Dispersal traits as benthic invertebrate assemblage drivers in a neotropical large river

2020 ◽  
Vol 193 (3) ◽  
pp. 275-283
Author(s):  
Miguel Saigo ◽  
Mercedes Marchese ◽  
Luciana Montalto
Keyword(s):  
Spatial Structure ◽  
Environmental Conditions ◽  
Distribution Patterns ◽  
Benthic Invertebrate ◽  
Large River ◽  
Species Dispersal ◽  
Dispersal Traits ◽  
Metacommunity Dynamics ◽  
Invertebrate Assemblage

Metacommunity theory is a mechanistic framework that explains the interdependence of local factors and regional processes as community drivers. Recent evidence suggests that dispersal mode is a key trait that potentially affects metacommunity dynamics. We analyzed the distribution patterns of benthic macroinvertebrates with different dispersal modes in the Middle Paraná, a neotropical large river. We assessed the relative importance of local environmental conditions and regional spatial structure as assemblage drivers. Aquatic and aerial dispersers presented Clementsian and Gleasonian structures, respectively. For both groups, local environmental conditions influenced community assembly, and spatial structure (overland distances) also affected the distribution of aerial dispersers. Our study highlights that the role of spatial structure as a driver of benthic metacommunities depends on species' dispersal modes. Aerial dispersers responded to regional spatial variables and it is likely that these organisms are also influenced by mass effects. Our results are consistent with current ideas of metacommunity dynamics in large rivers, where dispersal is not considered to limit the distribution of benthic organisms.

Implications of seasonal variation for biomonitoring with predictive models in the Fraser River catchment, British Columbia

2001 ◽  
Vol 58 (7) ◽  
pp. 1411-1417 ◽  
Author(s):  
Pamela F Reece ◽  
Trefor B Reynoldson ◽  
John S Richardson ◽  
David M Rosenberg
Keyword(s):  
Seasonal Variation ◽  
Test Site ◽  
Benthic Invertebrate ◽  
Large River ◽  
Reference Condition ◽  
Taxonomic Resolution ◽  
Reference Database ◽  
Fraser River ◽  
River Catchment ◽  
Invertebrate Assemblage

Reference-condition models for the Fraser River catchment were developed using samples collected during the autumn of 1994, 1995, and 1996. The goal of this study was to examine applicability to the reference-condition models of samples collected in other seasons and the effect of taxonomic resolution (genus and family) on model sensitivity to seasonal variation in the benthic invertebrate assemblage. Samples from eight streams representing interior, coastal, and large-river habitats were collected in spring, summer, autumn, and winter of 1995 and in spring of 1996. The benthic invertebrate assemblage changed seasonally such that the models could not be used for seasons other than autumn. The models were equally sensitive to seasonal variation when genus-level or family-level data were used. We recommend that test samples (i.e., samples collected from disturbed sites and meant for comparison with the reference database) be collected either during the autumn or over multiple sampling dates to reduce the possibility that seasonal shifts or stochastic events will lead to erroneous conclusions about the state of a test site.

scholarly journals Disentangling the role of connectivity, environmental filtering, and spatial structure on metacommunity dynamics

Oikos ◽  
2013 ◽  
pp. no-no ◽  
Author(s):  
C. Moritz ◽  
C. N. Meynard ◽  
V. Devictor ◽  
K. Guizien ◽  
C. Labrune ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Environmental Filtering ◽  
Metacommunity Dynamics

scholarly journals Temporal and Spatial Coexistence of Archaeal and BacterialamoAGenes and Gene Transcripts in Lake Lucerne

Archaea ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Elisabeth W. Vissers ◽  
Flavio S. Anselmetti ◽  
Paul L. E. Bodelier ◽  
Gerard Muyzer ◽  
Christa Schleper ◽  
...  
Keyword(s):  
Temporal Distribution ◽  
Water Layer ◽  
Distribution Patterns ◽  
Freshwater Ecosystems ◽  
Ammonia Oxidizers ◽  
Lake Lucerne ◽  
Ammonia Oxidizing Archaea ◽  
Gene Transcripts ◽  
Temporal And Spatial

Despite their crucial role in the nitrogen cycle, freshwater ecosystems are relatively rarely studied for active ammonia oxidizers (AO). This study of Lake Lucerne determined the abundance of bothamoAgenes and gene transcripts of ammonia-oxidizing archaea (AOA) and bacteria (AOB) over a period of 16 months, shedding more light on the role of both AO in a deep, alpine lake environment. At the surface, at 42 m water depth, and in the water layer immediately above the sediment, AOA generally outnumbered AOB. However, in the surface water during summer stratification, when both AO were low in abundance, AOB were more numerous than AOA. Temporal distribution patterns of AOA and AOB were comparable. Higher abundances ofamoAgene transcripts were observed at the onset and end of summer stratification. In summer, archaealamoAgenes and transcripts correlated negatively with temperature and conductivity. Concentrations of ammonium and oxygen did not vary enough to explain theamoAgene and transcript dynamics. The observed herbivorous zooplankton may have caused a hidden flux of mineralized ammonium and a change in abundance of genes and transcripts. At the surface, AO might have been repressed during summer stratification due to nutrient limitation caused by active phytoplankton.

scholarly journals Diversity, distribution and spatial structure of the cold-water coral fauna of the Azores (NE Atlantic)

2013 ◽  
Vol 10 (6) ◽  
pp. 4009-4036 ◽  
Author(s):  
A. Braga-Henriques ◽  
F. M. Porteiro ◽  
P. A. Ribeiro ◽  
V. de Matos ◽  
Í. Sampaio ◽  
...  
Keyword(s):  
Spatial Structure ◽  
Cold Water ◽  
Current Knowledge ◽  
Fish Habitat ◽  
Sustainable Use ◽  
Distribution Patterns ◽  
Taxonomic Diversity ◽  
Conservation Policies ◽  
Coral Fauna ◽  
By Catch

Abstract. Cold-water corals are widely considered as important structural components of benthic habitats, potentially enhancing local abundance in a variety of fish and invertebrate species. Yet, current knowledge of the taxonomic diversity and distribution patterns of these vulnerable, slow-growing organisms is scarce and fragmented, limiting the effectiveness of spatial management and conservation measures. We have conducted an exhaustive compilation of records of alcyonaceans, antipatharians, scleractinians and stylasterids available through present day to assess the diversity, distribution and spatial structure of coral assemblages in the Azores exclusive economic zone (EEZ). The resulting database comprises 2501 entries concerning historical oceanographic expeditions and other published sources, as well as unpublished data from bottom longline by-catch. Our taxonomic inventory appears to be fairly complete for the explored habitats, accounting for 164 species (79 alcyonaceans, 58 scleractinians, 18 antipatharians and 9 stylasterids), nine of which were documented for the first time. The Azores EEZ harbours a mixed coral fauna with several zoogeographic origins, showing the closest affinity with the Lusitanian–Mediterranean region. Very few apparent endemics were found (14%), and only in part supported by consistent sampling. Coral diversity is particularly high between 300 and 900 m depths, in areas recognized as traditional fishing grounds or exploitable fish habitat within the 100-mile limit of the EEZ. The composition of coral assemblages shows significant geographical structure among longitudinal sections of the study area at comparable depths (100–1500 m). There is no evidence of a possible role of the Mid-Atlantic Ridge or latitudinal effects underlying this pattern, which suggests that it may instead reflect assemblage variability among features. Stronger changes in species composition were found along the bathymetric gradient. Notwithstanding the mix of partially overlapping steno- and eurybathic species that characterize the vertical distribution of corals, there is a distinct transition from shallow (100–600 m) to intermediate (600–1000 m) depths. The analysis presented here constitutes a valuable contribution for efficient conservation policies of coral-associated vulnerable marine ecosystems and their sustainable use as fishing areas.

scholarly journals The role of spatial structure in the collapse of regional metapopulations

Ecology ◽  
2018 ◽  
Vol 99 (12) ◽  
pp. 2815-2822 ◽  
Author(s):  
Easton R. White ◽  
Andrew T. Smith
Keyword(s):  
Spatial Structure

scholarly journals Research of urban agglomerations in the aspect of implementation of the administrative and territorial reform in Ukraine (case study of Kharkiv region)

2019 ◽  
Keyword(s):  
Spatial Structure ◽  
Spatial Organization ◽  
Weighted Average ◽  
Evolutionary Potential ◽  
Statistical Parameters ◽  
Urban Agglomerations ◽  
Territorial Structure

In the modern context of, one of the main tasks in the regional development management is to optimally realize the complex potential of the territories, which requires a comprehensive study of the spatial structure and evolutionary potential of agglomerations of all levels in order to identify disparities in their development, correct imbalances and optimize the spatial organization of the region. The first step to solve this problem is to identify the spatial structure and evaluate the interconnections of agglomerations sequentially, from local to regional level. This is becoming more relevant in the context of administrative and territorial reform in Ukraine. The purpose of this study is to analyze the prospects for the development of urban agglomerations and the organization of the administrative and territorial structure of Kharkiv region in view of the prevailing influence of the city of Kharkiv and the Kharkiv agglomeration. The basic theoretical and methodological starting points of the study of urban agglomerations are presented; their characteristics and parameters of boundary determination were defined. The essence of the method of modeling of integral influence function (IIF modeling) was revealed, the author's research methodology was substantiated. The tendencies of introduction of administrative and territorial reform in Ukraine were analyzed. It was established that Kharkiv region occupies mediocre places in terms of formation of the united territorial communities, there were 23 ones in the oblast (3 of them are city, 12 town, 8 rural ones) by the end of 2019. The scheme for dividing into enlarged districts has not yet been approved. According to different plans / proposals, the existing 27 districts of the oblast should be consolidated into nine, seven, six or four enlarged districts (counties). All of the above proposals were considered by the authors, it is established that the existing projects do not fully cover the main prevailing factors of allocation of competitive districts, do not take into account the role of historically formed system of settlement, spatial-statistical parameters, integral potential of territories, urbanization and agglomeration. The authors performed the IIF modeling and constructed the IIF surface of the weighted average settlement potential of Kharkiv region by the base radius of influence (2, 10, 20, and 30 km), which allowed to determine the features of the Kharkov agglomeration structure and the interaction of the settlements in the region by different radiuses of interaction, primary agglomerations, prospective growth points. On the basis of the obtained results of IIF modeling, the author's model of administrative and territorial division of Kharkiv region into eight enlarged districts was proposed, given the specific features of the settlement system and the correlation of area and population of the modeled administrative and territorial units. The scientifically grounded division of the region into enlarged districts (counties) and stimulation of their development will contribute to the most complete and rational use of the territories potential, increase of economic, human, investment potential, rise of the level and quality of life of the population, etc.

scholarly journals Subcellular orchestration of alpha-synuclein variants in Parkinson’s disease brains revealed by 3D multicolor STED microscopy

2018 ◽  
Author(s):  
Tim E. Moors ◽  
Christina A. Maat ◽  
Daniel Niedieker ◽  
Daniel Mona ◽  
Dennis Petersen ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Lewy Bodies ◽  
Distribution Patterns ◽  
Alpha Synuclein ◽  
Label Free ◽  
Post Translational Modifications ◽  
Sted Microscopy ◽  
C Terminus

AbstractPost-translational modifications of alpha-synuclein (aSyn), particularly phosphorylation at Serine 129 (Ser129-p) and truncation of its C-terminus (CTT), have been implicated in Parkinson’s disease (PD) pathology. To gain more insight in the relevance of Ser129-p and CTT aSyn under physiological and pathological conditions, we investigated their subcellular distribution patterns in normal aged and PD brains using highly-selective antibodies in combination with 3D multicolor STED microscopy. We show that CTT aSyn localizes in mitochondria in PD patients and controls, whereas the organization of Ser129-p in a cytoplasmic network is strongly associated with pathology. Nigral Lewy bodies show an onion skin-like architecture, with a structured framework of Ser129-p aSyn and neurofilaments encapsulating CTT aSyn in their core, which displayed high content of proteins and lipids by label-free CARS microscopy. The subcellular phenotypes of antibody-labeled pathology identified in this study provide evidence for a crucial role of Ser129-p aSyn in Lewy body formation.

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