About Sha Lo Tung

Sha Lo Tung is a rare valley comprises a mix of habitats including freshwater wetland, located between Cloudy Hill in Kowloon and Wong Leng in Hong Kong. It spans approximately 56 hectares, with an altitude of around 100 metres, and it is a confluence of streams. The fertile soil, coupled with the surrounding mountains that shield the valley from winds, has created an ecologically rich valley basin. Three of its local streams and the riparian have been recognised as “Sites of Special Scientific Interest”. In the early years, the government’s “New Nature Conservation Policy” identified Sha Lo Tung as one of the 12 “Priority Sites for Enhanced Conservation”, ranking its ecological importance second only to the in Mai Po Inner Deep Bay Ramsar Site. This highlighted the unique and precious ecological value of the area.

Sha Lo Tung is best known for its dragonfly diversity. In the early 1990s, it was the site in Hong Kong for the world’s first sighting of the Spangled Shadow-emerald, followed by the discovery of the White-tipped Grappletail. As of today, over 80 species of dragonflies have been found in the area, accounting for over 60% of all dragonfly species in Hong Kong. Moreover, the area is home to a variety of rare freshwater fishes, amphibians, reptiles, mammals, butterflies, and birds, making it an ecological treasure trove in Hong Kong.

History

The history of Sha Lo Tung can be traced back to over 300 years ago when Hakka settlements had already established in the area. These later developed into two major villages of Cheung Uk and Lei Uk. In the past, the villagers lived off agriculture, utilising the geographical advantages of the highland river valleys to create irrigation channels and paddy fields, with rice cultivation being the main activity. In the 1960s, Sha Lo Tung was still lined with terraced fields, and the scale of wet cultivation was quite considerable.

By the 1970s, the villagers had begun to move away, with many even emigrating abroad, leading to a large amount of abandoned farmland in the area. Although the farmland was no longer cultivated, the irrigation systems of the past were still preserved, and Sha Lo Tung slowly evolved into an ecologically rich freshwater wetland.

In the 1990s, dragonfly experts discovered a large number of dragonfly species in the area, including species discovered for the first time globally; botanists also discovered at least 100 rare plant species in the valley. The unique ecological value of Sha Lo Tung was thus formally established.

The Journey of Conservation

Since the 1990s when Sha Lo Tung was recognised as a place of high ecological value, the pressures and conflicts arising from development in the area have also intensified. In fact, as early as the 1980s, developers had already started to acquire land to develop golf courses and residential developments. However, due to the discovery of valuable dragonflies and plants in the 1990s, environmental groups strongly opposed these development plans, which were ultimately shelved due to their failure to pass legal procedures. Some villagers who were unhappy with the restrictions on development, initiated “re-cultivation”, resulting in the destruction of large areas of farmland and irrigation channels. The paddy fields and wetlands became dry as a result, and a large number of weeds and invasive plants (such as Mikania) grew rapidly, even covering the river surface, severely damaging the local wetland ecology.

In addition, the abandoned village houses and vast fields in Sha Lo Tung attracted many war-game and off-road vehicle enthusiasts. War-gaming activities have resulted in bullet holes in many distinctive old buildings in the area, causing damage. An example would be Cheung Uk, which has been classified as a Grade II historical building. The off-road vehicles that roamed the area also had a far-reaching impact, damaging natural streams and the remaining irrigation systems of the past. There was also rampant illegal wildlife poaching in the area that left behind traps everywhere, among which turtle poaching became particularly serious.

Later in 2015, some villagers who were impatient with the slow progress of development, cleared out large areas of vegetation and planted Brassica. The Brassica field was a sea of yellow, and attracted many tourists to visit and take photos. It was also widely reported by the media then. However, in reality, it was destruction disguised as beauty. The cultivation of Brassica dried up the wetlands, further destroying the area’s precious wetland resources.

By 2017, the government announced in principle an agreement for non-in-situ land exchange to conserve Sha Lo Tung, through which the developers were allowed to build a golf course on the restored landfill in Shuen Wan, Tai Po, and in exchange, the private land in Sha Lo Tung would be transferred to the government. This addressed the challenges of promoting conservation on the private land. During the non-in-situ land exchange process, Green Power, with the support of the “Environment and Conservation Fund” and the “Countryside Conservation Funding Scheme”, initiated the “Habitat and Biodiversity Conservation Scheme in Sha Lo Tung” management agreement from 2018 to April 2024 to restore about 12 hectares of land in the area, including repairing historical irrigation systems, creating “eco-pond”, and rebuilding “artificial marshes”, and we have created more water bodies for the increasingly dry Sha Lo Tung, and at the same time, established more suitable habitats for dragonflies, freshwater fish, and amphibians.

Following the completion of the non-in-situ land exchange arrangement, Green Power was commissioned by the Agriculture, Fisheries and Conservation Department on 1 May 2024 under the Countryside Conservation Funding Scheme to proactively conserve this ecological treasure trove of Hong Kong through habitat management work. Promotion of public awareness and participation in the conservation of Sha Lo Tung through various public education activities are also underway.

Besides the worsening ecological situation due to gradual abandonment and deliberate human destruction over the past decades, Sha Lo Tung has also been affected by improper human activities and invasive alien plants. In addition to restoring the wetlands, we have strengthened related improvement works to specifically address four major issues faced by the area.

Golden Brassica field dried out the wetland in Sha Lo Tung

Sha Lo Tung is facing the thread of wetland degradation.

Threats and Countermeasures

Off-road Vehicles

The vast fields have attracted many off-road vehicle enthusiasts. However, these vehicles roamed without regard in the local wetlands and farmlands, destroying not only vegetation but also the irrigation facilities inherited from previous generations of farmers. Furthermore, the destruction of the original wetlands has accelerated the invasion of alien plants. These plants absorb a large amount of water from the soil, causing the wetlands to dry up and eventually destroying the entire wetland system.

We have now installed barriers on the roads to prevent off-road vehicles from entering Sha Lo Tung and installed cameras to monitor and prevent off-road vehicles from entering. Additionally, to also protect the wetland habitats, warning signs have been erected to remind drivers not to drive into the wetlands and marshes.

Illegal Poaching

Sha Lo Tung is home to a variety of freshwater fish, amphibians and reptiles, including many rare species. This has attracted poachers who capture and sell the wild animals for profit. Hunting equipment is often found in local streams, indicating rampant poaching. Hence, to monitor and curb illegal poaching, we have installed cameras and intensified the clean-up of hunting equipment.

Invasive Alien Plants

Mikania and Gairo Morning Glory are among the common invasive alien plants in Sha Lo Tung. They grow in large amounts and stifle the living space of native plants, significantly impacting the area’s unique wetland habitat. In the past, Sha Lo Tung was covered with native wetland vegetation. However, with the roaming of off-road vehicles, frequent wildfires, and repeated reclamation by humans, the area of native wetland vegetation has greatly reduced. Invasive plants that are better adapted to dry environments have been able to accelerate their invasion, which caused significant damage to the wetland habitat.

We have intensified the removal of invasive alien plants, and then replanted native wetland plants to prevent the re-invasion of the alien plants. Moreover, we have strengthened communication with villagers and farmers to help them understand the impact of invasive alien plants on wetland ecology and to prevent introduction of potentially invasive plants into Sha Lo Tung.

Hillfires

Due to the long history of Sha Lo Tung’s villages, there are many ancestral graves in and surrounding the area. During seasons for ancestral worship, tomb sweepers will often use fire to clear weeds and clean the graves. When they do not do so properly, or when fire sources are carelessly left behind after sacrificial rites, wildfires can occur. Hillfires burn up large areas of vegetation and destroy large tracts of forest in a short period of time. Frequent wildfires can also hinder the natural succession of forests. The lack of vegetation protection quickens soil erosion, which facilitates the exacerbation of siltation of local streams. In response, we have specifically targeted wildfire hotspots (such as the areas around graves) and increased weed clearing efforts, so as to create firebreaks to effectively prevent wildfires.