Research Background
Moso bamboo (Phyllostachys edulis) is an important species in subtropical forest ecosystems, providing both economic value and ecological functions. However, the long-term cultivation of monospecific moso bamboo forests often leads to constraints on soil nutrient cycling, declining soil fertility, and reduced productivity. In contrast, moso–broadleaf mixed forests can help improve soil conditions, enhance stand stability, and boost productivity. Yet, without effective management, moso bamboo can spread rapidly via rhizomes, altering community structure and inhibiting the regeneration of broadleaf trees. Consequently, a critical question arises: how does moso bamboo invasion affect the water and nutrient uptake of broadleaf trees, and how does it sustain their transient coexistence?
Recently, Professor Jiang’s team at Nanjing Forestry University published a study in Catena. Focusing on the invasion of Moso bamboo into broadleaf forests dominated by Quercus acutissima, the team integrated stable hydrogen and oxygen isotope analyses, root biomass assessments, and soil moisture and nutrient evaluations to systematically elucidate the plant water-use strategies and underground niche‑competition mechanisms underlying bamboo invasion.
Figure 1. Plot establishment and sampling point distribution in the study area
Research Methodology
Study Design: The study was conducted at the Yangtze River Delta Ecological Station. The study subjects included Moso bamboo and Mongolian oak in invaded plots, as well as Mongolian oak control plots that had not been invaded by Moso bamboo. Sample plots were established along an invasion gradient, with three 30 m × 400 m quadrats set up in both the invaded broadleaf forest area and the uninvaded control area.
Sample Collection: Soil samples from different horizons, plant branches, and soil water were collected to determine soil moisture content, water storage, and concentrations of C, N, P, and other parameters. Simultaneously, xylem water from plants and soil water were extracted, and their δ²H and δ¹⁸O values were measured to elucidate the sources of plant water.
It is worth noting that the research team used the LI-2100 Automated Vacuum Water Extraction System (Beijing Lijia United Technology Limited) to extract xylem water and soil water. This instrument operates on the principle of ultra‑low‑pressure vacuum distillation and freezing, enabling not only highly efficient (98%) recovery of xylem and soil water but also rigorous control over the extraction process, thereby minimizing isotope fractionation caused by evaporation and ensuring the accuracy of hydrogen and oxygen isotope analyses.
Data analysis: The study employed the MixSIAR model to quantitatively assess the contributions of different soil layers to plant water sources, and, by integrating water source information with root biomass data, calculated niche overlap to evaluate the underground resource competition between Moso bamboo and Mongolian oak.
Figure 2. The impact of moso-bamboo invasion on the SWS and litter water-holding capacity (LC) of Quercus variabilis
Figure 3. Average (±SD) water source for Quercus robur and Bambusa textilis in the invaded area (a) and the control area (b).
Figure 4. Average (± standard deviation) root biomass (RB) of Quercus variabilis and Bambusa tenuifolia
Figure 5. Impact of Moso bamboo invasion on the average nutrient content (± standard deviation) in different soil layers of Quercus variabilis
Figure 6. Relative similarity between Moso bamboo and Quercus variabilis (PS, calculated based on water source) and niche overlap (O, calculated based on root biomass).
Research Results
The invasion of Moso bamboo reduces soil water storage capacity but enhances the water-holding capacity of litter;
In the control plot, Quercus variabilis primarily absorbs water from the shallow soil layer;
Following the invasion of Moso bamboo, Quercus variabilis is compelled to seek water from deeper soil layers;
Moso bamboo primarily utilizes shallow, nutrient-rich water sources;
The overlap in root system niches indicates that Moso bamboo possesses a stronger competitive advantage.
Conclusion
Research indicates that the invasion of Moso bamboo has altered the patterns of belowground water and nutrient use in broadleaf forests. Moso bamboo preferentially exploits shallow, nutrient-rich water sources, while Mongolian oak shifts to deeper water reserves to sustain its survival. This study provides an important reference for understanding the mechanisms underlying Moso bamboo invasion and for the conservation of broadleaf forests. Moving forward, it will be essential to further examine the long-term impacts of the ongoing expansion of Moso bamboo on the growth, regeneration, and community stability of broadleaf trees, thereby furnishing a more scientifically grounded basis for managing Moso bamboo invasions and conserving broadleaf forests.
Journal published in: Catena [Impact Factor: 5.7]
Research institutions: Nanjing Forestry University, Beijing Forestry University, Jiangsu Provincial Public Welfare Forestry and State-owned Forest Farm Management Station, etc. Research site: Yangtze River Delta Ecological Long-term Observation Station
Equipment used: LI-2100 Automated Vacuum Water Extraction System
DOI: https://doi.org/10.1016/j.catena.2025.109687