounding habitats. To find out more, I wanted to do a more in-depth analysis!

So….what is the Mandai Project?

The ongoing development in Mandai is focused around the area where the Singapore Zoo and Night Safari are located. It aims to turn the area into a new, integrated wildlife park by relocating Jurong Bird Park to Mandai and building a Rainforest Park [2]. The project is due to be completed by 2023 and will feature a hotel occupying 4.6 ha with up to 400 rooms [3].

Fig 1. Map of upcoming attractions in Mandai. Source: https://www.mandai.com/


What are the issues?

Several critics have pointed out that this major development near Central Catchment Nature Reserve would have big impacts on local wildlife. The area contains several ecologically significant areas such as forests, grasslands and freshwater habitats [4]. Admittedly, I was disappointed when I heard about the scale and nature of the work as it will result in a large loss of forest cover, up to 70-80% [4] at the Bird Park land parcel. The developments would also result in further habitat fragmentation [4]. Moreover, the existing forests are home to several internationally endangered species, one of which is the Sunda Pangolin [4].

Fig 2. Circled in red, forests around the area which will be affected. Credits: Google Maps


Mitigation measures by Mandai Park Holdings (MPH)

Some interim mitigation measures were implemented by the developer (MPH) to soften the negative impacts on local fauna, such as rope bridges [5] for wildlife to cross roads safely. However, a spate of roadkill incidents [5] along Mandai Lake Road near the site calls into question the effectiveness of such measures.

Fig 3. Accident between a motorcycle and Sambar deer. Source: TODAY


Final thoughts

This seemingly nonchalant attitude towards conserving what is left of our natural habitats does not bode well for the future of our remaining green spaces. As I am typing, parts of the Tengah forest [6] and Lentor Forest [7] have been cleared for development as well. While the integration of the new attractions with the existing 3 wildlife parks will be a boost for tourism, I wonder if the loss of our indigenous wildlife is a worthwhile tradeoff. Given that work has already begun, we can only hope for the best.  Ultimately, Singapore aims to be a “City in a Garden” [8]. I really do hope the “garden” has some wild spaces left instead of being blanketed by well-manicured lawns and streetscapes.

Fig 4. Urban streetscape planted with Arundina Graminifolia. Source: Me


Till next time!

Ke Yao



[1]: Mandai. (n.d.). Retrieved from https://www.mandai.com/#


[2]: T. A. (2017, October 11). Banyan Tree Holdings to open its first resort in Singapore in Mandai. The Straits Times. Retrieved from https://www.straitstimes.com/singapore/environment/banyan-tree-holdings-to-open-its-first-resort-in-singapore-in-mandai


[3]: Fumiko, T. T. (2019, May 23). Mandai eco-resort to offer guests behind-the-scenes animal experiences. The Straits Times. Retrieved from https://www.straitstimes.com/singapore/mandai-eco-resort-to-offer-guests-behind-the-scenes-animal-experiences


[4]: Nature Society’s Position Paper on the Mandai Safari Park Holdings (MSPH) ’s Mandai Development Plan(Issue brief). (2016, September 2). Retrieved https://www.nss.org.sg/documents/NSS Position Paper on MSPH’s Mandai Development Final map & date.pdf


[5]: Singapore’s Mandai eco-resort: Paving paradise to put up an eco-resort. (2018, September 15). Retrieved from https://www.bbc.com/news/world-asia-44856567


[6]: N. C. (2018, October 30). Nature Society urges HDB to save more of Tengah new town’s forests for wildlife Read more at https://www.todayonline.com/singapore/nature-society-urges-hdb-save-more-tengah-new-towns-forests-wildlife. Retrieved from https://www.todayonline.com/singapore/nature-society-urges-hdb-save-more-tengah-new-towns-forests-wildlife


[7]: Z. Z. (2017, February 4). Check out how Lentor Forest has changed over the past few months. Retrieved from https://mothership.sg/2017/02/check-out-how-lentor-forest-has-changed-over-the-past-few-months/


[8]: Mission and History. (2019, September 6). Retrieved from https://www.nparks.gov.sg/about-us/mission-and-history

Fig 1: https://www.mandai.com/

Fig 3: https://www.todayonline.com/singapore/deer-dies-motorcyclist-injured-mandai-road-accident

Welcome to my blog!


Hello everyone! I am Ke Yao and I am currently a Year 1 student doing Bachelor of Environmental Studies (BES) at the National University of Singapore (NUS)

Now, a little more about myself….from a young age, I have always been interested in the natural environment. I cannot really put a finger on how this interest (Madness) started but I guess it was most likely due to inspiration from my mother who was a geography teacher. I would spend hours on end watching documentaries about deforestation from her teaching resources or indulging in CD-ROM Geography games about plate tectonics (Considered cutting-edge technology back then). Beyond that, my family visited the various parks and nature reserves quite often and I was always amazed by the myriad of flora and fauna to be seen and heard.

Having experienced the wonders of nature, the young me could not understand why human beings were still so adamant on destroying the natural environment. It was not until much later in school that I finally had a better understanding on the drivers behind habitat destruction and the complexity of the issue.

Me under a limestone outcrop in Thailand

Theme of my blog

How many of you have heard about Dendrobium Laciniosum [1], a species of orchid endemic to Singapore? You would be forgiven if you haven’t because it went extinct over 100 years ago [1] due to habitat clearance. We have decimated most of our natural habitats here in sunny Singapore such that very little of the original ecosystems remain intact and pristine. In the bigger scheme of things, the region is also developing in an unsustainable manner, often resulting in conflicting demands between development and conservation. Thus, my blog aims to explore the pressures on the natural environment in Singapore and the region, as well as measures undertaken to mitigate the effects.


Here’s a walkthrough of some issues I will be covering in my next few blog entries.

  • “Eco developments” in Singapore and whether they live up to their namesake
  • Impacts of sand extraction
  • Invasive species in Singapore

That’s all for now! See you guys soon!



[1]: KW, T. H., T, C. R., & KI, N. P. (2011). Biodiversity In Singapore: An Overview. In Singapore Biodiversity(pp. 26–27). Singapore: Editions Didier Millet.