Soil organic matter (SOM) refers to all carbon-containing organic matter in soil and is one of the most important indicators of soil fertility. The hyperspectral inversion analysis of SOM traditionally relies on laboratory chemical testing methods, which have the disadvantages of being inefficient and time-consuming. In this study, 69 soil samples were collected from the Honghu farmland area and a mining area in northwest China. After pretreatment, 10 spectral indicators were obtained. Ridge regression, kernel ridge regression, Bayesian ridge regression, and AdaBoost algorithms were then used to construct the SOM hyperspectral inversion model based on the characteristic bands, and the accuracy of the models was compared. The results showed that the AdaBoost algorithm based on a grid search had the best accuracy in the different regions. For the mining area in northwest China, $R_p^2$ = 0.91, $RMS{E}_p$ = 0.22, and $MA{E}_p$ = 0.2. For the Honghu farmland area, $R_p^2$ = 0.86, $RMS{E}_p$ = 0.72, and $MA{E}_p$ = 0.56. The detection of SOM content using hyperspectral technology has the characteristics of a high detection precision and high speed, which will be of great significance for the rapid development of precision agriculture.

Phytolacca americana, introduced to China in the 20th century for its medicinal properties, has posed a significant ecological and agricultural challenge. Its prolific fruit production, high reproductive coefficient, adaptability, and toxic roots and fruits have led to the formation of monoculture communities, reducing native species diversity and posing threats to agriculture, human and animal health, and local ecosystems. Understanding its potential distribution patterns at a regional scale and its response to climate change is essential for effective monitoring, management, and control. In this study, we utilized the Maxent model to simulate potential habitat areas of P. americana across three timeframes (current, 2050s, and 2070s) under three climate change scenarios (SSP126, SSP245, and SSP585). Leveraging data from 556 P. americana sites across China, we employed ROC curves to assess the prediction accuracy. Our findings highlight key environmental factors influencing P. americana’s geographical distribution, including the driest month’s precipitation, the coldest month’s minimum temperature, the wettest month’s precipitation, isothermality, and temperature annual range. Under current climate conditions, P. americana potentially inhabits 280.26 × 10⁴ km² in China, with a concentration in 27 provinces and cities within the Yangtze River basin and its southern regions. While future climate change scenarios do not drastically alter the total suitable area, the proportions of high and low-suitability areas decrease over time, shifting towards moderate suitability. Specifically, in the SSP126 scenario, the centroid of the predicted suitable area shifts northeastward and then southwestward. In contrast, in the SSP245 and SSP585 scenarios, the centroid shifts northward.

The effects of invasive species on the local community (e.g., structure and stability) are highly environmentally dependent. Invasions of amphibious species usually take place in both xeric and humid environments, yet they are relatively poorly understood. In this study, we analyzed the communities that were dominated by Alternanthera philoxeroides using ecological niche and interspecific association. A total of 66 species and 67 species were recorded in the xeric environment and humid environment, respectively. In both environments, species in family Gramineae, such as Echinochloa crusgalli and Cynodon dactylon, exhibited a higher level of importance values and greater ecological niche widths. The interspecific association and stability of the dominant species were weak and the dominant species were relatively independent of each other. In the xeric environment, A. philoxeroides was more compatible with E. crusgalli and C. dactylon in terms of ecological niche requirements and habitat suitability. In humid habitats, A. philoxeroides had a greater correlation with E. crusgalli, C. dactylon, and Persicaria lapathifolia, suggesting a higher possibility of concomitant occurrence. Overall, we suggested that during the revegetation after A. philoxeroides invasion, E. crusgalli and C. dactylon can be the alternative plants. Meanwhile, alternative control measures for A. philoxeroides invasion in agricultural fields should give more consideration to the use of plants with economic or ecological value.

Current knowledge on the fish gut microbiota has largely been obtained from experiments on laboratory-reared animals. Here, the crucian carp (Carassius auratus) with a mean weight of 159.9 ± 11.4 g (mean ± SD) were collected from their natural habitats (i.e., Wuhu lake and Poyang lake, China), and the gut microbiota were analysed by using the next-generation sequencing of 16S rRNA gene. We obtained more than 430,000 high-quality reads, which constituted more than 1200 operational taxonomy units (OTUs), revealing extremely diverse microbes in the fish gut. Proteobacteria, Fusobacteria, Bacteroidetes and Firmicutes were detected as the prominent phyla (each > 1% of total abundance) within the gut microbiota, regardless of the host habitat or the gut segment (i.e., foregut vs. hindgut). Although the microbes in the hindgut were more diverse (OTU number, Shannon and Chao1; One-way Anova, p > 0.05) than in the foregut, the host habitat had a significant role in shaping the community structures (MRPP, ANOSIM, PERMANOVA, p < 0.01). Interestingly, we also detected a set of common OTUs, whereby genera Aeromonas and Cetobacterium might comprise the core gut microbiota of crucian carp.

Urban lake scenic areas serve as crucial ecological barriers but face acute conflicts between expansion and conservation. Existing research has often overlooked microscale landscape fragmentation and its associated ecological effects. Focusing on the Wuhan East Lake ecotourism scenic area (Wuhan East Lake), this study investigated the spatiotemporal impacts of micro-scale land-use transitions on ecosystem service value (ESV). To evaluate the historical evolution of ESV from 2010 to 2024, an improved equivalent factor method was coupled with a patch-generating land-use simulation (PLUS) model. Spatial autocorrelation and landscape pattern metrics were then incorporated to diagnose structural degradation and establish a foundation for simulating the four development scenarios for 2035. Results demonstrate that sporadic construction expansion led to a decline in total ESV from 2.445 to 2.216 billion CNY, driving a pronounced “core-hot vs. edge-cold” spatial disparity. Among future projections, the Sustainable Development pathway emerges as optimal, effectively balancing economic demands with the need to minimize ecological fragmentation. Ultimately, this study contributes to the literature by integrating microscale landscape fragmentation analysis with a PLUS-based multi-scenario simulation to provide a refined understanding of ecosystem service dynamics in urban lake systems, thereby offering a scientific reference for resilient spatial planning and policymaking.

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.