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1

Egg size and reproductive effort in tench [ Tinca tinca [L.] ] females from heated waters

100%
Kamler E., Stachowiak J.
Polskie Archiwum Hydrobiologii
|
1992
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tom 39
|
nr 1
2
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Effect of the kind of habitat on flowering of Hierochloe repens [Host] Simonkai

86%
Gesinski K.
Acta Agrobotanica
|
2007
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tom 60
|
nr 2
Studies on flowering of Hierochloë repens were performed over the years 2005-2007 in five habitats located in Bydgoszcz. The first habitat is a degenerated fresh ryegrass meadow (Arrhenatheretum elatioris). Another one is a degenerated form of initial xerothermic swards (Tunico-Poetum compressae). The third habitat in which the occurrence of Hierochloë repens was found and flowering was analyzed is sandy sward (Koelerio-Corynephoretea). Yet another habitat is ruderal in character and it was located on the side of the road (Convolvulo-Brometum inermis). The last one is a fertile and moist habitat of elm-ash marshy meadow being gramineous herb fringe communities in character. The evaluation was based on the following analyses: morphological characters of inflorescences (length of inflorescence, stem length, number of inflorescence branches and number of spikelets), stem and inflorescence weight and reproduction effort as well as the share of generative individuals in the population and the number of generative individuals per m². Differences were found in the structure of Hierochloë repens inflorescence in the habitats analyzed. The biggest inflorescence, in terms of all the characters analyzed, was found in fertile elm-ash marshy meadow, and the smallest in poor xerothermic sward. The highest generative reproduction potential of Hierochloë repens was found in the ruderal habitats. They are the basic potential source of generative diaspora production, which can affect the spreading of this species in Poland.
3

The effects of elevation on the morpho-anatomical and ecological traits in Cyclamen coum subsp. coum Mill. populations in the Central Black Sea Region of Turkey in contrasting habitats

72%
Ozbucak T. B., Polat G., Akcin O. E., Kutbay H. G.
Polish Journal of Ecology
|
2017
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tom 65
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nr 2
The differences in morpho-anatomical, ecological and biochemical traits of Cyclamen coum subsp. coum, threatened plant listed in CITES (Convention on International Trade in Endangered Species of Wild Fauna & Flora) have been investigated in the central Black Sea region of Turkey in the context of its distribution at different altitudes. We found that shoot length, bulb width, leaf width and length, number of branches and flowers were significantly different along elevation gradient, whereas length of tubers, number of living and dead leaves, number of nodes, specific leaf area (SLA) and leaf mass area (LMA) values, did not differ significantly, PCA analysis revealed that leaf length and width, the number of branches, soil organic matter content and available potassium concentration and N concentrations of above and belowground parts and reproductive effort (RE3) played significant role in differentiation of the studied populations, while several other studied factor were found not significant. The reproductive effort of individuals from the sea level was higher. We suggest that significant differences in the studied traits may indicate the ecotypic differentiation among populations.
4

High reproductive effort and low recruitment rates of European beech: Is there a limit for the superior competitor?

72%
Szwagrzyk J., Gratzer G., Stepniewska H., Szewczyk J., Veselinovic B.
Polish Journal of Ecology
|
2015
|
tom 63
|
nr 2
European beech is a superior competitor among the trees of Central Europe, often growing in pure stands. We proposed a hypothesis, that once beech has reached dominance in forest community, it's recruitment could become limited due to the gradual accumulation of pathogens attacking seeds and seedlings. We employed data on seed production and germination along with a field experiment to estimate the germination success of beech in two old-growth forests. Beech produced more seeds than the co-occurring coniferous trees, but less than 1% of beechnuts germinated in the next season. In the field experiment, the percentage of decayed beechnuts was 57% in the Carpathians and 61% in the Alps. Most of the dead germinants and decayed beechnuts were infested by fungi. The average number of fungal colonies per one sample in the Carpathians was significantly higher after mast year than one year before, while the differences between the Alps and Carpathians after mast years were statistically not significant. Fungi have been isolated from practically all dead beechnuts and dead germinants. The number of beechnuts per seed trap, the number of germinants around it and the relative number of fungal colonies obtained from plastic boxes placed in the same sample plot were not significantly correlated. The mortality of germinants continued throughout the spring; the number of life germinants in the middle of May amounted to 0.87% of the initial number of beechnuts in the Carpathians and only 0.28% in the Alps. High rates of beechnut and germinant mortality could probably offset the huge reproductive effort of European beech in old-growth stands and limit the possibility to attain absolute dominance by that species. However, our hypothesis that the build-up of fungal pathogens on the forest floor old-growth stands is able to stop the regeneration of beech still needs to be tested using larger data sets.
5
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Reproductive effort as an element of life strategy of Lythrum salicaria L. populations

72%
Czarnecka B., Franczak M., Nowak K.
Acta Agrobotanica
|
2007
|
tom 60
|
nr 2
The aim of the study was to compare some life strategy traits of individuals of Purple Loosestrife Lythrum salicaria within three meadow populations existing under various habitat conditions. The study attempted to answer the following questions: Do different habitat conditions affect the biomass allocation between particular organs of individuals? Can the individuals belonging to different populations of the same species realise their own unique reproductive strategy, in other words, can their reproductive effort represent various levels? In the case of L. salicaria the reproductive effort, measured by the participation of inflorescence biomass in the biomass of aboveground parts of genets, exhibits similar values (14.2-15.1%) in all the study populations, despite their habitat conditions. This fact proves that at the population level, the reproductive effort is relatively stable. Great differences are visible in the case of particular individuals within each of the populations. Specific genets in a population, depending on the habitat microstructure and the biotic relations with other individuals both of their own and other species, may realise their own reproductive strategies, being a part of their life strategies.
6
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Dendroecological differences between Taxus baccata males and females in comparison with monoecious Abies alba

58%
Iszkulo G., Jasinska A. K., Sobierajska K.
Dendrobiology
|
2011
|
tom 65
Taxus baccata L. is a rare and endangered dioecious species in Europe. Species of this mating system are considered to be the most vulnerable to extinction. It is believed that one reason for this state may be the uneven reproductive effort and different habitat requirements of the two sexes. Silver fir and European yew have very similar ecological requirements, but fir is a monoecious species. The aim of this study was to compare the growth rate andthe effect of precipitation andtemperature on the annual tree-ring width of silver fir and both sexes of European yew. The study site was the Knyazhdvir reserve in western Ukraine, located near the limit of the geographical range of both species. Knyazhdvir reserve is the site of one of the last yew populations in Europe with a large number of individuals (about 15,000 individuals above 1.3 m height) growing alongside fir.Woodsamples were taken from 15 male and15 female specimens of T. baccata andfrom 15 specimens of A. alba and were subjected to a standard dendrochronological procedure. The results showed high positive correlation between the temperatures in February andMarch andthe tree-ring width in the studied species and genders. The response of annual tree-ring width to the examined climatic factors was relatively similar in yew andfir. However slight differences were foundbetween males andfemales of T. baccata. The growth rate decreased more rapidly in females compared to males, probably following sexual maturation. Precipitation in April hada positive effect on firs andfemale yews, but not on male yews. This confirms earlier reports of the requirement of female specimens of dioecious species for a higher humidity than male individuals.
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