In this post, Yongqiang Zhang—a PhD student at Peking University—shares his recently published paper: “Functional diversity of neighbors mediates sap flow density and radial growth of focal trees, but in different ways between evergreen and deciduous broadleaved species”. He underscores the importance of this research in advancing forest management practices by regulating species composition in the neighborhood, which can reduce water consumption by trees while ensuring forest growth and improving water use efficiency. Additionally, he shares his research experiences and encourages young colleagues to discover interesting ecological questions through fieldwork.
About the paper
The relationship between biodiversity and forest ecosystems has always been an intriguing topic in ecology. As research has progressed, ecologists have discovered that “species” can only represent part of the plant function, while functional diversity and community-weighted means calculated through plant traits representing functions can better predict functions from individual to ecosystem. Due to global changes, altered rainfall patterns have affected regional water resource availability, making plant water use an increasingly important focus. Recent studies have pointed out that neighborhood species richness and drought-tolerance traits modulate tree water use and growth responses to drought, providing new insights into the study of inter-tree relationships. Therefore, we obtained the plant traits of focal trees and their surrounding neighbors to investigate how the traits of the focal tree itself and the functional trait composition of surrounding trees (functional diversity, resource acquisitiveness, and water saver to spender) affect the focal trees’ sap flow and growth. We found that high functional diversity of the neighbourhood depressed sap flow density but promoted growth when considering all species, and thus promoted water use efficiency. We further found that the mechanisms differed between evergreen and deciduous broadleaved species. Our findings suggest that considering the functional trait composition of neighborhood communities will support effective afforestation and forest management.
About the research
Over the past several years, we conducted high-frequency monitoring of sap flow and growth in 48 individual trees at the BEF-China site. One of our primary challenges during fieldwork was mitigating damage from wildlife and insects, necessitating regular instrument checks and maintenance. Due to the fast growth of trees in subtropical regions, we had to reset growth monitoring instruments in both early and mid-growing seasons to ensure complete data collection within the instrument’s operational range. We are thankful for the collaborative efforts of our colleagues in instrument maintenance and field surveys, as well as the invaluable support from the BEF-China platform. The biodiversity and interspecies interactions have proven highly intriguing; understanding the influence of neighboring trees on focal trees remains a subject requiring further investigation.
About the author
Growing up in the countryside, I have always been close to nature. Childhood memories often bring to mind scenes of collecting plant seeds and fruits to nurture them. During my master’s studies, I had the privilege of traveling across China from north to south with my mentor, Professor Qiwu Sun, which allowed me to reconnect deeply with nature, broaden my horizons, and contemplate various relationships between species and the environment. In my doctoral studies at Peking University, under the guidance of the knowledgeable and kind Professor Zhiyao Tang, I delved deeply into ecology. Inspired by Professor Tang, my passion for nature remains strong, and I firmly believe that only by immersing oneself in nature can one discover more intriguing ecological questions. I encourage students pursuing ecology to venture into nature, personally investigate their interests, and perhaps find new inspirations.
Like the blog post? Read the research here
