The aquatic macrophytes of Lake Vechten. Species composition, spatial distribution and production

1982 ◽  
pp. 65-77 ◽  
Author(s):  
Elly P. H. Best
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Aquatic Macrophytes

scholarly journals Spatial distribution and temporal variation of microcrustaceans assembly (Cladocera and Copepoda) in different compartments of a reservoir in the brazilian semiarid region

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Josiane Souza Santos ◽  
Nadson Ressyé Simões ◽  
Sérgio Luiz Sonoda
Keyword(s):  
Spatial Distribution ◽  
Spatial Variation ◽  
Temporal Variation ◽  
Aquatic Macrophytes ◽  
Temporal Dynamics ◽  
Lateral Compartment ◽  
Spatial And Temporal Variation ◽  
Semiarid Region ◽  
Brazilian Semiarid ◽  
Significant Spatial Variation

Abstract Aim: The objective of this study was to investigate the spatial and temporal variation of microcrustacean assemblages of a reservoir in the Brazilian semiarid region. Methods Physical and chemical water variables and samples of microcrustaceans were collected at eight sites of the reservoir between July 2013 and November 2014, in a total of seven campaigns. For this study, the reservoir was categorized in two compartments: lateral and central. Results Limnological variables showed significant temporal variation (PERMANOVA, Pseudo-F = 19.51, p = 0.001). Higher turbidity values and suspended solids were observed in the rainiest months, while during the dry months, we measured higher values of transparency, dissolved oxygen, and chlorophyll-a. It was not found significant spatial variation of limnological variables (PERMANOVA, Pseudo-F = 0.96; p = 0.394). During the study period, ten species were recorded: four Cladocera (Ceriodaphnia cornuta, Daphnia gessneri, Diaphanosoma birgei and Diaphanosoma spinulosum ) three Copepoda Calanoida (Argyrodiaptomus azevedoi, Notodiaptomus cearensis and Notodiaptomus iheringi) and three Copepoda Cyclopoida (Macrocyclops albidus, Thermocyclops minutus and Thermocyclops decipiens). The microcrustacean assemblages showed significant temporal variation (PERMANOVA, Pseudo-F = 4.34; p = 0.001) as well as significant spatial variation (PERMANOVA, Pseudo-F = 9.46; p = 0.001). The highest values of abundance and richness were observed in the lateral compartment, this result is mainly related to the presence of aquatic macrophytes in this region, because the analysis of partial RDA indicated that limnological variables explained only 11% of this variation (Pseudo-F = 2.08, p = 0.001). Conclusions The results suggest that the seasonality of the semiarid is an important factor in the temporal dynamics of the limnological variables, while the aquatic macrophytes play an important role in the spatial distribution of the microcrustacean assembly.

scholarly journals Spatial distribution and species composition of small pelagic fishes in the Gulf of California

2006 ◽  
Author(s):  
Edgar Lanz ◽  
Manuel O. Nevárez Martínez ◽  
Juana López Martínez ◽  
Juan A. Dworak
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Gulf Of California ◽  
Pelagic Fishes

Some aspects of the ecology of bagrid catfishes in a southern Nigerian river

1991 ◽  
Vol 7 (2) ◽  
pp. 221-232 ◽  
Author(s):  
George Idodo-Umeh ◽  
Reginald Victor
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Rainy Season ◽  
Major Peak ◽  
Fish Yield ◽  
Southern Nigeria ◽  
Minor Peak ◽  
A Minor ◽  
Principal Species ◽  
Dry And Rainy Seasons

ABSTRACTSome aspects of the ecology of bagrid catfishes in River Ase, southern Nigeria were studied for a period of two years. Nine species of Bagridae were recorded and these accounted for 15.0% of the number and 24.4% of the weight of all fish captured. Chrysichthys nigrodigitatus and Chrysichthys auratus longifilis were the principal species. C. nigrodigitatus was a rainy season species, while C. auratus longifilis was abundant in both dry and rainy seasons. Both species showed a major peak in catches between 0600 and 0900 h. C. nigrodigitatus exhibited a minor peak in catches between 1500 and 2100h, while C. auratus longifilis showed a minor peak between 1500 and 1800h. The spatial distribution of C. nigrodigitatus and C. auratus longifilis populations was heterogeneous. Bagrid fishes were an important component in the fish yield of the study river and its species composition has been compared with those of other Nigerian waters. The distribution and abundance of C. nigrodigitatus and C. auratus longifilis are discussed in detail.

scholarly journals Stand structure indices as tools to support forest management: an application in Trentino forests (Italy)

2013 ◽  
Vol 59 (No. 4) ◽  
pp. 159-168 ◽  
Author(s):  
F. Pastorella ◽  
A. Paletto
Keyword(s):  
Spatial Distribution ◽  
Forest Management ◽  
Species Diversity ◽  
Species Composition ◽  
Tree Species ◽  
Stand Structure ◽  
Composite Index ◽  
Mutual Position ◽  
Tree Species Composition ◽  
North East

Stand structure and species diversity are two useful parameters to provide a synthetic measure of forest biodiversity. The stand structure is spatial distribution, mutual position, diameter and height differentiation of trees in a forest ecosystem and it highly influences habitat and species diversity. The forest stand and species diversity can be measured through indices that provide important information to better address silvicultural practices and forest management strategies in the short and long-term period. These indices can be combined in a composite index in order to evaluate the complex diversity at the stand level. The aim of the paper is to identify and to test a complex index (S-index) allowing to take into account both the tree species composition and the stand structure. S-index was applied in a case study in the north-east of Italy (Trentino province). The results show that the Norway spruce forests in Trentino province are characterized by a medium-low level of complexity (S-index is in a range between 0.14 and 0.46) due to a low tree species composition rather than to the stand structure (diametric differentiation and spatial distribution of trees).  

Environmental heterogeneity influences life‐form richness and species composition but not species richness of aquatic macrophytes in tropical coastal rivers

2020 ◽  
Vol 65 (11) ◽  
pp. 1894-1905
Author(s):  
Laís Samira Correia Nunes ◽  
Cristiane Akemi Umetsu ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Aquatic Macrophytes ◽  
Environmental Heterogeneity ◽  
Life Form ◽  
Coastal Rivers

Spatial distribution and temporal variation ofMicrocystis species composition and microcystin concentration in Lake Biwa

2005 ◽  
Vol 20 (3) ◽  
pp. 270-276 ◽  
Author(s):  
Kazuhiko Ozawa ◽  
Hiroki Fujioka ◽  
Minoru Muranaka ◽  
Atsushi Yokoyama ◽  
Yukimi Katagami ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Temporal Variation ◽  
Lake Biwa ◽  
Microcystin Concentration
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