Stochastic Abundance Models with Emphasis on Biological Communities and Special Diversity.

1980 ◽  
Vol 29 (1) ◽  
pp. 99
Author(s):  
J. D. Biggins ◽  
S. Engen
Keyword(s):  
Biological Communities

Life in Glacial and Alpine Rivers in Central Iceland in Relation to Physical and Chemical Parameters

2000 ◽  
Vol 31 (4-5) ◽  
pp. 411-422 ◽  
Author(s):  
Gísli Már Gíslason ◽  
Jón S. Ólafsson ◽  
Hákon Adalsteinsson
Keyword(s):  
Chemical Properties ◽  
Chemical Parameters ◽  
Invertebrate Fauna ◽  
Glacial Meltwater ◽  
Biological Communities ◽  
Relative Contribution ◽  
Glacial River ◽  
Alpine Rivers ◽  
Physical And Chemical ◽  
And Chemical Properties

The characteristics of stream and river ecosystems in arctic and alpine areas are determined mainly by the relative contribution of glacial meltwater, snowmelt, rainfall and groundwater. Each source generates a particular seasonal hydrological signature, affecting physical and chemical properties, and hence biological communities. The relative contribution of each source is sensitive to climate change. The study was concentrated on the glacial River W-Jökulsá and some non-glacial rivers in the central highlands of Iceland. The water in the glacial river was entirely glacial meltwater at the glacier margin, but the glacial contribution was about 20% 40 km downstream. However, its tributaries and non-glacial reference rivers were mainly springfed. The invertebrate fauna was confined to Chironomidae of the genus Diamesa close to the glacier, but other taxa (species and groups of species) occupied the river further downstream, where their diversity was close to that found in the reference rivers.

scholarly journals Invertebrate and Microbial Response to Hyporheic Restoration of an Urban Stream

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 481
Author(s):  
Sarah A. Morley ◽  
Linda D. Rhodes ◽  
Anne E. Baxter ◽  
Giles W. Goetz ◽  
Abigail H. Wells ◽  
...  
Keyword(s):  
Hyporheic Zone ◽  
Habitat Diversity ◽  
Urban Stream ◽  
Floodplain Restoration ◽  
Design Elements ◽  
Biological Communities ◽  
Taxa Richness ◽  
Restoration Technique ◽  
Microbial Response ◽  
Face Complex

All cities face complex challenges managing urban stormwater while also protecting urban water bodies. Green stormwater infrastructure and process-based restoration offer alternative strategies that prioritize watershed connectivity. We report on a new urban floodplain restoration technique being tested in the City of Seattle, USA: an engineered hyporheic zone. The hyporheic zone has long been an overlooked component in floodplain restoration. Yet this subsurface area offers enormous potential for stormwater amelioration and is a critical component of healthy streams. From 2014 to 2017, we measured hyporheic temperature, nutrients, and microbial and invertebrate communities at three paired stream reaches with and without hyporheic restoration. At two of the three pairs, water temperature was significantly lower at the restored reach, while dissolved organic carbon and microbial metabolism were higher. Hyporheic invertebrate density and taxa richness were significantly higher across all three restored reaches. These are some of the first quantified responses of hyporheic biological communities to restoration. Our results complement earlier reports of enhanced hydrologic and chemical functioning of the engineered hyporheic zone. Together, this research demonstrates that incorporation of hyporheic design elements in floodplain restoration can enhance temperature moderation, habitat diversity, contaminant filtration, and the biological health of urban streams.

Bacterial presence in polar regions associated with environment modification by chemical compounds including contaminants

2017 ◽  
Vol 25 (4) ◽  
pp. 481-491 ◽  
Author(s):  
Klaudia Kosek ◽  
Katarzyna Jankowska ◽  
Żaneta Polkowska
Keyword(s):  
Bacterial Communities ◽  
Chemical Compounds ◽  
Freshwater Ecosystems ◽  
Trophic Levels ◽  
Polar Regions ◽  
Bacterial Cells ◽  
Chemical Contamination ◽  
Climate Conditions ◽  
Biological Communities ◽  
Long Time

Microbes are omnipresent and diverse members of all biological communities. In marine and freshwater ecosystems, microorganisms form the base of the food chain supporting higher trophic levels. Even though microbes are generally thought to live in warm regions of Earth, many of them develop in cold climates. Polar regions remain relatively protected from widespread anthropogenic disturbances, which is a consequence of thier remoteness and extreme climate conditions. For a long time these regions were considered to be free from chemical contamination until scientists discovered a presence of pollutants there. Chemical contamination may induce serious disorders in the integrity of polar ecosystems influencing the growth of bacterial communities. Xenobiotics including persistent organic pollutants are transported thousands of kilometers by the air and ocean currents, and they are deposed in high-latitude regions and accumulate in all elements of the environment including bacterial communities. It is important to determine their concentration levels in bacterial cells to assess the possibility of contaminants becoming transferred to higher trophic levels; however, some species of bacteria are capable of metabolizing xenobiotics, which makes them less toxic or even removes them from the environment.

An isoclinal approach to the comparative statics of biological communities

1986 ◽  
Vol 48 (1) ◽  
pp. 59-75 ◽  
Author(s):  
Grant G. Thompson ◽  
W. Michael Booty ◽  
William J. Liss ◽  
Charles E. Warren
Keyword(s):  
Comparative Statics ◽  
Biological Communities

scholarly journals Benthic estuarine communities' contribution to bioturbation under the experimental effect of marine heatwaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Dolbeth ◽  
O. Babe ◽  
D. A. Costa ◽  
A. P. Mucha ◽  
P. G. Cardoso ◽  
...  
Keyword(s):  
Community Composition ◽  
Ecosystem Functioning ◽  
Structural Changes ◽  
Nutrient Release ◽  
Biological Communities ◽  
Thermal Change ◽  
Composition And Structure ◽  
Temperature Ranges ◽  
Negative Impacts ◽  
Heat Extremes

AbstractMarine heatwaves are increasing worldwide, with several negative impacts on biological communities and ecosystems. This 24-day study tested heatwaves' effect with distinct duration and recovery periods on benthic estuarine communities' diversity and contribution to ecosystem functioning experimentally. The communities were obtained from a temperate estuary, usually subjected to high daily thermal amplitudes. Our goal was to understand the communities' response to the thermal change, including the community descriptors and behavioural changes expected during heat extremes. We measured community composition and structural changes and the bioturbation process and nutrient release as ecosystem functioning measurements. Overall, our findings highlight the potential tolerance of studied estuarine species to the temperature ranges tested in the study, as community composition and structure were similar, independently of the warming effect. We detected a slight trend for bioturbation and nutrient release increase in the communities under warming, yet these responses were not consistent with the heatwaves exposure duration. Overall, we conclude on the complexity of estuarine communities’ contribution to functioning under warming, and the importance of scalable experiments with benthic organisms' responses to climate variability, accommodating longer time scales and replication. Such an approach would set more efficient expectations towards climate change mitigation or adaptation in temperate estuarine ecosystems.

Seasonal-dependence in the responses of biological communities to flood pulses in warm temperate floodplain lakes: implications for the “alternative stable states” model

2014 ◽  
Vol 76 (4) ◽  
pp. 579-594 ◽  
Author(s):  
Griselda Chaparro ◽  
María Soledad Fontanarrosa ◽  
María Romina Schiaffino ◽  
Paula de Tezanos Pinto ◽  
Inés O’Farrell
Keyword(s):  
Alternative Stable States ◽  
Floodplain Lakes ◽  
Stable States ◽  
Biological Communities ◽  
Flood Pulses ◽  
Warm Temperate ◽  
Seasonal Dependence

Introduction to the Northwest Ontario Lake Size Series (NOLSS)

1992 ◽  
Vol 49 (12) ◽  
pp. 2434-2444 ◽  
Author(s):  
E. J. Fee ◽  
R. E. Hecky
Keyword(s):  
Turbulent Energy ◽  
Morphological Similarity ◽  
Experimental Lakes Area ◽  
Mixing Depth ◽  
Biological Communities ◽  
Renewal Time ◽  
Northwest Ontario ◽  
Per Se ◽  
Lake Size ◽  
Size Series

The rationale, design, and limitations of the Northwest Ontario Lake Size Series (NOLSS) research program are described. The primary purpose of NOLSS is to discover how lake size per se influences limnological and fisheries phenomena, so that conclusions drawn from studies of particular lakes can be rigorously scaled and applied to lakes of other sizes. NOLSS consists of six lakes located in a remote wilderness region of Northwest Ontario. These lakes were chosen for their geological, hydrological, and morphological similarity (Canadian Shield geology; water renewal time> 5 yr; fully stratified in summer), but they form an exponential gradient in surface area (from 89 to 34 700 ha.) Associated with this gradient of lake size are gradients of physical properties (turbulent energy, mixing depth, thermal behaviour) to which biological communities must adapt. NOLSS fills the conspicuous gap in size that separates two well-studied groups of lakes in Northwest Ontario: the Experimental Lakes Area (ELA), where whole-lake manipulation experiments are performed, and the Laurentian Great Lakes (Nipigon, Superior), where these experiments find some of their most important applications.

Taxonomy and phylogeny of calcareous sponges (Porifera: Calcarea: Calcinea) from Brazilian mid-shelf and oceanic islands

Zootaxa ◽  
2017 ◽  
Vol 4311 (3) ◽  
pp. 301 ◽  
Author(s):  
FERNANDA AZEVEDO ◽  
ANDRÉ PADUA ◽  
FERNANDO MORAES ◽  
ANDRÉ ROSSI ◽  
GUILHERME MURICY ◽  
...  
Keyword(s):  
Species Richness ◽  
Morphological Characters ◽  
Oceanic Islands ◽  
Biological Communities ◽  
Calcareous Sponges ◽  
Molecular Approaches ◽  
Strategic Value ◽  
Molecular Tree ◽  
Trindade Island ◽  
Fernando De Noronha

Despite the enormous economic, scientific and strategic value of the Brazilian oceanic and mid-shelf islands (BOMIs), the biological communities of these islands are still poorly known. An example is their fauna of calcareous sponges (Porifera: Calcarea), with only six species described up to date. In the present study, we analysed the Calcinean sponges from the mid-shelf Abrolhos Archipelago and four of the five Brazilian oceanic islands (São Pedro e São Paulo Archipelago, Fernando de Noronha Archipelago, Rocas Atoll, and Trindade Island), using both morphological and molecular approaches for taxonomy. Fourteen species were found, of which 12 are new to science: Arturia trindadensis sp. nov., Borojevia tenuispinata sp. nov., B. trispinata sp. nov., Clathrina insularis sp. nov., C. lutea sp. nov., C. mutabilis sp. nov., C. zelinhae sp. nov., Ernstia citrea sp. nov., E. multispiculata sp. nov., E. rocasensis sp. nov., E. sanctipauli sp. nov., and E. solaris sp. nov. These results raised in 63% the species richness of calcareous sponges from the BOMIs. Clathrina aurea and Leucetta floridana were recollected and the former had its geographical distribution expanded. The molecular tree obtained confirmed the morphological identifications and allowed a discussion about the evolution of morphological characters, and the usefulness of some of those characters in the taxonomy of Calcinea. 

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