Ecological Environment Change Research Articles

Responses of Protozoan Communities to Multiple Environmental Stresses (Warming, Eutrophication, and Pesticide Pollution).

To explore the impacts of multiple environmental stressors on animal communities in aquatic ecosystems, we selected protozoa-a highly sensitive group of organisms-to assess the effect of environmental change. To conduct this simulation we conducted a three-factor, outdoor, mesocosm experiment from March to November 2021. Changes in the community structure and functional group composition of protozoan communities under the separate and combined effects of these three environmental stressors were investigated by warming and the addition of nitrogen, phosphorus, and pesticides. The results were as follows: (1) Both eutrophication and pesticides had a considerable promotional effect on the abundance and biomass of protozoa; the effect of warming was not considerable. When warming was combined with eutrophication and pesticides, there was a synergistic effect and antagonistic effect, respectively. (2) Eutrophication promoted α diversity of protozoa and affected their species richness and dominant species composition; the combination of warming and pesticides remarkably reduced the α diversity of protozoa. (3) Warming, eutrophication, and pesticides were important factors affecting the functional groups of protozoa. Interaction among different environmental factors could complicate changes in the aquatic ecological environment and its protozoan communities. Indeed, in the context of climate change, it might be more difficult to predict future trends in the protozoan community. Therefore, our results provide a scientific basis for the protection and restoration of shallow lake ecosystems; they also offer valuable insights in predicting changes in shallow lakes.

2019–2020年西安城市PM2.5、气体污染物及气象数据集

Air pollution in China has improved in recent years, but Central Shaanxi region continues to face great pressure and challenges in pollution control due to its unique geographical location and climatic conditions. The regional and complex air pollution, characterized by ozone (O3) and fine particulate matter (PM2.5), is becoming increasingly serious. More meticulous observation data are needed to clarify the causes of air pollution and provide scientific support for control policies. This dataset comprises the data on the concentrations of nitrogen oxides, sulfur dioxide, ozone and carbon monoxide in the atmosphere obtained by gas analyzer in Gaoxinzi Observation Site of the National Observation and Research Station of Regional Ecological Environment Change and Comprehensive Management in Guanzhong Plain. Weather stations collected data on temperature, humidity, air pressure, solar radiation, wind speed, wind direction and other meteorological parameters around the station. Offline PM2.5 filter membranes were measured and the mass concentrations were analyzed. The observation site is located in the urban area of Xi 'an, Shaanxi Province. The data covers the period from January 2019 to December 2020 with a resolution of 5 minutes for pollution gas data, one minute for meteorological data, and PM2.5 collected every 24 hours. Online instruments are calibrated monthly to ensure data quality, while the offline PM2.5 sampler is calibrated and maintained weekly to ensure its data quality. This dataset can provide fundamental data records for the atmospheric environment in Central Shaanxi Province and offer data support for further pollution evaluation, control, and treatment. Moreover, it can give researchers scientific insights into the processes, casual mechanisms, as well as prevention and control of atmospheric pollution in Central Shaanxi Province.

Research on the evaluation model of ecological environment change and its internal driving mechanisms

The primary objective of this paper is to delve into the underlying driving forces behind changes in the ecological environment. To achieve this, the paper not only analyzes the multifaceted social, economic, and natural aspects of the composite ecosystem but also develops an ecological environment change evaluation model employing the topological hierarchy-entropy weight method. This model serves as a valuable tool for assessing trends and determining the drivers of ecological change. As a case study, the paper focuses on Gaoqiao Town, located in Yan’an City, Shaanxi Province. It involves a meticulous process of processing multi-year remote sensing images of the study area,as well as image cropping to extract and decode natural index data. Additionally, the paper utilizes social and economic data alongside survey data from annual reports published by local governments within the study area. These datasets are then subjected to the proposed model to evaluate ecological changes in the region. The results show that the modelling approach introduced in this paper effectively captures the ecological changes and their underlying causes in the selected areas, and can provide valuable references for government departments to formulate wise ecological environmental protection and management policies.

High Frankia abundance and low diversity of microbial community are associated with nodulation specificity and stability of sea buckthorn root nodule.

Actinorhizal symbioses are gaining attention due to the importance of symbiotic nitrogen fixation in sustainable agriculture. Sea buckthorn (Hippophae L.) is an important actinorhizal plant, yet research on the microbial community and nitrogen cycling in its nodules is limited. In addition, the influence of environmental differences on the microbial community of sea buckthorn nodules and whether there is a single nitrogen-fixing actinomycete species in the nodules are still unknown. We investigated the diversity, community composition, network associations and nitrogen cycling pathways of the microbial communities in the root nodule (RN), nodule surface soil (NS), and bulk soil (BS) of Mongolian sea buckthorn distributed under three distinct ecological conditions in northern China using 16S rRNA gene and metagenomic sequencing. Combined with the data of environmental factors, the effects of environmental differences on different sample types were analyzed. The results showed that plants exerted a clear selective filtering effect on microbiota, resulting in a significant reduction in microbial community diversity and network complexity from BS to NS to RN. Proteobacteria was the most abundant phylum in the microbiomes of BS and NS. While RN was primarily dominated by Actinobacteria, with Frankia sp. EAN1pec serving as the most dominant species. Correlation analysis indicated that the host determined the microbial community composition in RN, independent of the ecological and geographical environmental changes of the sea buckthorn plantations. Nitrogen cycle pathway analyses showed that RN microbial community primarily functions in nitrogen fixation, and Frankia sp. EAN1pec was a major contributor to nitrogen fixation genes in RN. This study provides valuable insights into the effects of eco-geographical environment on the microbial communities of sea buckthorn RN. These findings further prove that the nodulation specificity and stability of sea buckthorn root and Frankia sp. EAN1pec may be the result of their long-term co-evolution.

Changes of coastline and tidal flat and its implication for ecological protection under human activities: Take China’s Bohai Bay as an example

The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area, which is also of great significance for understanding coastal ecological environment changes and even global changes. Based on field measurements, combined with Linear Regression (LR) model and Inverse Distance Weighing (IDW) method, this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay. The shoreline faces a high erosion chance under the action of natural factors, while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities. The implication of change rule for ecological protection and recovery is also discussed. Measures should be taken to protect the coastal ecological environment. The models used in this paper show a high correlation coefficient between observed and modeling data, which means that this method can be used to predict the changing trend of shoreline and tidal flat. The research results of present study can provide scientific supports for future coastal protection and management.©2024 China Geology Editorial Office.

Faunal Diversity and the Ecological Aspects of a Community-Based Fragmented Lowland Rainforest Patch in Western Province, Sri Lanka

Wawekale Rainforest Reserve (WRR) is a primary lowland tropical rainforest area in the Western Province of Sri Lanka, established with diversity, but disturbed by human activities such as rubber cultivation, logging, poaching, chemical release, and the collection of firewood. Visual Encounter Surveys (VES) were conducted for 100 hours in the year 2022, which covered wide habitat distribution. The herpetofaunal diversity was measured in the WRR which can indicate broader ecological shifts, environmental changes, or habitat degradation. Water quality was measured in the WRR area to determine the ecosystem health and human impact. The study reports 171 species in 73 families, including two Critically Endangered (1.17%), six Endangered (3.51%), 16 Vulnerable (9.36%), and 14 Near Threatened (8.19%) species according to the IUCN Red List. The study area showed 51 endemic faunal species in Sri Lanka, which represented 29.83% of endemism. Based on the observations conducted on the herpetofauna diversity, the Shannon-Wiener diversity index (H) was calculated and the overall herpetofauna (H’H) showed high diversity within the forest premises. The water quality of the forest fragment had an influence from anthropogenic activities such as removing forest cover, bathing, washing vehicles, and releasing agro-chemical compounds resulting in high water temperature, basic pH level, high electrical conductivity, and high total dissolved solid conditions. The WRR, designated under protection, exhibits the need for immediate remedial actions to mitigate human-induced pollution and deforestation, emphasizing the critical importance of implementing proactive conservation measures to sustain ecological integrity and preserve biodiversity.

Flood Risk Identification of Zhengzhou Metropolitan Area Based on Invest Model

Rainstorm and urban flood are always one of the most serious natural disasters in China due to the change of ecological environment, terrain conditions and climate change. Rainstorm and flood disasters seriously threaten the security and development of regional economy and society. Therefore, how to identify the high-risk areas of flood disasters is an important issue to be solved in the prevention of flood disasters. Taking Zhengzhou metropolitan area as the research object, based on the Urban Flood Risk Mitigation module of InVEST model, the vulnerability of flood disaster, the supply capacity of flood regulation service and the supply-demand ratio of ecosystem service in the study area are obtained through analysis, and the areas vulnerable to flood disaster in the study area are identified. The results show that : (1) The flood regulation service supply capacity is mainly manifested in the spatial distribution pattern of high in the west and low in the east. The northern Jiaozuo, northern Xinyang, western Zhengzhou and western Xuchang have higher supply service levels. (2) Affected by factors such as population density, economic development level and land use development degree, there are also obvious spatial differences in the spatial distribution of flood regulation service demand. The high demand area of flood regulation service is concentrated in the central urban area. (3) In areas with low population density and high vegetation coverage, the high supply and low demand of flood regulation services lead to a higher service supply-demand ratio. In the central urban area of the city, due to the large proportion of construction land and dense population, the supply and demand of services is relatively low.

Predicting Future Lake Water Storage Changes on the Tibetan Plateau under Different Climate Change Scenarios

The variation of lake water storage is an important indicator for studying both climate change and ecological environment changes. Previous studies have mainly focused on the lake storage changes in recent decades, and predicting future lake storage changes on the Tibetan Plateau under climate change scenarios remains a crucial gap. We addressed this gap by establishing prediction models for water storage changes in nine lakes using historical water storage and climate data from the past 29 years and predicting the water storage changes for the next 80 years under three scenarios based on Phase 6 of the Coupled Model Intercomparison Project (CMIP6) data. The Quantile-mapping (QM) method was applied to correct the precipitation data of CMIP6 with assimilated data. The results indicated that the prediction model performed well, with high correlation (R2 > 0.7 for the training set) and low mean absolute error (MSE < 0.1 km3). The results suggest that most lakes will experience a slight increase in water storage until 2050, followed by a rapid rise until 2100 under all three SSP (Shared Socioeconomic Pathways) scenarios, including SSP126, SSP245, and SSP585. By the end of the century, the total projected increase in lake water storage is estimated to be 189.676 ± 16.266 km3, 191.762 ± 10.683 km3, and 186.212 ± 6.441 km3 until 2100, respectively.

Primary driving factors of ecological environment system change based on directed weighted network illustrating with the Three-River Headwaters Region

The primary driving factors of ecological environment change have received significant attention. However, previous research methods for identifying the main drivers of ecological environment change have primarily relied on correlation analysis and regression analysis. While these methods can reveal co-occurrences, associations, and correlations among elemental characteristics, they often struggle to uncover the deep-seated interactions among elements within complex, unstable, nonlinear, and high-dimensional systems. To address this, we used the Three-River Headwaters Region as a case study and introduced a complex network model from the perspective of the ecological environment system to investigate the main driving factors of ecological environment change. In our analysis, we considered 12 factors related to the atmosphere, hydrology, vegetation, and soil, including evaporation, long-wave radiation, short-wave radiation, specific humidity, soil temperature, precipitation rate, soil water content, air temperature, air pressure, vegetation normalization index, wind speed, and natural surface runoff. Watersheds were selected as the fundamental units for constructing ecological environment datasets. We applied the Ensemble Empirical Mode Decomposition (EEMD) method and Hilbert-Huang Transform (HHT) to analyze causal relationships between time series pairs and constructed two directed weighted network models based on sub-catchments. The results showed that both network models yielded consistent conclusions, with the sparse network exhibiting higher efficiency. Radiation and temperature were identified as the primary driving factors of ecosystem change, and the water cycle was determined to be the ultimate manifestation of ecological system change throughout the Three-River Headwaters Region. Furthermore, based on node out-strength, we generated a vegetation protection priority map.

Monitoring and evaluation of vegetation restoration in the Ebinur Lake Wetland National Nature Reserve under lockdown protection.

For a long time, human activities have been prohibited in ecologically protected areas in the Ebinur Lake Wetland National Nature Reserve (ELWNNR). The implementation of total closure is one of the main methods for ecological protection. For arid zones, there is a lack of in-depth research on whether this measure contributes to ecological restoration in the reserve. The Normalized Difference Vegetation Index (NDVI) is considered to be the best indicator for ecological monitoring and has a key role to play in assessing the ecological impacts of total closure. In this study, we used Sentinel-2, Landsat-8, and Moderate Resolution Imaging Spectroradiometer (MODIS) remote sensing data to select optimal data and utilized Sen slope estimation, Mann-Kendall statistical tests, and the geographical detector model to quantitatively analyze the normalized difference vegetation index (NDVI) dynamics and its driving factors. Results were as follows: (1) The vegetation distribution of the Ebinur Lake Wetland National Nature Reserve (ELWNNR) had obvious spatial heterogeneity, showing low distribution in the middle and high distribution in the surroundings. The correlation coefficients of Landsat-8 and MODIS, Sentinel-2 and MODIS, and Sentinel-2 and Landsat-8 were 0.952, 0.842, and 0.861, respectively. The NDVI calculated from MODIS remote sensing data was higher than the value calculated by Landsat-8 and Sentinel-2 remote sensing images, and Landsat-8 remote sensing data were the most suitable data. (2) NDVI indicated more degraded areas on the whole, but the ecological recovery was obvious in the localized areas where anthropogenic closure was implemented. The ecological environment change was the result of the joint action of man and nature. Man-made intervention will change the local ecological environment, but the overall ecological environment change was still dominated by natural environmental factors. (3) Factors affecting the distribution of NDVI in descending order were as follows: precipitation > evapotranspiration > land use type > elevation > vegetation type > soil type > soil erosion > slope > temperature > slope direction. Precipitation was the main driver of vegetation change in ELWNNR. The synergistic effect of the factors showed two-factor enhancement and nonlinear enhancement, and the combined effect of the driving factors would increase the influence on NDVI.

Monitoring of ecological environment change in tourist attraction based on remote sensing images

Monitoring of ecological environment change in tourist attraction based on remote sensing images

2000–2020年丹江口水库（河南部分）水体面积数据集

Danjiangkou Reservoir serves as the water source of the South-to-North Water Diversion Project. The long-term monitoring of changes of surface water for the reservoir using the remote sensing images is of great significance in ensuring the water transfer volume of the South-to-North Water Diversion. In this study, we used multi-temporal Landsat remote sensing images to obtain a long-time series of spatial surface water datasets for Danjiangkou Reservoir (Henan ) based on Google Earth engine cloud platform through the relationship among modified Normalized Difference Water Index (mNDWI), Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI). This dataset includes the surface water of Danjiangkou Reservoir from 2000 to 2020. It can provide a basis for exploring the spatiotemporal changes of the surface water and ecological environment changes in Danjiangkou Reservoir.

2022年强高温期长江中游通江湖泊干旱数据集

Due to global warming and climate change, affected by climate anomalies, Yangtze River basin in China experienced the strongest high-temperature process since the complete meteorological observation records in 1961. This process led to the continuous low water level of Yangtze River tributaries and the rare phenomenon of "anti-depletion of flood season" in Poyang Lake and Dongting Lake, both of which were influenced by this climate event. Lakes are indicators of global climate change, and water area changes in lakes have become one of the sensitive indicators of regional ecological environment and climate change. In this study, we used the GEE cloud computing platform to call Sentienl-1 SAR data to calculate the sentinel-1 dual-polarized water index (SDWI). Then, we determined the optimal threshold value using the OTSU algorithm to obtain the final water change monitoring data at 10m resolution for the main body of Poyang Lake, Dongting Lake and their surrounding areas during extremely high temperatures in 2022. This dataset has been validated to with an overall accuracy of over 96% and a Kappa coefficient of 0.92. The dataset includes spatiotemporal variations in arid water bodies in the middle and lower reaches of the Yangtze River during extremely high temperatures in 2022. The dataset can offer data support and serve as a scientific foundation for sustainable lake water resources during extreme weather events, as well as for research on global climate change and the ecological evolution of lakes.

Spatio-temporal evolutionary analysis of surface ecological quality in Pingshuo open-cast mine area, China.

The open-pit mining area is highly affected by human activities, which aggravate soil erosion and disturb surface ecology, bringing many problems and challenges to its environmental management and restoration, which has received widespread attention. The establishment of an objective, timely and quantitative remote sensing monitoring, and evaluation system for the spatio-temporal evolution of the surface ecological environment in the open-pit mining area is of great significance for its environmental protection, management decisions, and sustainable social development. Based on the Google Earth Engine (GEE) platform, this paper uses Landsat images to construct and calculate the remote sensing ecological index (RSEI) of the Pingshuo open-cast mine area (POMA) from 1990 to 2020 and monitor and evaluate its surface ecological environment. Combined with the Theil-Sen median, Mann-Kendall test, and Hurst index, the spatio-temporal process was analyzed. The results showed that the ecological environmental quality of the mining area first decreased and then increased from 1990 to 2020. 1990-2000 was a period of serious ecological degradation, followed by improvement. The overall improvement area reached 87.03%, and the degradation was concentrated in the coal mining area. Between 1990 and 2020, the Hurst index of the mining area was 0.452, indicating that the region has a fragile ecological environment and has difficult maintaining its stability. The global Moran's I mean value of the RSEI of the study area is 0.92, which combined with Moran's scatter plot to indicate that there is a strong positive spatial correlation rather than a random distribution of its ecological environment. During the study period, the impact on the climate of the ecological environmental change of POMA was weak, and human factors such as coal mining, land reclamation, and social construction were the main driving forces for the change in ecological quality. The results of this study reveal the changing trend of surface ecology in the mining area over the past 30 years, which is helpful for understanding its impact mechanism on ecological quality and provides support for the management of the region.

Putting the dead to work: A new method to assess the autochthony of marine Ostracoda death assemblages

Sedimentary and paleontological records can be powerful means of reconstructing ecological and physical environmental changes, by using a variety of records extending proxies to extend chronologies beyond the reach of instrumental or manual records. Ostracods are often used as paleoenvironmental proxies. Estimating the population age structure could be a useful tool for assessing the influence of some environmental parameters on death assemblages and for determining the autochthoneity or allochthoneity of the species that make up the thanatocoenosis. In the literature, several methods based on population age structure have been proposed to distinguish autochthonous and allochthonous components of life/death ostracod assemblages.The Adult:Juveniles ratio analysis of a rich and well-preserved ostracod assemblage from one site in the circalittoral zone of Pontine Archipelago, in the central-eastern Tyrrhenian Sea, is presented. The new Specific Population Stage Index (SPS) is proposed, built upon the measurements of all growth stages in the assemblage. The population structure using the new SPS Index on three different grain sizes is tested against a list of putative in situ and transported ostracod specimens. The analysis on the small grain size (maximum heigth >63 µm) proved the most effective in describing the putative life ostracod assemblage, whereas in the largest grain size (maximum height >180 µm) the young instars of the smaller species are under-represented. This includes species generally under-represented in the fossil record of the Mediterranean, probably due to sample processing bias and not to the rarity of the species itself. Assessing the autochthoneity of modern/fossil assemblages has great potential for acquiring baseline information on ecosystems before the onset of human activities, making this an extremely powerful approach essential to evaluating anthropogenic impacts. This approach seeks to identify the in situ life assemblages within an ostracod population to ensure that paleoenvironmental interpretations are not biased by transported allochthonous elements.

Validity and Practicality of SSCS-Based Student Worksheet on Ecology Material and Environmental Change

This research aims to produce student worksheet based on SSCS (Search, Solve, Create and Share). This type of research is development research using the Plomp model. The development stage of this model starts from the initial investigation stage, the development or prototyping stage, and the assessment stage. The instruments used in this development research were teacher questionnaire sheets, student response questionnaire sheets, self-evaluation sheets, and SSCS-based LKPD validation sheets (Search, Solve, Create and Share) by experts, as well as SSCS-based LKPD practicality assessment sheets (Search, Solve, Create and Share) which is filled in by teachers and students. The results showed that the SSCS-based LKPD (Search, Solve, Create and Share) was very valid with a score of 86.31%. The practicality assessment of student assessment in field trials (group evaluation) with a score of 92.00% with very practical criteria, and the practicality assessment by the teacher obtained a score of 96.00% with very practical criteria. It can be concluded that the LKPD based on SSCS (Search, Solve, Create and Share) that has been developed is included in the category of very valid and very practical.

A NEW METHOD FOR IMPROVING THE ECOLOGICAL ENVIRONMENT INDEX BASED ON DOWNSCALING OF LAND SURFACE TEMPERATURE

Abstract. In the process of urban construction and development, the ecological environment has always been an important consideration factor. How to quickly monitor the long-term ecological environment quality changes in large urban areas is currently one of the main research hotspots. With the continuous development of remote sensing intelligent cloud computing technology, the application of remote sensing methods to monitor urban ecological environment quality changes is becoming more efficient and convenient. Based on the remote sensing ecological index (RSEI) on the remote sensing intelligent cloud platform Google Earth Engine (GEE), this article innovatively proposes an improved remote sensing ecological index (DS-RSEI, Downscale-RSEI). Using the normalized difference vegetation index (NDVI) and land cover data (LULC), terrain data as auxiliary data, the method of moving window and principal component analysis is used to implement spatial downscaling of the heat components in the index, which increases the resolution of the original MODIS land surface temperature (LST) 1000-meter resolution product to 500 meters. When fusing with other images, it can supplement missing image details and improve the ability to evaluate the ecological spatial details of complex urban blocks. Through a comparative analysis of the RSEI index and the DS-RSEI index proposed in this article, it can be seen that DS-RSEI can express the details of ecological environment changes better in complex blocks.

Ecological drivers of hunter-gatherer lithic technology from the Middle and Later Stone Age in Central Africa

Central Africa is a key region for examining patterns of hunter-gatherer inhabitation and engagement with ecological diversity and environmental change. In contrast to adjacent regions, however, the archaeological record of prehistoric hunter-gatherer populations in Central Africa is underrepresented in studies of recent human evolution. This limited engagement with Central African archaeological records in part stems from the complexities of identifying, excavating, and dating hunter-gatherer sites in what are today often heavily forested environments, a focus on named stone tool industries from undated sites to structure the record, and highly limited means to associate dated hunter-gatherer occupations with proxy records of environmental conditions. Here, we present a novel synthesis of prehistoric hunter-gatherer stone tool assemblages from dated Central African sites and use climate model datasets to illuminate the environmental and ecological landscapes in which they were deployed. Our results suggest a significant ecological shift occurred from 14,000 years ago onwards, associated with a greater engagement with broadleaf forests. We examine the extent to which a range of geographic and paleoclimatic drivers can explain patterns of gross assemblage composition and the appearance of individual lithic technologies highlighting the significant role of changes in altitude, precipitation, seasonality, and ecology. Notably, considerable continuity can be observed between the habitat ranges of contemporary hunter-gatherer populations in Central Africa and prehistoric occupations that significantly precede the appearance of farming lifeways in the region.

Quantifying the variation of Scaly-sided merganser’ population and their divergent response to changes in hydrological connectivity of rivers in a high-latitude water tower

The Scaly-sided Merganser (SSME) is a globally endangered waterbird species, primarily inhabiting rivers. In recognition of its precarious status, it was added to the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species in 2002. The SSME is highly sensitive to ecological environmental changes driven by changes in hydrological connectivity, particularly within riverine habitats. Changbai Mountain, a high-latitude water tower in the Northeast Asia, is considered one of the most optimal breeding grounds for the SSME worldwide. Its extensive water system and dense primary forest create an environment particularly well-suited for this species. Over the past 40 years, rivers within Changbai Mountain have experienced phases of hydropower development and ecological restoration. These activities have dramatically altered the hydrological connectivity of the area. However, the response of SSME to these changes in aquatic ecology, driven by shifts in hydrological connectivity, remains uncertain. We employed the AutoRegressive Integrated Moving Average (ARIMA) model to analyze changes in the population size of the SSME. Furthermore, the GeoDetector model was used to understand the impact of ecological changes on the maximum population size (MPS) and distribution of SSME in the context of alterations in hydrological connectivity. Our findings reveal that the restoration of hydrological connectivity, a method of ecological restoration, exerts a bidirectional influence on both the distribution and the MPS of SSME. Our findings can be summarized as follows. Firstly, there was a general trend of increase in both the distribution points and population size of the SSME. Secondly, the contribution of driving factors to the MPS of SSME was ranked in the following order: temperature > Connectivity Status Index (CSI) > river width > fish abundance > river depth > velocity > altitude > forest type. Thirdly, the impacts on the distribution and MPS of SSME were not due to a single factor, but rather a complex interplay of multiple factors. Finally, the construction of small hydropower stations significantly disrupted the hydrological connectivity of rivers, thereby altering the natural habitat of the SSME. The reduction in fish population, resulting from the loss of hydrological connectivity, adversely affected the MPS. Conversely, an increase in water temperature due to loss of hydrological connectivity positively impacted the MPS. However, these effects displayed heterogeneity across different rivers. Our study suggests that the construction of gravel dams may be a suitable approach in certain sections of the river, with a recommended height limit of 1.5 m. This research provides valuable insights for managers, offering a sustainable foundation for future energy planning and ecological restoration efforts.

Relationship of construction land expansion and ecological environment changes in the Three Gorges reservoir area of China

With the rapid development of urbanization, the disorderly construction land expansion takes up too much ecological space, leading to the exacerbation of the regional internal ecosystem. Therefore, exploring the coordinated relationship between construction land expansion and ecological environment change has become a key issue for regional sustainable development. Based on remote sensing technology, the evaluation system of construction land expansion and ecological environment change in the Three Gorges Reservoir area was constructed. The spatial–temporal evolution of construction land expansion and ecological environment change from 1995 to 2020 and their coordination were analyzed, and they were divided into coupling and coordinated development types. The research shows the following findings: Firstly, in the year 2020, the comprehensive value of construction land expansion reached 0.8635, an increase of more than 8 times compared to 1995, indicating a significant trend of rapid expansion. Secondly, the comprehensive value of ecological environment change from 1995 to 2020 remained between 0.4 and 0.6 and continued to change in a good direction. And improving the remote sensing ecological indicators has expanded the difference in ecological environment quality in the Three Gorges Reservoir Area. Thirdly, the coupled model increased from 0.0534 to 0.7951 from 1995 to 2020, which is in a low-level and slow-growing state, and social and economic development does not completely depend on destroying the ecological environment quality. Finally, three types of coordinated development are divided: ecological environment protection type, development and protection in tandem type, and ecological environment consumable type. Differentiated regulation strategies and suggestions are also proposed.