Community structure and species richness in the Mediterranean-type soil fauna

1994 ◽  
pp. 37-45 ◽  
Author(s):  
A. Legakis
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Soil Fauna ◽  
The Mediterranean

Effect of Bt Corn (Bt 38) Cultivation on Community Structure of Collembola

2019 ◽  
Vol 113 (1) ◽  
pp. 1-5
Author(s):  
Liang Chang ◽  
Xinyuan Song ◽  
Baifeng Wang ◽  
Donghui Wu ◽  
Gadi V P Reddy
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Field Study ◽  
Morphological Traits ◽  
Soil Fauna ◽  
Bt Corn ◽  
Transgenic Corn ◽  
Community Characteristics ◽  
Bt Crops ◽  
Bacterium Bacillus

Abstract Transgenic corn has been modified to express a gene derived from the bacterium Bacillus thuringiensis (Bt) to combat lepidopteran pests. Bt proteins and the altered chemical composition of Bt crops may affect the role the soil fauna plays in the decomposition of Bt plants. A 2-y field study and a laboratory feeding experiment using corn leaves were conducted in northeastern China to investigate the effect of Bt corn—consisting of Bt corn (Bt 38) and a near-isoline of non-Bt corn (Z 58)—on the abundance, species richness, morphological traits, community structure, and fitness of soil Collembola. A total of 4,419 collembolans, comprised of 22 species, were recovered in this study. We found that Bt corn cultivation did not significantly affect abundance, species richness, or community structure of Collembola. Some rare isotomids of the genera Desoria Nicolet, 1841 (Collembola: Isotomidae) and Folsomia Willem, 1902 (Collembola: Isotomidae) were only recorded in non-Bt corn varieties and not in Bt corn varieties. Morphological traits, including the number of ocelli, body size, body pigmentation level, furca development, antennal length, and antenna:head ratio of Collembola were not changed by transgenic corn cultivation in the 2-y field study. Our results clearly found that the Bt corn did not affect community characteristics or traits of Collembola during this 2-y field study.

scholarly journals Effect of fire on a monodominant floating mat of Cyperus giganteus Vahl in a neotropical wetland

2015 ◽  
Vol 75 (1) ◽  
pp. 114-124 ◽  
Author(s):  
M. Rocha ◽  
CC. Santos Júnior ◽  
GA. Damasceno-Júnior ◽  
VJ. Pott ◽  
A. Pott
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Annual Variation ◽  
Floristic Composition ◽  
Large Area ◽  
Characteristic Species ◽  
Cyperus Giganteus ◽  
Pantanal Wetland ◽  
Floating Mat ◽  
Adult Plants

The rhizomatous Cyperus giganteus, abundant in the Pantanal wetland, can dominate extense floodable areas as monodominant communities. The Jacadigo lake has a large area of C. giganteus, where we performed an evaluation on community structure during two months in 2010, before it was hit by a wildfire which top-killed the vegetation, compared to ten months post-fire. We utilized 40 plots of 1m × 1m, along permanent trails, assessing two strata: the upper, near the inflorescence of adult plants, and the lower, close to the water level. Our results show that fire does not affect dominance of C. giganteus, as it maintained the same cover as before fire; species richness is not much altered either - 28 before fire and 34 thereafter. Fire changed the floristic composition, due to the annual variation of species and the ability of some plants to colonize gaps and to regrow after fire from underground organs and seeds. The stratification of the vegetation with characteristic species of upper and lower strata was similar after fire.

scholarly journals Do syntopic host species harbour similar symbiotic communities? The case ofChaetopterusspp. (Annelida: Chaetopteridae)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2930 ◽  
Author(s):  
Temir A. Britayev ◽  
Elena Mekhova ◽  
Yury Deart ◽  
Daniel Martin
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Host Species ◽  
Interspecific Interactions ◽  
Single Species ◽  
Intraspecific Interactions ◽  
Mean Intensity ◽  
Species Dominance ◽  
High Species Richness ◽  
Symbiotic Community

To assess whether closely related host species harbour similar symbiotic communities, we studied two polychaetes,Chaetopterussp. (n = 11) andChaetopteruscf.appendiculatus(n = 83) living in soft sediments of Nhatrang Bay (South China Sea, Vietnam). The former harboured the porcellanid crabsPolyonyxcf.heokandPolyonyxsp., the pinnotherid crabTetriassp. and the tergipedid nudibranchPhestillasp. The latter harboured the polynoid polychaeteOphthalmonoe pettiboneae, the carapid fishOnuxodon fowleriand the porcellanid crabEulenaios cometes, all of which, exceptO. fowleri, seemed to be specialized symbionts. The species richness and mean intensity of the symbionts were higher inChaetopterussp. than inC.cf.appendiculatus(1.8 and 1.02 species and 3.0 and 1.05 individuals per host respectively). We suggest that the lower density ofChaetopterussp. may explain the higher number of associated symbionts observed, as well as the 100% prevalence (69.5% inC.cf.appenciculatus). MostChaetopterussp. harboured two symbiotic species, which was extremely rare inC.cf.appendiculatus, suggesting lower interspecific interactions in the former. The crab and nudibranch symbionts ofChaetopterussp. often shared a host and lived in pairs, thus partitioning resources. This led to the species coexisting in the tubes ofChaetopterussp., establishing a tightly packed community, indicating high species richness and mean intensity, together with a low species dominance. In contrast, the aggressive, strictly territorial species associated withC.cf.appendiculatusestablished a symbiotic community strongly dominated by single species and, thus, low species richness and mean intensity. Therefore, we suggest that interspecific interactions are determining species richness, intensity and dominance, while intraspecific interactions are influencing only intensity and abundance. It is possible that species composition may have influenced the differences in community structure observed. We hypothesize that both host species could originally be allopatric. The evolutionary specialization of the symbiotic communities would occur in separated geographical areas, while the posterior disappearance of the existing geographical barriers would lead to the overlapped distribution.

scholarly journals COMMUNITY STRUCTURE ECHINODERMS (ASTEROIDEA, OPHIUROIDEA, ECHINOIDEA AND HOLOTHUROIDEA) IN THE MARINE NATIONAL PARK EAST SULAWESI WAKATOBI

2016 ◽  
Vol 8 (1) ◽  
pp. 357-366 ◽  
Author(s):  
Eddy Yusron
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
National Parks ◽  
National Park ◽  
Diversity Index ◽  
Dead Coral ◽  
Evenness Index ◽  
Different Types ◽  
High Level ◽  
Richness Index

A study on Echinoderms community structure in marine national parks of Wakatobi, Southeast Sulawesi was conducted in six locations, i.e., Waha Beach, Coastal Sombo, Beach Houses, Beach Kapota, Banakawa beach, and Umala beach in October 2013. All of the six parks were located the Wakatobi territorial waters with coordinates of 5°06'25" S and 123°124'10 E. The results showed of 18 species of echinoderms representing six different types of Asteroidea, two types of Ophiuroidea, six types of Echinoidea, and four types of Holothuroidea. Group of starfish or Asteroidea was the most prominent on seagrass area. Based on the six transects sites, it turned out that the group of starfish (Asteridea) occupied a relatively high level of species richness. From the quantitative analysis values, we obtained diversity index (H) of 1.105 in Sombu, the highest evenness index (J) of 0.989 was found in Umala, and the highest species richness index values (D) of 0.132 was obtained in kapota. It seemed that all echinoderm groups were generally like seagrass microhabitat (12 types). While, sand and dead coral habitats were only occupied by 8 (eight) echinoderm groups. Keywords: echinoderms, diversity, Wakatobi, Southeast Sulawesi

scholarly journals Fighting the Minotaur: Resistance to technological change in the Mediterranean sponge fishing industry, 1840-1922

2020 ◽  
Vol 32 (2) ◽  
pp. 337-353
Author(s):  
Maïa Fourt ◽  
Daniel Faget ◽  
Thierry Pérez
Keyword(s):  
Nineteenth Century ◽  
Community Structure ◽  
Technological Change ◽  
Aegean Sea ◽  
Fishing Industry ◽  
Financial Investments ◽  
Geographical Expansion ◽  
The Mediterranean ◽  
Hard Hat

In the first half of the nineteenth century, industrialization increased the demand for sponges extracted by the sponge fishermen of the Dodecanese Archipelago in the Aegean Sea. This had widespread repercussions, leading to increasing numbers of sponge fishermen, the geographical expansion of fishing zones and the evolution and diversification of fishing techniques. In this context, foreign sponge traders imposed the hard-hat diving suit, which enabled divers to remain underwater for several hours without surfacing. It was therefore perceived as being more efficient than traditional skin-diving. But this equipment greatly exacerbated the physical risks faced by the divers, with injuries and fatalities increasing markedly. It also required heavy financial investments that compounded the losses of fishermen and their families. With hindsight, these investments were catalysts of the major socio-economic upheaval that followed. As well as provoking mass revolt among the islanders of the Dodecanese, this entailed modifications in crews and community structure as a nascent model of capitalist organization marked the development of the sponge fishery.

scholarly journals Environmental conditions alter successional trajectories on an ephemeral resource: a field experiment with beetles in dead wood

Oecologia ◽  
2020 ◽  
Vol 194 (1-2) ◽  
pp. 205-219
Author(s):  
Ole Petter Laksforsmo Vindstad ◽  
Tone Birkemoe ◽  
Rolf Anker Ims ◽  
Anne Sverdrup-Thygeson
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Ambient Temperature ◽  
Dead Wood ◽  
Species Turnover ◽  
Experimental Studies ◽  
Developmental Rate ◽  
Fungal Community Composition ◽  
Species Richness And Abundance ◽  
Ephemeral Resources

Abstract Successional processes can be observed for many organisms and resources, but most studies of succession have focused on plants. A general framework has been proposed, advocating that successional patterns in species turnover are predominantly driven by competition, dispersal or abiotic limitation, and that the patterning of species accumulation over time gives clues to which process is most influential in a given system. We applied this framework to succession in communities of wood-living beetles, utilizing ephemeral resources in the form of 60 experimentally created dead aspen high stumps. High stumps were created at sun-exposed sites (high ambient temperature; favourable abiotic conditions) and shaded sites (low ambient temperature; abiotically limiting conditions). The sites were intermixed, ensuring similar dispersal opportunities. Beetle species richness and abundance were monitored with flight interception traps over four consecutive years. Consistent with predictions from the tested framework, several beetle functional groups accumulated species more slowly at the unfavourable shaded sites than at the favourable exposed sites. Species richness at the exposed sites increased rapidly to a plateau, consistent with a limiting effect of competition on community development. Similar results were obtained for beetle abundance and community structure. Part of the variance in beetle community structure was jointly explained by habitat and fungal community composition, suggesting that differences in the composition and developmental rate of fungal communities in the two habitats contributed to the observed patterns. Targeted experimental studies are now required to decisively establish what processes underlie the contrasting successional trajectories in the two environments.

scholarly journals Zooplankton of a stressed area in the Damietta coast of the Mediterranean Sea

2017 ◽  
Vol 58 (2) ◽  
pp. 245-260 ◽  
Author(s):  
Wael S. Eltohamy ◽  
Ahmad Alzeny ◽  
Yasmine A. M. Azab
Keyword(s):  
Community Structure ◽  
Mediterranean Sea ◽  
Ballast Water ◽  
Environmental Variables ◽  
Species Invasions ◽  
The Mediterranean ◽  
June July ◽  
Zooplankton Communities ◽  
The Impact ◽  
Univariate Analyses

The spatial pattern of zooplankton communities at Damietta coast, southeastern Mediterranean was studied to assess the impact of human activities on the abundance and community structure. Twenty-five stations from five different stressed sites were sampled in June-July 2014. Thirty-four zooplankton taxa were recorded, in addition to the larvae of copepods and meroplankton. Copepoda was the most abundant group among which, Oithona nana, Euterpina acutifrons, and Parvocalanus cirrostratus were the most frequent. The calanoid copepod Pseudodiaptomus trihamatus is a new record for the Mediterranean Sea that may have been introduced via ballast water. Multivariate/Univariate analyses demonstrated that 1) the environmental variables and zooplankton communities represented significant differences among five sites; 2) the spatial variations of community structure were undoubtedly due to land-based effluents; and 3) among all environmental variables, salinity and phytoplankton biomass had the major determining effects on the spatial patterns of zooplankton categories. The results indicates that not only the discharged water makes the Damietta coast at risk, but also the ballast water is not less dangerous. Hence, we emphasize the need for activation of the ballast water management to reduce the risk of future species invasions.

scholarly journals Responses of community structure and diversity to nitrogen deposition and rainfall addition in contrasting steppes are ecosystem-dependent and dwarfed by year-to-year community dynamics

2019 ◽  
Vol 124 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Xuejun Yang ◽  
Zhenying Huang ◽  
Ming Dong ◽  
Xuehua Ye ◽  
Guofang Liu ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Global Change ◽  
Nitrogen Deposition ◽  
Community Composition ◽  
Community Dynamics ◽  
Environmental Variability ◽  
The Other ◽  
Desert Steppe ◽  
Typical Steppe

Abstract Background and Aims Long-term studies to disentangle the multiple, simultaneous effects of global change on community dynamics are a high research priority to forecast future distribution of diversity. Seldom are such multiple effects of global change studied across different ecosystems. Methods Here we manipulated nitrogen deposition and rainfall at levels realistic for future environmental scenarios in three contrasting steppe types in Mongolia and followed community dynamics for 7 years. Key Results Redundancy analyses showed that community composition varied significantly among years. Rainfall and nitrogen manipulations did have some significant effects, but these effects were dependent on the type of response and varied between ecosystems. Community compositions of desert and meadow steppes, but not that of typical steppe, responded significantly to rainfall addition. Only community composition of meadow steppe responded significantly to nitrogen deposition. Species richness in desert steppe responded significantly to rainfall addition, but the other two steppes did not. Typical steppe showed significant negative response of species richness to nitrogen deposition, but the other two steppes did not. There were significant interactions between year and nitrogen deposition in desert steppe and between year and rainfall addition in typical steppe, suggesting that the effect of the treatments depends on the particular year considered. Conclusions Our multi-year experiment thus suggests that responses of community structure and diversity to global change drivers are ecosystem-dependent and that their responses to experimental treatments are dwarfed by the year-to-year community dynamics. Therefore, our results point to the importance of taking annual environmental variability into account for understanding and predicting the specific responses of different ecosystems to multiple global change drivers.

Spruce monoculture establishment affects functional traits of soil microarthropod communities

Biologia ◽  
2013 ◽  
Vol 68 (3) ◽  
Author(s):  
Jitka Farská ◽  
Kristýna Prejzková ◽  
Josef Rusek
Keyword(s):  
Community Structure ◽  
Functional Traits ◽  
Trophic Structure ◽  
Soil Fauna ◽  
Beech Forest ◽  
Functional Approach ◽  
Beech Stand ◽  
Response To Environmental Change ◽  
Soil Microarthropod ◽  
South Bohemia

AbstractStructure and density of soil microarthropod communities (Oribatida and Collembola) were studied in one natural beech forest and one spruce monoculture planted on a former beech stand in South Bohemia (Czech Republic). The spruce monoculture establishment increased microarthropod densities (93,000 ind. m−2 in the natural beech forest vs. 400,540 ind. m−2 in the spruce monoculture for Oribatida; 66,360 ind. m−2 in the natural beech forest vs. 136,360 ind. m−2 in the spruce monoculture for Collembola); additionally, it changed greatly the community structure in terms of species composition and functional traits. In the spruce monoculture, groups susceptible to disturbance were suppressed. The oribatid trophic structure changed as well with opportunistic herbifungivorous species increasing in the monoculture at the expense of fungivorous species. Similarly, hemiedaphic collembolans increased in the monoculture at the expense of euedaphic species. We conclude that the “functional approach” seems to be fruitful in revealing soil fauna response to environmental change.

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