A Competition Hierarchy among Boreal Ants: Impact on Resource Partitioning and Community Structure

Oikos ◽  
1988 ◽  
Vol 51 (2) ◽  
pp. 135 ◽  
Author(s):  
Riitta Savolainen ◽  
Kari Vepsäläinen ◽  
Kari Vepsalainen
1982 ◽  
Vol 64 (2) ◽  
pp. 125-143 ◽  
Author(s):  
Glen A. Smith ◽  
Janet S. Nickels ◽  
William M. Davis ◽  
Robert F. Martz ◽  
Robert H. Findlay ◽  
...  

Web Ecology ◽  
2008 ◽  
Vol 8 (1) ◽  
pp. 125-134 ◽  
Author(s):  
M. Behangana ◽  
L. Luiselli

Abstract. Community structure was studied across six different habitat types in an amphibian assemblage constituted by 24 species belonging to five families, from Lake Nabugabo, Uganda. We employed a suite of different statistical methods, including univariate, multivariate, and Monte Carlo procedures to investigate the randomness/nonrandomness and the seasonal effects (wet versus dry season) of the community assembly. We calculated for each species in each habitat type an index of relative abundance by using a time constrained counting technique, with 48 1-h counts for each habitat type. Co-occurrence was analysed by C score with 30 000 simulations; resource partitioning patterns by RA2 and RA3 algorithms with 30 000 simulations; and apparent dissimilarity among species in terms of habitat use by UPGMA dendrograms. After pooling data from wet and dry seasons, it resulted that the amphibian community was non-randomly assembled according to C-score analyses, but both RA2 and RA3 were unable to uncover any competitive structure for the dataset. Seasonal effects were evident, and although C score analyses confirmed a nonrandom structure for the community under study (particularly in wet season), RA3 showed that species with high relative abundance tended to significantly concentrate in one habitat type (swamp forest) rather than to partition the habitat resource. UPGMA dendrograms grouped the species differently in dry versus wet seasons. Overall, the comparative evidence of 1) non-random community structure according to C-score analysis, and 2) absence of resource partitioning according to niche overlap null models analysis, suggests that community organization in Lake Nabugabo amphibians is generated by habitat affinities rather than by interspecific competition.


SIMBIOSA ◽  
2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Notowinarto Notowinarto ◽  
Ramses Ramses ◽  
Mulhairi Mulhairi

Bulang districts Batam Islands of  Riau province (Riau Islands), its consists of many islands with as well as having the potential diversity of coastal marine life in particular kinds of macro algae or seaweed. Conducted research aimed to determine the structure of macro- algal communities in the intertidal zone islands. The results of the identification of algal species found 16 species are: the Order of Chlorophyceae as 6 spesies; Order Phaeophyceae as 2 spesies; and Order Rhodophyceae as 8 spesies. The community structure at the five stations showed the highest values were found in the island of dominance Cicir (D ' = 0.79) , uniformity index values on Tengah Island (E ' = 0.99) , while the island Balak had the highest diversity index (H ' = 0.88) , with the abundance patterns of population structure on the island is pretty good Central . Results of correlation analysis of regression between IVI types of algae with the conditions of environmental quality suggests that there is a significance (Fhit ˃ F table and the value of r = > 90 %) between IVI algae Halimeda sp and Cryptarachne polyglandulosa at each station with a temperature parameter surface (⁰C) , depth temperature (⁰C) and pH values. Keywords : Algae, Community Structure, Important Value Index.


2018 ◽  
Vol 81 (2) ◽  
pp. 109-124 ◽  
Author(s):  
JL Pinckney ◽  
C Tomas ◽  
DI Greenfield ◽  
K Reale-Munroe ◽  
B Castillo ◽  
...  

2014 ◽  
Vol 73 (1) ◽  
pp. 51-67 ◽  
Author(s):  
A Jain ◽  
M Bandekar ◽  
J Gomes ◽  
D Shenoy ◽  
RM Meena ◽  
...  

2020 ◽  
Vol 640 ◽  
pp. 79-105
Author(s):  
ET Porter ◽  
E Robins ◽  
S Davis ◽  
R Lacouture ◽  
JC Cornwell

Anthropogenic disturbances in the Chesapeake Bay (USA) have depleted eastern oyster Crassostrea virginica abundance and altered the estuary’s environment and water quality. Efforts to rehabilitate oyster populations are underway; however, the effect of oyster biodeposits on water quality and plankton community structure are not clear. In July 2017, we used 6 shear turbulence resuspension mesocosms (STURMs) to determine differences in plankton composition with and without the daily addition of oyster biodeposits to a muddy sediment bottom. STURM systems had a volume-weighted root mean square turbulent velocity of 1.08 cm s-1, energy dissipation rate of ~0.08 cm2 s-3, and bottom shear stress of ~0.36-0.51 Pa during mixing-on periods during 4 wk of tidal resuspension. Phytoplankton increased their chlorophyll a content in their cells in response to low light in tanks with biodeposits. The diatom Skeletonema costatum bloomed and had significantly longer chains in tanks without biodeposits. These tanks also had significantly lower concentrations of total suspended solids, zooplankton carbon, and nitrite +nitrate, and higher phytoplankton carbon concentrations. Results suggest that the absence of biodeposit resuspension initiates nitrogen uptake for diatom reproduction, increasing the cell densities of S. costatum. The low abundance of the zooplankton population in non-biodeposit tanks suggests an inability of zooplankton to graze on S. costatum and negative effects of S. costatum on zooplankton. A high abundance of the copepod Acartia tonsa in biodeposit tanks may have reduced S. costatum chain length. Oyster biodeposit addition and resuspension efficiently transferred phytoplankton carbon to zooplankton carbon, thus supporting the food web in the estuary.


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