Search Results (28)

Habitat utilization is a critical determinant of animal survival and reproductive success. Clarifying species-specific habitat preferences provides essential insights into ecological requirements and forms the basis for sound conservation planning. The Temminck’s Tragopan (Tragopan temminckii), a medium-sized, sexually dimorphic pheasant endemic to montane forests of central and southern China, is classified as a nationally protected Class II species. Nevertheless, its fine-scale habitat selection during the breeding season remains inadequately documented. In 2024, we conducted a field investigation in the Laojunshan National Nature Reserve, Sichuan Province, to examine microhabitat use during this critical period. Our analysis revealed a significant preference for sites characterized by greater tree and bamboo height, higher canopy and bamboo cover, increased litter coverage, and taller shrub layers. In contrast, the species consistently avoided locations dominated by dense, tall herbaceous vegetation. Principal Component Analysis identified six principal components, collectively explaining 71.78% of the total environmental variance. The first component was primarily associated with bamboo structural attributes, the second with tree-layer structure, and the third with proximity to forest edges and streams. These findings indicate that effective conservation of this pheasant requires targeted forest management practices that preserve this specific suite of habitat characteristics, which are essential for ensuring reproductive success and long-term population viability. Full article

Genipin, one of Gardenia jasminoides’ bioactive components, exhibits superior therapeutic efficacy compared to geniposide, though it is present in much lower concentrations. Conventional hydrolysis methods using acids or organic solvents can enhance genipin yield but often raise environmental and safety concerns. This study aimed to increase genipin production through whole-cell bioconversion of geniposide to genipin using lactic acid bacteria (LABs). A total of 191 LAB strains were isolated from kimchi. Levilactobacillus sp. LN180102 showed the highest bioconversion activity, which was up to 40%. Docking analysis and esculin assay confirmed the beta-glucosidase activity. The anti-inflammatory effects of the fermented extract were enhanced by 28.5% in RAW 264.7 cells in vitro. Additionally, Levilactobacillus sp. LN180102 is probiotic-friendly and exhibits a high tolerance for phenol, bile, and acid. In their entirety, these discoveries have the potential to illuminate the ways in which Gardenia jasminoides can be functionally improved through whole-cell bioconversion, thereby enabling individuals to lead healthier lifestyles. Full article

Reproductive strategies represent a fundamental aspect of life-history evolution and are shaped by environmental heterogeneity across geographic gradients. This study investigated geographic variation in reproductive traits of the swelled vent frog (Nanorana quadranus), a stream-breeding species in China’s Qinling–Daba Mountains. Male reproductive traits were assessed across 10 populations, including testicular asymmetry, relative testis size, sperm morphology, and sperm count. Female reproductive traits were examined in 12 populations, focusing on body mass and absolute fecundity. Results indicated no significant difference in bilateral testicular asymmetry (p > 0.05). Both relative testis size and sperm count increased with latitude. Sperm length correlated positively with testis size. Conversely, female body mass and age increased with altitude, while absolute fecundity was positively correlated with body mass. Environmental analysis revealed that sperm length exhibited significant positive correlations with aspect and seasonal evapotranspiration anomaly (SEA). Relative testis size was regulated by mean diurnal temperature range (Bio2) and precipitation of the wettest month (Bio13). Furthermore, female absolute fecundity correlated with the minimum temperature of the coldest month (Bio6). These findings demonstrate that reproductive strategies in N. quadranus adapt to geographic and environmental gradients, reflecting adaptive plasticity to local ecological pressures. This study advances understanding of amphibian reproductive adaptation and highlights the importance of incorporating environmental factors in life-history research. Full article

Resource-based cities, characterized by a prolonged dependence on resource extraction and persistent urban expansion, frequently exhibit significant imbalances between the supply and demand of ecosystem services (ESs). Understanding how various types of resource-based cities respond to urbanization in terms of ESs supply–demand relationships is crucial for advancing sustainable urban development. This study examines three representative resource-based cities in Sichuan Province—Nanchong (growing), Luzhou (declining), and Panzhihua (mature)—to analyze changes in six key ESs from 2000 to 2020, including soil retention, carbon sequestration, water yield, habitat quality, food production, and recreational services. Ordinary least squares (OLS) regression and random forest (RF) models were employed to evaluate the effects of gross domestic product (GDP) density, construction land proportion (CLP), and population (POP) density on the ecosystem service supply–demand ratio (ESDR), and to explore variations in sensitivity among these cities. The results demonstrate that (1) ESs’ supply–demand patterns differ significantly among the three city types. Nanchong exhibited a declining supply and increasing demand for regulating services; Luzhou displayed improvements in its water yield and recreational services but persistent degradation of habitat quality; and Panzhihua achieved notable gains in carbon sequestration and habitat quality. (2) Urbanization generally reduced the ESDR across all three cities. However, the GDP density positively influenced the ESDR in Nanchong, while the CLP and the POP density exerted widespread negative effects. In Luzhou, the ESDR was primarily constrained by the CLP, whereas in Panzhihua, both the CLP and the POP density significantly reduced the ratio. (3) The sensitivity analysis revealed distinct response patterns: Nanchong was most sensitive to CLP, Luzhou responded most strongly to GDP density, and Panzhihua was highly sensitive to both GDP density and POP density. These findings underscore the necessity of formulating city-type-specific development strategies—such as land restoration, population control, and industrial upgrading—tailored to different types of resource-based cities, in order to reconcile urbanization with ecosystem service dynamics, promote green transformation, and contribute to the achievement of the Sustainable Development Goals (SDGs). Full article

In regions characterized by complex terrain and diverse pollution sources, high-precision air pollution prediction remains challenging due to nonlinear spatiotemporal coupling and the difficulty of modeling local pollutant agglomeration. To address these issues, this study proposes a CNN–LSTM–Transformer multimodal prediction framework integrated with Bayesian Optimization. First, the Local Moran’s Index (LMI) is introduced as a spatial perception feature and concatenated with pollutant concentration sequences before being input into the CNN module. This design enhances the model’s ability to identify local pollutant clustering and spatial heterogeneity. Second, the LSTM architecture adopts a dual-channel structure: the main channel employs bidirectional LSTM to extract temporal dependencies, while the auxiliary channel uses unidirectional LSTM to capture evolutionary trends. A Transformer with a multi-head attention mechanism is then introduced to perform global modeling. Bayesian Optimization is employed to automatically adjust key hyperparameters, thereby improving the model’s stability and convergence efficiency. Empirical results based on atmospheric pollution monitoring data from Sichuan Province during 2021–2024 demonstrate that the proposed model outperforms various mainstream methods in predicting six pollutants in Chengdu. For instance, the MAE for PM_2.5 decreased by 14.9–22.1%, while the coefficient of determination (R²) remained stable between 87% and 89%. The accuracy decay rate across four-day forecasts was controlled within 12.4%. Furthermore, in PM_2.5 generalization prediction tasks across four other cities—Yibin, Zigong, Nanchong, and Mianyang—the model exhibited superior stability and robustness, achieving an average R² of 87.4%. These findings highlight the model’s long-term stability and regional generalization capability, offering reliable technical support for air pollution prediction and control strategies in Sichuan Province and potentially beyond. Full article

Mountain ecosystems offer valuable opportunities to study species distribution and diversity along altitudinal gradients, particularly for amphibians. This research examined amphibian species distribution, diversity, and conservation across an elevational gradient in the Tangjiahe National Nature Reserve, part of the Hengduan Mountains in southwestern China. A total of 25 amphibian species, encompassing 8 families and 2 orders, were documented, including three newly recorded species: Fejervarya kawamurai, Polypedates braueri, and Boulenophrys minor. Among these, eight species were designated as “threatened” under IUCN criteria and are listed on China’s Biodiversity Red List. Caijiaba exhibited the highest species diversity, whereas Shuichiping had the lowest. Fourteen species were found in terrestrial-farmland and aquatic-lotic habitats, which supported the greatest species richness. The distribution pattern along the altitudinal gradient showed peaks in species richness at 900–1100 m and 1900–2100 m elevation bands, with higher elevations displaying reduced richness. These findings highlighted the spatial characteristics of amphibian distribution and diversity across altitudinal ranges in the Tangjiahe National Nature Reserve and provide insights for formulating conservation policies and adaptive habitat management strategies. Full article

Spiders are among the predominant predatory arthropods in rice field ecosystems. Although the potential of spiders for controlling pests during the growth stages of rice is well known, few studies have focused on the overwintering habits of spiders after rice harvesting. In the present study, we aimed to evaluate the potential of rice stubble as an overwintering microhabitat for spiders in winter-fallowed rice fields. To this end, we investigated the arthropod community composition and analyzed the prey spectra of common predators in rice stubble in winter-fallowed rice fields in Nanchong City, Sichuan Province, China. The results showed that abundant predatory arthropods, particularly spiders, were present in the rice stubble, followed by other arthropods and pests. Dietary analysis via DNA metabarcoding revealed the prey availability and/or predation frequency of spiders is low in winter rice fields. Nevertheless, pests and other arthropods (particularly collembolans) within rice stubble serve as food resources for predators, particularly spiders, in winter-fallowed rice fields. Our results confirm that rice stubble provides overwintering microhabitats for spiders in winter-fallowed fields. Therefore, it is particularly important to properly manage rice stubble in winter-fallowed rice fields to enhance the biological pest control services of predators (including spiders). In addition, our findings highlight the potential of rice stubble as a habitat for the artificial reproduction of spiders for pest control in rice fields. Full article

Brain size asymmetry differs considerably across species, including humans, vertebrates, and invertebrates. The subtle structural, functional, or size differences between the two brain sides are associated with processing specific cognitive tasks. To evaluate the differences between the sizes of the left and right sides of the whole brain and brain regions and the effect of predation risk (i.e., snake density) on brain size asymmetry among Chinese anurans, we compared the differences between the left and right hemisphere sizes of the whole brain and brain regions among anuran species and analyzed the correlations between the predation risk and size asymmetry index of the brain and brain regions. We found that when one side of the brain was consistently larger than the other, there was a significant difference between the sizes of the left and right sides of the brain and brain regions, displaying directional asymmetry of the whole brain and brain regions. We also found that total brain size was positively correlated with the size asymmetry index of the olfactory bulb and optic tecta when the left hemispheres of the whole brain and brain regions were larger than the right ones. Meanwhile, the index of telencephalon size asymmetry was positively correlated with predation risk when the right hemispheres of the brain and brain regions were larger than the left ones. However, there were non-significant differences between the sizes of the left and right sides of the brain and brain regions across 99 species of anurans. Our findings suggest that an increased predation risk linked to sociality is likely to drive an increase in right telencephalon size. Full article

With urbanization, ozone (O₃) pollution and the urban heat island (UHI) effect have become increasingly prominent. UHI can affect O₃ production and its dilution and dispersion, but the underlying mechanisms remain unclear. This study investigates the spatial and temporal distribution of O₃ pollution and the UHI effect, as well as the influence of UHI on O₃ pollution in the Sichuan Basin. Atmospheric pollution data for O₃ and NO₂ from 2020 were obtained from local environmental monitoring stations, while temperature and single-layer wind field data were sourced from ERA5-Land, a high-resolution atmospheric reanalysis dataset provided by the European Centre for Medium-Range Weather Forecasts (ECMWF). The results indicate the following: (1) O₃ concentrations in the Sichuan Basin exhibit distinct seasonal variations, with the highest levels in spring, followed by summer and autumn, and the lowest in winter. In terms of spatial variation, the overall distribution is highest in western Sichuan, second highest along the Sichuan River, and lowest in central Sichuan. (2) There are significant regional differences in UHII across Sichuan, with medium heat islands (78.63%) dominating western Sichuan, weak heat islands (82.74%) along the Sichuan River, and no heat island (34.79%) or weak heat islands (63.56%) in central Sichuan. Spatially, UHII is mainly distributed in a circular pattern. (3) Typical cities in the Sichuan Basin (Chengdu, Chongqing, Nanchong) show a positive correlation between UHII and O₃ concentration (0.071–0.499), though with an observed temporal lag. This study demonstrates that UHI can influence O₃ concentrations in two ways: first, by altering local heat balance, thereby promoting O₃ production, and second, by generating local winds that contribute to the diffusion or accumulation of O₃, forming distinct O₃ concentration zones. Full article

This study seeks to improve the accuracy of air conditioning load forecasting to address the challenges of load management in power systems during high-temperature periods in the summer. Given the limitations of traditional forecasting models in capturing different frequency components and noise within complex load sequences, this paper proposes a multi-level decomposition forecasting model using complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), sample entropy (SE), variational mode decomposition (VMD), and long short-term memory (LSTM). First, CEEMDAN is used for the preliminary decomposition of the raw air-conditioning load series, with modal components aggregated by sample entropy to generate high-, medium-, and low-frequency subsequences. VMD then performs a secondary decomposition on the high-frequency subsequence to reduce its complexity, while LSTM is applied to each subsequence for prediction. The final prediction result of the air-conditioning load is obtained through reconstruction. To validate model performance, this paper uses air-conditioning load data from Nanchong City and Sichuan Province, for experimental analysis. Results show that the proposed method significantly outperforms the LSTM model without decomposition and other benchmark models in prediction accuracy, with the Root Mean Square Error (RMSE) reductions ranging from 40.26% to 74.18% and the Modified Mean Absolute Percentage Error (MMAPE) reductions from 37.75% to 73.41%. By employing the SHAP (Shapley additive explanations) method for both global and local interpretability, the model reveals the influence of key factors, such as historical load and temperature, on load forecasting. The decomposition and aggregation approach introduced in this paper substantially enhances forecasting accuracy, providing a scientific foundation for power system load management and dispatch. Full article

Chromosome numbers and morphology are important characteristics of a species and its evolution. Root tips are the most commonly used tissue as a source of actively dividing cells for chromosome visualization in plants. Previously, rapidly growing root tips were collected from germinating kernels or from seedlings growing in pots or fields. However, the use of adventitious roots (ARs) derived from aerial tissue as meristems for chromosome visualization has always been overlooked. Here, we successfully induced ARs in 12 materials that were investigated, with the exception of Sorghum nitidum. Using ARs meristem we obtained high-quality chromosome spreads for Morus alba, Broussonetia papyrifera, Lolium multiflorum, Sorghum sudanense, S. propinquum, S. bicolor × S. sudanense, Zea mays, Z. mexicana, Glycine max, Medicago sativa, and Brassica napus. The results reported here demonstrate that layering is an alternative and effective method for producing meristematic cells for high-quality chromosome preparation in plant species producing ARs. For species that produce ARs by layering, this protocol is particularly valuable for the development of cost-effective and high-throughput non-invasive cytogenetic studies. Full article

Stomata are essential for photosynthesis and water-use efficiency in plants. When expressed in transgenic Arabidopsis thaliana plants, the potato (Solanum tuberosum) proteins EPIDERMAL PATTERNING FACTOR 2 (StEPF2) and StEPF-LIKE9 (StEPFL9) play antagonistic roles in regulating stomatal density. Little is known, however, about how these proteins regulate stomatal development, growth, and response to water deficit in potato. Transgenic potato plants overexpressing StEPF2 (E2 plants) or StEPFL9 (ST plants) were generated, and RT-PCR and Western blot analyses were used to select two lines overexpressing each gene. E2 plants showed reduced stomatal density, whereas ST plants produced excessive stomata. Under well-watered conditions, ST plants displayed vigorous growth with improved leaf gas exchange and also showed increased biomass/yields compared with non-transgenic and E2 plants. E2 plants maintained lower H₂O₂ content and higher levels of stomatal conductance and photosynthetic capacity than non-transgenic and ST plants, which resulted in higher water-use efficiency and biomass/yields during water restriction. These results suggest that StEPF2 and StEPFL9 functioned in pathways regulating stomatal development. These genes are thus promising candidates for use in future breeding programs aimed at increasing potato water-use efficiency and yield under climate change scenarios. Full article

Climate change promotes variations in distribution ranges, potentially leading to biodiversity loss and increased extinction risks for species. It is crucial to investigate these variations under future climate change scenarios for effective biodiversity conservation. Here, we studied the future distribution ranges of 268 Testudoformes species under climate change using habitat models, specifically species distribution models (SDMs), to assess their conservation status. Our results have indicated that over half of species are projected to experience declines in their potential distribution ranges under two scenarios. In particular, we found that three critically endangered species—Three-striped roofed turtle (Batagur dhongoka), Durango mud turtle (Kinosternon durangoense), and Colombian mud turtle (Kinosternon dunni)—displayed extraction of their distribution ranges and faced extinction under global climate change. Additionally, our analysis revealed that the potential distribution ranges of some species might increase under future climate scenarios. However, these findings must be interpreted with caution as they do not account for other significant factors such as biological invasions, population structure, land-use change, anthropogenic disturbances, and inter-organism interrelationships. Future studies should incorporate these factors to provide a more comprehensive assessment of extinction risks. Our findings suggest that climate change, in conjunction with habitat degradation and human activities, must be considered when assessing the extinction risks of Testudoformes. Full article

The increasing global population is leading to a decline in cropland per person, aggravating food security challenges. The global implementation of land consolidation (LC) has created new farmland and increased productivity. LC is a critical strategy in China for ensuring food security and gaining significant government support. This article investigates the impact of LC on farmland productivity in Sichuan Province in 2020. We utilize time series remote sensing data to analyze LC’s impact on farmland capacity. This study uses Sentinel and Landsat satellite data to calculate CumVI and assesses the LC project’s spatiotemporal evolution. To evaluate LC’s effectiveness, we create indexes for yield level and stability and employ Getis-Ord Gi* to identify spatial differentiation in LC’s impact. GeoDetector and GWR examine the impact of natural factors like elevation, slope, soil organic carbon, and rainfall on the effectiveness of LC. The research results show that: (1) After the implementation of LC, 55.51% of the project areas experienced significant improvements in agricultural productivity; the average increase rate of yield level is 7.74%; and the average increase rate of yield stability is 12.40%. Overall, LC is significant for improving farmland capacity. (2) The effectiveness of LC exhibits spatial differences and correlations in different areas. The main location for high-value agglomeration of yield levels is Nanchong City, while the northern part of Guangyuan City primarily hosts low-value agglomeration areas. (3) Natural conditions influence LC’s effectiveness. In terms of affecting the yield level of LC, the driving factors from high to low are SOC, elevation, slope, and rainfall. In terms of affecting the yield stability of LC, the driving factors, from high to low, are elevation, SOC, slope, and rainfall. LC’s effectiveness is influenced by different natural conditions that have different effects. Full article

Global climate change drives variations in species distribution patterns and affects biodiversity, potentially increasing the risk of species extinction. Investigating the potential distribution range of species under future global climate change is crucial for biodiversity conservation and ecosystem management. In this study, we collected distributional data for 5282 reptile species to assess their conservation status based on distributional ranges using species distribution models. Our predictions indicate that the potential distribution ranges for over half of these species are projected to decrease under different scenarios. Under future scenarios with relatively low carbon emissions, the increase in the number of threatened reptiles is significantly lower, highlighting the importance of human efforts. Surprisingly, we identified some endangered species that are projected to expand their distribution ranges, underscoring the potential positive effects of climate change on some special species. Our findings emphasize the increased extinction risk faced by reptile species due to climate change and highlight the urgent need to mitigate the effects of habitat degradation and human activities on their potential distribution in the future. Full article