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The Ponto-Caspian and native amphipod life history in the Daugava River, Latvia

Paidere Jana, Brakovska Aija

Oceanological and Hydrobiological Studies

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2022

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Vol. 51, No. 3

268--282

EN

Population structure, reproductive parameters and other life history traits are among the main preconditions for alien amphipods’ successful invasion. In the freshwaters of Northern Europe, i.e. Latvia, the overall life history of alien Ponto-Caspian amphipods is little known. Furthermore, the population structure and reproductivity of native Gammarus pulex have not been studied in Latvian freshwaters. The aim of the study was to describe the life history of Gammarus varsoviensis, Pontogammarus robustoides and the coexistent G. pulex. Their population structure, reproductive period and fecundity in the Daugava River were evaluated as part of this study from 2017 to 2019. The results revealed that the reproductive period of G. varsoviensis and P. robustoides lasted from four to five months, with up to three generations per year and a high proportion of juveniles. The average number of eggs for G. varsoviensis was 31 (maximum: 69) and for P. robustoides 28 (maximum: 81), with ovigerous females of both species being an average of 11.3 mm. Gammarus pulex had one generation per year with a high proportion of juveniles. The average number of eggs per brood was 27 (maximum: 41) with the average size of ovigerous females being 10.7 mm.

2

Variation in the Timing of Reproduction and Clutch Size of Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus in the Saharan Atlas of Algeria

Adamou A.-L., Kouidri M., Bańbura A., Ouakid M. L., Chabi Y., Bańbura J.

Polish Journal of Ecology

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2015

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Vol. 63, nr 4

599--607

EN

We examined the variation in the date of the onset of egg laying and clutch size in three peripheral populations of the Afrocanarian Blue Tits Cyanistes teneriffae ultramarinus at the edge of the species and subspecies geographic range. This study was carried out in three study sites, 130–290 km apart, in similar geographic conditions of the South Border Range of the Saharan Atlas in Algeria. Mean altitudes of nesting territories were between 1327 and 1437 m a.s.l. Habitats of the study sites were covered by the secondary, human-modified vegetation, ranging from a maquis shrubland, with the Holm oak Quercus ilex shrubs to woodlands dominated by the Atlas cedar Cedrus atlantica or by the Aleppo pine Pinus halepensis. 169 wooden nest-boxes were monitored for breeding parameters (laying dates and clutch sizes) during the breeding seasons 2007–2009 and 2011–2013. The timing of egg laying was relatively late for the latitude of the study sites, with overall mean laying dates varying between the study sites from 4 to 13 May. The laying date was influenced by the altitude of nesting sites, with the dates being delayed with increasing altitude. Overall mean clutch size differed between the study sites from 5.91 at Djelfa to 8.43 at Aflou. Clutch size tended to decrease with the advance of the breeding season. Because the study populations inhabit areas of similar physical conditions (climate and altitude), the main inter-population source of variation in the breeding parameters studied was probably variation in habitat quality.

3

Road-side herbaceous vegetation : life history groups and habitat preferences

Sera B.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

69-79

EN

The study examine s the vegetation diversity (235 herbaceous species) in variable road-site types in terms of life history components (life traits) like life form, type of pollination, seed dispersal, spreading ability, life strategy according to Grime's classification, and in terms of habitat preferences using Ellenberg's indicator value (in relation to light, temperature, moisture, nitrogen, soil pH and soil salinity). Plants registered as alien species were evaluated also according to invasive status, level of abundance, introduction mode and land use habitat. Study localities (9 sites) were situated in the Ceskomoravska highlands and the South Bohemian regions (Czech Republic). The plant species were recorded in the bands (width in range of 1.5-3.0 m) along the verge of two types of roads (motorways with median stripes) and secondary roads (II and III classes). In total - road length of about 15 km and the total area of roadside vegetation of about 8 ha were surveyed. The annual/therophyte species with a tendency to seed dispersed by wind, preferring a light and dry habitat, and having the RC (competitiveruderal) life strategy were mainly found along the motorways. It means that road verges along motorways are quite insolated and constitute the dry habitats, probably suitable for ruderal, weedy, non-native, and invasive species. On the contrary, species with a tendency to vegetative reproduction and the C (competitive) strategy occur mainly along the secondary roads. It seems that the secondary roads are alternative habitats for grassland flora. Species occurred on the verges of the secondary roads do not belong to the particular group of the life traits. The salt tolerant species Puccinellia distans (Jacq.) Parl. was found along all types of roads. Almost 24% of all recorded herbaceous species growing in road-sites were alien species.

4

Patterns of genetic diversity in populations of Filipendula ulmaria (L.) at different stages of succession on a meadow abandoned for 30 years

Falińska K., Lembicz M., Jarmołowski A., Borkowska L.

Polish Journal of Ecology

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2010

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Vol. 58, nr 1

27-40

EN

Genetic diversity and spatial variation of two populations of Filipendula ulmaria (L.) were analysed at the initial stage (macroforbs) and the late succession stage (forest community) during a 30-year succession on the abandoned meadows in Białowieża National Park. The study demonstrated a high level of genetic diversity in both populations (D = 0.86 and D = 0.79 in the population at the initial and late succession stage, respectively). Significant genetic differentiation was observed at the cross-population level (FST = 0.008, P <0.001). Among 303 ramets in the population at the initial stage 261 genotypes were detected, of which 24 were clonal, and the remaining (237) were unique (91%). In the population at the late succession stage 92 genotypes were detected among 116 ramets of which 10 were clonal, and 82 unique (89%). The results did not confirm a hypothesis that the low level of the population.s genetic diversity should be expected at the late succession stage. Additionally, the study demonstrates that the prolonged clonal spreading does not always result in genetic monotony of a population. It has been demonstrated that the high level of genetic diversity in the population of clonal species F. ulmaria could be the result of temporal changes in life history traits of long-lived genets. The formation of gaps caused by the disintegration of senile genets and the permanent recruitment of seedlings over 30 years of population development reinforce the appearance of new genets. This process was reflected in both populations by the domination of unique genets and spatial pattern of genotypic diversity.

5

The effect of salinity on freshwater crustaceans

Grzesiuk Małgorzata, Mikulski Andrzej

Polish Journal of Ecology

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2006

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Vol. 54, nr 4

669-674

EN

Recent advancing industrialization and urbanization have increased salt concentrations in formerly-freshwater habitats. Freshwater animals are being affected, especially those like crustaceans that are unable to emigrate to escape the problem. The effects of increased salinity, first observed at the molecular level, are found to extend to the levels of the individual, population, community and ecosystem. Crustacean morphology, behaviour and life histories may be influenced, with growth rate, and age and size at first reproduction, being disturbed, along with clutch and neonate size. Mortality rates are also elevated where the salt concentration is high, though susceptibility to salt differs both between species and between clones of the same species. The effect may be to modify the composition of crustacean assemblages in terms of the species and clones present.