scholarly journals CHIRONOMID COMMUNITIES IN THE LITTORAL ZONE ON THE WESTERN COAST OF THE

2007 ◽  
Author(s):  
Lyubov Kravtsova
Keyword(s):  
Spatial Distribution ◽  
Species Diversity ◽  
Littoral Zone ◽  
Western Coast ◽  
Font Size ◽  
Chironomid Larvae ◽  
Baikal Basin ◽  
Shannon’S Index

<strong><span style="font-size: x-small; font-family: TimesNewRoman,Bold;"><span style="font-size: x-small; font-family: TimesNewRoman,Bold;"><p align="left">Abstract</p></span></span></strong><span style="font-size: x-small; font-family: TimesNewRoman;"><span style="font-size: x-small; font-family: TimesNewRoman;"><p align="left">The spatial distribution of chironomid</p><p align="left">communities in the littoral zone (0-20 m) of the</p><p align="left">western coast of the southern Baikal basin is</p><p align="left">investigated. The fauna is composed of 16 species</p><p align="left">and forms of chironomid larvae, comprising 10</p><p align="left">communities. It has been found that the</p><p align="left">communities are characterized by rather poor</p><p align="left">species diversity; Shannon’s index varies from</p><p align="left">0.7 to 2.1 bit. Their distribution is affected by</p><p align="left">hydro-lithodynamic conditions, type of bottom</p><p align="left">sediments and macrophyte development. The</p><p align="left">peak of maximal biomass of chironomid larvae</p><p align="left">on the facies of non-rounded rock debris near</p><p>Berezovy Cape is recorded in spring.</p></span></span>

scholarly journals Population dynamics and feeding ecology of the invasive Caucasian dwarf goby, Knipowitschia caucasica, in a freshwater habitat in Ukraine

2020 ◽  
pp. 26
Author(s):  
Alexander Didenko ◽  
Igor Buzevych ◽  
Yuriy Volikov ◽  
Svitlana Kruzhylina ◽  
Alexander Gurbyk
Keyword(s):  
Population Dynamics ◽  
Littoral Zone ◽  
Diet Composition ◽  
Sampling Site ◽  
Age Groups ◽  
Stomach Contents ◽  
Seasonal Fluctuations ◽  
Chironomid Larvae ◽  
High Diversity ◽  
Two Age Groups

Population dynamics and feeding patterns of invasive Knipowitschia caucasica were studied in the littoral zone of the lower Stugna River. The abundances of this goby showed significant inter-annual and seasonal fluctuations. The studied population of K. caucasica was represented by two age groups (0 and I). Fish die after their first breeding season. In total, 58 prey items were identified in the diet of K. caucasica at the sampling site. The most abundant prey were copepods and cladocerans, while the most frequently encountered prey were copepods and chironomid larvae. Copepods were represented mainly by Cyclopoidae. Cladocerans included 21 taxa, among which the most abundant were Diaphanosoma sp., Acroperus harpae, and Disparalona rostrata; chironomids included 22 taxa, among which the most abundant was Cricotopus sylvestris. The diet composition showed seasonal dynamics, where copepods predominated in January to April and in August-September, chironomid larvae were especially important in May to July, while cladocerans were most important in November-December. The relatively high diversity of both phytophilous and open-bottom-dwelling prey organisms in the stomach contents of K. caucasica indicates that this species fed on a large variety of benthic habitats including among macrophytes and open areas.

scholarly journals ESTRUTURA HORIZONTAL DE UM TRECHO DE FLORESTA OMBRÓFILA DENSA DAS TERRAS BAIXAS NA RESERVA BIOLÓGICA DE SOORETAMA, LINHARES, ES

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Alessandro de Paula ◽  
João Juares Soares
Keyword(s):  
Spatial Distribution ◽  
Distribution Pattern ◽  
Species Distribution ◽  
Ecological Groups ◽  
Horizontal Structure ◽  
Shannon’S Index ◽  
Dense Forest ◽  
Ombrophilous Forest ◽  
Dense Ombrophilous Forest ◽  
Biological Reserve

Este trabalho teve como objetivo analisar a estrutura fitossociológica horizontal de um trecho da vegetação arbórea de uma floresta de tabuleiro. Foi realizada uma amostragem fitossociológica em 100 parcelas contíguas de 10 x 10 m, sendo amostrados os indivíduos com PAP ≥ 15 cm. Construiu-se a distribuição diamétrica e estimou-se o padrão de distribuição espacial das espécies. Foram amostrados 1519 indivíduos, distribuídos entre 265 espécies, 138 gêneros e 44 famílias. O índice de Shannon (H’) estimado foi de 4,87 nats/ind. As espécies com os maiores VI foram Rinorea bahiensis (Moric.) Kuntze, Eriotheca macrophylla (K. Schum.) A. Robyns e Sterculia speciosa K. Schum. Em relação aos grupos ecológicos, as secundárias tardias obtiveram mais que o dobro do VC e VI das secundárias iniciais. A distribuição diamétrica apresentada pelas pioneiras foi truncada, sendo que a das secundárias iniciais foi ampla. A predominância de espécies tolerantes ao sombreamento nos estágios iniciais de crescimento reforça a ideia de que o estádio sucessional encontra-se avançado. Foram encontradas 10 espécies com padrão de distribuição espacial agregado e 29 aleatório.Palavras-chave:Fitossociologia; estrutura horizontal; Floresta Ombrófila Densa; floresta de tabuleiro; floresta atlântica. AbstractHorizontal structure of Ombrophilous dense forest of lowlands in Sooretama Biological Reserve, Linhares. This work aimed to analyze horizontal structure of arboreal vegetation from a “tableland” forest. A phytosociological sample was carried out on 100 contiguous plots of 10 X 10 meters. We sampled the individuals with PBH ≥ 15 cm, built up the diametric distribution and estimated spatial species distribution pattern. We sampled 1519 individuals, which were distributed into 265 species, 138 genera and 44 families. Shannon’s Index (H’) was estimated at 4.87 nats/ind. Species with the highest IV were Rinorea bahiensis (Moric.) Kuntze, Eriotheca macrophylla (K. Schum.) A. Robyns and Sterculia speciosa K. Schum. In relation to ecological groups, the late secondary species obtained CV and IV, twice as much as the early secondary ones. Pioneers presented truncated diametric distribution, as long as the early secondary had a broader one. Shadow tolerant species predominance reinforces that successional stadium is advanced. It had been found 10 species with aggregated spatial distribution and 29 random ones.Keywords:              Phytosociology; horizontal structure; Dense Ombrophilous Forest; tabuleiro forest; atlantic forest.

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). &nbsp;

Reproductive cycles of the bivalva molluscs Atactodea striata (Gmelin), Gafarium tumidum Roding and Anadara scapha (L.) in New Caledonia

1992 ◽  
Vol 43 (2) ◽  
pp. 393 ◽  
Author(s):  
J Baron
Keyword(s):  
Microscopic Examination ◽  
Shell Length ◽  
Sexual Differentiation ◽  
Littoral Zone ◽  
New Caledonia ◽  
Breeding Period ◽  
Western Coast ◽  
Hot Season ◽  
Reproductive Cycles ◽  
Macroscopic Examination

Monthly samples of the bivalves Atactodea striata, Gafrariurn turnidum and Anadara scapha were collected over 1 year from the littoral zone on the south-western coast of New Caledonia. A. striata and G. turnidum were studied by macroscopic examination of gonads and microscopic examination of gamete smears. For A. scapha, only microscopic examination was used. A. striata and G. turnidum are dioecious, whereas A. scapha is a protandric hermaphrodite. Sexual differentiation begins at a shell length of 20 mm for A. striata and G. turnidum and 22 mm for A. scapha. The three species have an extended or continuous breeding period, although, in all three, sexual activity peaks in the hot season.

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