scholarly journals Roles of environmental variables and land usage as drivers of dung beetle assemblage structure in mopane woodland

2013 ◽  
Vol 39 (3) ◽  
pp. 313-327 ◽  
Author(s):  
Adrian L. V. Davis ◽  
Anthony M. Swemmer ◽  
Clarke H. Scholtz ◽  
Christian M. Deschodt ◽  
B. Power Tshikae
Keyword(s):  
Environmental Variables ◽  
Dung Beetle ◽  
Assemblage Structure ◽  
Land Usage ◽  
Mopane Woodland

scholarly journals Mesoscale variations in the assemblage structure and trophodynamics of mesozooplankton communities of the Adriatic basin (Mediterranean Sea)

2021 ◽  
Author(s):  
Emanuela Fanelli ◽  
Samuele Menicucci ◽  
Sara Malavolti ◽  
Andrea De Felice ◽  
Iole Leonori
Keyword(s):  
Food Web ◽  
Food Webs ◽  
Mediterranean Sea ◽  
Environmental Variables ◽  
Complex Structure ◽  
Assemblage Structure ◽  
Trophic Levels ◽  
Ecosystem Functions ◽  
Food Web Structure ◽  
Adriatic Basin

Abstract. Zooplankton are critical to the functioning of ocean food webs because of their utter abundance and vital ecosystem roles. Zooplankton communities are highly diverse and thus perform a variety of ecosystem functions, thus changes in their community or food web structure may provide evidence of ecosystem alteration. Assemblage structure and trophodynamics of mesozooplantkon communities were examined across the Adriatic basin, the northernmost and most productive basin of the Mediterranean Sea. Samples were collected in June–July 2019 along coast-offshore transects covering the whole western Adriatic side, consistently environmental variables were also recorded. Results showed a clear separation between samples from the northern-central Adriatic and the southern ones, with a further segregation, although less clear, of inshore vs. off-shore stations, the latter mostly dominated in the central and southern stations by gelatinous plankton. Such patterns were mainly driven by chlorophyll-a concentration (as a proxy of primary production) for northern-central stations, i.e. closer to the Po river input, and by temperature and salinity, for southern ones, with the DistLM model explaining 46 % of total variance. The analysis of stable isotopes of nitrogen and carbon allowed to identify a complex food web characterized by 3 trophic levels from herbivores to carnivores, passing through the mixed feeding behavior of omnivores, shifting from phytoplankton/detritus ingestion to microzooplankton. Trophic structure also spatially varied according to sub-area, with the northern-central sub-areas differing from each other and from the southern stations. Our results highlighted the importance of environmental variables as drivers of zooplanktonic communities and the complex structure of their food webs. Disentangling and considering such complexity is crucial to generate realistic predictions on the functioning of aquatic ecosystems, especially in high productive and, at the same time, overexploited area such as the Adriatic Sea.

scholarly journals Is microclimate-driven turnover of dung beetle assemblage structure in regenerating coastal vegetation a precursor to re-establishment of a forest fauna?

2012 ◽  
Vol 17 (3) ◽  
pp. 565-576 ◽  
Author(s):  
Adrian L. V. Davis ◽  
Rudi J. van Aarde ◽  
Clarke H. Scholtz ◽  
Robert A. R. Guldemond ◽  
Johan Fourie ◽  
...  
Keyword(s):  
Dung Beetle ◽  
Assemblage Structure ◽  
Coastal Vegetation

Seasonal Changes in Epipelic Diatoms Along an Intertidal Shore, Berrow Flats, Somerset

1991 ◽  
Vol 71 (3) ◽  
pp. 579-596 ◽  
Author(s):  
Deborah R. Oppenheim
Keyword(s):  
Organic Matter ◽  
Salt Marsh ◽  
Water Content ◽  
Seasonal Changes ◽  
Environmental Variables ◽  
Interstitial Water ◽  
Seasonal Pattern ◽  
Environmental Variable ◽  
Assemblage Structure ◽  
Epipelic Diatoms

Seasonal changes in the assemblage structure of dominant epipelic diatoms were studied along a transect crossing a salt marsh, sandflat, and mudflat of an estuarine intertidal shore at Berrow Flats, Somerset, UK. Seasonal changes in cell numbers displayed different patterns in the salt marsh and sandflat/mudflat. At salt marsh sites highest numbers of individuals were recorded in summer followed by a smaller autumn growth, while in the sandflat lower numbers showed no seasonal pattern. Repeated annual patterns in the succession of taxa were not observed as environmental conditions changed at the study site with time. Measurements of salinity, pH, interstitial water content, air and soil temperature were taken together with the diatom samples. A canonical correspondence analysis was employed to relate seasonal changes in assemblage structure to measured environmental variables. Total percentage variation in the first four axes of the species/site-environmental biplots ranged between 54 and 66°. In winter, sites and species separated most significantly along gradients of salinity and levels of organic matter. In spring and autumn, interstitial water content became a more significant environmental variable. By summer steep gradients in pH, levels of organic matter, and hypersaline conditions separated sites and assemblages into more discrete groups when compared to the more even spread of points in the other seasons. The results indicate that different combinations of environmental variables influence diatom assemblage structure seasonally.

Spatial distribution and assemblage structure of macrobenthic invertebrates in a brackish lake in relation to environmental variables

2005 ◽  
Vol 63 (1-2) ◽  
pp. 167-176 ◽  
Author(s):  
Atsushi Nanami ◽  
Hajime Saito ◽  
Takahiro Akita ◽  
Kei-ichiro Motomatsu ◽  
Hisami Kuwahara
Keyword(s):  
Spatial Distribution ◽  
Environmental Variables ◽  
Assemblage Structure ◽  
Brackish Lake
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