Ecosystem Stability Research Articles

Effects of Heavy Grazing on Interspecific Relationships at Different Spatial Scales in Desert Steppe of China

This study investigates the effects of grazing intensity and spatial scale on the important values, interspecific relationships, and community stability of desert steppe plant communities in Siziwang Banner, Inner Mongolia, China. Using vegetation data collected at three spatial scales (50 m × 50 m, 25 m × 25 m, and 2.5 m × 2.5 m) under two grazing conditions (no grazing and heavy grazing), we employed ecological statistics, including variance ratio analysis, χ2 tests, and the Jaccard index, to analyze species interactions and community structure. The results indicated that the important values of species vary with both spatial scale and grazing intensity; for example, Stipa breviflori and Chenopodium aristatum exhibited significantly higher important values in heavily grazed areas. Larger spatial scales enhanced the dominance of Cleistogenes songorica and Chenopodium aristatum, while smaller scales favored Stipa breviflori and Caragana stenophylla. Furthermore, interspecific associations were stronger in heavy grazing conditions. The community demonstrated consistent instability; however, no grazing areas were more stable than heavily grazed ones. These findings highlight that species importance, interspecific relationships, and community stability are closely linked to grazing intensity and spatial scale, emphasizing the critical role of sustainable grazing management in maintaining the long-term stability and resilience of desert steppe ecosystems. By emphasizing the need for targeted and sustainable management strategies, this study aims to contribute to the restoration and preservation of these vital ecosystems.

Integrating Mixed Livestock Systems to Optimize Forage Utilization and Modify Woody Species Composition in Semi-Arid Communal Rangelands

Communally owned rangelands serve as critical grazing areas for mixed livestock species such as cattle and goats, particularly in the arid and semi-arid regions of Southern Africa. This study aimed to evaluate the nutritional composition and woody species composition of communal rangelands where cattle and goat flocks graze together and to investigate the influence of grazing intensity on vegetation dynamics. Vegetation surveys were conducted across varying grazing intensities to assess species richness, biomass, and dietary preferences, while soil properties were analyzed to determine their interaction with vegetation attributes. Stepwise regression and path analyses were used to explore the relationships between soil characteristics, vegetation structure, and livestock dietary choices. The results revealed that high grazing pressure significantly reduced grass biomass (p = 0.003) and woody species density (p = 0.007) while increasing shrub cover (p = 0.018). Nutritional analysis indicated that goats preferred woody shrubs, which contributed 42.1% of their diet compared to 27.8% for cattle (p = 0.008). Regression analysis further showed that soil organic carbon (p = 0.002) and tree height (p = 0.041) were strong predictors of shrub cover. Seasonal variation significantly affected forage availability and nutritional content, with higher crude protein levels recorded during the wet season (p = 0.007). These findings suggest that grazing management strategies should be tailored to the distinct forage needs of cattle and goats to maintain the productivity and ecological stability of communal rangelands. A holistic approach that considers livestock dietary preferences, vegetation composition, and soil health is essential for sustainable rangeland management in mixed-species grazing systems.

Climate-smart forestry: an AI-enabled sustainable forest management solution for climate change adaptation and mitigation

AbstractClimate change is the most severe ecological challenge faced by the world today. Forests, the dominant component of terrestrial ecosystems, play a critical role in mitigating climate change due to their powerful carbon sequestration capabilities. Meanwhile, climate change has also become a major factor affecting the sustainable management of forest ecosystems. Climate-Smart Forestry (CSF) is an emerging concept in sustainable forest management. By utilizing advanced technologies, such as information technology and artificial intelligence, CSF aims to develop innovative and proactive forest management methods and decision-making systems to address the challenges of climate change. CSF aims to enhance forest ecosystem resilience (i.e., maintain a condition where, even when the state of the ecosystem changes, the ecosystem functions do not deteriorate) through climate change adaptation, improve the mitigation capabilities of forest ecosystems to climate change, maintain high, stable, and sustainable forest productivity and ecosystem services, and ultimately achieve harmonious development between humans and nature. This concept paper: (1) discusses the emergence and development of CSF, which integrates Ecological Forestry, Carbon Forestry, and Smart Forestry, and proposes the concept of CSF; (2) analyzes the goals of CSF in improving forest ecosystem stability, enhancing forest ecosystem carbon sequestration capacity, and advocating the application and development of new technologies in CSF, including artificial intelligence, robotics, Light Detection and Ranging, and forest digital twin; (3) presents the latest practices of CSF based on prior research on forest structure and function using new generation information technologies at Qingyuan Forest, China. From these practices and reflections, we suggested the development direction of CSF, including the key research topics and technological advancement.

Comparative Analysis of Tillage Practices on Soil Characteristics in Vertisol for Groundnut-based Cropping System

Tillage practices in groundnut-based Vertisol systems is essential for improving soil health and maximizing agricultural productivity. This study investigates the impact of tillage practices and cropping systems on soil physical and chemical properties in the Vertisol region of Karnataka during the 2022-23 Kharif and Rabi seasons. Conducted at the MARS, UAS, Dharwad, the experiment utilized a strip plot design, comparing minimum tillage with crop residue incorporation (M1) and conventional tillage without residue (M2) across four cropping systems. Findings revealed that minimum tillage significantly enhanced soil properties, demonstrating improved porosity (52.14%), maximum water holding capacity (55.97%) and soil aggregate stability (62.42%) while reducing bulk density (1.27 Mg m⁻³) at the surface layer. Among cropping systems, the groundnut + pigeon pea combination showed superior soil characteristics, with porosity at 50.88%, MWHC at 55.05%, and reduced bulk density of 1.31 Mg m⁻³ at 0-15 cm depth. Additionally, minimum tillage led to higher soil organic carbon (7.65 g kg⁻¹) and available NPK levels (315.8 kg ha⁻¹ N, 44.06 kg ha⁻¹ P, 324.53 kg ha⁻¹ K), particularly in the groundnut + pigeon pea system. These findings emphasize the efficacy of conservation agriculture techniques, reinforcing existing research that highlights how minimum tillage and leguminous cropping systems enhance soil health and foster sustainable farming practices. Such results are pivotal for promoting sustainable agricultural development, as they illustrate that implementing these practices can lead to significant improvements in soil vitality, crucial for boosting crop yields and ensuring ecological stability in Karnataka's Vertisol region.

Carbon fate and potential carbon metabolism effects during in-situ cyanobacterial inhibition by artemisinin sustained-release algaecides.

Carbon pools and microbial carbon metabolism can be significantly altered due to the diverse organic matter properties and low pH characteristics of artemisinin sustained-release algaecides (ASAs). These effects have still not been systematically studied, leading to uncertainty in the application of ASAs for cyanobacterial management in natural waters. This study assessed the effects of ASAs on carbon fate, carbon metabolism and potential ecological impacts during in-situ cyanobacterial inhibition. In the initial phase of ASAs-induced cyanobacterial inhibition (2-10 days), the carbon pool underwent significant changes due to the increased proportion of C4 plant-derived organic matter (97%), humification level (FI =0.9-1.5), and inorganic carbon concentration (TIC = 80-110mg/L). The cyanobacterial apoptosis triggered by ASAs produced particulate organic carbon, which provided a bioavailable carbon source for bacterial metabolism. ASAs enhanced the connection between bacteria and the carbon pool, as well as their carbon metabolism capabilities, by increasing the relative abundance of Proteobacteria (33.1%-37.3%), bacterial diversity, the proportion of Alphaproteobacteria and Betaproteobacteria (19.3%-29.5%) involved in carbon metabolism, and the complexity of the environment-bacteria co-occurrence network. These effects contributed to maintaining long-term ecosystem stability and resistance to cyanobacterial proliferation. Our findings elucidate the influence of bacterial carbon metabolism by ASAs as one of an important mechanism for achieving cyanobacterial inhibition in natural water, and emphasize the important role of bacteria in maintaining ecological stability during in situ cyanobacterial management.

Dynamics and biodiversity of microbial community among seasons in Shanxi mature vinegar fermentation by semisolid-solid process.

Understanding the changes in microbial communities across different seasons is crucial for ensuring the quality of Shanxi mature vinegar (SMV) by the semisolid-solid process. In a complete seasonal cycle, the richness and diversity of fungi were higher than those of bacteria. The microbial community in summer fermentation was significantly different compared to the other three seasons. For example, the dominant microorganisms such as Acetobacter and Lactobacillus decreased in summer. Screening or modifying this group of bacteria to enhance their tolerance to high fermentation temperature is an approach to improve industrial SMV fermentation. Through co-occurrence network analysis, eight highly connected genera were identified, which may play important roles in ecosystem stability. These results also lay a theoretical foundation for the further development of multi-microbial co-fermentation. This work provides an understanding of SMV fermentation from a seasonal perspective and offers new guidance for the process control of grain vinegar brewing.

Light grazing increased but heavy grazing decreased the abundance and family richness of soil arthropods community in an alpine grassland in the Qinghai Lake Basin.

Soil arthropods are important biological components of the soil food web, which are highly sensitive to environmental disturbances and can rapidly respond to changes in the external environment, then reflect the stability and health of the soil ecosystem. We investigated the community structure of soil arthropod and their responses to grazing intensity along soil depth (from topsoil to subsoil) through a manipulated grazing treatment with four intensity levels (no grazing, light grazing, moderate grazing and heavy grazing) in an alpine grassland in the Qinghai Lake basin. The results showed that: (1) Collembola was the dominant group in the experimental site. (2) Nearly two-thirds of the individuals were distributed in the topsoil (0-10 cm), and grazing did not cause soil arthropods to migrate from the topsoil to deeper soil layers. (3) Light grazing had a positive effect on increasing the individual number, family richness and diversity of soil arthropods, while heavy grazing had the opposite effect, exerting a negative impact on the soil arthropod community. (4) When the grazing intensity did not exceed moderate grazing (i.e. stocking rate of 3.86 Tibetan sheep·hm-2), grazing would have a positive effect on the soil arthropod community. In summary, light grazing is the intensity of disturbance that has a positive effect on the soil arthropod community in this region. This study not only revealed the impact of grazing on the community structure of soil arthropods but also aided in assessing the potential effects of grazing activities on the stability of soil ecosystems, providing scientific evidence for the sustainable management of alpine grasslands.

Interactive Effects of Anthropogenic Stressors on the Temporal Changes in the Size Spectrum of Lake Fish Communities

ABSTRACTThe size spectrum represents a powerful approach for quantifying the effects of environmental changes from individuals to communities in aquatic ecosystems. However, our understanding of its temporal stability in freshwater ecosystems is still limited. In the present study, we used a size spectrum approach to investigate the responses of 126 lake fish communities to changes in the intensity of three common anthropogenic stressors (i.e., global warming, nutrient loading and biological invasions) in French natural lakes and reservoirs over an average 5‐year time period. Using a backward selection on a full model including all possible effects of stressors on the size spectrum slope, we demonstrated that (i) increasing summer temperature shifted fish abundance towards the largest size classes, resulting in a flatter size spectrum slope and (ii) nutrient loading and biological invasions were associated with a shift towards smaller size classes in natural lakes, while the opposite effect was observed in reservoirs. In addition, these two stressors interacted in determining changes in the size structure of fish communities, complicating what the size spectrum can reveal about changes in stressor intensity during monitoring programs. All predictors accounted for a limited part of the observed changes in size spectra, and further investigations are needed to fully apprehend the interplay between natural and human‐induced drivers of the temporal changes in size spectra in contrasting environmental conditions.

Evaluating the influence of human disturbance on the ecosystem service scarcity value: an insightful exploration in Guangxi region

Investigating how human disturbance affects the ecosystem service scarcity value (ESSV) is crucial for maintaining ecosystem stability and achieving sustainable development goals (SDGs). This study separately assessed ESSV and human disturbance in Guangxi from 1990 to 2020, revealing their spatiotemporal distribution differences over time. The environmental Kuznets curve (EKC) is used to analyze the interrelationship between the two, with the purpose of filling the gap in current research. The main results are as follows: (1) From 1990 to 2020, ESSV in Guangxi increased significantly and reached its highest value in 2020. Under the four scenarios, ESSV increased significantly in Scenarios 2 and 4. Spatially, high ESSV was mainly distributed in some cities in central, southern, western and northeastern Guangxi. (2) The index of human disturbance in Guangxi continued to increase during the study period, with a high level of human disturbance in the central urban area and a low level of human disturbance in the peripheral areas, which were distributed in a radial pattern. (3) According to the EKC, the relationship between ESSV and human disturbance in Guangxi followed an inverted N-shaped curve. In addition, after 2010, the coupling and coordination level was dominated by “slightly balanced development”, and the area of “ESSV significantly lagged” gradually increased. This study provides a new perspective for understanding ESSV and its relationship with human disturbances, and provides an important reference for the sustainable management of ecosystems and the formulation of ecological conservation policies.

Litter Removal Counteracts the Effects of Warming on Soil Bacterial Communities in the Qinghai–Tibet Plateau

Climate warming and high-intensity human activities threaten the stability of alpine meadow ecosystems. The stability of the soil microbial community is crucial for maintaining ecological service function. However, the effects of warming and litter removal on microbial interactions, community-building processes, and species coexistence strategies remain unclear. In this study, we used a fiberglass open-top chamber to simulate global change, and moderate grazing in winter was simulated by removing above-ground litter from all plants in the Qinghai–Tibet Plateau, China, to investigate the effects of warming, litter removal, and interactions on soil microbial communities. The treatments included (1) warming treatment (W); (2) litter removal treatment (L); (3) the combined treatment (WL); and (4) control (CK). The results show that compared with the control treatment, warming, litter removal, and the combined treatments increased bacterial Shannon diversity but reduced fungal Shannon diversity, and warming treatment significantly changed the bacterial community composition. Warming, litter removal, and the combined treatments reduced the colinear network connectivity among microorganisms but increased the modularity of the network, and the average path distance and average clustering coefficient were higher than those in the control group. Stochastic processes played a more important role in shaping the microbial community composition, and soil–available phosphorus and soil ammonium contributed more to the βNTI of the bacterial community, while total phosphorus and NAG enzyme in the soil contributed more to the βNTI of the fungal community. Notably, litter removal counteracts the effects of warming on bacterial communities. These results suggest that litter removal may enhance bacterial community stability under warming conditions, providing insights for managing alpine meadow ecosystems in the context of climate change.

Effects of Perennial Alfalfa on the Structure and Function of Soil Micro-Food Webs in the Loess Plateau

The Loess Plateau is one of the most vulnerable areas in the world. Numerous studies have been conducted to investigate alfalfa fields with different planting years. Soil microorganisms and nematodes are vital in ecosystem functionality and nutrient cycling. Therefore, comprehending their response to alfalfa fields with varying years of planting is essential for predicting the direction and trajectory of degradation. Alfalfa fields with different planting years (2 years, 9 years, and 18 years) were used as the research object, and farmland was used as the control (CK). High-throughput sequencing and morphological methods determined the community composition of microorganisms and nematodes. Carbon metabolic footprints, correlation networks, and structural equations were used to study soil microorganisms and nematode interactions. Principal component analysis (PCA) results showed that alfalfa fields with different planting years significantly impacted soil microorganisms and nematode community structures. Planting alfalfa significantly increased the nematode channel ratio (NCR) and Wasilewska index (WI), but significantly reduced the soil nematode PPI/MI and dominance (λ). The correlation network results indicated that, for the 2-year and 18-year treatments, the total number of links and positive links are higher than other treatments. Conversely, the 9-year treatment had fewer positive links and more negative links compared to other treatments. Additionally, the keystone species within each network varied based on the treatment years. Structural equation results show that alfalfa planting years directly impact soil fungal community structure and plant-parasitic nematodes’ carbon metabolism omnivorous-predatory nematodes. Furthermore, the carbon metabolism of omnivorous-predatory nematodes directly influences soil organic carbon fixation. Moreover, as the duration of alfalfa planting increases, the metabolic footprint of plant-parasitic nematodes decreases while that of omnivorous-predatory nematodes rises. Among treatments varying in alfalfa planting durations, the 9-year treatment exhibited the most incredible energy conversion and utilization efficiency within the soil food web, demonstrating the most stable structure. This study reveals optimal alfalfa planting duration for soil ecosystem stability in the Loess Plateau. Future research should explore sustainable crop rotations and alfalfa–soil–climate interactions for improved agricultural management.

Dominant drivers of vegetation changes in key ecological barrier of northeastern Tibetan Plateau since 2000: Human impacts or natural forces?

Human activities and natural forces have profoundly influenced vegetation ecosystems in the Tibetan Plateau over the recent decades. However, contributions of these two driving forces to vegetation changes remain controversial, especially in the ecological barriers like the Qilian Mountains (QM) in the northeast where many protecting measures and strategies were applied to enhance ecosystem stability and services. Our study employed a process-based model and a multi-perspective assessment method to determine dominant drivers of vegetation changes in the QM since 2000. The result indicated that human activity changes contributed 40.74% to the significant vegetation amelioration of the QM as a whole, which is comparable to natural forces. Areas dominated by human activity changes accounted for 18.42% of the entire region, which were mainly distributed in grassland restoration area, oasis agricultural area and forestry protection area. In these areas, increased human activities (including desertified grassland restoration, agricultural irrigation and fertilization, forest protections and afforestation) mainly promoted the vegetation amelioration. Yet, natural forces resulted in amelioration in partial alpine grasslands in southeastern QM, accounting for 10.53% in area. Areas dominated by both human activity changes and natural forces, mainly in grazing grasslands, accounted for 47.80%. Variations in grazing intensity and climate jointly determined fluctuations in vegetation therein. Additionally, there remained 23.25% areas lack of obvious drivers, generally with sparse vegetation. Ecological protections and agricultural measures significantly promoted the vegetation amelioration of the QM since 2000. The findings could provide essential insights for protection and construction of the ecological barriers in the Tibetan Plateau.

From nature to urbanity: exploring phyllosphere microbiome and functional gene responses to the Anthropocene.

The Anthropocene exerts various pressures and influences on the stability and function of the Earth's ecosystems. However, our understanding of how the microbiome responds in form and function to these disturbances is still limited, particularly when considering the phyllosphere, which represents one of the largest microbial reservoirs in the terrestrial ecosystem. In this study, we comprehensively characterized tree phyllosphere bacteria and associated nutrient-cycling genes in natural, rural, suburban, and urban habitats in China. Results revealed that phyllosphere bacterial community diversity, richness, stability, and composition heterogeneity were greatest at the most disturbed sites. Stochastic processes primarily governed the assembly of phyllosphere bacterial communities, although the role of deterministic processes (environmental selection) in shaping these communities gradually increased as we moved from rural to urban sites. Our findings also suggest that human disturbance is associated with the reduced influence of drift as increasingly layered environmental filters deterministically constrain phyllosphere bacterial communities. The intensification of human activity was mirrored in changes in functional gene expression within the phyllosphere microbiome, resulting in enhanced gene abundance, diversity, and compositional variation in highly human-driven disturbed environments. Furthermore, we found that while the relative proportion of core microbial taxa decreased in disturbed habitats, a core set of microbial taxa shaped the distributional characteristics of both microbiomes and functional genes at all levels of disturbance. In sum, this study offers valuable insights into how anthropogenic disturbance may influence phyllosphere microbial dynamics and improves our understanding of the intricate relationship between environmental stressors, microbial communities, and plant function within the Anthropocene.

Development of Highway Construction Route Selection Based on Ecological Sensitivity Evaluation and Intervention Optimization Strategy Research

Ecological sensitivity is an essential indicator for measuring the degree of ecological fragility of a region, and traditional highway routing ignores the ecological benefits of regional nature, which causes irreversible impacts on the natural environment. Based on the AHP method, this paper carries out a comprehensive assessment of the ecological sensitivity of the K0+000~K56+438 section of the Guanzhuang Tourist Highway in the Zhangjiajie Wuling Mountain Area from 2000 to 2020, and it utilizes the spatial autocorrelation analysis method to reveal the pattern of its spatial and temporal changes in ecological sensitivity. The following results were obtained. (1) The ecological condition of the study area is gradually improving, and the areas with higher sensitivity are mainly distributed in the northeast and southwest of the study area. (2) The ecological sensitivity of the study area has strong spatial autocorrelation, but the autocorrelation has been reduced in recent years, and the distribution of the ecological sensitivity has been gradually discretized. (3) There are problems of high ecological risk and construction difficulty in the traditional highway route selection scheme of the A line. The optimized route selection scheme, the K line, can effectively avoid highly sensitive areas by adjusting the route and bridge settings. Finally, the article proposes engineering construction suitability and ecological restoration strategies for different road sections regarding vegetation cover, landscape risk, and geological hazards. This study establishes a set of comprehensive technical chains for tourism highway routing in ecologically fragile areas based on the spatial and temporal evolution of sensitivity, which provides new ideas for traditional highway routing and is of great significance for maintaining the balance and stability of ecosystems within the road area.

Analysis of landscape vegetation ecology and cellular structure in nature reserves based on an improved analytic hierarchy process

With the increasing severity of global environmental issues, natural reserves have become crucial areas for maintaining biodiversity and protecting natural ecosystems. The ecological status of landscape vegetation and the characteristics of cellular structures within these reserves have become focal points of research. However, traditional evaluation methods have limitations when dealing with the complex ecosystems of natural reserves, making it difficult to assess the relationship comprehensively and accurately between vegetation ecology and cellular structures. Therefore, this paper proposes an analysis of landscape vegetation ecology and cellular structure in natural reserves based on an improved Analytic Hierarchy Process (AHP). By incorporating fuzzy set theory and expert scoring mechanisms, the evaluation process is enhanced in terms of objectivity and precision. An evaluation index system for landscape vegetation ecology and cellular structure in natural reserves is constructed, covering aspects such as vegetation species richness, community structural complexity, and ecological functional stability. This systematic approach reflects the ecological status of vegetation and cellular structure characteristics, providing scientific support for targeted protection and management measures.

Transcriptomic Analysis of Non-Specific Immune Responses in the Rice Field Eel (Monopterus albus) Infected with Pallisentis (Neosentis) celatus

Parasitic infestations present significant threats to the physiological health and ecological stability of aquatic species, frequently compromising immune defenses and elevating mortality rates. This study was conducted to elucidate the non-specific immune responses induced by Pallisentis (Neosentis) celatus infection in Monopterus albus, with a focus on intestinal histopathology and transcriptome gene expression. A histopathological examination revealed minor alterations in intestinal villi under low-level infection. A transcriptome analysis, performed using Illumina sequencing technology, identified 347 upregulated and 298 downregulated genes involved in critical biological pathways, such as lipid metabolism, immune responses, and the regulation of inflammatory processes. GO and KEGG analyses indicated the upregulation of immune-related pathways, including the RIG-I-like and IL-17 signaling pathways, highlighting a robust intestinal immune response. Conversely, the complement pathway was found to be downregulated, with significant suppression of C9, suggesting that the parasite may engage in immune evasion. Fluorescein-labeled C9 antibody assays confirmed reduced complement C9 levels in the infected tissues. A real-time PCR analysis identified the differential expression of eight genes, including C5, maats1, CFI, and gmnc, which were consistent with the sequencing results. These findings suggest that Pallisentis (Neosentis) celatus infection compromises intestinal health, induces inflammation, and activates non-specific immune responses in Monopterus albus. However, Pallisentis (Neosentis) celatus appears to evade the host immune response by suppressing the activation of complement components, thereby facilitating its reproductive parasitism.

Modeling the Impact of Global Warming on Ecosystem Dynamics: A Compartmental Approach to Sustainability

Environmental degradation driven by human activities has heightened the need for sustainable development strategies that balance economic growth with ecological preservation. This study uses a compartmental model approach to examine the effects of global warming on ecosystem dynamics, focusing on how rising temperatures alter interactions across trophic levels. Three case studies of varying complexity, including a human ecosystem incorporating social and economic factors, were analyzed by integrating feedback loops between greenhouse gas emissions, temperature anomalies, and ecosystem responses. The results quantitatively demonstrate that even minor disruptions in one part of an ecosystem can cause significant instability across trophic levels, potentially driving the system to collapse in a short period. These findings from all case studies highlight the cascading impacts of global warming, underscoring the intricate relationship between climate change and ecosystem stability. Furthermore, this study offers qualitative insights into the potential consequences of climate change on biodiversity and resource availability in real ecosystems, highlighting the vulnerability of such systems and the importance of incorporating feedback mechanisms into environmental policy and decision-making processes. The approach employed in this study offers a more robust framework for understanding ecosystem responses and for developing strategies to enhance resilience against climate change, thereby protecting the long-term sustainability of ecosystems.

Changes in Soil Physicochemical Properties and Fungal Communities Following a Forest Fire in the Pine Forest of Uljin, Republic of Korea

Soil samples from the rhizosphere of pine (Pinus densiflora) stands in the fire-disturbed Uljin forest were collected to analyze their physicochemical properties and fungal communities. In the burned area, soil pH decreased by 0.56, and organic matter content decreased by 0.32%p compared to the undisturbed area. Fungal community analysis revealed that all alpha diversity indices decreased in the burned area, but there were no differences according to fire severity. Soil pH, available phosphorus, and total nitrogen showed a positive correlation with the alpha diversity. Additionally, beta diversity analysis also indicated significant differences in the fungal communities between the burned area and the control sites (p value = 0.031). The changes in fungal communities were considered to be influenced by the decline in the order Atheliales, genus Russula, and genus Trechispora. A prediction analysis of the functional traits of fungi showed that the number of fungi involved in nutrient absorption and decomposition decreased in the burned area. It seems that the soil restoration of pine forests is progressing very slowly, as the soil fungi related to nutrient absorption by pine trees have not recovered even 18 months after the forest fire. Therefore, it is necessary to monitor continuous fungal communities in pine forest restoration after a forest fire to determine forest ecosystem restoration success and stabilization.

Functional diversity and resilience of bivalves after the Permian-Triassic mass extinction

The Permian-Triassic mass extinction was the largest extinction event in the Phanerozoic eon, with profound taxonomic and ecological effects on the ecosystem function. Functional diversity, a facet of biodiversity, could reflect the ecosystem function and stability. Although previous studies have shown that the functional richness of global marine organisms was decoupled from their taxonomic diversity during the mass extinctions, the evolution of functional diversity during the Permian-Triassic mass extinction and its aftermath is still under debate. The ecologically diverse clade bivalves may be more representative for understanding the evolution of functional diversity. To investigate the evolutionary dynamics of the functional diversity of bivalves, a global bivalve dataset of 8929 occurrences from the latest Permian to the Late Triassic was constructed. Functional richness, functional evenness, and functional redundancy were calculated to reflect the functional diversity in this study. Our results showed that the functional richness of bivalves was slightly affected by the Permian-Triassic mass extinction, decoupled from the significant decrease in taxonomic diversity. Meanwhile, a decrease in functional redundancy and an increase in functional evenness were observed after the mass extinction. In addition, bivalves showed high resilience to the mass extinction by maintaining the ecospace and reducing the functional redundancy. The high taxonomic diversity, high functional richness, high functional redundancy and relatively higher proportion of infaunal bivalves during the Late Triassic indicate that the Mesozoic marine revolution was already underway.

A Critical Evaluation of Network Approaches for Studying Species Interactions

Ecological networks of species interactions are popular and provide powerful analytical tools for understanding variation in community structure and ecosystem functioning. However, network analyses and commonly used metrics such as nestedness and connectance have also attracted criticism. One major concern is that observed patterns are misinterpreted as niche properties such as specialization, whereas they may instead merely reflect variation in sampling, abundance, and/or diversity. As a result, studies potentially draw flawed conclusions about ecological function, stability, or coextinction risks. We highlight potential biases in analyzing and interpreting species-interaction networks and review the solutions available to overcome them, among which we particularly recommend the use of null models that account for species abundances. We show why considering variation across species and networks is important for understanding species interactions and their consequences. Network analyses can advance knowledge on the principles of species interactions but only when judiciously applied.