Identifying relationships among multiple ecosystem services (ESs) at different scales and the factors affecting such relationships is the foundation for sustainable ecosystem management. A case study was conducted in the Sihu Lake Basin, an agricultural basin in Central China, to examine the interactions among ESs across different scales and the responses to landscape pattern changes (2000–2020). The results indicate that (1) agricultural land and wetlands were converted into construction land and gradually decreased in size; forestland and artificial channels gradually increased in size. (2) ESs had spatial heterogeneity in their strength at the grid and county scales. (3) Most relationships between ESs were synergistic at the grid and county scales, and most correlations increased as the scale increased due to landscape consistency. (4) The landscape metrics explained approximately 45.56–61.06% of the variations in ESs, and the main influencing factor was agricultural land. Our results demonstrated that the construction of rivers and channels, dense and widely distributed agricultural land and construction land were more positively correlated with increasing crop production and nitrogen export, whereas forestland exhibited a stronger contribution to increasing carbon storage and water yield. These findings explore appropriate management methods for agricultural development and ecological conservation in agricultural basins.

Paddy soils developed from various parent materials are widely distributed in the subtropical region in China and have a non-negligible but unclear potential to consume nitrous oxide (N₂O) due to long-term flooding. This study selected three of the most common paddy soils in subtropical China, developing from quaternary red soil (R), lake sediment sand (S), and alluvial soil (C), to study their total N₂O consumption and total nitrogen (N₂) production using N₂-free microcosm experiments. These paddy soils were treated with N₂O addition (N₂O treatment) or helium (He) addition (CK treatment) and incubated under flooding and anoxic conditions. The results showed that three alluvial soils (C1, C2, and C3) consumed over 99.93% of the N₂O accumulated in the soil profile, significantly higher than R and S soils (p < 0.05). And the N₂ production in three C soils was also significantly higher than other soils, accounting for 81.61% of the total N₂O consumption. The main soil factors affecting N₂O consumption in C, S, and R soils were soil clay content (p < 0.05), soil sand content (R² = 0.95, p < 0.001), and soil available potassium (AK) (p < 0.01), respectively. These results indicate flooding paddy soils, no matter the parent materials developed, could consume extremely large amount of N₂O produced in soil profiles.

Excessive copper (Cu) content in soil can affect plant growth and also cause damage to the soil ecosystem, making it one of the risk control projects for agricultural land soil pollution in China. Alternanthera philoxeroides exhibits stronger colonization ability in heavy metal-contaminated soil, but its physiological and ecological mechanisms of tolerance to excessive Cu remain unclear. A greenhouse incubation experiment was conducted to study the multifaced responses of A. philoxeroides to Cu stress at artificially augmented concentrations of 0, 250, 500, and 1000 mg kg⁻¹. The results showed that A. philoxeroides exhibited high tolerance to Cu²⁺, with a tolerance index (TI) exceeding 60%. As the Cu concentration increased from 0 mg kg⁻¹ to 500 mg kg⁻¹, root biomass and Cu concentration in the root increased. Additionally, soluble sugar (SS) and malondialdehyde (MDA) contents, and catalase (CAT) and peroxidase (POD) activities of A. philoxeroides continued to increase, whereas superoxide dismutase (SOD) enzyme activity, branch number, leaf area, and net photosynthetic rate kept declining. However, the trend of these indicators was opposite when Cu²⁺ concentrations were above 500 mg kg⁻¹, while the canopy area and underground root system of A. philoxeroides increased. These results suggested A. philoxeroides displayed a standing “silent” tolerance strategy to survive when soil copper was lower than 500 mg kg⁻¹ concentrations, and an “escape” strategy to avoid high copper stress by expanding the above- and below-ground areas of plants when soil copper concentrations were higher than 500 mg kg⁻¹. This study recommends the controlled utilization of A. philoxeroides for pollution remediation in Cu-contaminated soil areas where most local native plants are unable to survive.

Alternanthera philoxeroides (A. philoxeroides) is one of the worst invasive alien species in the world and poses serious threats to both ecological security and agricultural production in China. However, the effects of environmental factors on its growth across different habitat types remain insufficiently understood. To reveal the determining natural factors influencing the growth of A. philoxeroides, fieldwork, including 50 sample quadrats in six field sites, was conducted in the Yangtze River Basin of Hubei Province. In every quadrat, soil properties, soil moisture, pH, soil temperature, soil nutrients (N, P, and K), light intensity, plant cover, and aboveground plant fresh biomass were measured. Cluster analysis showed that A. philoxeroides habitats can be divided into five cluster groups: wetland, grassland, forest understory, farmland and aquatic communities. The results showed that both total community biomass and A. philoxeroides biomass were positively correlated with water content, whereas no significant relationships were found between biomass and soil nutrients, including N, P, and K. The biomass of A. philoxeroides was significantly higher in aquatic habitats, while no significant differences were observed among the other four terrestrial habitats. These findings suggest that hydrological management, together with early control in aquatic habitats, may be an effective strategy to limit the spread of A. philoxeroides.