A new study published in PNAS shows that tree diversity consistently promotes aboveground biomass through fostering greater canopy structural complexity (CSC). Species complementarity is the main driver, with its positive effects strengthening over time.
Led by Prof. LIU Xiaojuan from the Institute of Botany of the Chinese Academy of Sciences, the researchers integrated 4-year, UAV-borne LiDAR assessments of tree crowns and ground-based growth measurements of 38,088 trees growing in 482 plots containing different numbers of tree species. These measurements were taken within a large forest biodiversity experiment in southeast China (BEF-China) 11 to 15 years after planting.
According to the corresponding author Prof. LIU, "this study suggests that forest managers should consider increasing CSC by selective harvesting and replanting diverse species to sustain high productivity over longer time spans."
The researchers found that increased CSC largely explained the positive biodiversity–productivity relationships. Additionally, the overyielding observed in mixtures was driven by the positive relationships between complementarity effects and CSC, with these positive effects consistently strengthening over timeThis suggests that in mixed stands different species can better fill the aboveground canopy space with their non-overlapping tree crowns, while in less diverse or even monocultures the canopy space is not occupied so evenly and thus light used less efficiently. "These findings are the first to demonstrate such complementary use of aboveground space in a tree biodiversity experiment", said Prof. Bernhard Schmid, one of the core authors of the study.
The study demonstrates the need to consider CSC and its role in mediating biodiversity complementarity effects to promote biomass production, carbon storage, and thus contribute to climate change mitigation in long-term afforestation projects.
Canopy overview of plots with different species richness of BEF-China experiment (Image by DENG Xianglu)
A new study published in PNAS shows that tree diversity consistently promotes aboveground biomass through fostering greater canopy structural complexity (CSC). Species complementarity is the main driver, with its positive effects strengthening over time.
Led by Prof. LIU Xiaojuan from the Institute of Botany of the Chinese Academy of Sciences, the researchers integrated 4-year, UAV-borne LiDAR assessments of tree crowns and ground-based growth measurements of 38,088 trees growing in 482 plots containing different numbers of tree species. These measurements were taken within a large forest biodiversity experiment in southeast China (BEF-China) 11 to 15 years after planting.
According to the corresponding author Prof. LIU, "this study suggests that forest managers should consider increasing CSC by selective harvesting and replanting diverse species to sustain high productivity over longer time spans."
The researchers found that increased CSC largely explained the positive biodiversity–productivity relationships. Additionally, the overyielding observed in mixtures was driven by the positive relationships between complementarity effects and CSC, with these positive effects consistently strengthening over timeThis suggests that in mixed stands different species can better fill the aboveground canopy space with their non-overlapping tree crowns, while in less diverse or even monocultures the canopy space is not occupied so evenly and thus light used less efficiently. "These findings are the first to demonstrate such complementary use of aboveground space in a tree biodiversity experiment", said Prof. Bernhard Schmid, one of the core authors of the study.
The study demonstrates the need to consider CSC and its role in mediating biodiversity complementarity effects to promote biomass production, carbon storage, and thus contribute to climate change mitigation in long-term afforestation projects.
Canopy overview of plots with different species richness of BEF-China experiment (Image by DENG Xianglu)