Size structure and species composition of plankton communities in deep Ontario lakes with and without Mysis relicta and planktivorous fish

1996 ◽  
Vol 53 (2) ◽  
pp. 315-325 ◽  
Author(s):  
M Jane R. Almond ◽  
Ellen Bentzen ◽  
William D Taylor
Keyword(s):  
Species Composition ◽  
Size Structure ◽  
Planktivorous Fish ◽  
Mysis Relicta ◽  
Plankton Communities

Variability of size structure and species composition in Caribbean octocoral communities under contrasting environmental conditions

2018 ◽  
Vol 165 (2) ◽  
Author(s):  
Georgios Tsounis ◽  
Peter J. Edmunds ◽  
Lorenzo Bramanti ◽  
Bonnie Gambrel ◽  
Howard R. Lasker
Keyword(s):  
Species Composition ◽  
Environmental Conditions ◽  
Size Structure

scholarly journals Complex Analyses of Plankton Structure and Function

2001 ◽  
Vol 1 ◽  
pp. 119-132 ◽  
Author(s):  
Karl E. Havens
Keyword(s):  
Size Structure ◽  
Experimental Studies ◽  
Structure And Function ◽  
Size Spectrum ◽  
Phytoplankton Productivity ◽  
Resource Managers ◽  
Carbon Transfer ◽  
And Function ◽  
Freshwater Plankton ◽  
Plankton Communities

This paper critically evaluates some complex methods that have been used to characterize the structure and function of freshwater plankton communities. The focus is on methods related to plankton size structure and carbon transfer. The specific methods reviewed are 1) size spectrum analysis, 2) size-fractionated phytoplankton productivity, 3) size-fractionated zooplankton grazing, 4) plankton ecological transfer efficiency, and 5) grazer effects on phytoplankton community structure. Taken together, these methods can provide information on community ecological properties that are directly related to practical issues including water quality and fisheries productivity. However, caution is warranted since application without a complete understanding of assumptions and context of the manipulations could lead to erroneous conclusions. As an example, experimental studies involving the addition or removal of zooplankton, especially when coupled with nutrient addition treatments, could provide information on the degree of consumer vs. resource control of phytoplankton. Resource managers subsequently could use this information in developing effective measures for controlling nuisance algal biomass. However, the experiments must be done critically and with sufficient safeguards and other measurements to ensure that treatments (e.g., zooplankton exclosure by screening of water) actually are successful and do not introduce other changes in the community (e.g., removal of large algae). In all of the methods described here, the investigator must take care when generalizing results and, in particular, carry out a sufficient number of replications to encompass both the major seasonal and spatial variation that occurs in the ecosystem.

scholarly journals Environmental and ecological factors mediate taxonomic composition and body size of polyplacophoran assemblages along the Peruvian Province

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian M. Ibáñez ◽  
Melany Waldisperg ◽  
Felipe I. Torres ◽  
Sergio A. Carrasco ◽  
Javier Sellanes ◽  
...  
Keyword(s):  
Body Size ◽  
Species Composition ◽  
Size Structure ◽  
Environmental Gradients ◽  
Ecological Factors ◽  
Taxonomic Composition ◽  
Latitudinal Gradients ◽  
Size Segregation ◽  
Biogeographic Patterns ◽  
Diversity Gradient

Abstract Intertidal communities’ composition and diversity usually exhibit strong changes in relation to environmental gradients at different biogeographical scales. This study represents the first comprehensive diversity and composition description of polyplacophoran assemblages along the Peruvian Province (SE Pacific, 12°S–39°S), as a model system for ecological latitudinal gradients. A total of 4,775 chitons from 21 species were collected on twelve localities along the Peruvian Province. This sampling allowed us to quantitatively estimate the relative abundance of the species in this assemblage, and to test whether chitons conform to elementary predictions of major biogeographic patterns such as a latitudinal diversity gradient. We found that the species composition supported the division of the province into three ecoregional faunal groups (i.e. Humboldtian, Central Chile, and Araucanian). Though chiton diversity did not follow a clear latitudinal gradient, changes in species composition were dominated by smaller scale variability in salinity and temperature. Body size significantly differed by ecoregions and species, indicating latitudinal size-structure assamblages. In some localities body size ratios differed from a random assemblage, evidencing competition at local scale. Changes in composition between ecoregions influence body size structure, and their overlapping produce vertical size segregation, suggesting that competition coupled with environmental conditions structure these assemblages.

Crustacean Plankton of 146 Alpine and Subalpine Lakes and Ponds in Western Canada

1971 ◽  
Vol 28 (3) ◽  
pp. 311-321 ◽  
Author(s):  
R. Stewart Anderson
Keyword(s):  
Species Composition ◽  
National Parks ◽  
Copepod Species ◽  
Physical Factors ◽  
Western Canada ◽  
Cladoceran Species ◽  
Subalpine Lakes ◽  
Crustacean Plankton ◽  
Large Predators ◽  
Plankton Communities

Investigations of crustacean plankton communities in 146 alpine and subalpine waters in some western Canadian national parks and environs showed that species composition varied little from year to year and that there was a mean of 2.93 species per community Diaptomus arcticus occurred in 60% of the communities. More cladoceran species than copepod species were found, but there were usually more copepod than cladoceran species in a community. Many of the species found in subalpine waters did not occur in alpine waters, where they were probably limited more by physical factors — such as temperature and morphometry — and the presence of large predators than by altitude. Except for anostracans, few species seemed to be restricted to either lakes or ponds in the study area. Congeneric occurrences of large cladocerans or nonpredaceous diaptomid copepods were uncommon, as were co-occurrences of large cladocerans and nonpredaceous diaptomids.

The spatial distribution of plankton communities in a Slope Water anticyclonic Oceanic eDDY (SWODDY) in the southern Bay of Biscay

2004 ◽  
Vol 84 (3) ◽  
pp. 501-517 ◽  
Author(s):  
Emilio Fernández ◽  
Florentina Álvarez ◽  
Ricardo Anadón ◽  
Susana Barquero ◽  
Antonio Bode ◽  
...  
Keyword(s):  
Size Structure ◽  
Biological Properties ◽  
Trophic Levels ◽  
Bay Of Biscay ◽  
Pelagic Ecosystem ◽  
Oceanic Eddy ◽  
Oceanic Eddies ◽  
Planktonic Community ◽  
Water Parcel ◽  
Plankton Communities

Slope Water anticyclonic Oceanic eDDIES (SWODDIES) are typical mesoscale features of open-ocean waters of the southern Bay of Biscay which usually develop in winter by shedding from the seasonal poleward current flowing along the northern Spanish slope. These eddies have been intensively studied from the physical perspective. However, their effect on the distribution of biological properties and on the functioning of the pelagic ecosystem has not been assessed so far. To this aim, a sea-truth, multidisciplinary and comprehensive study of a SWODDY was carried out in summer 1998. The eddy, radius of ≈50 km, was initially centred at 45·5°N 6·0°W, being characterized by a relatively homogeneous core of water in the centre of the eddy extending from 80 to about 200 dbar. In the central region of the core, temperature (12·55–12·75°C) and salinity (≈35·70) values were higher than outside the eddy. The optical properties of the eddy also differed from those of the surrounding waters. A distinct biological signature was found associated with the eddy. Depth-integrated chlorophyll-a concentrations were 25% higher at the eddy centre where upward doming of the seasonal pycnocline (up to 30 dbar) occurred. Enhanced phytoplankton biomass was related to a higher contribution of >10 μm cells, mainly represented by diatoms and chrysophyceans. Phytoplankton and mesozooplankton species composition in and outside the eddy differed significantly reflecting the coastal origin of the water parcel trapped by the eddy. The sharp modification of the planktonic community composition, biomass and associated size-structure caused by slope water oceanic eddies are likely to exert a significant effect upon the upper trophic levels of the pelagic ecosystem of the southern Bay of Biscay.

Advance regeneration and trajectories of stand development following the mountain pine beetle outbreak in boreal forests of British Columbia

2015 ◽  
Vol 45 (10) ◽  
pp. 1327-1337 ◽  
Author(s):  
Elizabeth M. Campbell ◽  
Joseph A. Antos
Keyword(s):  
British Columbia ◽  
Species Composition ◽  
Boreal Forests ◽  
Mountain Pine Beetle ◽  
Size Structure ◽  
Fire Disturbance ◽  
Active Management ◽  
Advance Regeneration ◽  
Mountain Pine ◽  
Pine Beetle

A mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreak has recently spread into boreal forests, with unknown consequences for this ecosystem. We intensively sampled 12 stands affected by the current outbreak in northern British Columbia to determine the potential of western boreal forests to recover from this novel disturbance. We sampled the species composition, size structure, and spatial distribution (using 5 m × 5 m subplots, 40 per stand) of live and dead trees and used a variety of analyses, including ordinations, to assess potential developmental trajectories of stands. Advance regeneration (stems < 10 m tall) varied greatly in abundance among stands (50–18 280 stems·ha−1). However, most subplots contained at least one individual; only three stands had many empty subplots. We conclude that most stands have enough advance regeneration and residual canopy trees to form a nearly continuous new canopy. Ordinations indicate that species composition will shift substantially and become more divergent among stands. Species of high economic value will remain common, though, and active management will not be necessary in most stands to maintain productive forests. However, this novel disturbance will have very different effects on these forests than the typical fire-disturbance regime and is likely to deflect these forests into new successional trajectories.

scholarly journals Size-selective fishing drives species composition in the Celtic Sea

2012 ◽  
Vol 69 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Samuel Shephard ◽  
Tak Fung ◽  
Jennifer E. Houle ◽  
Keith D. Farnsworth ◽  
David G. Reid ◽  
...  
Keyword(s):  
Species Composition ◽  
Relative Abundance ◽  
Size Structure ◽  
Large Species ◽  
Strongly Correlated ◽  
Large Fish ◽  
Fish Community Structure ◽  
Community Size ◽  
Two Indices ◽  
Celtic Sea

Abstract Shephard, S., Fung, T., Houle, J. E., Farnsworth, K. D., Reid, D. G., and Rossberg, A. G. 2012. Size-selective fishing drives species composition in the Celtic Sea. – ICES Journal of Marine Science, 69: 223–234. Fishing alters community size structure by selectively removing larger individual fish and by changing the relative abundance of different-sized species. To assess the relative importance of individual- and species-level effects, two indices of fish community structure were compared, the relative abundance of large fish individuals (large fish indicator, LFI) and the relative abundance of large fish species (large species indicator, LSI). The two indices were strongly correlated for empirical data from the Celtic Sea and for data from simulated model communities, suggesting that much of the variability in the LFI is caused by shifts in the relative abundance of species (LSI). This correlation is explained by the observation that most of the biomass of a given species is spread over few length classes, a range spanning the factor 2 of individual length, such that most species contributed predominantly to either the small or the large component of the LFI. The results suggest that the effects of size-selective fishing in the Celtic Sea are mediated mainly through changes in community composition.

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