More reason to foster tree diversity in Hong Kong (Issue Date: 26 June, 2023)
| South China Morning Post
| Dr. Jeffrey Hung, Chief Executive Officer, Friends of the Earth (HK)
Forests are a critical component of the Earth’s ecosystem, covering approximately 30 per cent of the planet’s land surface. They house an enormous variety of plant and animal species, regulate the global climate and maintain the water cycle. Carbon storage in forests also plays a crucial role in mitigating climate impacts.
A recent study published in Nature shows that increasing tree diversity can enhance soil carbon storage by 30-32 per cent and nitrogen storage by 42-50 per cent over 10 years or longer. This strengthens the argument for Hong Kong to do more to increase species diversity in its forests.
Different tree species occupy and provide different niches, supporting a habitat for crucial soil microorganisms and fungi species. Forests with multiple tree species exhibit greater resilience to pests and diseases, limiting the spread of species-specific pathogens, lowering tree mortality rates and increasing carbon storage.
Tree diversity can improve soil fertility in forests through enhanced nutrient cycling, and increased litter quality and decomposition rates.
The recognition that diverse tree communities enhance carbon storage and soil fertility in forests highlights the importance of promoting and maintaining tree diversity to maximise ecosystem services.
Thus, the Hong Kong government should encourage the reproduction of native tree species through natural succession and by planting a mix of species in reforestation efforts. It should also avoid the conversion of diverse forests into monoculture plantations or other land uses that reduce tree diversity, and protect existing diverse forests from degradation and fragmentation through establishing protected areas and sustainable land use planning.
Maintaining healthy forest ecosystems is essential for the planet’s well-being, and tree diversity is a crucial factor in achieving this goal.