Stream invertebrate communities are primarily shaped by hydrological factors and ultimately fine-tuned by local habitat conditions

Benthic macroinvertebrate communities are frequently applied as indicators of aquatic ecosystem health as many species are responsive to pollution and abrupt changes in their surroundings. The qualities of benthic invertebrate communities greatly depend on habitat conditions. Thus the diversity in benthic community varies with different habitat conditions. This investigation on the structure of the benthic invertebrate communities was conducted on river Ichamati, a trans-boundary river between India and Bangladesh to assess the cumulative effects of water quality on the aquatic biota. The study period extended from February 2011 to January 2014 at three sites from Majdiah to Hasanabad (in West Bengal, India) a stretch of 124km. A total of 23 macrobenthic species belonging to three phyla, five classes and nine orders were identified. Fifteen species of benthic invertebrates belonging to Mollusca, three species under Annelida and five species under Arthropoda were found. The highest abundance density (3633.33 indiv.m-2) and species richness (18 species) were recorded up-stream (Majdiah) where marginal habitats covered by macrophytes were significantly higher than at other sites. Both the organic carbon (4.41±1.11) and organic matter (7.48±1.56) of soil at this site were the maximum thus influencing the richness of benthic macroinvertebrate communities. Hydrological variables, viz, dissolved oxygen, pH, alkalinity; hardness, salinity, nutrients, calcium, and magnesium were studied to determine their influences on the benthic community in the upper, middle- and down-streams of the river, respectively. Shannon’s diversity index (0.95–2.07; 0.00–0.72; 0.00–0.64), dominance index (0.57–0.86; 0.00–0.44; 0.00–0.44), evenness index (0.72–0.95; 0.61–1.00; 0.00–1.00), Margalef index (0.72–2.23; 0.00–1.32; 0.00-0.28) of the upper, middle- and down-streams were calculated. Benthic macroinvertebrate density was correlated with hydrological variables which indicated that the abiotic factors had either direct or inverse influence on the richness and abundance; however, the abiotic factors did not correlate identically in all three sites.

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The Role of Competition and Local Habitat Conditions for Determining Occupancy Patterns in Grebes

Waterbirds ◽

10.1675/1524-4695(2003)026[0209:trocal]2.0.co;2 ◽

2003 ◽

Vol 26 (2) ◽

pp. 209 ◽

Cited By ~ 8

Author(s):

Erik E. Osnas

Keyword(s):

Habitat Conditions ◽

Occupancy Patterns ◽

Local Habitat

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Impacts of ecosystem fragmentation on plant populations: generalising the idiosyncratic

Australian Journal of Botany ◽

10.1071/bt03037 ◽

2003 ◽

Vol 51 (5) ◽

pp. 471 ◽

Cited By ~ 214

Author(s):

Richard J. Hobbs ◽

Colin J. Yates

Keyword(s):

Reproductive Output ◽

Terrestrial Ecosystems ◽

Population Viability ◽

Habitat Conditions ◽

Plant Populations ◽

Factors Affecting ◽

Successful Recruitment ◽

Ecosystem Fragmentation ◽

Animal Populations ◽

Local Habitat

Fragmentation of natural vegetation is one of the most pervasive changes in terrestrial ecosystems across the Earth. Developing a general understanding of how fragmentation affects plant and animal populations is essential to meet the pressing need for guidelines for the management of fragmented systems. Nevertheless, this general understanding has to take account of differences in ecosystem types and different biogeographic, evolutionary and ecological backgrounds against which fragmentation impacts are played out in different parts of the world. Here, we examine fragmentation impacts on plant populations by considering the processes underlying fragmentation. We suggest that it is critical to focus on the key processes that are important in particular situations, rather than assuming that the same factors are likely to be important everywhere. In other words, there are inevitable limits to generalisation because of the idiosyncratic nature of the geography, history and biota of different regions. Studies on the effects of fragmentation on plant populations have focused on a limited subset of plant types and have concentrated heavily on reproductive output rather than actual regeneration success. These studies have indicated a clear impact of fragmentation on fecundity, but there is no clear signal in terms of the actual importance of this in relation to population viability. Other factors including local habitat conditions, disturbance and competition from weeds may be just as important as the classical biogeographical impacts of fragmentation. Generalisations based on a clear assessment of key life-history processes may be valuable tools in developing management responses to ecosystem fragmentation, but this requires considerably more emphasis on factors affecting successful recruitment as well as factors affecting fecundity.

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Local habitat conditions explain the variation in the strength of self‐thinning in a stream salmonid

Ecology and Evolution ◽

10.1002/ece3.1591 ◽

2015 ◽

Vol 5 (16) ◽

pp. 3231-3242 ◽

Cited By ~ 6

Author(s):

Knut Marius Myrvold ◽

Brian P. Kennedy

Keyword(s):

Habitat Conditions ◽

Local Habitat ◽

Stream Salmonid

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What do we learn from cultures in the omics age? High-throughput sequencing and cultivation of leaf-inhabiting endophytes from beech (Fagus sylvatica L.) revealed complementary community composition but similar correlations with local habitat conditions

MycoKeys ◽

10.3897/mycokeys.20.11265 ◽

2017 ◽

Vol 20 ◽

pp. 1-16 ◽

Cited By ~ 16

Author(s):

Abu Bakar Siddique ◽

Anis Mahmud Khokon ◽

Martin Unterseher

Keyword(s):

Community Composition ◽

Fagus Sylvatica ◽

High Throughput ◽

High Throughput Sequencing ◽

Habitat Conditions ◽

Fagus Sylvatica L ◽

Local Habitat

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Effect of mowing on the structure of sedge communities in the Chwiszczej river valley (Białowieża forest)

Quaestiones Geographicae ◽

10.2478/v10117-012-0009-5 ◽

2012 ◽

Vol 31 (3) ◽

pp. 33-39 ◽

Cited By ~ 1

Author(s):

Aleksander Kołos

Keyword(s):

River Valley ◽

Habitat Conditions ◽

Edge Zone ◽

Floristic Richness ◽

Białowieża Forest ◽

Habitat Factors ◽

Meadow Species ◽

Different Parts ◽

Local Habitat

Abstract. The paper presents the results of the 4-year studies on the influence of mowing on sedge communities structure in the near-edge zone and in the riverbed-adjacent zone of the Chwiszczej River valley (Białowieża Forest). It was assumed that various habitat conditions in different parts of the valley could modify effects of mowing. The floristic richness of sedge dominated patches increases under the influence of mowing in both zones of the valley, mainly as a result of growing number of meadow species. These changes are determined by habitat factors only in the central part of the valley, where ground water’s dynamics is the biggest. Effects of mowing are almost completely canceled by long-lasting flooding. Such flooding may affect on sedge communities’ structure stronger than mowing. Irrespective of local habitat conditions, mowing is favorable to spread of Calamagrostis stricta, which is species of high competitiveness. Its domination could lead to decrease of floristic richness in rush communities.

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Community Composition of Bacteria Isolated from Swiss Banknotes Varies Depending on Collection Environment

10.1101/2021.12.01.470750 ◽

2021 ◽

Author(s):

Anna M. Bischofberger ◽

Alex R. Hall

Keyword(s):

Microbial Communities ◽

Community Composition ◽

Taxonomic Diversity ◽

Habitat Conditions ◽

Geographic Structure ◽

Structure Similarity ◽

Associated Surfaces ◽

Microbial Community Assembly ◽

Butcher Shops ◽

Local Habitat

AbstractHumans interact constantly with surfaces and associated microbial communities in the environment. The factors shaping the composition of these communities are poorly understood: some proposed explanations emphasize the influence of local habitat conditions (niche-based explanations), while others point to geographic structure and the distance among sampled locations (dispersal-based explanations). However, the relative roles of these different drivers for microbial community assembly on human-associated surfaces are not clear. Here, we used a combination of sampling, sequencing (16S rRNA) and culturing to show that the composition of banknote-associated bacterial communities varies depending on the local collection environment. Using banknotes collected from various locations and types of shops across Switzerland, we found taxonomic diversity dominated by families such as Pseudomonadaceae, Staphylococcaceae and Streptococcaceae, but with banknote samples from particular types of shops (especially butcher shops) having distinct community structure. By contrast, we found no evidence of geographic structure: similarity of community composition did not decrease with increasing distance among sampled locations. These results show that microbial communities associated with banknotes, one of the most commonly encountered and exchanged human-associated surfaces, can reflect the local environmental conditions (in this case, the type of shop), and the signal for this type of variation was stronger than that for geographic structure among the locations sampled here.

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