Comparison of fungal endophyte communities in the invasive panicoid grass Hyparrhenia hirta and the native grass Bothriochloa macra

2007 ◽  
Vol 55 (2) ◽  
pp. 178 ◽  
Author(s):  
Ian R. White ◽  
David Backhouse
Keyword(s):  
Community Structure ◽  
Native Species ◽  
Fungal Endophytes ◽  
Diversity Indices ◽  
Fungal Endophyte ◽  
Plant Interactions ◽  
Similar Frequency ◽  
Degree Of Dominance ◽  
Significant Difference ◽  
Stems And Leaves

Communities of fungal endophytes from roots, stems and leaves of the introduced grass Hyparrhenia hirta (Coolatai grass) and the native species Bothriochloa macra (redgrass) were compared at two sites to identify characteristics that may be associated with invasiveness of H. hirta. The most frequently isolated fungi from both hosts were species of Nigrospora, Alternaria, Cladosporium, Phoma, Epicoccum, Fusarium and Periconia. Most of these occurred at a similar frequency in the two hosts, although Nigrospora sphaerica was much more frequently isolated from H. hirta at both sites. There was little support for the hypothesis that the introduced species (H. hirta) would have a less diverse endophyte community than the native species. There was a greater degree of dominance by the most frequent species in communities from H. hirta than from B. macra, leading to lower diversity indices, but no significant difference in species richness. Cluster analysis of the endophyte communities suggested that host had a greater influence than site on community structure, and that this was expressed mostly in the relative frequency of fungi isolated from stems and leaves, with very similar fungal communities present in the roots of both species at both sites. Analysis of co-occurrence showed no evidence that competition among fungi affected community structure within individual plants. The dominance of N. sphaerica in H. hirta was therefore due to fungus–plant interactions rather than fungus–fungus interactions. Interactions with N. sphaerica could potentially affect the population ecology of H. hirta.

The Study on Protozoan Community Structure of Zhalong Wetland

2014 ◽  
Vol 535 ◽  
pp. 470-473
Author(s):  
Yao Zhou ◽  
Zhi Gang Xie
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Native Species ◽  
Water Environment ◽  
Species Number ◽  
Zhalong Wetland ◽  
Quality Of Water ◽  
Protozoan Community ◽  
Significant Difference ◽  
Mining Water

The zhalong wetland water environment is an important part of the ecological environment, The protozoan community structure of Zhalong wetland was researched in this article. We can monitoring water pollution degree through the analysis of protozoan population, this research investigated protozoa population structure in qiqihar zhalong wetland through the PFU method and direct mining water in water samples, and analyse the physiological and biochemical parameters to assess the quality of water quality changes during May-October in 2012, the result show that 74 protozoa were observed including ciliate fleshiness shrimp center, flagellate less. In comparison with clean water inside, can use light and feed on algae native species number is more, different water quality in different conditions, protozoa composition has a very significant difference.

scholarly journals Sponge-Associated Amphipod Communities as Bioindicators for Pollution

2021 ◽  
Author(s):  
◽  
Ronja Hauke
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Sex Ratios ◽  
Diversity Indices ◽  
Life Cycle Stage ◽  
Sponge Species ◽  
Pollution Level ◽  
Sponge Tissue ◽  
Pollution Levels ◽  
Significant Difference

<p>Pollution negatively impacts organisms across all marine ecosystems. Coastal areas are particularly vulnerable to pollution due to their proximity to human settlements. Amphipods are commonly used as bioindicators to monitor pollution burdens, due to their high sensitivities and their ubiquity. Pollution can reduce amphipod abundance, species richness, evenness and diversity. Community structure, proportionality of adults to juveniles and sex ratios may also be affected. Sponges often harbour high densities of amphipods, offering food, refuge and nurseries to their symbionts. Sponge-associated amphipods differ in their level of specialization on their host. This study provides first insights into the usefulness of sponge-associated amphipod communities as bioindicators. For this, it hypothesized that amphipod densities, species diversity, community structure, sex ratio and age proportionality will differ according to pollution levels.  To test this, sponges were collected from three sites with varying degrees of pollution in Wellington Harbour. The sponges were weighed, and their volume was measured. They were dissected and their amphipods were identified to species level, counted, measured (length) and their sex and life cycle stage (adult or juvenile) were recorded. From this data, amphipod densities, species richness, evenness and Shannon-Wiener diversity indices were calculated and compared among pollution levels. Community structure was also compared between sites and sponge species. Pollution level significantly affected species richness, evenness, diversity and community structure. The highest values for species richness, evenness and diversity were found in sponges from the least polluted. The lowest levels of these factors were found in sponges from the most polluted site. Sponges from the intermediate site generally harboured moderate richness, evenness and diversity compared to the other sites. Community composition was significantly affected by pollution, although effect sizes differed between sponge species. Higher pollution levels seemed to favour dominance of species that are better adapted to living in sponges. Generalists seemed to thrive in low to intermediate pollution levels. The majority of sex ratios measured had a female bias, which appeared to increase with increasing pollution although the difference was not statistically significant. The proportion of adults also showed a non-significant increase with pollution level. There was no significant difference in amphipod abundance per litre of sponge tissue between pollution levels, possibly because pollution levels may have been too low to cause a reduction in amphipod density. These results show that sponge-associated amphipod communities are useful as bioindicators, as amphipod diversity, richness and evenness were significantly reduced by pollution and the sponge association allows for these community-scale comparisons to be made within an easily measurable framework. Species evenness in particular provided an accurate indication of different pollution levels.</p>

scholarly journals Sponge-Associated Amphipod Communities as Bioindicators for Pollution

2021 ◽  
Author(s):  
◽  
Ronja Hauke
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Sex Ratios ◽  
Diversity Indices ◽  
Life Cycle Stage ◽  
Sponge Species ◽  
Pollution Level ◽  
Sponge Tissue ◽  
Pollution Levels ◽  
Significant Difference

<p>Pollution negatively impacts organisms across all marine ecosystems. Coastal areas are particularly vulnerable to pollution due to their proximity to human settlements. Amphipods are commonly used as bioindicators to monitor pollution burdens, due to their high sensitivities and their ubiquity. Pollution can reduce amphipod abundance, species richness, evenness and diversity. Community structure, proportionality of adults to juveniles and sex ratios may also be affected. Sponges often harbour high densities of amphipods, offering food, refuge and nurseries to their symbionts. Sponge-associated amphipods differ in their level of specialization on their host. This study provides first insights into the usefulness of sponge-associated amphipod communities as bioindicators. For this, it hypothesized that amphipod densities, species diversity, community structure, sex ratio and age proportionality will differ according to pollution levels.  To test this, sponges were collected from three sites with varying degrees of pollution in Wellington Harbour. The sponges were weighed, and their volume was measured. They were dissected and their amphipods were identified to species level, counted, measured (length) and their sex and life cycle stage (adult or juvenile) were recorded. From this data, amphipod densities, species richness, evenness and Shannon-Wiener diversity indices were calculated and compared among pollution levels. Community structure was also compared between sites and sponge species. Pollution level significantly affected species richness, evenness, diversity and community structure. The highest values for species richness, evenness and diversity were found in sponges from the least polluted. The lowest levels of these factors were found in sponges from the most polluted site. Sponges from the intermediate site generally harboured moderate richness, evenness and diversity compared to the other sites. Community composition was significantly affected by pollution, although effect sizes differed between sponge species. Higher pollution levels seemed to favour dominance of species that are better adapted to living in sponges. Generalists seemed to thrive in low to intermediate pollution levels. The majority of sex ratios measured had a female bias, which appeared to increase with increasing pollution although the difference was not statistically significant. The proportion of adults also showed a non-significant increase with pollution level. There was no significant difference in amphipod abundance per litre of sponge tissue between pollution levels, possibly because pollution levels may have been too low to cause a reduction in amphipod density. These results show that sponge-associated amphipod communities are useful as bioindicators, as amphipod diversity, richness and evenness were significantly reduced by pollution and the sponge association allows for these community-scale comparisons to be made within an easily measurable framework. Species evenness in particular provided an accurate indication of different pollution levels.</p>

scholarly journals Microbial Community Structure Drives Predatory Myxobacteria Distribution Under Different Compost Manures

2021 ◽  
Author(s):  
Wei Dai ◽  
Ning Wang ◽  
Wenhui Wang ◽  
Xianfeng Ye ◽  
Zhongli Cui ◽  
...  
Keyword(s):  
Community Structure ◽  
High Throughput Sequencing ◽  
Soil Microbial Communities ◽  
Alpha Diversity ◽  
Distribution Patterns ◽  
Diversity Indices ◽  
Community Diversity ◽  
Microbial World ◽  
Significant Difference ◽  
Compost Manure

Abstract Myxobacteria are unique predatory microorganisms with a distinct social lifestyle. The associated taxa play key roles in the microbial food webs in different ecosystems and regulate the community structures of soil microbial communities. Compared with conditions under conventional management, under organic conditions, myxobacteria abundance increases in the soil, which could be related to the presence of abundant myxobacteria in the applied compost manure. In the present study, high-throughput sequencing technologies were used to investigate the distribution patterns and drivers of predatory myxobacteria community distribution patterns in four common compost manures. According to the results, there was a significant difference in predatory myxobacteria community structure among different compost manure treatments (P < 0.05). The alpha-diversity indices of myxobacteria community under swine manure compost were the lowest (Observed OTU richness = 13.25, Chao1 = 14.83, Shannon = 0.61), and those under wormcast were the highest (Observed OTU richness = 30.25, Chao1 = 31.65, Shannon = 2.62). Bacterial community diversity and Mg2+ and Ca2+ concentrations were the major factors influencing myxobacteria distribution patterns under different compost manure treatments. In addition, pH, total nitrogen, and organic carbon influenced myxobacteria distribution in compost manure. The predator–prey relationship between prey bacteria and myxobacteria and the interaction between myxobacteria and specific bacterial taxa (Micrococcales) in compost manure could explain the influence of bacteria on myxobacteria community structure. Further investigations on the in-situ distribution patterns of predatory myxobacteria and the key bacteria influencing their distribution are would advance our understanding of the ecological distribution patterns and functions of predatory microorganisms in the microbial world.

Microbial community structure and trichloroethylene degradation in groundwater

2005 ◽  
Vol 51 (6) ◽  
pp. 433-439 ◽  
Author(s):  
J A Humphries ◽  
A M.H Ashe ◽  
J A Smiley ◽  
C G Johnston
Keyword(s):  
Community Structure ◽  
Clone Library ◽  
Sequence Data ◽  
Restriction Analysis ◽  
Diversity Indices ◽  
Department Of Energy ◽  
Tetrazolium Chloride ◽  
Degrading Bacteria ◽  
Trichloroethylene Degradation ◽  
Rdna Clone

Trichloroethylene (TCE) is a prevalent contaminant of groundwater that can be cometabolically degraded by indigenous microbes. Groundwater contaminated with TCE from a US Department of Energy site in Ohio was used to characterize the site-specific impact of phenol on the indigenous bacterial community for use as a possible remedial strategy. Incubations of14C-TCE-spiked groundwater amended with phenol showed increased TCE mineralization compared with unamended groundwater. Community structure was determined using DNA directly extracted from groundwater samples. This DNA was then analyzed by amplified ribosomal DNA restriction analysis. Unique restriction fragment length polymorphisms defined operational taxonomic units that were sequenced to determine phylogeny. DNA sequence data indicated that known TCE-degrading bacteria including relatives of Variovorax and Burkholderia were present in site water. Diversity of the amplified microbial rDNA clone library was lower in phenol-amended communities than in unamended groundwater (i.e., having Shannon–Weaver diversity indices of 2.0 and 2.2, respectively). Microbial activity was higher in phenol-amended ground water as determined by measuring the reduction of 2-(p-iodophenyl)-3(p-nitrophenyl)-5-phenyl tetrazolium chloride. Thus phenol amendments to groundwater correlated with increased TCE mineralization, a decrease in diversity of the amplified microbial rDNA clone library, and increased microbial activity.Key words: community structure, trichloroethylene, degradation, groundwater.

scholarly journals Phytoremediation Potential of Native Herbaceous Plant Species Growing on a Paradigmatic Brownfield Site

2021 ◽  
Vol 232 (7) ◽  
Author(s):  
N. Matanzas ◽  
E. Afif ◽  
T. E. Díaz ◽  
J. R. Gallego
Keyword(s):  
Plant Species ◽  
Contaminated Soils ◽  
Native Species ◽  
Low Cost ◽  
Plantago Lanceolata ◽  
Herbaceous Plant ◽  
Plant Interactions ◽  
Aerial Parts ◽  
Medicago Lupulina ◽  
Icp Ms

AbstractPhytomanagement techniques using native species allow the recovery of contaminated soils at low cost and circumvent the ecological risks associated with the use of non-native species. In this context, a paradigmatic brownfield megasite highly contaminated by As and Pb was sampled in order to analyze soil–plant interactions and identify plant species with phytoremediation potential. A survey was first carried out in a 20-ha area to obtain an inventory of species growing spontaneously throughout the site. We then performed another survey in the most polluted sub-area (1 ha) within the site. Pseudototal concentrations of contaminants in the soil, aerial parts of the plants, and roots were measured by ICP-MS. A detailed habitat classification was done, and a specific index of coverage was applied by means of a 1-year quadrat study in various sampling stations. Results converged in the selection of six herbaceous species (Dysphania botrys, Lotus corniculatus, Lotus hispidus, Plantago lanceolata, Trifolium repens, Medicago lupulina). All of these plants are fast-growing, thereby making them suitable for use in phytostabilization strategies. Furthermore, they are all easy to grow and propagate and are generally self-sustaining. All six plants showed accumulation factors below 1, thus revealing them as pseudomethallophytes and excluders. However, L. hispidus and M. lupulina showed translocation capacity and are considered worthy of further study.

scholarly journals Effects of Ecological Restoration Using Non-Native Mangrove Kandelia obovata to Replace Invasive Spartina alterniflora on Intertidal Macrobenthos Community in Maoyan Island (Zhejiang, China)

2021 ◽  
Vol 9 (8) ◽  
pp. 788
Author(s):  
Qiuxuan Wang ◽  
Carlos Duarte ◽  
Li Song ◽  
George Christakos ◽  
Susana Agusti ◽  
...  
Keyword(s):  
Community Structure ◽  
Ecological Restoration ◽  
Spartina Alterniflora ◽  
Diversity Index ◽  
Invasion History ◽  
Kandelia Obovata ◽  
Wiener Diversity Index ◽  
Significant Difference ◽  
Spatial Differences ◽  
Average Biomass

Spartina alterniflora has extensively invaded the coastline of China, including in Maoyan Island of Zhejiang Province. Ecological restoration has been conducted using non-native mangrove Kandelia obovata to replace S. alterniflora in an attempt to restore the impacted intertidal zones. To illustrate the ecological effectiveness of the restoration projects, macrobenthos communities were studied among different habitats within the restored areas, including one non-restored S. alterniflora marsh (SA) and three differently-aged restored K. obovata stands planted in 2003, 2009, and 2011 respectively (KF14, KF8, and KF6). Besides, one unvegetated mudflat (MF) adjacent to the non-restored S. alterniflora marsh and one K. obovata forest transplanted in 2006 (RKF) at a previously barren mudflat without invasion history of S. alterniflora were set as reference sites. A total of 69 species of macrobenthos were collected from Maoyan Island, and the species richness was dominated by gastropoda (23 species), polychaeta (18 species), and malacostraca (16 species). There was no significant difference between the six sites in terms of the abundance of macrobenthos, with the average values of abundance peaking in KF6 (734.7 ind m−2) and being lowest in RKF (341.3 ind m−2). The six sites had significant differences in terms of the biomass of macrobenthos. The KF8 site contained the highest average biomass (168.3 g m−2), whereas the MF site had the lowest (54.3 g m−2). The Shannon-Wiener diversity index and Pielou’s evenness index of the macrobenthos did not exhibit significant differences among the six sites. However, the results of permutational multivariate analysis of variance (PERMANOVA) revealed significant spatial differences in the macrobenthos community structure between the sites. Since KF14 shared a similar macrobenthos community structure with RKF, while representing a strikingly different structure from SA, we infer that ecological restoration using K. obovata can restore the macrobenthos community to resemble to a normally planted K. obovata forest about 15 years after restoration.

scholarly journals The use of diversity indices for local assessment of marine sediment quality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinya Hosokawa ◽  
Kyosuke Momota ◽  
Anthony A. Chariton ◽  
Ryoji Naito ◽  
Yoshiyuki Nakamura
Keyword(s):  
Community Structure ◽  
Sample Size ◽  
Small Sample Size ◽  
Benthic Communities ◽  
Sediment Quality ◽  
Diversity Indices ◽  
Small Sample ◽  
Species Density ◽  
Local Case ◽  
Two Indices

AbstractDiversity indices are commonly used to measure changes in marine benthic communities. However, the reliability (and therefore suitability) of these indices for detecting environmental change is often unclear because of small sample size and the inappropriate choice of communities for analysis. This study explored uncertainties in taxonomic density and two indices of community structure in our target region, Japan, and in two local areas within this region, and explored potential solutions. Our analysis of the Japanese regional dataset showed a decrease in family density and a dominance of a few species as sediment conditions become degraded. Local case studies showed that species density is affected by sediment degradation at sites where multiple communities coexist. However, two indices of community structure could become insensitive because of masking by community variability, and small sample size sometimes caused misleading or inaccurate estimates of these indices. We conclude that species density is a sensitive indicator of change in marine benthic communities, and emphasise that indices of community structure should only be used when the community structure of the target community is distinguishable from other coexisting communities and there is sufficient sample size.

scholarly journals Tree Diversity Reduces Fungal Endophyte Richness and Diversity in a Large-Scale Temperate Forest Experiment

Diversity ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 234 ◽  
Author(s):  
Eric A. Griffin ◽  
Joshua G. Harrison ◽  
Melissa K. McCormick ◽  
Karin T. Burghardt ◽  
John D. Parker
Keyword(s):  
Phylogenetic Diversity ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Spatial Scales ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Tree Diversity ◽  
Trophic Levels ◽  
Community Diversity ◽  
And Function

Although decades of research have typically demonstrated a positive correlation between biodiversity of primary producers and associated trophic levels, the ecological drivers of this association are poorly understood. Recent evidence suggests that the plant microbiome, or the fungi and bacteria found on and inside plant hosts, may be cryptic yet important drivers of important processes, including primary production and trophic interactions. Here, using high-throughput sequencing, we characterized foliar fungal community diversity, composition, and function from 15 broadleaved tree species (N = 545) in a recently established, large-scale temperate tree diversity experiment using over 17,000 seedlings. Specifically, we tested whether increases in tree richness and phylogenetic diversity would increase fungal endophyte diversity (the “Diversity Begets Diversity” hypothesis), as well as alter community composition (the “Tree Diversity–Endophyte Community” hypothesis) and function (the “Tree Diversity–Endophyte Function” hypothesis) at different spatial scales. We demonstrated that increasing tree richness and phylogenetic diversity decreased fungal species and functional guild richness and diversity, including pathogens, saprotrophs, and parasites, within the first three years of a forest diversity experiment. These patterns were consistent at the neighborhood and tree plot scale. Our results suggest that fungal endophytes, unlike other trophic levels (e.g., herbivores as well as epiphytic bacteria), respond negatively to increasing plant diversity.

A light and electron microscope study of the fungal endophytes in the sporophyte and gametophyte of Lycopodium cernuum with observations on the gametophyte–sporophyte junction

1992 ◽  
Vol 70 (1) ◽  
pp. 58-72 ◽  
Author(s):  
Jeffrey G. Duckett ◽  
Roberto Ligrone
Keyword(s):  
Root Nodules ◽  
Fungal Endophytes ◽  
Fungal Endophyte ◽  
Peninsular Malaysia ◽  
Epidermal Cells ◽  
Host Cells ◽  
Wall Material ◽  
Intercellular Spaces ◽  
Host Cytoplasm ◽  
Fungal Associations

The ventral epidermal cells of the photosynthetic, surface-living gametophytes of Lycopodium cernuum, collected from moist shaded banks in Peninsular Malaysia, contain an aseptate fungus. In some cells the hyphae are thick walled and form coils encapsulated by a thin layer of host wall material. In others the fungus is thin walled and shows limited differentiation into larger trunk hyphae and arbuscules. The adjacent host cytoplasm, separated from the fungus by a granular interfacial matrix, contains numerous chloroplasts, mitochondria, and microtubules. The hyphae contact the substratum via the ventral walls of the epidermal cells and the rhizoids are free from infection. In the protocorm and root nodules, aseptate hyphae initially colonize mucilage-filled schizogenous intercellular spaces. Subsequent invasion of the host cells is associated with the development of massive overgrowths of host wall material. The fungal associations in L. cernuum share a mixture of attributes otherwise found in different angiosperm mycorrhizae and in mycotrophic relationships in liverworts. Wall ingrowths are present in both the gametophyte and sporophyte cells in the placenta of L. cernuum. The very limited development of the placenta, compared with L. appressum, certain bryophytes and ferns, the diminutive size, and early senescence of the gametophytes of L. cernuum are all linked to the presence of the protocorm. This massive absorptive organ, homologous to a foot, in terms of its position in sporophyte ontogeny, but external to the parent gametophyte, derives its nutrition partly from photosynthesis and partly from its fungal endophyte. Key words: chloroplasts, Lycopodium, mycorrhiza, pteridophytes, root nodules, symbiosis, transfer cells.

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