All About Green

Tree Management: The Ultimate Test in the Typhoon Season

Aug 2023
Author: Green Power
Urban trees with pedestrians passing by

Every year, typhoon season poses a test to our cities' contingency response capabilities in areas such as drainage and flood management, traffic coordination, and swift emergency response. At the same time, it is also a challenge for every single tree in the city. Whether these seemingly robust urban trees can withstand the onslaught of strong winds becomes a testament to the authorities' daily efforts in planting, managing, maintaining, and monitoring them.

Currently, tree management efforts in Hong Kong are primarily led by the Development Bureau. The Bureau sets the direction and works in collaboration with eight tree management departments to oversee around 1.7 million trees across Hong Kong. This year, the Development Bureau announced 10 “enhancement measures” aimed at improving the capability and quality of tree management in Hong Kong.

Among these 10 measures were mentions of strengthening risk assessments for trees in areas with higher pedestrian and vehicular traffic before the typhoon season. However, legislative documents have revealed that each tree management staff is responsible for nearly 3,000 trees on average. Among them, the Architectural Services Department has an astonishing average of over 30,000 trees per person to manage. Evidently, it is challenging for the government alone to cover all the trees in high-risk areas across Hong Kong.

Engaging the public in tree management

Taking inspiration from the concept of citizen scientists, the government should empower citizens with the ability to assess tree risks through education. By fostering public participation from the grassroots level, the government and citizens can collectively monitor the trees within their communities. In fact, many tree-related issues can be identified through simple observations, so citizens can easily get involved.

Presently, the government has installed QR codes on 200,000 roadside trees to allow citizens to report high-risk trees easily. However, citizens have not been adequately informed about tree health and management, nor have sufficient attempts been made to mobilise the public. Adequate publicity measures have also not been carried out. As a result, existing measures to promote collective tree monitoring with citizens have not been utilised effectively.

Climate change increases challenge in tree management

The impacts of climate change have intensified in recent years, and it is now necessary to consider the more frequent occurrences of extreme weather and adapt accordingly when it comes to tree management. According to a study published in the scientific journal "Nature Climate Change" in 2022, over 70% of urban forests worldwide will face threats in the coming years due to changing temperatures and rainfall patterns. However, the "enhancement measures" released by the government do not seem to take into account the impact of climate change, indicating a limited understanding of the challenges that urban trees are facing.

To tackle climate change, newly planted trees should consist of drought-resistant and wind-tolerant species. Additionally, with rising temperatures facilitating the spread of pests and diseases, authorities need to remain vigilant about international developments and assist arboriculturists and landscapers in acquiring up-to-date expertise to address emerging challenges.

Trees not only beautify the cityscape, but also fulfil various functions, such as cooling the environment, improving air quality, reducing noise pollution, and promoting biodiversity. They are an indispensable element in creating a liveable urban environment. For a sustainable future in Hong Kong, the authorities must work harder to protect and monitor every tree in the city to realise the vision of "People-Trees-Harmony".