Species Composition Of Communities Research Articles

Larger and older church forests promote bird species richness, diversity and resilience across northwest Ethiopia's deforested landscapes

Birds are vital bioindicators of biodiversity and ecosystem health, but their persistence and ecological roles are under severe threat from human activities in the Lake Tana Basin, Ethiopia. Rapid land and forest degradation driven by agricultural expansion, urbanization, and the rising demand for fuelwood imperil avian community structure and ecosystem functions in this region. However, amidst this ecological challenge, church forests have emerged as crucial sanctuaries. Despite their small size and isolation from each other by mainly agricultural land-use, these church forests provide indispensable ecosystem services and play a pivotal role in preserving biodiversity. Understanding the significance of church forests for avian biodiversity and the factors influencing bird species richness and community composition is paramount. To this end, a comprehensive survey was conducted in 24 church forests between November and December 2018. Data collection involved both point counts utilizing Audiomoth acoustic loggers and transect surveys. The study revealed a total of 131 bird species in the surveyed church forests, including endemic and threatened species. These birds exhibited diverse foraging habits and functional traits. Notably, church forest size and canopy cover were positively associated with species richness, highlighting the importance of preserving and potentially expanding these forested areas. Furthermore, the research identified key factors driving the similarity of bird communities in church forests, notably forest surface area, canopy cover, and altitude. Importantly, resilience metrics demonstrated significant positive relationships with species richness, emphasizing the conservation value of these unique ecosystems. Our study underscores the critical role of church forests in safeguarding avian biodiversity in the Lake Tana Basin, and our findings advocate for conservation efforts aimed at preserving and enhancing the region's church forests, as their continued degradation could jeopardize both ecological and socio-economic potential in this network of remnant forests.

Variation in CSR plant strategies along soil and climate gradients: A comparison between rocky outcrops and nearby rangelands

AbstractQuestionRocky outcrops in mountains represent unique ecosystems characterized by a series of stress‐inducing features on living organisms. Despite numerous studies focusing on plant diversity and species community composition in these ecosystems, less attention has been given to understanding plant strategies in response to their challenging environment. This is essential, especially considering the existence of numerous endemic species facing climate change and human disturbances.LocationThe study was conducted in six sites located in rocky outcrops and their nearby rangelands across a rainfall gradient (160–910 mm) and under different soil fertility levels in northern Iran.MethodsWe used competitor, stress tolerator and ruderal (CSR) strategies as functional groups to examine the responses of plant communities to environmental variation. The composition of plant species and functional traits were evaluated in ninety 1‐m2 plots. The influence of 10 soil and 5 bioclimatic factors on CSR plant strategies was examined along the rainfall gradient.ResultsOur results showed changes in CSR strategies from stress‐tolerant species (S) in rocky outcrops toward intermediate strategies (S/CSR) in rangelands. Soil organic carbon, electrical conductivity and sand were consistently correlated with shifts from S towards C and R strategies in rangelands. Silt and sodium (Na) affected the presence of S strategies in outcrops. The stressful conditions induced by a fine soil texture and Na in outcrops were particularly effective in establishing the dominance of the S strategy.ConclusionsWe identified patterns of shifts in CSR plant strategies that align with changes in environmental gradients. Although stress‐tolerant species (S) were the dominant strategy in most cases, this shifted towards intermediate strategies (SR and CSR) under more benign environmental conditions. In outcrops, these changes were primarily aligned with soil parameters, whereas in rangelands, both soil and climate variables were correlative. However, these correlations varied between soil and climate factors, as well as between outcrop and rangeland landscapes.

Effects of gradual increase of ciprofloxacin and cefotaxime on nitrogen and phosphorus removal and microbial community in moving bed biofilm reactor

To clarify the effects of trace amount of antibiotics in wastewater on biofilm reactor, this study explored the effects of gradual increase of ciprofloxacin (CIP) and cefotaxime (CTX) ranging from 100 to 1000 ng·L−1 on the nitrogen and phosphorus removal and microbial community in a moving bed biofilm reactor (MBBR). Under different phases of CIP and CTX gradual increase, the resilience of culturable functional bacteria including ammonifying bacteria, nitrite oxidizing bacteria, aerobic denitrifying bacteria and phosphorus accumulating organisms in the biofilm was analyzed. High-throughput sequencing analysis was used to reveal the microbial community structure and species composition of functional bacteria. The results indicated that the treatment performance of MBBR was temporarily affected by trace CIP and CTX and returned to its original level within 1–2 days. Ammonifying bacteria exhibited strong resilience in trace CIP and CTX stress environments. Trace CIP and CTX altered the microbial community structure in biofilm, but the performance of nitrogen and phosphorus removal in MBBR was slightly affected. This might attribute to the rapid proliferation of Thauera, Dechloromonas and Candidatus_Accumulibacter on the carrier biofilm. The research results help to deepen the understanding of the impact of trace antibiotics on the MBBR and to provide a reference for the development of microbial germplasm resources for biological nitrogen and phosphorus removal from wastewater under antibiotic stress conditions.

Species composition and structural organization of the littoral zooplankton communities in the Oleksandrivka Reservoir (Ukraine)

Today, the issue of researching reservoirs, which are an important source of human water supply and are significantly affected by anthropogenic factors, is gaining more and more relevance. Research on the Oleksandrivka Reservoir is highly important since the safety of operation of the South-Ukrainian NPP depends on the functioning of this reservoir. The research material was samples of littoral zooplankton, which is a bioindicator of changes in the aquatic environment. During the research, both classical methods and the original method of standardizing the number and localization of zooplankton sampling stations within different types of reservoir were used. As a result of original research, the species composition and structural organization of littoral zooplankton communities in different parts of the Oleksandrivka Reservoir were analyzed for the first time. A total of 126 species of zooplankton were registered, of which 96 were observed in this reservoir for the first time. The rotifer Euchlanis dapidula was discovered for the first time in the fauna of Ukraine. The peculiarities of the formation of the faunal spectrum, trophic groups, complex of dominant species, distribution of biotopes, distribution in different parts of the reservoir, density, biomass, as well as seasonal and daily dynamics of littoral zooplankton groups were also clarified. It was established that the biomass of phytoplankton has a statistically significant effect on the density and biomass of zooplankton.

Germination phenology alters species coexistence outcomes

Abstract Species‐specific phenological responses to changing climate are reshuffling the timing of species interactions, however we do not fully understand the consequences of these changes for species' population dynamics and community composition. In this study, we experimentally manipulated the timing of germination for five annual plant species from southern California and used pairwise competition experiments and coexistence theory to quantify how phenological shifts may impact species interactions and coexistence. We found that phenological shifts may help promote coexistence when they confer an advantage for competitively inferior species, but in other cases promote dominance by competitively superior species. Earlier germination generally increased species' performance relative to competitors, but the relative changes in intra‐and inter‐specific interactions caused more complex effects on niche and fitness differences. Phenological differences tended to reduce stabilising niche differences for many species pairs and reduced overall coexistence probabilities. Synthesis. While phenological differences among species have typically been considered a form of niche partitioning, it seems increasingly likely that phenological offsets could destabilise species coexistence. The net effects of changing phenology on species coexistence will depend on the complex combinations of effects on intra‐ and inter‐specific interactions, which remain challenging to predict.

Arbuscular mycorrhizal fungi associated with alpine meadow multifunctionality in a warmer climate with variable precipitation

In addition to supporting plant productivity and nutrient cycling, arbuscular mycorrhizal (AM) fungi contribute to multiple functions within terrestrial ecosystems. However, as ecosystems face increasing temperatures and changes in precipitation, these factors may affect how AM fungi interact with ecosystem multifunctionality. Here, we investigated how warming and precipitation changes affected plant and AM fungal communities, as well as ecosystem multifunctionality in a field experiment in an alpine meadow on the eastern Tibetan Plateau that had warming and precipitation change (40% increase or decrease) manipulated experimentally from 2017. Less AM fungal diversity and evenness resulted from warming combined with increased precipitation. Increased precipitation had a significant negative indirect effect on ecosystem multifunctionality through its direct effect on grass biomass and then on AM fungal community composition. Both warming and precipitation had a positive indirect effect on ecosystem multifunctionality through their direct negative effect on AM fungal diversity and positive effect on soil moisture. We conclude that alterations in the species diversity and community composition of AM fungi due to warming and precipitation change mediate ecosystem multifunctionality. Warmer, humid conditions contribute to higher ecosystem multifunctionality, driven by climate change-induced interactions between plants and AM fungi.

Uniqueness of tree stand composition and soil microbial communities are related across urban spruce-dominated forests

ContextUrban forest soils represent significant reservoirs of biodiversity in cities. Retaining this diversity under urban land-use change requires understanding on how species richness, community assembly and uniqueness of species assemblages are related to local forest characteristics and surrounding landscape structure.ObjectivesOur aim was to assess the significance and relative importance of logging history, tree species composition and urbanization in shaping soil microbial communities across urban spruce-dominated forest landscapes. We investigated responses of microbial diversity from three complementary viewpoints: local diversity, community assembly patterns and community uniqueness.MethodsWe collected soil bacterial and fungal metabarcoding data from 73 spruce-dominated forest sites distributed in three urban centers across southern Finland. We related these data to measurements of logging intensity, tree species composition and degree of urbanization.ResultsLogging intensity, tree species composition and urbanization affected site-scale microbial diversity, but the effects varied between microbial groups. Only logging intensity had a significant imprint on microbial assembly, and this effect was restricted to bacteria. Relative uniqueness of microbial assemblages at the landscape-scale was coupled with the uniqueness of tree species composition in all microbial groups, and further affected by tree diversity in saprotrophic fungi and urbanization in ectomycorrhizal fungi.ConclusionsIn the context of urban spruce-dominated forests, locally diverse tree stands are not necessarily the same as those that contribute the most to landscape-scale diversity. Identifying and preserving contrasting tree stand structures, which support distinctive soil microbial assemblages, may be the winning strategy in maintaining a wide range of soil microbial diversity.

Diatoms’ Diversity in the Assessment of the Impact of Diamond and Oil and Gas Mining on Aquatic Ecosystems of the Central Yakut Plain (Eastern Siberia, Yakutia) Using Bioindication and Statistical Mapping Methods

Diamond and oil and gas production carries risks to the aquatic ecosystem. In Eastern Siberia, on the territory of the Central Yakut Plain, mining development of the Yakut diamond-bearing province and Tas-Yuryakh oil and gas condensate field has been underway for several decades. But the problem of studying negative consequences in the region is covered only from the point of view of the impact on terrestrial ecosystems. The purpose of this study was to assess the impact of diamond and oil and gas production on the aquatic ecosystems of the region using the bioindicative properties of diatoms. The work used previously widely tested methods of ecological mapping, JASP, and species–environments relationship analysis. The results of chemical analysis of water showed that in oil and gas production areas, there is no pollution with petroleum products, but the concentration of silicon and zinc is increased. The study identified key pollutants in the Central Yakut Plain and demonstrated the effectiveness of diatoms as bioindicators. Elevated chloride levels were found in diamond mining areas, and increased copper levels were noted in oil production regions. In the diatom flora of the region, 144 species were identified, of which 137 are indicator species. Natural and anthropogenic clusters of environmental factors are identified, characterized by a specific effect on the species composition and taxonomic structure of diatom communities. The results obtained are suitable for assessing the level of anthropogenic impact on aquatic communities of photosynthetic microorganisms in permafrost conditions.

Optimising species detection probability and sampling effort in lake fish eDNA surveys

Environmental DNA (eDNA) metabarcoding is transforming biodiversity monitoring in aquatic environments. Such an approach has been developed and deployed for monitoring lake fish communities in Great Britain, where the method has repeatedly shown a comparable or better performance than conventional approaches. Previous analyses indicated that 20 water samples per lake are sufficient to reliably estimate fish species richness, but it is unclear how reduced eDNA sampling effort affects richness, or other biodiversity estimates and metrics. As the number of samples strongly influences the cost of monitoring programmes, it is essential that sampling effort is optimised for a specific monitoring objective. The aim of this project was to explore the effect of reduced eDNA sampling effort on biodiversity metrics (namely species richness and community composition) using algorithmic and statistical resampling techniques of a data set from 101 lakes, covering a wide spectrum of lake types and ecological quality. The results showed that reliable estimation of lake fish species richness could, in fact, usually be achieved with a much lower number of samples. For example, in almost 90% of lakes, 95% of complete fish richness could be detected with only 10 water samples, regardless of lake area. Similarly, other measures of alpha and beta-diversity were not greatly affected by a reduction in sample size from 20 to 10 samples. We also found that there is no significant difference in detected species richness between shoreline and offshore sampling transects, allowing for simplified field logistics. This could potentially allow the effective sampling of a larger number of lakes within a given monitoring budget. However, rare species were more often missed with fewer samples, with potential implications for monitoring of invasive or endangered species. These results should inform the design of eDNA sampling strategies, so that these can be optimised to achieve specific monitoring goals.

Long-Term Monitoring of Macroinvertebrate Community Assemblages and Species Composition on the Coast of Dokdo, East Sea of Korea

Dokdo Island’s diverse marine ecosystem requires long-term monitoring to understand the effects of rapid environmental changes, such as global warming, on macrobenthos species and communities. Current studies are often short-term and limited, highlighting the need for extended research to predict future changes to ecosystems. This study analyzed the environmental variables influencing macrobenthos through long-term monitoring. In total, 511 species (spp./23.4 m2) were identified with an abundance of 1709.9 individuals/m2 and a diversity of 2.9. Since 2020, there has been a decline in both the number of species and diversity, attributed to changes in sediment composition, particularly an increase in gravel and sand. The dominant species include the crustacean Abludomelita denticulata (17.6%), the polychaete Haplosyllis spongiphila (6.8%), the bivalve Glycymeris munda (5.6%), the polychaete Opisthodonta uraga (5.3%), and the bivalve Limatula japonica (3.8%). The macrobenthos community differs each year, as the dominant species G. munda has decreased in abundance since 2022 and L. japonica since 2021. Depth and gravel sediment strongly correlated with community variation. Site-specific analysis also showed significant differences, with depth, bottom temperature, and sediment composition as the influencing factors. These species thrive in cold water but their abundance declines with an increase in temperature. Continuous long-term monitoring is essential to understand and protect the Dokdo ecosystem amid rapid environmental changes. Long-term monitoring studies have revealed more species than have short-term studies, showing annual and site-specific environmental changes, including sediment erosion and bottom temperature increases. These changes have affected macrobenthos diversity, abundance, and community composition, necessitating ongoing research to determine the persistence of these trends and to protect the ecosystem.

Effects of humic acid application on bacterial diversity under maize cultivation

AbstractThe fundamental ecosystem processes in soil are regulated by microbial communities, and community diversity is implicated by soil environmental conditions. Humic acid (HA) improves soil quality and fertility, stimulating the microbial environment, but the detailed effects remain poorly understood. We investigated the effects of HA rates on soil bacterial diversity, particularly on species richness and community composition in the rhizosphere of corn (Zea mays). Inorganic fertilizer (T2), HA 0.5% (T3), HA 1.0% (T4), HA 1.5% (T5), and HA 2.0% (T6) were applied in soil. Initial soil (O1) and control after harvesting (T1) were included. A total of 3601 operational taxonomic units were captured from the overall sample, and analysis of 16S ribosomal ribonucleic acid amplicon sequencing data indicated that HA did not notably impact species richness. Intriguingly, HA induced changes in bacterial community composition, along with the relative prevalence of specific taxa. Certain associations between soil chemical properties and abundance distribution have been uncovered. Notably, exchangeable Mg2+, Ca2+, and available phosphorus were strongly related to the relative abundance of bacterial phyla. Furthermore, HA potentially shaped the specific bacterial taxa, as the application of HA at different rates had distinct effects on the member of bacterial abundance of each taxon. These findings enhance our understanding of communities potentially being increased or shifted by HA rate addition in short‐term corn cultivation.

Long-Term Contaminant Exposure Alters Functional Potential and Species Composition of Soil Bacterial Communities in Gulf Coast Prairies.

Environmental pollution is a persistent threat to coastal ecosystems worldwide, adversely affecting soil microbiota. Soil microbial communities perform critical functions in many coastal processes, yet they are increasingly subject to oil and heavy metal pollution. Here, we assessed how small-scale contamination by oil and heavy metal impacts the diversity and functional potential of native soil bacterial communities in the gulf coast prairie dunes of a barrier island in South Texas along the northern Gulf of Mexico. We analyzed the bacterial community structure and their predicted functional profiles according to contaminant history and examined linkages between species diversity and functional potential. Overall, contaminants altered bacterial community compositions without affecting richness, leading to strongly distinct bacterial communities that were accompanied by shifts in functional potential, i.e., changes in predicted metabolic pathways across oiled, metal, and uncontaminated environments. We also observed that exposure to different contaminants can either lead to strengthened or decoupled linkages between species diversity and functional potential. Taken together, these findings indicate that bacterial communities might recover their diversity levels after contaminant exposure, but with consequent shifts in community composition and function. Furthermore, the trajectory of bacterial communities can depend on the nature or type of disturbance.

Coccinellidae on native and introduced spruce in central Europe: conservation implications in urban areas

The abundance and species composition of adult ladybird communities (Coleoptera: Coccinellidae) were investigated on two congeneric trees, native Norway spruce (Picea abies) and the introduced blue spruce (Picea pungens), at four locations in Slovakia (central Europe). For two years (2021–2022), coccinellid adults were sampled using a standard method involving beating branches at monthly intervals from April to November. Although the species composition of the communities on both spruce species was similar, the abundance of the entire coccinellid community as well as the abundance of individual species was significantly greater on Norway spruce than on blue spruce. With the current decline of Norway spruce as a result of several negative factors, blue spruce has emerged as a suitable substitute host plant for coccinellid communities in urban areas.

Airborne DNA reveals predictable spatial and seasonal dynamics of fungi

Fungi are among the most diverse and ecologically important kingdoms in life. However, the distributional ranges of fungi remain largely unknown as do the ecological mechanisms that shape their distributions1,2. To provide an integrated view of the spatial and seasonal dynamics of fungi, we implemented a globally distributed standardized aerial sampling of fungal spores3. The vast majority of operational taxonomic units were detected within only one climatic zone, and the spatiotemporal patterns of species richness and community composition were mostly explained by annual mean air temperature. Tropical regions hosted the highest fungal diversity except for lichenized, ericoid mycorrhizal and ectomycorrhizal fungi, which reached their peak diversity in temperate regions. The sensitivity in climatic responses was associated with phylogenetic relatedness, suggesting that large-scale distributions of some fungal groups are partially constrained by their ancestral niche. There was a strong phylogenetic signal in seasonal sensitivity, suggesting that some groups of fungi have retained their ancestral trait of sporulating for only a short period. Overall, our results show that the hyperdiverse kingdom of fungi follows globally highly predictable spatial and temporal dynamics, with seasonality in both species richness and community composition increasing with latitude. Our study reports patterns resembling those described for other major groups of organisms, thus making a major contribution to the long-standing debate on whether organisms with a microbial lifestyle follow the global biodiversity paradigms known for macroorganisms4,5.

Evidence of thermophilization in Afromontane forests

Thermophilization is the directional change in species community composition towards greater relative abundances of species associated with warmer environments. This process is well-documented in temperate and Neotropical plant communities, but it is uncertain whether this phenomenon occurs elsewhere in the tropics. Here we extend the search for thermophilization to equatorial Africa, where lower tree diversity compared to other tropical forest regions and different biogeographic history could affect community responses to climate change. Using re-census data from 17 forest plots in three mountain regions of Africa, we find a consistent pattern of thermophilization in tree communities. Mean rates of thermophilization were +0.0086 °C·y−1 in the Kigezi Highlands (Uganda), +0.0032 °C·y−1 in the Virunga Mountains (Rwanda-Uganda-Democratic Republic of the Congo) and +0.0023 °C·y−1 in the Udzungwa Mountains (Tanzania). Distinct from other forests, both recruitment and mortality were important drivers of thermophilzation in the African plots. The forests studied currently act as a carbon sink, but the consequences of further thermophilization are unclear.

Urban forest species selection for improvement of ecological benefits in Polish cities - The actual and forecast potential

Trees in cities perform important environmental functions: they produce oxygen, filter pollutants, provide habitat for wildlife, mitigate stormwater runoff, and reduce the effects of climate change, especially in terms of lowering temperatures and converting carbon dioxide from the atmosphere into stored carbon. Generally, to increase the environmental benefits of urban forests, the number of trees is increased, directly influencing the canopy coverage. However, little is known about potential of modifying the species composition of urban tree communities in order to increase ecological benefits. Planting and managing trees to increase canopy is particularly challenging in city centres, where the dense, often historic infrastructure of buildings and roads do not allow for a significant increase in greenspace. Estimations of canopy cover obtained through i-Tree Canopy analysis unveiled significant potential to increase canopy cover in historical urban areas in Polish cities from 15-34% to 31–51%. This study models the ecological benefits of urban forests in Polish cities, focusing on how different species compositions can enhance environmental functions such as carbon sequestration and pollution filtration. Two main scenarios were analyzed: one involving the addition of trees based on the most common species currently planted (“standard option” SO), and another incorporating changes to the species composition to enhance ecological benefits (“city specific option” SCO). Acer platanoides (14.5%) and Tilia cordata (11.45%) were the most frequently species of Polish cities. Betula pendula, Quercus robur, Robinia pseudoacacia, Fraxinus excelsior, Acer pseudoplatanus, Aesculus hippocastanum and Acer campestre were also common species in urban forest communities (up to 5%). The diverse range of tree species in Polish cities contributes significantly to the overall carbon sequestration potential. The results suggest that modifying species composition could significantly increase carbon sequestration rates by 47.8%–114% annually, with the city specific option (SCO) being the most effective in enhancing carbon sequestration potential. This highlights the importance of strategic species selection in urban forestry practices to maximize environmental benefits and mitigate climate change effects.

Comment on “Solar parks can enhance bird diversity in agricultural landscape” by Jarčuška et al.

This commentary critiques the methodology, interpretation of results, and broader implications of a study by Jarčuška et al. (2024). We argue that the study's design and analysis fail to conclusively demonstrate any causal link between solar parks and bird diversity or community composition. Furthermore, focusing solely on species diversity and community composition, the study overlooks the importance of functional diversity and functional structure of communities in assessing the ecological impacts of solar parks on agricultural ecosystems. By exposing these shortcomings and recommending well-established methods for future research, we aim to ensure robust and informative studies that guide balanced decision-making for conservation and all stakeholders.

Phytoplankton community structure in the dry zone reservoirs of Sri Lanka at the declining phase of the tropical monsoon

We studied the phytoplankton community structure and their relationship to the physicochemical properties of water by selecting five major freshwater reservoirs; Bandagiriya, Kattakaduwa, Lunugamvehera, Ridiyagama, and Tissa in the Southern dry zone of Sri Lanka during the declining phase of tropical monsoon rainfall (December 2019 to January 2020). Fifty-seven species, dominated by Cyanophyta (63%), followed by Chlorophyta, Bacillariophyta, and Euglenophyta were identified morphologically and through DNA sequencing. The majority of Cyanophyta were filamentous forms (62%) with approximately 88% being cyanotoxin producing species. The species composition of phytoplankton communities is reservoir specific. Microcystis was dominant in Lunugamvehera while the diatom Melosira was dominant in Ridiyagama, Kattakaduwa and Tissa. The lowest phytoplankton density and diversity were observed in Bandagiriya mainly due to high turbidity and total suspended solids which interfere with light penetration through the water column. Physicochemical properties of water were significantly different among reservoirs, leading to reservoir specific correlations between phytoplankton density and physicochemical properties of water which might have been driven by the inter-correlative effects of biotic and abiotic factors at the time of sampling. Therefore, the interactive effects might be responsible for the observed variations in phytoplankton community composition. Thus, the present study provides important information on the phytoplankton community structure at the onset of successional episodes in five tropical freshwater reservoirs in relation to their spatial variations in hydrological regimes and physicochemical properties. Such data would provide essential information for planning and implementation of reliable and efficient strategies for monitoring, sampling, forecasting, and managing algal blooms.

Temporal dynamics of parasite populations and communities of blue sea catfish Ariopsis guatemalensis (Günther, 1864), in a eutrophic coastal lagoon from Mexican Pacific

ABSTRACT The temporal dynamics of parasite populations and communities of blue sea catfish Ariopsis guatemalensis from a tropical eutrophic coastal lagoon was studied during an annual cycle. A total of 620 adult fishes were collected between January and December 2019. Eleven taxa of parasites were identified, three of monoxenous (single-host life cycle), and eight of heteroxenous (multi-host life cycle) parasites. The infection levels of two monoxenous (Neotetraonchus vegrandis and Ergasilus sp.) and five heteroxenous (Austrodiplostomum sp. Pseudoacanthostomum panamense, Pseudoleptorhynchoides lamothei, Contracaecum sp. and Hysterothylacium perezi) parasite species varied between sampling months and/or climatic seasons. The infection dynamics of these group of parasites were influenced by environmental changes generated by the dry/rainy cycle, which can affect the availability of intermediate host populations, and the feeding and reproductive behaviour of the host. Although the species composition of the parasite communities remains quite stable over time, its structure registers important changes mainly during the rainy season. Some host traits such as the feeding and reproductive behaviour, body size, physical condition, and sex of the host, as well as the temporal replacement of numerically dominant parasite species, were the main factors responsible for variations in the parasite community structure.

Warming enhanced the interaction effects of fungi and fungivores and soil potassium mineralization in tropical forest

Potassium (K) cycling in forest systems has received less attention than nitrogen (N) and phosphorus (P) cycles, despite its critical role in maintaining primary production and regulating water economy and use under climate warming. This study conducted a 10-year study in which we translocated dominant tropical forest tree seedlings and underlying soil (i.e., in situ soil) from high-altitude sites (600 m a.s.l.) to lower altitude sites at 300 m a.s.l. (+1.0 °C) and 30 m a.s.l. (+2.1 °C) to simulate climate warming in southern China. We investigated soil microbial and nematode communities, soil and foliar K concentrations at the aggregate level, and tree growth under different altitude sites. Microbial community was characterized by high-throughput sequencing, nematodes were identified to the genus level using microscope. The findings revealed that warming treatments significantly (p < 0.01) increased soil fungal gene abundance (+78 % at 300 m and +62 % at 30 m), fungal/bacterial abundance ratio (+121 % at 300 m and +101 % at 30 m), and soil fungivore abundance (+274 % at 300 m and +233 % at 30 m). These results indicate a shift in the soil decomposition pathway from bacterial to fungal-based channels. In addition, warming amplifies the interactions between fungi and fungivores. Aggregates had few effects on microbial biomass, but had significant effect on nematode abundance. Soil microcosm experiments consistently demonstrated that addition of the dominant fungivore Aphelenchoides significantly (p < 0.05) enhanced soil-exchangeable K by stimulating fungal gene abundance and activity. Furthermore, warming-induced changes in forest communities were observed. At the species-specific tree level, Syzygium rehderianum demonstrated the ability to take advantage of this scenario, exhibiting increased K uptake (−4% at 300 m and +32 % at 30 m). This may be attributed to the species being ectomycorrhizal-forming, where colonizing root surfaces can mobilize interlayer and structural K from the minerals. In contrast, Machilus breviflora exhibited lower foliar K concentrations (−42 % at 300 m and −41 % at 30 m) and reduced growth. However, warming had little effect on Schima superba, Myrsine seguinii, Itea chinensis, and Ardisia lindleyana growth. Warming-induced changes in the plant–soil system K cycle highlight the emergence of a new ecosystem structure with different soil web structures and distinct plant community species composition. Our results prompt further research to understand the microbiome-mediated complexities of understudied nutrient cycles, which are likely to be further altered in the future owing to climate change.