Turnover is replaced by nestedness with increasing geographical distance in bacterial communities of coastal shallow lakes

2020 ◽  
Vol 71 (9) ◽  
pp. 1086
Author(s):  
Marla Sonaira Lima ◽  
Fabiana Schneck ◽  
Ng Haig They ◽  
Luciane Oliveira Crossetti ◽  
Juliana Elisa Bohnenberger ◽  
...  
Keyword(s):  
Shallow Lakes ◽  
Bacterial Communities ◽  
Local Environment ◽  
Dispersal Limitation ◽  
Geographical Distance ◽  
Environmental Filters ◽  
Species Sorting ◽  
Relative Contribution ◽  
Β Diversity ◽  
The Relationship

In this study we measured the relative contribution of two components of β-diversity, turnover and nestedness, of bacterioplankton among 25 shallow lakes in southern Brazil and tested their relationship with local (environment, chlorophyll-a and biomass of phytoplanktonic classes) and landscape variables, as well as geographical distance. We predicted that turnover would be the largest share of total β-diversity due to the variation of local characteristics among lakes. Further, we expected nestedness to increase at the expense of turnover with increasing geographical distance among lakes due to dispersal limitation. The results indicated a higher contribution of turnover than nestedness to total β-diversity, which was driven by local factors. When the relationship between β-diversity components and the spatial extent between each lake and all other lakes was considered, turnover was replaced by nestedness with increasing geographical distance for 8 (the furthermost lakes) of the 25 lakes likely because of a combination of decreasing dispersal due to distance and richness differences due to wind-driven mass effects. The results of this study suggest a role for nestedness as an indicator of dispersal limitation owing to geographical distance and wind dispersal, and for turnover as an indicator of species sorting because of environmental filters for these freshwater bacterial communities.

scholarly journals Strategic resources and smallholder performance at the bottom of the pyramid

2019 ◽  
Vol 22 (3) ◽  
pp. 365-380 ◽  
Author(s):  
Matthias Olthaar ◽  
Wilfred Dolfsma ◽  
Clemens Lutz ◽  
Florian Noseleit
Keyword(s):  
Large Scale ◽  
Business Environment ◽  
Agricultural Economics ◽  
Local Market ◽  
Bottom Of The Pyramid ◽  
Fine Grained ◽  
Strategic Resources ◽  
Relative Contribution ◽  
The Relationship ◽  
Resource Based Theory

In a competitive business environment at the Bottom of the Pyramid smallholders supplying global value chains may be thought to be at the whims of downstream large-scale players and local market forces, leaving no room for strategic entrepreneurial behavior. In such a context we test the relationship between the use of strategic resources and firm performance. We adopt the Resource Based Theory and show that seemingly homogenous smallholders deploy resources differently and, consequently, some do outperform others. We argue that the ‘resource-based theory’ results in a more fine-grained understanding of smallholder performance than approaches generally applied in agricultural economics. We develop a mixed-method approach that allows one to pinpoint relevant, industry-specific resources, and allows for empirical identification of the relative contribution of each resource to competitive advantage. The results show that proper use of quality labor, storage facilities, time of selling, and availability of animals are key capabilities.

scholarly journals Soil Nutrient and Vegetation Diversity Patterns of Alpine Wetlands on the Qinghai-Tibetan Plateau

2021 ◽  
Vol 13 (11) ◽  
pp. 6221
Author(s):  
Muyuan Ma ◽  
Yaojun Zhu ◽  
Yuanyun Wei ◽  
Nana Zhao
Keyword(s):  
Species Diversity ◽  
Tibetan Plateau ◽  
Soil Properties ◽  
Soil Ph ◽  
Plant Biomass ◽  
Principal Component ◽  
Vegetation Diversity ◽  
Vegetation Biomass ◽  
Relative Contribution ◽  
The Relationship

To predict the consequences of environmental change on the biodiversity of alpine wetlands, it is necessary to understand the relationship between soil properties and vegetation biodiversity. In this study, we investigated spatial patterns of aboveground vegetation biomass, cover, species diversity, and their relationships with soil properties in the alpine wetlands of the Gannan Tibetan Autonomous Prefecture of on the Qinghai-Tibetan Plateau, China. Furthermore, the relative contribution of soil properties to vegetation biomass, cover, and species diversity were compared using principal component analysis and multiple regression analysis. Generally, the relationship between plant biomass, coverage, diversity, and soil nutrients was linear or unimodal. Soil pH, bulk density and organic carbon were also significantly correlated to plant diversity. The soil attributes differed in their relative contribution to changes in plant productivity and diversity. pH had the highest contribution to vegetation biomass and species richness, while total nitrogen was the highest contributor to vegetation cover and nitrogen–phosphorus ratio (N:P) was the highest contributor to diversity. Both vegetation productivity and diversity were closely related to soil properties, and soil pH and the N:P ratio play particularly important roles in wetland vegetation biomass, cover, and diversity.

A computational insight into the relationship between side chain IR line shapes and local environment in fibril-like structures

2021 ◽  
Vol 154 (8) ◽  
pp. 084105
Author(s):  
Sandra M. V. Pinto ◽  
Nicola Tasinato ◽  
Vincenzo Barone ◽  
Laura Zanetti-Polzi ◽  
Isabella Daidone
Keyword(s):  
Local Environment ◽  
Side Chain ◽  
Line Shapes ◽  
The Relationship ◽  
Insight Into

scholarly journals Environment drives high phylogenetic turnover among oceanic bacterial communities

2012 ◽  
Vol 8 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Thomas Pommier ◽  
Emmanuel J. P. Douzery ◽  
David Mouillot
Keyword(s):  
Bacterial Communities ◽  
Environmental Gradient ◽  
Regional Scale ◽  
Environmental Filtering ◽  
Species Level ◽  
Geographical Distance ◽  
Abiotic Conditions ◽  
High Connectivity ◽  
Phylogenetic Lineages ◽  
Marine Microbial Communities

Although environmental filtering has been observed to influence the biodiversity patterns of marine bacterial communities, it was restricted to the regional scale and to the species level, leaving the main drivers unknown at large biogeographic scales and higher taxonomic levels. Bacterial communities with different species compositions may nevertheless share phylogenetic lineages, and phylogenetic turnover (PT) among those communities may be surprisingly low along any biogeographic or environmental gradient. Here, we investigated the relative influence of environmental filtering and geographical distance on the PT between marine bacterial communities living more than 8000 km apart in contrasted abiotic conditions. PT was high between communities and was more structured by local environmental factors than by geographical distance, suggesting the predominance of a lineage filtering process. Strong phenotype-environment mismatches observed in the ocean may surpass high connectivity between marine microbial communities.

scholarly journals Sandhills, sandbanks, waterways, canals and sacred lakes at Sais in the Nile Delta

2021 ◽  
Vol 70 (1) ◽  
pp. 129-143
Author(s):  
Penelope Wilson ◽  
Hosni Ghazala
Keyword(s):  
Nile Delta ◽  
Local Environment ◽  
Capital City ◽  
Neolithic Period ◽  
Natural Landscape ◽  
Archaeological Data ◽  
Human Interactions ◽  
Ancient City ◽  
The Relationship ◽  
Common Era

Abstract. The paper explores the relationship between the archaeological zones of the ancient city of Sais at Sa el-Hagar, Egypt, and the natural landscape of the western central Nile Delta and, in particular, the extent to which the dynamic form of the landscape was an element in the choice of settlement location. Furthermore, settlement at Sais has been determined to have existed at several locations in the immediate environs of the current archaeological zones from the Neolithic period, around 4000 BCE (Before Common Era), to the modern day, suggesting that the local environment was conducive to sustainable settlement, culminating in the establishment of a capital city in the 7th century BCE. The nature of the settlement, its immediate environs and waterway systems will, thus, be described, based on correlation of geological, geophysical, remote sensing and archaeological data, in order to establish if and when human interactions in the landscape can be determined to be reactive or proactive.

scholarly journals Exploration of Intrinsic Microbial Community Modulators in the Rice Endosphere Indicates a Key Role of Distinct Bacterial Taxa Across Different Cultivars

2021 ◽  
Vol 12 ◽  
Author(s):  
Pei Wang ◽  
Xiao Kong ◽  
Hongsong Chen ◽  
Youlun Xiao ◽  
Huijun Liu ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Microbial Network ◽  
Β Diversity ◽  
Group I ◽  
Α Diversity ◽  
Microbe Interactions ◽  
Endophytic Bacterial Community ◽  
Group Ii

Microbial communities associated with the plant phyllosphere and endosphere can have both beneficial as well as detrimental effects on their hosts. There is an ongoing debate to which extend the phyllosphere and endosphere microbiome assembly is controlled by the host plant how pronounced cultivar effects are. We investigated the bacterial and fungal communities from the phyllosphere and endosphere of 10 different rice cultivars grown under identical environmental conditions in the frame of a targeted approach to identify drivers of community assembly. The results indicated that the endophytic bacterial communities were clearly separated into two groups. The α-diversity and microbial network complexity within Group I were significantly lower than in Group II. Moreover, the genera Nocardioides, Microvirga, and Gaiella were significantly more abundant in Group II and only present in the interaction networks of this group. These three genera were significantly correlated with α- and β-diversity of the endophytic bacterial community and thus identified as major drivers of the endosphere community. We have identified keystone taxa that shape endophytic bacterial communities of different rice cultivars. Our overall findings provide new insights into plant-microbe interactions, and may contribute to targeted improvements of rice varieties in the future.

scholarly journals Dante’s kindling box

2017 ◽  
Vol 86 (1) ◽  
pp. 22-23
Author(s):  
Josiah Marquis ◽  
Meriem Benlamri ◽  
Elizabeth Dent ◽  
Tharmitha Suyeshkumar
Keyword(s):  
Air Pollution ◽  
Forest Fire ◽  
Biomass Burning ◽  
Psychological Health ◽  
Forest Fires ◽  
Air Pollutants ◽  
Local Environment ◽  
Hazardous Air Pollutants ◽  
Area Burned ◽  
The Relationship

Almost half of the Canadian landscape is made up of forests, but the amount of forest surface area burned every year has been growing steadily since 1960.1 This can be problematic due to the effects that forest fires have not only on the local environment but also on the globe as a whole. A forest fire or vegetation fire is defined as any open fire of vegetation such as savannah, forest, agriculture, or peat that is initiated by humans or nature.2 Vegetation fires contribute heavily to air pollution and climate change and are in turn exacerbated by them as well. Air pollution increases due to emissions from these fires, which contain 90-95% carbon dioxide and carbon monoxide as well as methane and other volatile compounds.2 Emissions from forest fires also contribute to global greenhouse gases and aerosol particles (biomass burning organic aerosols),2 leading to indirect and direct consequences to human health. In contrast to biomass burning for household heating and cooking, catastrophic events of forest fires and sweeping grassland fires result in unique exposures and health consequences. In this case report, the relationship between environmental hazardous air pollutants and the potential physiological and psychological health effects associated with the forest fire that affected Fort McMurray, AB in May 2016 are considered.

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