Effects of Moso Bamboo (Phyllostachys edulis) Forest Stand Density on Root Growth and Soil Quality for Shoot Production Under a Long-Term Bamboo-Stocking Retention Model

Bamboo forest density is a factor that critically impacts the growth of moso bamboo, soil quality, and productivity. In this study, four bamboo forest density treatment groups were established under a long-term bamboo-stocking retention model, namely 1200 ± 100, 1800 ± 100, 2400 ± 100, and 3000 ± 100 plants·hm^-2, while a traditional management model focused on selective logging, with a bamboo forest density of 2100 ± 100 plants·hm^-2 (CK), serving as the control group. The study aimed to investigate the impact of bamboo forest density on bamboo shoots, roots, and soil, identify key influencing factors, and determine the optimal management density for this management model. Under the novel management model, bamboo shoot yield and number exhibited a unimodal response to stand density. At a density of 2400 plants·hm^-2, the bamboo shoot yield reached its highest value of 18,822 kg·hm^-2, with 7080 shoots·hm^-2. Under the density of 2400 plants·hm^-2, the specific root length, specific root surface area and total nitrogen, phosphorus and potassium contents of 0-1 mm fine roots were higher, and the contents of soil organic matter, total nitrogen, available phosphorus and available potassium were also better. Correlation analysis showed that the bamboo shoot yield and the number of shoots were closely related to soil quality (water content, organic matter, total nitrogen, available phosphorus and available potassium), and the effect of root total nitrogen content on shoot yield was particularly significant (the explanation rate was 75.7%). The comprehensive growth status assessment (D3 > D4 > D2 > CK > D1) showed that there were differences in the performance of different density treatment groups. This information could help bamboo farmers improve yield while protecting soil quality.