27 January 2021
28 October 2014
CUHK Develops Novel Tree Guard Monitoring System
to Safeguard Invaluable Trees and Monitor Collapse Risk

Two professors of The Chinese University of Hong Kong (CUHK), Prof. CHIU Siu Wai, School of Life Sciences and Prof. CHENG Chun Hung, Department of Systems Engineering and Engineering Management, have jointly developed an innovative ‘Tree Guard Monitoring System’, with a sponsorship from the Chung Chi College. The automatic monitoring system allows round-the-clock surveillance against possible tree theft, as well as risk of collapse for tilt and sick trees.  The system can be adopted by country parks, property managements as well as garden managements.  The novel system will be exhibited at the InnoCarnival 2014 to be held next month. 

As early as the Song Dynasty, farmers in Hong Kong planted Incense trees for producing and exporting fragrant products. The precious Incense trees have been in high demand, especially among the illegal traffickers in the mainland.  The endangered and vulnerable Incense trees are conserved by The State Council of China as a national protection wild plant (second class).  In Hong Kong, thefts of Incense trees, as well as the Buddhist Pine, another precious species known as the ‘Fung Shui’ tree, have been very frequent recently.  The incidents have prompted Prof. CHIU Siu Wai and Prof. CHENG Chun Hung, with a team of CUHK students and staff (including Mr. Stanley LO and Mr. Sam HUNG from the Department of Systems Engineering and Engineering Management), to develop the novel ‘Tree Guard Monitoring System’ to protect the plants, as well as to monitor the collapse risk of hazardous trees. 

The ‘Tree Guard Monitoring System’ consists of multiple sensors, such as sonic, temperature, humidity and tilt sensors, which are integrated into a hardware device with wireless communication capabilities for continuous monitoring. When the device is mounted on the tree, alerts will be sent to the control room when abnormal activities on the trees, such as sawing and hammering are identified. The same principles can be applied to monitoring tilt and sick trees.  

The natural environment is complicated and ever changing. For instance, a storm may destroy the devices, and minor movement may trigger the alarm system.  Therefore it is a great challenge for the researchers to develop a robust system with the least chance of false alarms.  Nonetheless, Mr. Lo and Mr. Hung insisted on carrying on the research and development of the system. 

Prof. CHENG Chun Hung explains, ‘The “Tree Guard Monitoring System” utilizes various wireless technologies to form a scalable wireless mesh network for transmitting sensor data to the control center.  The wireless communication network can be scaled up for wider coverage in two dimensions: 1) expansion within a tree group with  low-bandwidth, low-energy wireless communication; and 2) extending the coverage in multiple tree groups with Wi-Fi network communication, which should be readily available in many private premises and government facilities.’ 

Prof. CHIU Siu Wai said, ‘The system can provide useful real-time data for the tree management teams to devise proactive and reactive measures for safeguarding trees. In future, we also hope to set an early warning mechanism for trees with collapse risk, so that preventive measures can be carried out as early as possible to avoid accidents and casualties.’ 

Albeit difficult, Professor Chiu and Prof. Cheng still deemed it worthwhile to develop the system for protecting the trees and people’s lives. CUHK has been actively undertaking tree management research and offering recommendations to the authorities.  In October 2010, Prof. CHIU Siu Wai urged the government to formulate a sustainable tree strategy and establish a tree health database in Hong Kong to improve the effectiveness of tree management.  She has developed two novel tree management skills—‘paint coating’ and ‘micro-drill sampling’, which can help prevent trees from dying due to pest infestations, prevent Incense trees from producing resin, as well as detect hidden tree diseases and structural defect at an early stage.  Professor Chiu has held five different ‘Tree pests and treatment workshops’, in which various experts introduced common tree diseases, controlling strategies for sick trees, and shared tree management experience. Participants could learn and practise on-site during the workshop.

CUHK’s participation in InnoCarnival 2014

CUHK will participate in the InnoCarnival 2014, organized by the Innovation and Technology Commission of the Hong Kong Special Administrative Region Government, from 1 to 9 November at the Hong Kong Science Park.  Eighteen innovative projects developed by CUHK researchers will be showcased to inspire youngsters’ interest in science, engineering and mathematics.

Members of the public are welcome to visit CUHK’s booth at the InnoCarnival 2014, to learn more about the Tree Guard Monitoring technology and other recent innovative projects. Interactive games are also available to deepen visitors’ knowledge of the showcased projects.


1 to 9 November 2014


10:00 am to 7:00 pm


Convention Centre 3, 1/F., 12W, Phase 3, Hong Kong Science Park, Sha Tin

Website of InnoCarnival 2014: http://www.itm.gov.hk/

The research team led by Prof. CHIU Siu Wai (3rd right), School of Life Sciences, and Prof. CHENG Chun Hung (3rd left), Department of Systems Engineering and Engineering Management, has jointly developed an innovative ‘Tree Guard Monitoring System’.

The ‘Tree Guard Monitoring System’ allows round-the-clock surveillance against possible tree theft, as well as risk of collapse for tilt and sick trees.