Species Diversity Of Communities Research Articles

Rodents mediate the relationship between seed rain, seed bank, and plant community with increased grazing disturbance.

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems.

Epiphytic and endophytic bacteria on Camellia oleifera phyllosphere: exploring region and cultivar effect

The epiphytic and endophytic bacteria play an important role in the healthy growth of plants. Both plant species and growth environmental influence the bacterial population diversity, yet it is inconclusive whether it is the former or the latter that has a greater impact. To explore the communities of the epiphytic and endophytic microbes in Camellia oleifera, this study assessed three representative C. oleifera cultivars from three areas in Hunan, China by Illumina high-throughput sequencing. The results showed that the diversity and species richness of endophytic microbial community in leaves were significantly higher than those of microbial community in the epiphytic. The diversity and species richness of epiphytic and endophytic microbes are complex when the same cultivar was grown in different areas. The C. oleifera cultivars grown in Youxian had the highest diversity of epiphytic microbial community, but the lowest abundance, while the cultivars grown in Changsha had the highest diversity and species richness of endophytic microbes in leaves. It was concluded that the dominant phylum mainly included Proteobacteria, Actinobacteriota and Firmicutes through the analysis of the epiphytic and endophytic microbial communities of C. oleifera. The species and relative abundances of epiphytic and endophytic microbial community were extremely different at the genus level. The analysis of NMDS map and PERMANOVA shows that the species richness and diversity of microbial communities in epiphytes are greatly influenced by region. However, the community structure of endophytic microorganisms in leaves is influenced by region and cultivated varieties, but the influence of cultivars is more significant. Molecular ecological network analysis showed that the symbiotic interaction of epiphytic microbial community was more complex.

Riparian woody plant communities in the Romanian Carpathians: Species diversity and community structure of Salix and Hippophaë communities.

Riparian woody plant communities, including shrubs and trees, are essential for maintaining biodiversity, protecting against floods, reducing erosion, and transporting nutrients. However, these habitats are greatly threatened by human activities, particularly agricultural land acquisition, and the introduction of invasive species. This study examined species diversity and interspecific association in riparian woody plant communities along rivers in the Romanian Carpathians. The study focused on communities of Salix purpurea, S. alba, and Hippophaë rhamnoides in mountain regions, with varying sampling efforts at different sites for each species. A total of 174 plant species were found, predominantly herbaceous (77.9%), followed by trees (11.6%) and shrubs (10.5%). While S. alba and S. purpurea communities show high species richness and abundance, S. alba has slightly higher diversity (H' ≈ 2.23, SD = 0.28) than S. purpurea (H' ≈ 1.69, SD = 0.42). Contrarily, significant differences exist between H. rhamnoides and S. alba communities in species richness (p = .007) and Shannon diversity (p = .004). PCA analysis elaborated on distinct distribution patterns of plant associations within habitats S. purpurea community, H. rhamnoides community, and S. alba community. Four invasive species (Oenothera biennis L. and Oxalis stricta L. in S. alba communities, Reynoutria sachalinensis Nakai in both S. purpurea and H. rhamnoides communities, and Erigeron canadensis L. in H. rhamnoides communities) were identified, as requiring conservation efforts. Hemicryptophytes dominate species richness, while microphanerophytes and megaphanerophytes significantly contribute to plant abundance. H. rhamnoides formed Hippophaë rhamnoides dunes (2160) Natura 2000 habitat, while S. alba created galleries within the 92A0 Salix alba and Populus alba habitat. In conclusion, the findings from this study highlight the importance of preserving riparian habitats because their value goes beyond local or regional considerations and extends to the global scale due to their unique characteristics.

Impacts of Soil Properties on Species Diversity and Structure in Alternanthera philoxeroides-Invaded and Native Plant Communities.

Soil properties can affect plant population dynamics and the coexistence of native and invasive plants, thus potentially affecting community structure and invasion trends. However, the different impacts of soil physicochemical properties on species diversity and structure in native and invaded plant communities remain unclear. In this study, we established a total of 30 Alternanthera philoxeroides-invaded plots and 30 control plots in an area at the geographical boundary between North and South China. We compared the differences in species composition between the invaded and native plant communities, and we then used the methods of regression analysis, redundancy analysis (RDA), and canonical correspondence analysis (CCA) to examine the impacts of soil physicochemical properties on four α-diversity indices and the species distribution of these two types of communities. We found that A. philoxeroides invasion increased the difference between the importance values of dominant plant species, and the invasion coverage had a negative relationship with the soil-available potassium (R2 = 0.135; p = 0.046) and Patrick richness index (R2 = 0.322; p < 0.001). In the native communities, the species diversity was determined with soil chemical properties, the Patrick richness index, the Simpson dominance index, and the Shannon-Wiener diversity index, which all decreased with the increase in soil pH value, available potassium, organic matter, and ammonium nitrogen. However, in the invaded communities, the species diversity was determined by soil physical properties; the Pielou evenness index increased with increasing non-capillary porosity but decreased with increasing capillary porosity. The determinants of species distribution in the native communities were soil porosity and nitrate nitrogen, while the determinants in the invaded communities were soil bulk density and available potassium. In addition, compared with the native communities, the clustering degree of species distribution in the invaded communities intensified. Our study indicates that species diversity and distribution have significant heterogeneous responses to soil physicochemical properties between A. philoxeroides-invaded and native plant communities. Thus, we need to intensify the monitoring of soil properties in invaded habitats and conduct biotic replacement strategies based on the heterogeneous responses of native and invaded communities to effectively prevent the biotic homogenization that is caused by plant invasions under environmental changes.

Yeast communities of a North American hybrid wine grape differ between organic and conventional vineyards.

To compare the species diversity and composition of indigenous yeast communities of hybrid grapes from conventionally and organically cultivated vineyards of an emerging cool-climate wine producing region. Illumina MiSeq sequences from L'Acadie blanc grape musts were processed and filtered to characterize indigenous yeast communities in organic and conventional vineyards of the Annapolis Valley wine region in Nova Scotia, Canada. While cultivation practice was not associated with yeast diversity or species richness, there was a strong effect on yeast community composition, with conventional vineyards characterized by higher proportions of Sporidiobolales and Filobasidium magnum, and organic vineyards supporting Filobasidium species other than F. magnum and higher proportions of Symmetrospora. There was also variation in yeast community composition among individual vineyards, and from year to year. This is the first comprehensive assessment of yeasts associated with hybrid grapes grown using different cultivation practices in a North American cool climate wine region. Communities were dominated by basidiomycete yeasts and species composition of these yeasts differed significantly between vineyards employing organic and conventional cultivation practices. The role of basidiomycete yeasts in winemaking is not well understood, but some species may influence wine characteristics.

Prevalence, genetic diversity and eco-epidemiology of pathogenic Leptospira species in small mammal communities in urban parks Lyon city, France.

Rodents are recognized as the main reservoirs of Leptospira spp. Rats, in particular, serve as hosts for the widely predominant Leptospira interrogans serovar Icterohaemorrhagiae, found worldwide. Several studies have shown the importance of other reservoirs, such as mice or hedgehogs, which harbor other leptospires' serovars. Nevertheless, our knowledge of circulating Leptospira spp. in reservoirs other than rats remains limited. In this context, we proposed an eco-health approach to assess the health hazard associated with leptospires in urban green spaces, where contacts between human/small mammals and domestic animals are likely. We studied the prevalence, the diversity of circulating strains, and epidemiology of pathogenic Leptospira species in small terrestrial mammal communities (rodents and shrews), between 2020-2022, in two parks in Lyon metropolis, France. Our study showed a significant carriage of Leptospira spp. in small terrestrial mammals in these parks and unveiled a global prevalence rate of 11.4%. Significant variations of prevalence were observed among the small mammal species (from 0 to 26.1%), with Rattus norvegicus exhibiting the highest infection levels (26.1%). We also observed strong spatio-temporal variations in Leptospira spp. circulation in its reservoirs. Prevalence seems to be higher in the peri-urban park and in autumn in 2021 and 2022. This is potentially due to differences in landscape, abiotic conditions and small mammal communities' composition. Our study suggests an important public health relevance of rats and in a lesser extent of other rodents (Apodemus spp., Clethrionomys glareolus and Mus musculus) as reservoirs of L. interrogans, with rodent species carrying specific serogroups/serovars. We also emphasize the potential hazard associated between the shrew Crocidura russula and L. kirschneri. Altogether, these results improve our knowledge about the prevalence of leptospirosis in an urban environment, which is an essential prerequisite for the implementation of prevention of associated risks.

Scale-dependent effects of herbivory on moss communities in Arctic wetlands: A 25-year experiment.

Arctic ecosystems are undergoing rapid changes, including increasing disturbance by herbivore populations, which can affect plant species coexistence and community assemblages. Although the significance of mosses in Arctic wetlands is well recognized, the long-term influence of medium-sized herbivores on the composition of moss communities has received limited attention. We used data from a long-term (25 years) Greater Snow Goose (Anser caerulescens atlanticus) exclusion experiment in Arctic tundra wetlands to assess changes in the composition of moss communities at multiple spatial scales (cell, 4 cm2; quadrat, 100 cm2; exclosure, 16 m2). We investigated how snow goose grazing and grubbing can alter the composition of the moss community by measuring changes in alpha and beta diversity, as well as in the strength of plant interspecific interactions between moss species. Our results indicate that goose foraging significantly increased species diversity (richness, evenness, and inverse Simpson index) of moss communities at the cell and quadrat scales but not the exclosure scale. Goose foraging reduced the dissimilarity (beta diversity) of moss communities at all three scales, mainly due to decreased species turnover. Furthermore, goose foraging increased positive interaction between moss species pairs. These findings emphasize the critical role of geese in promoting moss species coexistence and increasing homogeneity in Arctic wetlands. This study illustrates how top-down regulation by herbivores can alter plant communities in Arctic wetlands and highlights the importance of considering herbivores when examining the response of Arctic plant biodiversity to future climate change.

Avifaunal Diversity in Managed Urban Ecosystem: A Case Study of Banaras Hindu University, Varanasi

University campuses are becoming important places for conducting a large number of studies on plant and animal taxa including avian diversity. However, a systematic study on the avian diversity in the Banaras Hindu University (BHU) campus (Asia’s largest residential university campus) of Varanasi is still lacking. The present study deals with the species abundance, diversity and species richness of avian communities in the BHU campus. We conducted a bird survey in the BHU campus between 2019 and 2020. Employing line-transect method, a total of 141 bird species under 62 families were recorded from the study area. A rich diversity of species recorded indicates the importance of the university campuses in urbanized region to serve as a critical habitat for birds. To conserve this rich bird diversity of the campus, we suggest sustainable management of habitats through restoration of degraded habitats, reduction in habitat destruction, conservation awareness programmes and increased research on assessment of diversity.

Differential Analysis of Island Mountain Plant Community Characteristics: Ecological Sensitivity Perspectives

Island plants form the foundation for maintaining the ecology of an island. With the development of the island’s infrastructure, its ecosystems become damaged to a certain extent. A comprehensive understanding of island habitats and plant community characteristics is crucial for the development of island plant communities. This paper focuses on Pingtan Island in Fujian Province, China, as the research subject. Firstly, considering the significance of the wind environment on the island, this study constructed a wind environment model for the entire island of Pingtan to evaluate the ecological sensitivity from a macro perspective. Subsequently, 33 typical sample plots were selected based on different ecologically sensitive areas to conduct a micro-survey and the characterization of the montane plant communities on Pingtan Island. The findings reveal that (1) Pingtan Island’s ecological sensitivity is dominated by areas with ecological insensitivity (35.72%), moderate ecological sensitivity (33.99%), and high ecological sensitivity (18.02%). The soil texture, wind environment, and land use type are the primary influencing factors in the ecological sensitivity of Pingtan Island. (2) A total of 47 families, 82 genera, and 93 species of plants were investigated in a typical sample site in the mountainous area of Pingtan Island. The plant community structure was dominated by the successional stage of shrubs and herbs. There is some similarity in the plant composition of different ecologically sensitive areas. High ecologically sensitive areas have more species. As sensitivity increases, the dominant species in the three ecologically sensitive areas continue to undergo plant succession from Acacia confusa to Pinus thunbergii to Eurya emarginata. (3) Both community characteristics and species diversity vary between sensitive areas. The canopy density (CD) and the mean height of tree layer (MHTL) are higher in moderate ecologically sensitive areas. The mean tree diameter at breast height (MDBH) and the mean height of shrub layer (MHSL) are higher in high ecologically sensitive areas, while the mean height of herb layer (MHHL) is higher in extreme ecologically sensitive areas. Four diversity indicators increase with increasing sensitivity. In the moderate and high ecologically sensitive areas, Casuarina equisetifolia and A. confusa thrive, with Pinus thunbergii showing the opposite trend. However, species diversity is better characterized by A. confusa and P. thunbergii, with C. equisetifolia being the least diverse. Both the community characteristics and species diversity of P. thunbergii are optimal in extreme ecologically sensitive areas. In this study, the ecological sensitivity of Pingtan Island and the characteristics of montane plant communities were systematically analyzed to explore more stable montane plant communities on the island, aiming to provide a scientific basis and model reference for the ecological restoration and sustainable development of Pingtan Island and other islands.

Bacterial communities of planktonic bacteria and mature biofilm in service lines and premise plumbing of a Megacity: Composition, Diversity, and influencing factors

Although simulated studies have provided valuable knowledge regarding the communities of planktonic bacteria and biofilms, the lack of systematic field studies have hampered the understanding of microbiology in real-world service lines and premise plumbing. In this study, the bacterial communities of water and biofilm were explored, with a special focus on the lifetime development of biofilm communities and their key influencing factors. The 16S rRNA gene sequencing results showed that both the planktonic bacteria and biofilm were dominated by Proteobacteria. Among the 15,084 observed amplicon sequence variants (ASVs), the 33 core ASVs covered 72.8 %, while the 12 shared core ASVs accounted for 62.2 % of the total sequences. Remarkably, it was found that the species richness and diversity of biofilm communities correlated with pipe age. The relative abundance of ASV2 (f_Sphingomonadaceae) was lower for pipe ages 40–50 years (7.9 %) than for pipe ages 10–20 years (59.3 %), while the relative abundance of ASV10 (f_Hyphomonadaceae) was higher for pipe ages 40–50 years (19.5 %) than its presence at pipe ages 20–30 years (1.9 %). The community of the premise plumbing biofilm had significantly higher species richness and diversity than that of the service line, while the steel-plastics composite pipe interior lined with polyethylene (S-PE) harbored significantly more diverse biofilm than the galvanized steel pipes (S-Zn). Interestingly, S-PE was enriched with ASV27 (g_Mycobacterium), while S-Zn pipes were enriched with ASV13 (g_Pseudomonas). Moreover, the network analysis showed that five rare ASVs, not core ASVs, were keystone members in biofilm communities, indicating the importance of rare members in the function and stability of biofilm communities. This manuscript provides novel insights into real-world service lines and premise plumbing microbiology, regarding lifetime dynamics (pipe age 10–50 years), and the influences of pipe types (premise plumbing vs. service line) and pipe materials (S-Zn vs. S-PE).

Productivity and Species Diversity of Plant Communities Are Higher inside than outside the West Ordos National Nature Reserve, Northern China.

Nature reserves play an important role in the protection of biological habitats and the maintenance of biodiversity, but the performance and mechanisms of desert steppe nature reserves in improving plant community productivity, biodiversity and soil nutrient content are still largely unknown. To investigate the conservation effects of desert steppe nature reserve management on plant productivity and biodiversity, we compared the plant biomass, diversity and soil nutrient content inside and outside the West Ordos National Nature Reserve through sample survey, biomass determination, diversity index calculation and soil nutrient content determination. We found the following: (1) The aboveground biomass and belowground biomass of plant communities in the nature reserve were significantly larger than those outside the reserve; and the aboveground biomass of plant communities in shrub-steppe was significantly larger than that of herb grassland in both the nature reserve and the outside of the reserve. (2) The Margalef richness index, Shannon-Wiener index and Simpson index were significantly greater in the reserve than outside the nature reserve. In the desert steppe, the establishment of the nature reserve increased the α-diversity of the plant community. (3) The soil organic carbon (SOC) and soil total nitrogen (STN) were greater in the nature reserve than outside the reserve, and for the 10-20 cm and 20-40 cm soil layers, the SOC and STN were significantly greater in the core protected zone of the reserve than outside the reserve. The reserve significantly increased the nutrient content of the deeper soil layers. (4) The aboveground biomass of the plant community had a significant positive linear relationship with the species richness index, the Shannon index, and the Simpson index. There was a positive correlation between the diversity of the plant community and the soil nutrients. In summary, the nature reserve improved local plant productivity, biodiversity and the soil nutrient content, and the soil nutrient content in deeper soil layers may be the driving factor for the increase in productivity and biodiversity, which deepens our understanding of the conservation effectiveness of the nature reserve and its mechanisms.

Diversity of fungal community and quality evaluation of Spatholobus Suberectus Dunn during the process of mildew

Spatholobus suberectus Dunn as a traditional Chinese herbal medicine, which is susceptible to being infected by molds during storage. In order to explore the diversity characteristics of fungal community and the quality evaluation of Spatholobus suberectus Dunn during the process of mildew. The study used high-throughput sequencing technology to detect the diversity characteristics of fungal community, high-performance liquid chromatography (HPLC) and ultraviolet spectrophotometry (UV-spectrophotometry) methods to detect the content of flavonoids, and enzyme-linked immunosorbent assay (ELISA) method to detect the content of Aflatoxins B1 (AFB1). The result showed that the fungi of all samples belonged to 14 phyla, 336 genera, and the dominant fungi at the early stage of mildew was not obvious, while that at middle and late stages of mildew was Aspergillus. The species diversity of fungal community was the highest at the early stage of mildew, while the species richness of fungal community was the highest at the late stage of mildew. The content of AFB1 showed an upward trend, while the content of flavonoids showed a downward trend during the process of mildew. In brief, the diversity of fungal community decreased gradually, and the number of dominant fungi increased gradually, and the quality of Spatholobus suberectus Dunn decreased gradually during the process of mildew.

Modern plant fodder resources of the steppes and meadows of the ancient Chir landscape of the “Tsimlyansky” nature reserve

In 2022, studies of the species diversity of plant communities, their aboveground mass and the resource-feeding potential of various types of steppes and meadows in the “Tsimlyansky” nature reserve were conducted. The method of vegetation cover mowing (n = 29) in seven types of steppes and meadows determined the aboveground mass of 101 species of herbaceous plants within the ancient Chir landscape of the Don-Tsimlyansk sand massif. The species richness of plant communities varies between (5.7±1.7) – (14.0±1.2) species/0.25 m2 and averages 10.1±1.0 species/0.25 m2. The average share of cereal species in the communities is 23%, and grasses are almost 3 times more – 64%. The total aboveground biomass in 7 types of steppes and meadows varies between (197.4±25.6) – (379.1±92.5) g/m2. The accumulated mort (necro) mass is (152.2±12.5) – (411.9±43.9) g/m2.

Microbial Community Response to Alpine Meadow Degradation and Its Impact on Soil Nutrient Cycling

The degradation of alpine meadows on the Qinghai–Tibet Plateau is a major issue affecting both the ecology and the economy. Microorganisms play an important role in soil nutrient cycling and the regulation of ecosystem function. This study aimed to investigate the species composition and diversity of microbial communities and understand the response of microbial communities to changes in physicochemical properties resulting from meadow degradation. In this study, the soil bacterial and fungal communities’ composition and diversity of alpine meadows of degradation gradient were sequenced by high-throughput sequencing. During the process of grassland degradation, there were 59 bacterial taxa and 29 fungal taxa showing significant differences. The relative abundance of meadow pathogenic fungi significantly increased (p &lt; 0.05). PICRUSt2 analysis showed a decrease in synthesis-related functional gene abundance and an increase in metabolism-related functional gene abundance. FUNGuild analysis showed that symbiotic and saprophytic nutrient fungi decreased significantly (p &lt; 0.05). The soil nutrient cycling was mainly influenced by the beta diversity of microbial communities. Grassland degradation affects soil structure, thereby affecting the diversity of soil microbial composition and functional soil nutrient content. This work reveals the response of microbial communities to the degradation of alpine meadows and their impact on nutrient cycling, providing theoretical support for the protection and sustainable development of alpine meadows.

Response of Soil Fungal Community to Biochar Application Under Different Irrigation Water Salinity

Saline water irrigation can alleviate the shortage of freshwater resources in the northwest arid zone, but long-term saline water irrigation can damage the soil fungal community structure. To alleviate the harm caused by salinity, biochar is used as a soil amendment to improve the soil fungal community structure. To investigate the intrinsic link between biochar application and the structural diversity of fungal communities in saline soils, two irrigation water salinity levels were set:0.35 dS·m-1 (fresh water) and 8.04 dS·m-1 (saline water). At each irrigation water salinity, two levels of biochar application were set:0 t·hm-2 (no application) and 3.7 t·hm-2 (application). High-throughput sequencing results showed that compared to that under fresh water irrigation, saline water irrigation increased fungal community species diversity and decreased fungal community species richness; biochar application under saline water irrigation reduced soil fungal community species diversity and species richness. The dominant fungal phyla in the soils of each treatment were Ascomycota, Mortierellomycota, Basidiomycota, Chytridiomycota, Glomeromycota, Rozellomycota, and Cysticercales, and the dominant genera were Gibberella, Chaetomium, Sarocladium, Stachybotrys, and Fusarium. Compared to that under freshwater irrigation, saline water irrigation significantly increased the relative abundance of Basidiomycota and Chytridiomycota and significantly decreased the relative abundance of Ascomycota and Rozellomycota. The application of biochar under saline irrigation significantly increased the relative abundance of Ascomycota and Sarocladium but significantly decreased the relative abundance of Basidiomycota, Chaetomium, and Fusarium. LEfSe analysis showed that under the condition of no biochar application, saline irrigation reduced the number of potential biomarkers of fungal communities, whereas the application of biochar under the condition of saline irrigation increased the number of potential biomarkers of fungal communities. These results indicated that the application of biochar can improve the saline soil environment and fungal community structure and provide a theoretical basis for reasonable brackish water irrigation and soil fertilization in arid areas.

Overgrazing on unmanaged grassland interfered with the restoration of adjacent grazing-banned grassland by affecting soil properties and microbial community.

A "grazing ban" policy has been implemented in some pastoral areas in China to fence degraded grasslands for restoration. However, fencing increased grazing pressures in unmanaged grasslands. Based on the mechanism of negative edge effect, we investigated whether overgrazing on unmanaged grassland interfered with the restoration of adjacent grazing-banned grassland by affecting soil properties and microbial community using a sample in Hulun Buir of Inner Mongolia, in order to optimize the "grazing ban" policy. Plant and soil were sampled in areas 30 m away from the fence in unmanaged grassland (UM) and in areas 30 m (adjacent to UM) and 30-60 m (not adjacent to UM) away from the fence in the grazing-banned grassland (F-30 m and F-60 m). The species richness and diversity of plant communities and the ASV number of fungal communities significantly decreased in F-30 m and UM, and the Simpson index of the bacterial community significantly decreased in F-30 m compared with F-60 m. The abundance of fungi involved in soil organic matter decomposition significantly decreased and the abundance of stress-resistant bacteria significantly increased, while the abundance of bacteria involved in litter decomposition significantly decreased in UM and F-30 m compared with F-60 m. The simplification of plant communities decreased in soil water and total organic carbon contents can explain the variations of soil microbial communities in both UM and F-30 m compared with F-60 m. The results of PLS-PM show that changes in plant community and soil microbial function guilds in UM may affect those in F-30 m by changing soil water and total organic carbon contents. These results indicate that overgrazing on unmanaged grassland interfered with the restoration of adjacent grazing-banned grassland by affecting soil properties and microbial community. The grazing-banned grasslands should be adjusted periodically in order to avoid negative edge effects.

Species diversity and distribution-pattern determinants of African rivulines (Cyprinodontiformes: Nothobranchiidae) in rainforest streams of southern Cameroon

Understanding the community structure and ecology of fish populations in rainforest streams is a prerequisite for any actions towards their exploitation, management or conservation. We examined the community structure and species diversity of nothobranchiids (African rivulines) in rainforest streams of Cameroon’s southern plateau and part of the coastal plain, using data on 19 environmental variables for ecological indices and multivariate analyses. In total, 1 019 individual cyprinodontiforms assigned to 14 species (largely species of Aphyosemion) were collected, for a global sampling effort of 78.6%. The presence of nothobranchiids in the study area was associated with several local environmental factors common to all sampling sites, mainly canopy cover above the watercourse and physicochemical characteristics of the stream habitat. Distribution of the species was strongly spatially structured, driven by the site’s elevation and the water temperature, and influenced primarily by the riparian vegetation, substrate type, water conductivity and flow velocity. However, fish species richness did not differ significantly between the five sectors sampled and by elevation. The nothobranchiid communities were highly diverse (Shannon’s H′ = 2.28 ± 0.05; Pielou’s J = 0.87) and the species evenly distributed. Seven species were exclusive to a single sector, others were prevalent in multiple sectors, and no species was common to all sectors. Affinities between species were relatively few, though there were exceptions, and most species tended to exclude each other. These findings highlight nothobranchiids as local fish assemblages having high biotic integrity and responsiveness to environmental degradation. In tropical Africa, these fishes often occupy fragile habitats influenced by anthropogenic activities. A better understanding of the unifying role of habitat in ecology will assist management efforts to promote biodiversity conservation.

Sampling origins and directions affect the minimum sampling area in forest plots

AbstractQuestionsThe minimum sampling area (minimum area) is the smallest space that reflects species composition and characteristics of a plant community. The quantitative concept of minimum area is often estimated using species–area relationships (SARs) and has become the classical foundation for managing protected areas. However, sampling designs to determine the minimum area in different forest types have not been systematically evaluated.LocationChina.MethodsWe used tree census data from three forest dynamic plots, each with a size of 25–60 ha, in different climatic zones in China to determine the minimum areas of woody plants and to analyze the effects of species richness and topographic heterogeneity on the minimum areas by changing sampling origin and direction.ResultsWe found that mainly sampling design affects the estimation of woody plant species richness and required minimum area in different forest types. The estimated size of the minimum areas required was several hectares and varied significantly with sampling origin and direction, and showed a difference of approximately 1.5–2 times in the forest plots. Topographic heterogeneity significantly affected the minimum area through changes in species composition.ConclusionsSampling origin and direction should be considered when using SARs to estimate the minimum area and species diversity in communities. Such a comprehensive approach of sampling can contribute to a better understanding of vegetation characteristics and the minimum area required for a conservation census in heterogeneous environments.

Ecological state of the natural park “Ivano-Arakhleisky”

The article presents the results of studies of the biodiversity of pyrogenically disturbed areas in the forest communities of the Ivano- Arakhleisky natural park, the identification of rare and specially protected plant species listed in the Red Book of the Trans-Baikal Territory and the Russian Federation. The lakes of the Ivano-Arakhlei system are located in the southeastern part of the Vitim plateau of the Osinovy and Yablonovy ridges. The territory of the park is characterized by the ecological value of natural areas, and is also a popular recreation area for citizens. Aquatic and terrestrial ecosystems are subject to anthropogenic impacts. Currently, digressive processes are dominant in the development of vegetation cover, leading to a simplification of the structure and a decrease in the species diversity of communities. Synanthropic plant species were recorded in the studied flora. The volume of ecosystem services provided directly depends on the biodiversity of the natural park. The general ecological condition of the study area is deteriorating due to an increase in anthropogenic pressure - forest fires, illegal logging, uncontrolled “wild” tourism, procurement of medicinal raw materials, and collection of beautiful flowering plants in bouquets.

Diurnal versus nocturnal pollination in a subalpine wetland: From network structure to plant reproduction

Diurnal and nocturnal pollinators are fundamental for the functioning of natural ecosystems and food security. However, differences between diurnal and nocturnal pollination networks and the contribution of these pollinators to plant fecundity have not been assessed comprehensively within a community context. In the Dajiuhu subalpine wetland of central China, we supplemented data from an intensive field survey with the analysis of pollen loads carried by diurnal and nocturnal pollinators to compare the structures of diurnal and nocturnal pollination networks using network parameters. Simultaneously, we compared the contribution of diurnal and nocturnal pollinators to plant reproduction of the nine dominant species based on stigma pollen placement. We found that although diurnal and nocturnal pollination networks exhibited a similar structural organisation, the diurnal network displayed greater stability and broader interaction with pollinators and plants compared to the nocturnal network. However, nocturnal pollinator species tended to establish less generalised interactions with the available floral resources. Both diurnal and nocturnal pollinators played a significant role in plant reproduction, and nocturnal pollination can result in greater pollen germination. In terms of stability, the lower redundancy of links within nocturnal networks suggests they may be more vulnerable to the temporary or permanent disappearance of plant resources in the study area. Our findings highlight the differences in the contributions of diurnal and nocturnal pollinators to plant reproduction at the community level, demonstrating that nocturnal pollinators are not redundant in maintaining species diversity in communities. This knowledge should play a pivotal role in preventing future pollination declines and improving pollinator conservation efforts.