Chinese scientists are studying how the diversity of tree species in artificial forests could affect their carbon storage capacity.
China is home to the world's largest expanse of artificial forests, comprising over a third of the global total. Scientists have found that more such forests don't necessarily translate into more carbon storage capacity. The location, the selection of tree species, the timing and maintenance all could make a difference.
In China, the practice of monoculture or growing a single plant species in a large area has raised people's concerns about their vulnerability to external disturbances, such as disease.
In Qianjiangyuan Forest National Park in east China's Zhejiang Province, a team of young scientists has embarked on a project to learn from the trees in the natural forests to find the solution.
"How do we use the laws of nature to build artificial arrangements and systems? Monoculture is not workable. Basic research can provide solutions to which tree species can grow together to achieve efficient carbon storage, which could help realize the combination of biodiversity conservation and climate change mitigation," said Ma Keping, a researcher at the Chinese Academy of Sciences.
The use of laser technology is revolutionizing the understanding of natural forests.
"Whether it is a lab research or a natural forest research, it has been proven that diversity is beneficial to forest ecosystem productivity and carbon storage," said Ma.
But the question remains: how can increased biodiversity boost a forest's capability to store carbon?
Liu Xiaojuan, another researcher at the Chinese Academy of Sciences, is spearheading a decade-long research project that seeks to answer this question, not within the confines of a laboratory, but in the natural environment.
Liu's research involves comparing plots of land planted with a single species of tree to those with a diversity of 2 to 24 species. The most biodiverse plots mimic the natural forests of Qianjiangyuan, which hosts up to 24 different tree species.
"We compared the carbon storage per mu of monoculture forest with forest composed of 16 species, and we found that after 8 years, the carbon storage of 16-species forest is twice that of monoculture forest," said Liu.
The findings reveal that forests with a rich variety of species develop a complex, intangible network for the exchange of water and microbes. This network enables the trees to optimize sunlight absorption so that their canopies interlock without overshadowing each other.
"For any individual tree, the rate of growth is actually relative to its neighbors. If we combine the data from different altitudes, we can learn more on the suitable combinations of tree species for artificial forests," said Ma.