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Diversity of spruce ectomycorrhizal morphotypes in four mature forest stands in Poland
No full textEctomycorrhizal communities structure of Norway spruce (Picea abies L. (Karst.) was studied in four mature forest stands: Brenna, Salmopol, Zwierzyniec and Mirachowo. Morphological classification was used to distinguish the major mycorrhizal types associated with spruce in different forest types. Three of the foreststands were located within the natural geographical range of Norway spruce (Brenna, Salmopol, Zwierzyniec) and one (Mirachowo) was located in so-called “spruce-less zone”. The sites differed in terms of environmental pollution. The mountain sites (Brenna, Salmopol) were characterized by relatively high levels of air pollution. The upland forest stand (Zwierzyniec), located in the southeastern part of Poland, was affected by a moderate pollution. The lowland stand in northern Poland (Mirachowo) was free from direct impact of anthropogenic pollution. The level of mycorrhizal colonization was 100% at all the study sites. Thirty-seven mycorrhizal morphotypes were distinguished in total. The number of ectomycorrhizal morphotypes varied between sites from 12 in Salmopol to 28 in Zwierzyniec. From one to three dominant morphotypes were found at the study site. Site-specific morhotypes were also observed. The frequency of mycorrhizal morphotypes differed between the forest stands
Wpływ glinu na siewki sosny zwyczajnej inokulowane dwoma szczepami grzyba Suillus luteus: tolerancyjnym i wrażliwym na glin
No full textMycorrhizal syntheses of pine seedlings were conducted with Suillus luteus (L.) S.F. Gray, a strain
No 14 characterised by high tolerance to Al3+ ions and a strain No 62, sensitive to aluminium. The experiment
was performed as a semi-sterile culture in a peat-perlite medium with Al3+ ion concentration of 11 mM.
Abundant coralloid and cluster mycorrhizas of S. luteus were formed on roots of the inoculated plants at the
beginning of the experiment. Aluminium treatment limited mycorrhizal morphotypes to single and dichotomous
and significantly reduced the total number of mycorrhizal tips but had no effect on extramatrical mycelium
development in the potting substrate. Al treatment did not affect growth of the above-ground part of the
tested plants but significantly reduced root growth of mycorrhizal seedlings. The effect of Al on the internal
nutrient status was variable and not very much pronounced. A considerable amount of Al was absorbed by
the roots and translocated to the shoots. Mycorrhiza formation with both strains of S. luteus did not prevent
Al3+ translocation to the upper parts of the tested seedlings. The results suggest that low pH and high Al
availability may harmfully influence mycorrhizal symbiosis of Scots pine (Pinus sylvestris L.) by anega tive effect
on fine-root production and fewer short root tips available for colonisation rather than through a direct
negative effect of Al3+ ion concentrations on extramatrical mycelium in the soil.Syntezę mikoryzową siewek sosny (Pinus sylvestris)
z odpornym naglin szczepem Suillus luteus nr
14 i wrażliwym na glin szczepem nr 62 przeprowadzono
w warunkach półsterylnych w szklarni. Po
nawiązaniu mikoryzy siewki przez 6 miesięcy traktowano
roztworem glinu o stężeniu 11 mM przy pH =
3,8. W warunkach kontrolnych (bez glinu) oba
szczepy S. luteus tworzyły obfite mikoryzy pojedyncze
oraz dichotomicznie i koralowato rozgałęzione.
Traktowanie glinem zredukowało morfotypy mikoryzowe
do pojedynczych i dichotomicznych oraz
znacząco zmniejszyło całkowitą liczbę wierzchołków
mikoryzowych na korzeniach siewek, ale
nie ograniczyło rozwoju grzybni ekstramatrykalnej.
Wwarunkach kontrolnych (bez glinu) rozwój grzybni
ekstramatrykalnej, mierzony zawartością ergosterolu
w podłożu był podobny w przypadku obu testowanych
szczepów. Traktowanie glinem spowodowało
pewien wzrost rozwoju grzybni ekstramatrykalnej
szczepu tolerancyjnego i nieznaczne zahamowanie
wzrostu szczepu wrażliwego. Glin ograniczył
znacząco wzrost korzeni, natomiast nie stwierdzono
negatywnego wpływu glinu na wzrost części nadziemnych
siewek. Siewki traktowane glinem absorbowały
w korzeniach znaczne ilości tego metalu,
który był także przemieszczany do pędów. Stwierdzono
niewielki wpływ glinu na zawartość pierwiastków
mineralnych w siewkach. Badania wykazały,
że przy zastosowanym wysokim stężeniu glinu
szczep Nr 14 wyselekcjonowany w warunkach in vitro
jako odporny na glin, nie zahamował przemieszczania
jonów Al3+ do części nadziemnych siewek sosny.
Wyniki sugerują, że szkodliwe działanie jonów
glinu na symbiozę mikoryzową w warunkach niskiego
pH polegara czej naogra niczeniu liczby wierzchołków
korzeni drobnych, które potencjalnie mogą
tworzyć mikoryzy, niż nabezpośrednim wpływie na
grzybnię mikoryzową
Wplyw fungicydow stosowanych w ochronie szkolek lesnych na rozwoj mikoryz siewek sosny. Czesc I. Badania zawartosci ergosterolu w korzeniach
No full textAktywność fizjologiczna ektomikoryz w średnio zanieczyszczonym lesie (zlewnia potoku Ratanica, południowa Polska)
No full textEctomycorrhizas of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.) were sampled in a
mature forest ecosystem exposed for more than 40 years to moderate levels of gaseous and dust pollutants.
Soil of the forest site was characterised by low pH and accumulation of heavy metals (Pb, Mn, Zn, Cu, Cd, Fe).
Mycorrhizal vitality and enzyme activity of the root-surface and soil acid phosphatase (AcPase) were studied
at 17 measurement points (0–5 cm soil depth) in relation to the content of inorganic phosphate (Pi) and aluminium
ions (Al3+) in the soil. Anatomy of Scots pine and beech mycorrhizas taken from different measurement
points was observed. The concentration of essential nutrients (C, N, P, Ca, Mg) and the ratios Ca/Al,
Mg/Al and N/P were analysed in fine roots. High concentrations of Al3+ in the soil (40–118 meq kg-1) and low
levels of Pi (12–44 mg P2O5 kg-1) were accompanied by high activity of the root-surface AcPase of pine and
beech mycorrhizas (25–67 and 33–86 μmol pNP g-1 fresh weight h-1, respectively) and soil AcPase (6.8–22.4
μmol pNP g-1 dry weight h-1). The results indicate that fine tree roots are undoubtedly under stress as evidenced
by a disturbance in P uptake and accumulation. However, the high vitality of mycorrhizas and the
high Ca/Al ratio in fine roots suggest that the defence mechanisms of mycorrhizas and the rhizosphere are
still able to ameliorate the influence of anthropogenic pollution.Badania ektomikoryz sosny (Pinus sylvestris L.) i
buka( Fagus sylvatica L.) prowadzono na Pogórzu Karpackim
w dorosłym drzewostanie, który przez ponad
40 lat znajdował się pod wpływem gazowych i
pyłowych zanieczyszczeń powietrza o średnich stężeniach.
Gleby badanego ekosystemu leśnego cechowało
niskie pH oraz znaczna akumulacja metali ciężkich
(Pb, Mn, Zn, Cu, Cd, Fe). Badano zależność
między stężeniem nieorganicznego fosforanu w glebie,
a aktywnością enzymatyczną kwaśnej fosfatazy
mikoryz i gleby. Analizowano także stężenia pierwiastków
odżywczych (C, N, P, Ca, Mg) oraz jonów
glinu (Al3+) w korzeniach drobnych. Mikoryzy sosny i
buka były analizowane pod względem budowy anatomicznej
oraz żywotności. Stwierdzono stosunkowo
wysokie stężenie jonów Al3+ w glebie (40–118 meq
kg-1) i niski poziom nieorganicznego fosforanu (Pi) (12–44 mg P2O5 kg-1). Jednocześnie zarejestrowano
wysoką aktywność powierzchniowej kwaśnej fosfatazy
mikoryz sosny i buka(odpowiednio, 25–67 i 33–86
μmoli pNP g-1 świeżej masy h-1) oraz kwaśnej fosfatazy
gleby (6,8–22,4 μmoli pNP g-1 suchej masy h-1).
Stężeniafosforu w korzeniach drobnych (poniżej stężeń
uważanych za optymalne) oraz wysoki stosunek
N/P pokazują, że pobieranie i akumulację fosforu
przez systemy korzeni drobnych sosny i bukajest niedostateczne,
mimo wysokiej aktywności kwaśnej fosfatazy.
Budowa anatomiczna mikoryz, stosunkowo
duży udział żywych mikoryz w systemie korzeni
drobnych oraz wysoki stosunek Ca/Al w korzeniach
sosny i buka(odpowiednio, 1,79 i 2,38) sugerują, że
mechanizmy obronne mikoryz i mikroorganizmów
ryzosfery mają zdolność łagodzenia wpływu zanieczyszczeń
antropogenicznych
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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