scholarly journals Keystone role of Eurasian beaver Castor fiber in creating the suitable habitat over the core breeding range for forest specialist species the three-toed woodpecker Picoides tridactylus

2019 ◽  
Vol 25 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Krzysztof Pietrasz ◽  
Dawid Sikora ◽  
Tomasz Chodkiewicz ◽  
Magdalena Ślęzak ◽  
Bartłomiej Woźniak

The European breeding range of the three-toed woodpecker Picoides tridactylus overlaps with the distribution range of coniferous and mixed forests with domination of Norway spruce Picea abies or European silver fir Abies alba. The paper describes a new breeding site of the three-toed woodpecker in the Sobibór Forest, eastern Poland outside the distribution range of these two tree species and its relationship with Eurasian beaver Castor fiber. The birds occurred in dead alder forests and were recorded 3–4 years after forest started to decline due to the high level of surface waters associated with the keystone role of the beaver. The decaying cycle of trees was possible because the area settled by woodpeckers was protected as a nature reserve.

2021 ◽  
Vol 30 (1) ◽  
pp. 78-89
Author(s):  
Nataliya O. Kryuchenko ◽  
Edward Ya. Zhovinsky ◽  
Petr S. Paparyga

he objective of the paper was determining biogeochemical peculiarities of ac- cumulation of chemical elements (Mn, Ni, Сo, V, Cr, Zr, Cu, Pb, Zn, Ba, P) by wild-grow- ing shrubs (stems and leaves) – bog bilberry (Vaccіnium uliginоsum), European blueberry (Vaccinium myrtillus L.), alpine juniper (J. communis subsp. alpina); perennial herbaceous plants (flowers and leaves) – common tormentil (Potentіlla erecta (L.) Hampe), willow gentian (Gentiana asclepiadea), true sedges (Carex); and trees (needles) of European silver fir (Abies alba) on nine plots in the Svy- dovets Massif of the Ukrainian Carpathians. The results we obtained based on field surveys (selection of samples of soil and vegeta- tion) and interpretation of their analysis allowed us to determine the total regional background of chemical elements in soils and ash of plants using emission spectral analysis. We assessed the total concentration of chemical elements in soils of the plots (least to highest): the Apshynets Ridge – the Herashaska Polonyna – Drahobratske Lake – the Svydovets stream – Apshynets Lake – Herashaske Lake – the Zhuravlyne Bog – Vorozheske Lake (group of small lakes) – Vorozheske Lake (large) and determined the dependence on type of soil and pH. We determined that for wild-growing herbaceous plants the biogeochemical activity of species increases in the following sequence: true sedges - willow gentian - common tormentil; for wild-growing shrubs (bog bilberry, European blueberry, alpine juniper) such a sequence is impossible to determine due to the great difference between the values on different plots. We determined the role of each plant as medicinal for treating microelement deficiency in Cu, Zn, Co. We determined that in the plot of the Herashaska Polonyna, the needles of alpine juniper contain a maximum amount of Zn and Co, the needles and leaves of bog bilberry – Cu, Zn, Co; the flowers and leaves of common tormentil by Apshynets Lake and European silver fir near the area of the Svydovets stream – Cu. We calculated the daily dose of each element according to species of plants to overcome microelementosis. The results of biogeochemical surveys may be the basis for determining and recommending plants as medicinal, and also of geochemical and biogeochemical monitoring studies.


Author(s):  
Robert J. Needham ◽  
Martin Gaywood ◽  
Angus Tree ◽  
Nick Sotherton ◽  
Dylan Roberts ◽  
...  

Globally, freshwaters are the most degraded and threatened of all ecosystems. In northern temperate regions, beaver (Castor spp.) reintroductions are increasingly used as a low-cost and self-sustaining means to restore river corridors. River modifications by beavers can increase availability of suitable habitat for fish, including salmonids. This study investigated the response of a population of brown trout (Salmo trutta) to reintroduced Eurasian beaver (Castor fiber) habitat modifications in northern Scotland. The field site comprised two streams entering a common loch; one modified by beavers, the other unaltered. Electrofishing and PIT telemetry surveys indicated abundance of post-young-of-the-year (post-YOY) trout was higher in the modified stream. Considering juvenile year groups (YOY and post-YOY) combined, abundance and density varied with year and season. In the modified stream, fork length and mass were greater, there was a greater variety of age classes, and mean growth was positive during all seasons. Beavers had profound effects on the local brown trout population that promoted higher abundances of larger size classes. This study provides important insight into the possible future effect of beavers on freshwater ecosystems.


2018 ◽  
Vol 64 (No. 6) ◽  
pp. 245-250 ◽  
Author(s):  
Podrázský Vilém ◽  
Vacek Zdeněk ◽  
Kupka Ivo ◽  
Vacek Stanislav ◽  
Třeštík Michal ◽  
...  

The effects of silver fir (Abies alba Miller) on the soil compared to Norway spruce (Picea abies (Linnaeus) H. Karsten) were evaluated. Altitude of the study site is 790 m a.s.l., mild slope of 10° facing SW, forest site is spruce-beech on acid soil. The forest floor and top soil horizons (L + F1, F2 + H, Ah) were sampled in 4 replications beneath unmixed Norway spruce and silver fir groups. Comparing the soil-forming effects of both species, few significant differences were found in the Ah horizon – contents of total C, N, exchangeable Al and plant available Ca were higher beneath spruce. The soil improving role of silver fir compared to spruce was confirmed at the studied locality.


2018 ◽  
Vol 644 ◽  
pp. 1371-1379 ◽  
Author(s):  
Roberto Cazzolla Gatti ◽  
Terry V. Callaghan ◽  
Inna Rozhkova-Timina ◽  
Anastasia Dudko ◽  
Artyom Lim ◽  
...  

2017 ◽  
Vol 59 (1) ◽  
pp. 45-58
Author(s):  
Ewa Maria Pawlaczyk ◽  
Alina Bączkiewicz ◽  
Katarzyna Buczkowska ◽  
Maria Anna Bobowicz

Abstract Progeny from 19 family lines of silver fir (Abies alba Mill.) from a small, native and isolated population from the Tisovik Reserve (Belarusian part of Białowieża Primeval Forest) growing in an experimental plot near Hajnówka (Polish part of Białowieża Primeval Forest) were analysed in terms of 4 nuclear microsatellite DNA loci and 9 isozyme systems with 14 loci. The aim of this study was to determine the genetic variation within and between progeny lines. Analysis of isozyme loci showed that all progeny lines, except the progeny lines T6 and T16, were characterised by an excess of heterozygotes and 20% of the detected variation occurred between progeny. Progeny formed two groups. Microsatellite loci showed that 6 progeny lines demonstrated an excess of heterozygotes and 12 an excess of homozygotes. On an average, the population was in the Hardy-Weinberg equilibrium. Analysis of molecular variance (AMOVA) showed that 14% of the detected variation occurred between offspring and the remaining 86% within progeny lines. The most distinct progeny line was Tl, where the highest number of alleles per locus was detected. Generally, progeny of Tisovik is characterised by high level of differentiation as the offspring of isolated population that have limited number of individuals to crossing (only 20). In some progeny line, the private alleles that are detected may be the result of pollination from Polish part of Białowieża Forest where in 1920s and 1930s of XX century had planted the seedling of silver fir of unknown origin. The substructuring of population is observed, and the detected deficiency of heterozygotes may be ostensible as a result of the Wahlund effect. Such pattern of genetic structure could also be an effect of harsh environmental conditions exerting selection pressure and modifying the genetic composition of this population.


Acrocephalus ◽  
2013 ◽  
Vol 34 (156-157) ◽  
pp. 27-32 ◽  
Author(s):  
Draženko Rajković ◽  
Draško Grujić ◽  
Radosav Novčić ◽  
Radislav Mirić

Abstract The altitudinal distribution, breeding density and population size of Tengmalm’s Owl Aegolius funereus was studied in Kopaonik National Park (central Serbia) during the 2011 and 2012 breeding seasons. The size of the study area was 24 km2. The survey method applied was a line transect in combination with stop points and playback of territorial male call. During the two-year research project, 37 territories were located. In Kopaonik National Park, Tengmalm’s Owl males inhabit Norway Spruce Picea abies, mixed Norway Spruce-Silver Fir Abies alba and Norway Spruce-European Beech Fagus sylvatica forests in the altitudinal belt stretching between 1,367 and 1,689 m a.s.l. The breeding density in the studied area was 8.3 territories/10 km2 in 2011 and 7.1 territories/10 km2 in 2012. Total population estimate of Tengmalm’s Owl in Kopaonik National Park is substantially higher than previously assumed, its 42-49 breeding territories making it currently the most important breeding site in Serbia.


2011 ◽  
Vol 6 (4) ◽  
pp. 587-596 ◽  
Author(s):  
Zuzana Vondráková ◽  
Kateřina Eliášová ◽  
Lucie Fischerová ◽  
Martin Vágner

AbstractThe somatic embryogenesis of conifers is a process susceptible to exogenous phytohormonal treatments. We report the effects of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) and the auxin inhibitor p-chlorophenoxyisobutyric acid (PCIB) on the endogenous level of the auxin indole-3-acetic acid (IAA) and on the anatomical composition of early somatic embryos of Abies alba (European silver fir). The embryogenic suspensor mass (ESM) of Abies alba proliferated on a medium supplemented by 2,4-D as well as on an auxin-free medium. The endogenous level of IAA was significantly higher in the ESM cultivated on a medium supplemented by 2,4-D. The decrease in the endogenous level of IAA in the first week of maturation is one of the most important stimuli responsible for the subsequent development of embryos. However, suppression of IAA synthesis by an auxin inhibitor did not stimulate the development of embryos. The maturation of somatic embryos from the globular to the cotyledonary stage occurs when the concentration of endogenous auxin in the ESM (including the embryos) increases. Early somatic embryos proliferating on a medium supplemented by auxin had an increased probability of maturing successfully. Exogenous auxin treatment during maturation did not compensate for the auxin deficiency during proliferation.


2017 ◽  
Vol 14 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Melissa Kelly

This article uses the concepts of ‘transnational social fields’ and ‘habitus’ to explore the multifaceted role families play in shaping the aspirations of onward migrating youth. The article draws on biographical life history interviews conducted with the children of Iranian migrants who were raised in Sweden but moved to London, UK as adults. The findings of the study suggest that from a young age, all the participants were pressured by their parents to perform well academically, and to achieve high level careers. These goals were easier to achieve in London than in Sweden for several reasons. Interestingly, however, participants’ understandings of what constituted success and their motivations for onward migration were nuanced and varied considerably by gender. The study contributes to an understanding of the role of multi-sited transnational social fields in shaping the aspirations of migrant youths, as well as the strategies taken up by these migrants to achieve their goals.


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