Professor Zhenhong Hu’s team found that tree species identities regulate soil nutrient cycling.
Update time:2024-09-27
Recently, the research results of Professor ZhenhongHu's team from the College of Soil and Water Conservation Science and Engineering (Institute of Soil and Water Conservation) were published in two articles titled "Tree functional group mediates the effects of nutrient addition on soil nutrients and fungal communities beneath" in the classic agricultural and forestry science journal Plant and soil. decomposing wood”and "Tree species identity drives the vertical distribution of soil carbon and nutrients concentrations in the Loess Plateau, China"in Plant and Soil. Doctoral students Ma Longlong and Zheng Yuxiong are the first authors of the paper respectively, and Professor Zhenhong Hu is the corresponding author.
Outcome 1: Dead wood contains large amounts of carbon and nutrients, and its decomposition has a considerable impact on soil chemical cycles and biological communities in forest ecosystems. Both tree species identities and nutrient additions have significant effects on wood decomposition rates. However, little is known about how the interaction of these factors affects soil biogeochemistry under wood decomposition. Based on this, this study set up field experiments with nitrogen and phosphorus additions to analyze how nutrient input affects the decomposition of dead wood of angiosperms and gymnosperms in subtropical forests on soil nutrients, microbial biomass, and saprophytic fungal communities. The results showed that phosphorus addition could significantly increase the total carbon, total phosphorus and microbial biomass carbon and phosphorus contents in soil more than nitrogen addition. These effects are particularly pronounced in soils underlying angiosperms compared to gymnosperms, which may be related to the higher decomposition rates of angiosperms and their sensitivity to phosphorus. Likewise, the presence and abundance of soil saprophytic fungal communities were closely related to phosphorus addition, with specific fungal responses more pronounced under angiosperms than gymnosperms. This study highlights the critical role that tree species attributes play in regulating the response of soil nutrient dynamics and fungal community structure to wood decomposition in subtropical forests.
Fig.1 Schematic diagram of the mechanism of the effects of nitrogen and phosphorus addition on soil saprophytic fungal communities and nutrient cycling under dead wood
Outcome 2: Afforestation has significantly increased vegetation carbon storage on the Loess Plateau, but it has led to new ecological problems such as water shortages and imbalanced soil carbon and nutrient cycles in the region. In addition, how different silvicultural tree species characteristics affect carbon and nutrient concentrations in deep soils remains uncertain. This study selected three typical tree species and models for vegetation restoration on the Loess Plateau—pure black locust forests, pure pine forests, and mixed forests of pine and black locust trees—to explore the effects of these tree species and restoration models on soil carbon and nutrients. The results showed that soil carbon and nutrient contents among different tree species across the entire soil vertical profile (0-200 cm) were strongly affected by species characteristics. In the surface soil (0-60 cm), the soil organic carbon, total nitrogen and ammonia nitrogen contents of the black locust forest were significantly higher than those of the pine forest and mixed forest, while the total phosphorus content was significantly lower than that of other plantations. In deep soil (60-200 cm), the total nitrogen, nitrate nitrogen and total phosphorus contents of black locust forest are lower than those of other plantations. Organic carbon and nitrogen concentrations in surface soils are mainly affected by microbial biomass carbon and nitrogen, while nitrogen and phosphorus concentrations in deep soils are mainly controlled by fine root biomass. The research conclusion emphasizes that planting black locust, an exotic tree species with high root biomass and nitrogen-fixing ability, on the Loess Plateau may aggravate the consumption of nitrogen and phosphorus in deep soil. It also emphasizes the importance of tree species selection in the process of dryland afforestation.
Figure 2 Effects of different plantation types on deep soil carbon and nutrient cycling on the Loess Plateau
The above research work was funded by the National Natural Science Foundation of China (32271853), the Basic and Applied Basic Research Fund of Guangdong Province (2022A1515010663), the Key Laboratory of Ecological Environment and Meteorology of the Qinling Mountains and Loess Plateau (2021K-7), the Shaanxi Forestry Science and Technology Innovation Project (SXLK2022-05-3) and the Science Foundation of China Higher Education Universities (2452021127).
© Institute of Soil and Water Conservation
News
Professor Zhenhong Hu’s team found that tree species identities regulate soil nutrient cycling.
Recently, the research results of Professor ZhenhongHu's team from the College of Soil and Water Conservation Science and Engineering (Institute of Soil and Water Conservation) were published in two articles titled "Tree functional group mediates the effects of nutrient addition on soil nutrients and fungal communities beneath" in the classic agricultural and forestry science journal Plant and soil. decomposing wood”and "Tree species identity drives the vertical distribution of soil carbon and nutrients concentrations in the Loess Plateau, China"in Plant and Soil. Doctoral students Ma Longlong and Zheng Yuxiong are the first authors of the paper respectively, and Professor Zhenhong Hu is the corresponding author.
Outcome 1: Dead wood contains large amounts of carbon and nutrients, and its decomposition has a considerable impact on soil chemical cycles and biological communities in forest ecosystems. Both tree species identities and nutrient additions have significant effects on wood decomposition rates. However, little is known about how the interaction of these factors affects soil biogeochemistry under wood decomposition. Based on this, this study set up field experiments with nitrogen and phosphorus additions to analyze how nutrient input affects the decomposition of dead wood of angiosperms and gymnosperms in subtropical forests on soil nutrients, microbial biomass, and saprophytic fungal communities. The results showed that phosphorus addition could significantly increase the total carbon, total phosphorus and microbial biomass carbon and phosphorus contents in soil more than nitrogen addition. These effects are particularly pronounced in soils underlying angiosperms compared to gymnosperms, which may be related to the higher decomposition rates of angiosperms and their sensitivity to phosphorus. Likewise, the presence and abundance of soil saprophytic fungal communities were closely related to phosphorus addition, with specific fungal responses more pronounced under angiosperms than gymnosperms. This study highlights the critical role that tree species attributes play in regulating the response of soil nutrient dynamics and fungal community structure to wood decomposition in subtropical forests.
Fig.1 Schematic diagram of the mechanism of the effects of nitrogen and phosphorus addition on soil saprophytic fungal communities and nutrient cycling under dead wood
Outcome 2: Afforestation has significantly increased vegetation carbon storage on the Loess Plateau, but it has led to new ecological problems such as water shortages and imbalanced soil carbon and nutrient cycles in the region. In addition, how different silvicultural tree species characteristics affect carbon and nutrient concentrations in deep soils remains uncertain. This study selected three typical tree species and models for vegetation restoration on the Loess Plateau—pure black locust forests, pure pine forests, and mixed forests of pine and black locust trees—to explore the effects of these tree species and restoration models on soil carbon and nutrients. The results showed that soil carbon and nutrient contents among different tree species across the entire soil vertical profile (0-200 cm) were strongly affected by species characteristics. In the surface soil (0-60 cm), the soil organic carbon, total nitrogen and ammonia nitrogen contents of the black locust forest were significantly higher than those of the pine forest and mixed forest, while the total phosphorus content was significantly lower than that of other plantations. In deep soil (60-200 cm), the total nitrogen, nitrate nitrogen and total phosphorus contents of black locust forest are lower than those of other plantations. Organic carbon and nitrogen concentrations in surface soils are mainly affected by microbial biomass carbon and nitrogen, while nitrogen and phosphorus concentrations in deep soils are mainly controlled by fine root biomass. The research conclusion emphasizes that planting black locust, an exotic tree species with high root biomass and nitrogen-fixing ability, on the Loess Plateau may aggravate the consumption of nitrogen and phosphorus in deep soil. It also emphasizes the importance of tree species selection in the process of dryland afforestation.
Figure 2 Effects of different plantation types on deep soil carbon and nutrient cycling on the Loess Plateau
The above research work was funded by the National Natural Science Foundation of China (32271853), the Basic and Applied Basic Research Fund of Guangdong Province (2022A1515010663), the Key Laboratory of Ecological Environment and Meteorology of the Qinling Mountains and Loess Plateau (2021K-7), the Shaanxi Forestry Science and Technology Innovation Project (SXLK2022-05-3) and the Science Foundation of China Higher Education Universities (2452021127).