应用生态学报最新文献

There are obvious contradictions between the development of plateau mountain urban agglomerations and the protection of ecological environment, with the quality of habitat being closely related to land use changes during urbanization. Based on the land use data of central Yunnan urban agglomeration in 2000, 2010, and 2020, we analyzed the spatio-temporal variations of land use and habitat quality, and used PLUS model and InVEST model to predict the status of land use and habitat quality in 2030 under three scenarios: natural development, urban deve-lopment, and ecological protection. The results showed that the artificial surface area of the study area increased significantly from 2000 to 2020, mainly distributed in the areas with very low and medium topographic gradients, most of which were transformed from the cultivated land in the dam area with slow slope. Habitat quality decreased significantly, especially from 2010 to 2020. The area with extremely high habitat quality decreased significantly, while the area with very low habitat quality and low habitat quality increased significantly. In the three scenarios, under the ecological protection scenario, the area of extremely low habitat quality would be the smallest, the area of extremely high habitat quality would be the largest, and the area of deterioration would be the least in 2030, which was more in line with the high-quality economic and social development of the central Yunnan urban agglomeration.

Successive crop harvest results in soil silicon (Si) loss, which constantly reduces soil available Si. Agricultural measures that can increase the availability of soil Si are in urgent need in agroecosystems. Enhanced weathering of silicate minerals can effectively replenish soil Si, which will promote plant uptake of Si, formation of plant phytolith occluded carbon (PhytOC), and the sequestration of atmospheric CO₂. In addition, the process of silicate mineral weathering can promote soil carbon (C) sequestration. In this study, we applied silicate mineral wollasto-nite powder to rice fields in Liaoning Province to investigate effects of the enhanced weathering process on soil available Si, changes in phytolith carbon (PhytOC) content in plant-soil systems, and the content of various soil C forms. The results showed that the application of wollastonite powder could significantly increase the available Si content in the surface soil (53%), promote rice dry biomass production (12% increase in rice grains and 4% increase in straw), increase the phytOC content (4% increase in rice grains and 26% increase in straw), which together resulted in 25% increase in phytOC production fluxes. The application of wollastonite powder tended to increase both inorganic and organic C content in the soil, resulting in 13% increases of soil total C content. In summary, enhanced weathering of silicate minerals could effectively increase soil available Si in paddy soil, promote rice Si absorption and phytOC formation, and enhance soil CO₂ sequestration, achieving the effect of coordinated carbon sequestration from both above- and below-ground.

Understanding the impacts of freeze-thaw action on soil microbial nutrient limitation can provide important support for sustainable utilization of black soil resources. We analyzed the impacts of freeze-thaw action on soil microbial nutrient limitation on a slope farmland located in a typical thick Mollisol region of Keshan County, Heilongjiang Province. We examined the responses of soil microbial nutrient limitation to soil erosion rates through measuring soil nutrient, soil microbial biomass, and soil enzyme activities before and after freeze-thaw under natural conditions, and estimated the soil erosion rates by ¹³⁷Cs tracing technology. The results showed that: 1) soil erosion rates of slope farmland ranged from 479.31 to 7802.33 t·km^-2·a^-1, with an average value of 2751.02 t·km^-2·a^-1. 2) Under freeze-thaw process, soil water-soluble organic nitrogen and microbial biomass carbon (MBC) of slope farmland significantly decreased by 27.9% and 37.3%, respectively. However, the freeze-thaw process did not affect soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), water-soluble organic carbon, soil available phosphorus, microbial biomass nitrogen and phosphorus. 3) Under freeze-thaw action, the activities of β-1,4-glucosidase, L-leucine aminopeptidase and β-1,4-N-acetyl-glucosaminidase significantly decreased by 43.2%, 11.0%, and 25.5%, respectively. The results of the enzyme quantification vector model indicated that soil microorganisms were limited by carbon and phosphorus availability. The freeze-thaw action weakened the relative carbon limitation of soil microorganisms and strengthened the phosphorus limitation. 4) The structural equation model analysis indicated that freeze-thaw action had a direct positive effect on relative phosphorus limitation and a negative effect on relative carbon limitation in soil microorganisms. Soil erosion rates had a direct negative effect on relative carbon limitation of soil microorganisms. 5) Soil erosion rates had significantly negative influences on SOC and TN before and after freeze-thaw, TP after freeze-thaw, MBC after freeze-thaw, and vector length before freeze-thaw. Overall, freeze-thaw action reduced the activities of soil carbon and nitrogen acquisition enzymes and further changed the resource limitation of soil microorganisms. Our results could improve the understanding of the mechanisms regarding freeze-thaw action impact on the limitation of soil microbial resource in the Chinese Mollisol region and provide scientific support for nutrient management of slope farmland.

Benggang (collapsing hill) erosion is one of the most serious ecological problems in the south of China. Understanding the relationship between Benggang erosion and landscape pattern is conducive to the study of Benggang occurrence and development from the perspective of landscape ecology, with great significance for Benggang prevention and ecological protection. We classified the Lanxi River Basin in Anxi County, Fujian Province into 32 small watersheds. 16 landscape pattern indices were selected from five aspects, including landscape shape, fragmentation, connectivity, diversity, and quantitative structure. We analyzed the relationship between Benggang erosion and landscape pattern and its mutual influence by dividing the types of landscape in the sub-watersheds. The results showed that the maximum patch index, aggregation index, spreading index, and patch combination index were representative for characterizing the regional landscape pattern. Based on those characteristics, the sub-watersheds in the study area were classified into two categories, i.e. high-disturbance and low-disturbance. In the high-disturbance sub-watersheds, the correlation between Benggang erosion and landscape shape, fragmentation, and connectivity was significant (Moran's I of 0.595, 0.605, and -0.545, respectively), indicating that the more irregular and fragmented the landscape shape, the lower the connectivity between the landscapes, the more prone to Benggang erosion. In the low-disturbance sub-watersheds, the correlation between Benggang erosion and fragmentation, connectivity, and diversity were significant (Moran's I of -0.482, -0.322, and 0.498, respectively), indicating that the higher the degree of aggregation and connectivity between landscapes, and the lower the degree of fragmentation, the less prone to Benggang erosion. For the effect of landscape pattern on Benggang erosion, regardless of high and low-disturbance sub-watersheds, the more complex the landscape shape, the more dispersed and fragmented the distribution was, the more likely it was to promote Benggang erosion. For the effect of Benggang erosion on landscape pattern, the high-disturbance sub-watersheds were more susceptible to the effect of Benggang erosion than the low-disturbance sub-watersheds, which would make the landscape shape more complex, the fragmentation degree increase, and the connectivity degree decrease. Our results can not only provide reference for the prevention and control of erosion, but also provide new ideas for the ecological management of small watersheds in southern China.

Jilin Province is an important ecological security barrier in Northeast China as it is located at the junction of the Northeast forest belts and the northern sand prevention belts. In recent years, Jilin Province has actively carried out ecological protection and restoration projects, resulting in a continuous improvement trend for the overall ecological environment. However, the evolution patterns and mechanisms of habitat quality are largely unkown. We applied the InVEST model and geographic detector method to analyze the changes in habitat quality and evaluate the main driving factors from 2000 to 2020. The results showed that the average habitat quality in Jilin Province showed a slight downward trend, and that the spatial heterogeneity characteristics of habitat quality in east and west gradually increased. The degree of habitat degradation presented a single nuclear radiation pattern centered on Changchun City. Vegetation factors and terrain factors were the first and secondary causes of spatial heterogeneity of habitat quality, respectively. The average habitat quality within the eco-redline of Jilin Province was showing an increasing trend year by year, which was consistent with the overall distribution of regions with extremely high habitat quality levels. There was a local spatial dislocation (the phenomenon of extremely high habitat quality levels not within the eco-redline) in the eastern part of Jilin Province. Our results could provide reference basis for ecosystem protection and the spatial pattern optimization.

We investigated food composition and feeding selectivity of jellyfish (Rhopilema esculentum) from the coastal aquaculture ponds in Liaodong Bay by DNA metabarcoding technology. The DNA from environmental water samples and stomach contents of R. esculentum were extracted and sequenced by high-throughput sequencing with 18S rDNA V4 region and mitochondrial cytochrome c oxidase subunit I (COI) as metabarcoding markers. Based on 18S rDNA metabarcoding, we detected 27 phyla in the stomach contents of R. esculentum, in which Mollusc was the dominant phylum followed by Arthropod, and 34 phyla in the environmental water samples, in which Pyrrophyta was the dominant phylum followed by Ciliophora and Ascomycota. Using COI metabarcoding, 18 phyla were detected in the stomach contents of R. esculentum, with Mollusc as the dominant phylum and followed by Arthropod. 22 phyla were detected in the environmental water samples, in which Proteobacteria was the dominant phylum followed by Pyrrophyta and Arthropod. Results of both methods indicated R. esculentum food included Mollusc, Arthropod, Streptophyta, Ciliophora, Pyrrophyta, Bacillariophyta, Chlorophyta, fungi, bacteria, etc. We analyzed the feeding selectivity of R. esculentum by the Ivlev selection index and found that they preferred small- and medium-sized zooplankton like Mollusc and Arthropod. Our results showed that DNA metabarcoding technology has the potential to investigate the feeding habits of jellyfish species.

Quantitative evaluation of urban ecological carrying capacity is a critical foundation for measuring urban sustainable development in the new era. This review would enrich the concept and connotation of urban ecological carrying capacity by sorting out its components and characteristics. We categorized the methods for quantifying urban ecological carrying capacity into static evaluation methods, including ecological footprint method, comprehensive evaluation method, state space method, net primary productivity method, and carbon-oxygen balance method, as well as dynamic simulation prediction methods, including system dynamics models, BP neural network prediction models, and grey prediction models. We further summarized both the advantages and disadvantages of these quantitative evaluation methods. Finally, we predicted the development trends of quantitative evaluation methods for urban ecological carrying capacity, and put forward further in-depth research from aspects such as strengthening theoretical foundations, constructing indicator systems, establishing evaluation principles, and optimizing methods.

Niche conservatism is essential for predicting the risk of alien species invasions. Currently, the changes of climate niche of Solidago canadensis during its invasion in China are still not clear. Using principal component analysis, we examined the climate niche shifts of S. canadensis during its invasion and analyzed its potential distribution in China. The results showed that, throughout its invasion in China, S. canadensis retained the climate niche characteristics of its native range (Stability index: 0.776), exhibiting strong niche conservatism. However, there were notable differences between the climate niches of the invasive and native populations. Such differences were primarily caused by the high level of niche unfilling (Unfilling index: 0.818) in its climate niche. Moreover, a certain degree of niche expansion (Expansion index: 0.224) was observed. These indicated that the invasion of this species was far from saturation and still had significant potential for further expansion in China. Therefore, the climate niche of S. canadensis primarily exhibited a conservative state after invading China, but there was also a certain degree of niche shift. S. canadensis was mainly in a stable invasion stage in East, Central, South, and Southwest China, while it was in a localized adaptation stage in the North and West China. These regions were the focus areas for prevention and control measures against S. canadensis in the future. The main climatic factors affecting the distribution of S. canadensis were precipitation of the driest month and mean temperature of the coldest quarter. During its invasion in China, the climate niche of S. canadensis shifted towards areas with higher temperature in the coldest quarter, drier in the dry season, and more precipitation in the warm and humid seasons. In conclusion, our results suggested that S. canadensis has strong adaptability, and the expansion of climate niche may further promote its invasion in China.

We investigated the effects of exogenous abscisic acid (ABA) on grain filling, starch accumulation, and endogenous hormones in maize (both the heat-tolerant maize variety Zhengdan 958 (ZD958) and the heat-sensitive variety Xianyu 335 (XY335)) under early post-anthesis high temperature stress by simulating high temperature stress for a period of 6 to 12 days post-anthesis in 2022 and 2023. There were three treatments: spraying water at ambient temperature as the control, spraying water at high temperature, and spraying ABA at high temperature. The results showed that early post-anthesis high temperature stress resulted in a significant reduction in grain weight and yield in maize, with XY335 showing a greater reduction than ZD958. The application of ABA mitigated the effects of high temperature stress on grain weight and yield, with the mean yield of ZD958 and XY335 over the two years being increased by 9.6% and 12.3%, respectively. High temperature stress inhibited the activities of enzymes involved in starch synthesis in the grain, resulting in reduced starch content. In contrast, ABA application after high temperature stress increased the activities of sucrose synthase, ADP-glucose pyrophosphorylase, granule-bound starch synthases, soluble starch synthase, and starch branching enzyme, thereby promoting starch accumulation. High temperature stress disturbed the balance of endogenous hormones in the grain, resulting in inhibition of grain filling, whereas ABA application mitigated the adverse effects of high temperature stress on endogenous hormone levels by increasing zeatin riboside, indole-3-acetic acid, and ABA levels and decreasing gibberellin level, which increased grain filling rate, prolonged filling duration, and improved filling characteristics. The grain filling characteristics, starch accumulation, endogenous hormone levels, and grain yield were more sensitive to exogenous ABA regulation in XY335 than in ZD958 under early post-anthesis high temperature stress. In conclusion, exogenous ABA could improve maize grain filling characteristics, promote starch accumulation, and regulate endogenous hormone levels, and ultimately increase grain weight and yield under early post-anthesis high temperature stress.

To understand the habitat distribution characteristics of Larimichthys polyactis in summer in Jiangsu coastal waters, we analyzed the relationship between resource density and habitat environment of L. polyactis by using a two-stage generalized additive model based on the survey data of fishery resources in August 2022, combined with the data of bottom water temperature, bottom salinity, depth, chlorophyll-a and prey species. The results showed that the average resource density of L. polyactis in summer was 15.03 kg·km^-2, which mainly distributed in the outer sea area of Lusi Fishing Ground and the middle sea area of Haizhou Bay Fishing Ground. The occurrence probability of L. polyactis was mainly affected by water depth and chlorophyll-a, with the contribution rate of water depth and chlorophyll-a being 40.8% and 10.2%, respectively. The resource density was mainly affected by water depth, chlorophyll-a, bottom salinity and the abundance of Chaemrichthys stigmatias. The bottom salinity was the variable with the largest deviation explanation (19.4%). Our results suggested that resource density of L. polyactis is closely related to its physiological habits, marine environment and the distribution of prey species.