To investigate the impact of phosphorus input on phosphorus output in the Three Gorges Reservoir Area, this study utilized the Net Anthropogenic Phosphorus Input (NAPI) model and the improved Export Coefficient Model (ECM) to analyze the spatiotemporal characteristics of phosphorus input and output from 2006 to 2021, as well as their response relationship. The results showed that the annual NAPI value initially increased and then decreased, with a peak in 2015. The distribution of NAPI values exhibited spatial clustering among counties, with phosphorus fertilizers contributing the most to NAPI, averaging 64.42% annually. Total phosphorus (TP) output fluctuated around 2500 tons per year with a slowly increasing trend, and the areas with high TP values shifted from the northeastern to the southwestern parts of the reservoir area. Dryland contributed the most to TP, with an annual average of 41.25%. There was a positive correlation between TP and NAPI, with the phosphorus input from human food and animal feed (Pim) having the greatest overall impact on TP, followed by non-food phosphorus input (Pnf) and phosphorus fertilizer input (Pfer). Pim was found to generate more TP per unit than Pnf and Pfer. The phosphorus output rate ranged from 1.18% to 2.26%, with an annual average of 1.78%. The proportion of Pim had the greatest influence on the phosphorus output rate, followed by the proportion of Pnf, with the output rate increasing as the proportions of Pim and Pnf increased. In contrast, the proportion of Pfer was negatively correlated with the phosphorus output rate. Pim posed the greatest threat to potential regional phosphorus pollution risks. This study provides scientific references for water environment management in the Three Gorges Reservoir Area.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |