Temat: population diversity - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Pseudamnicola exilis (Frauenfeld, 1863) in southern Greece: a remnant of a flock of species (Rissooidea: Hydrobiidae)?
Autorzy:: Szarowska, M.
Falniowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/83483.pdf
Data publikacji:: 2011
Wydawca:: Uniwersytet Mikołaja Kopernika. Wydział Biologii i Ochrony Środowiska. Stowarzyszenie Malakologów Polskich
Tematy:: Pseudamnicola exilis
Greece
Rissooidea
Hydrobiidae
phylogenesis
animal population
shell
morphology
gene flow
reproductive organ
diversity
Opis:: The morphology of shell, penis, and female reproductive organs was studied in five populations of Pseudamnicola exilis (Frauenfeld) from southern Peloponnese and Kithira Island (Greece). No interpopulation differences were found in any of the characters. Thirty eight sequences of mitochondrial cytochrome oxidase subunit I (COI) and nuclear ribosomal 18S RNA genes were analysed. In COI 19 haplotypes, high haplotypy diversity, low nucleotide diversity in each population, and restricted gene flow between populations were found. NCA indicated allopatric fragmentation for all populations, and long-distance colonisation and/or past fragmentation for populations 4 and 5. Mismatch distribution in the most polymorphic population 4 reflected a bottleneck followed by population growth. The values of K2P interpopulation distances, though relatively low, pointed to congeneric distinct species within the Rissooidea. The monophyly of Pseudamnicola/Adrioinsulana clade was confirmed. Most probably the studied populations of Pseudamnicola were part of a flock of vicariant species little differentiated in morphology and ecology, many of which must have disappeared due to human impact.
Źródło:: Folia Malacologica; 2011, 19, 3
1506-7629
Pojawia się w:: Folia Malacologica
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Diversity of economic and social development of rural areas of the Konecki Poviat
Autorzy:: Kiniorska, I.
Wronska, J.
Powiązania:: https://bibliotekanauki.pl/articles/60653.pdf
Data publikacji:: 2008
Wydawca:: Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:: diversity
economic development
social development
rural area
Swietokrzyskie voivodship
birth rate
migration
unemployment
business
population
private business
Opis:: This study outlines the diversification of social and economic development in selected municipalities of Konecki Poviat of the Świętokrzyskie Voivodeship. It is based on statistical data contained in available statistical sources published by the Polish Central Statistical Office (GUS). Social and economic development has been assessed in connection with characteristics of population and economy. The period of transformation triggered numerous phenomena facilitating development of rural areas; however, it also introduced negative social and economic processes. The analysis emphasized the existence of numerous alarming demographic and social phenomena, which are the strongest on the outskirts of the Konecki Poviat. The population has dropped, partially due to declining birth rate. Moreover, in the analyzed period of time the outflow of population has decreased, presumably due to slumping urban labour market. Furthermore, in the area of this study ageing of population has been discovered as a result of decreased fertility and longer life expectancy. Social and economic transformations have considerable impact on changes in the labour market. With decreased industrial employment, the rate of unemployment has risen. Within all unemployed the most numerous group is composed of people at the age of 25-34. Unfavourable unemployment structure is preserved due to educational barriers for the population of rural areas. The second serious problem is inability to pull oneself together in the new reality. In order to overcome this negative phenomenon it is vital to find new ways of stimulating activity of the population. In the late few years the number of registered private business entities increased with the greatest group in trade and repairs. This is connected with relatively low costs of establishing such businesses. It should be noted that the development of the Konecki Poviat is diversified. Far better parameters related to description of demographic, social and economic phenomena are recorded in rural areas near towns than in municipalities located on the outskirts of the Poviat.
Źródło:: Infrastruktura i Ekologia Terenów Wiejskich; 2008, 06
1732-5587
Pojawia się w:: Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Seasonal composition and population density of zooplankton in Lake Timsah, Suez Canal, Egypt
Autorzy:: El-Sherbiny, M.M.
Al-Aidaroos, A.M.
Gab-Alla, A.
Powiązania:: https://bibliotekanauki.pl/articles/47480.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: cladoceran
composition
copepod
dissolved oxygen
diversity
Egypt
Lake Timsah
mollusc
physicochemical condition
population density
rotifer
salinity
Suez Canal
zooplankton
Opis:: Zooplankton composition and abundance were investigated seasonally at ten sites in Lake Timsah and the adjacent, connected western lagoon in relation to the physicochemical conditions. A total of 42 taxa (including larval stages) were identified, among them 21 species of copepods, 6 rotifers, 5 cladocerans, 1 chaetognath and 1 urochordate. Copepods represented the predominant component (77.7% of the total community), followed by rotifers, molluscs, cladocerans and (9.2, 4.7 and 3.9% respectively), while other groups collectively formed about 4.5% of the total zooplankton population. Summer was the most productive season with an average count of 40 864 individuals m−3. The dominant copepod species were Paracalanus crassirostris and Oithona nana representing 28.3 and 24.3% of the total zooplankton respectively. The total zooplankton count, including copepods, and its dominant species showed significant positive correlations with temperature, pH and total phytoplankton density. However, negative correlations were detected between densities of rotifers, and salinity and dissolved oxygen.
Źródło:: Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Zmienność proweniencyjna olszy czarnej w Polsce
Provenance variability of black alder in Poland
Autorzy:: Rożkowski, R.
Mejnartowicz, L.
Guzicka, M.
Dorobek, K.
Chmura, D.J.
Powiązania:: https://bibliotekanauki.pl/articles/979576.pdf
Data publikacji:: 2019
Wydawca:: Polskie Towarzystwo Leśne
Tematy:: lesnictwo
drzewa lesne
olsza czarna
Alnus glutinosa
proweniencje
wysokosc drzew
piersnice drzew
piersnicowe pole przekroju
miazszosc drzew
zmiennosc proweniencyjna
alnus glutinosa
diameter
diversity
height
population
productivity
stem straightness
Opis:: European black alder (Alnus glutinosa (L.) Gaertn.) is a widespread tree species associated with wetlands and riparian ecosystems, thus it plays an important ecological role. Due to its fast growth and favorable wood properties it also has a potential to satisfy a growing demand for wood and fiber. However, its growth potential is not fully realized in Poland. In this study we investigated variation in growth traits, productivity, and stem straightness among 11 populations of European black alder originating from the lowland distribution of the species in Poland. The common−garden experiment located in 1968 in Kórnik (mid−western Poland) has been so far the only provenance experiment with this species in our country. We measured height and diameter of all trees at the site, assessed stem straightness in a 5−step scale (1−crooked; 5−straight), and calculated productivity at age of 50 years, which should be considered close to the rotation age. We found significant variation among populations in all investigated traits. The difference in productivity between the best and the worst provenance reached 75%. Using published and unpublished data from previous measurements at this site we also analyzed a trend in provenance ranking through time. The best and worst provenance could be identified at age 16 years, but many ranking shifts took place afterwards at the intermediate rank positions. We conclude that growth, productivity and stem quality of black alder could be improved through selection of favorable provenances within the species. Selection decisions can be made at the age below the half the rotation age, although decisions at 3/4 of rotation age would be more precise.
Źródło:: Sylwan; 2019, 163, 10; 830-838
0039-7660
Pojawia się w:: Sylwan
Dostawca treści:: Biblioteka Nauki