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Vitality of European Beech (Fagus sylvatica L.) at the Limit of Its Natural Range in Poland

Dobrowolska D.

Polish Journal of Ecology

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2015

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Vol. 63, nr 2

260--272

EN

The European beech is a major component of central European forests, and the eastern limit of its range lies in Poland. However, the Holocene migration of the beech is not yet finished, especially in NE Poland, so the northern distribution of the beech continues to change. The main goal of this study was to determine if the beech will reach its northern limit in the future. The investigation was carried out in 18 beech stands in Poland. To study the status of the health of the trees, circular plots were established in grids of different sizes. The basal beech stand area ranged from 3.7 m2 ha-1 to 31.2 m2 ha-1. The density of trees exceeded a hundred trees per hectare in most of the plots (61%), and the average degree of defoliation was not greater than 60% in all of the investigated stands. Environmental conditions influenced defoliation of beech trees (Fisher's test, F = 4.0204; P <0.0001). The vitality of the beech trees varied between stands (Kruskal-Walis test, H = 139.7433, P <0.0001) and was rather good in 56% of the study plots. Seedlings and saplings were observed in all of the investigated stands, and they covered from 5 to 39% and 21 to 80% of the study plots, respectively. Spontaneous beech regeneration was widespread and differed from stand to stand as well as within stands in all of the study plots. The number of tall seedlings in most of the study plots (56%) was greater than 10,000 individuals per hectare. The factors limiting beech regeneration were stand density and herb cover, and the number of beech seed trees influenced the quantity of small seedlings. Beech tree density positively influenced the number of small seedlings, and the strength of the correlation was moderate and statistically significant (Pearson correlation, r = 0.349). Beech tree density influenced the vitality of tall and small saplings (Pearson's correlations, r = 0.673 and r = 0.361, respectively). The spontaneous regeneration and strong vitality of seedlings and saplings suggests that beech can create stable stands in the future and that it is an expansive tree species both within its continuous range and at the limit of its distribution. It is quite possible that beech will reach its north-eastern limit in Poland in the future.

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High Reproductive Effort and Low Recruitment Rates of European Beech: Is There a Limit for the Superior Competitor?

Szwagrzyk J., Gratzer G., Stępniewska H., Szewczyk J., Veselinovic B.

Polish Journal of Ecology

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2015

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Vol. 63, nr 2

198--212

EN

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.

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Importance of coarse woody debris (CWD) for moisture control and survival of Norway spruce (Picea abies L. Karst.) seedlings

Pichlerová M., Homolák M., Pichler V., Kurjak D., Jaloviar P.

Polish Journal of Ecology

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2013

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Vol. 61, nr 3

471--476

EN

Highly decayed coarse woody debris (CWD) is an important seedbed substrate in various forest ecosystems. In Europe, this particularly holds for spruce forests on shallow soils with insufficient water-holding capacity. Effect of Norway spruce (Picea abies L. Karst.) seedlings cover on CWD moisture was investigated under field conditions. Our hypothesis was that if CWD provides moisture benefits for successful recruitment and further growth of spruce seedlings, CWD water content should be considerably reduced in nurse logs compared to logs without spruce seedlings. The study was conducted in a natural subalpine Norway spruce forest located in the massif of Poľana (1351 m a.s.l.), Western Carpathians, Slovakia. Six downed spruce logs in advanced stage of decay were selected in the forest, three of them covered with advanced seedlings and the remaining logs devoid of them. CWD moisture was measured by Time Domain Reflectometry during two vegetation periods (2007, 2008). Average difference between CWD moisture in logs with and without advanced seedlings was –0.09 and thus significant at P = 0.02 according to t-test. Based on the tested assumption that throughfall was comparable for both groups of logs, the assessed evaporation of the seedlings cover reached ca 0.73 mm day-1 m-2 of CWD surface (in the horizontal projection) during one vegetation period. This rate is generally comparable with seedlings growing in soils under unconstrained moisture conditions. The role of nurse logs in the recruitment of spruce seedlings is therefore mainly important on soils with limited water-holding capacity.

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The Pinus rotundata Link bog forests on mined peat bogs - is the conservation of undisturbed edge an effective tool for its protection?

Unar P., Janík D., Souček J., Vrška T., Adam D., Král K., Hort L.

Polish Journal of Ecology

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2012

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Vol. 60, nr 4

707--715

EN

Peat mining has a serious impact on the Pinus rotundata Link habitat. The possibility of sustaining a vital Pinus rotundata bog forest on undisturbed edges of mined peat bog was assessed. 28.7 ha of undisturbed edge of Borkovická blata peat bog were sampled by regular grid of circular sample plots. Data about tree layer, natural regeneration of woody species as well as herb layer were collected. The impact of mined area drainage on vegetation communities in the undisturbed edge of peat bogs was discovered. The original Pinus rotundata bog forest is getting older and it is gradually being replaced by forest stands dominated by Picea abies (L.) Karsten, Betula pendula Roth and B. pubescens Ehrh. The character of vegetation changes more rapidly with the increasing vertical distance of the remaining fragment and the mined part. This secondary elevation represents a serious problem in the water regime restoration and consequent revitalisation of the Pinus rotundata bog forest on the undisturbed edge of the mined peat bog.

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Morphological plasticity of leaves in natural regeneration of Fagus sylvatica L. : effects of direct and diffuse light, ontogeny and shoot type

Jarcuska B.

Polish Journal of Ecology

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2011

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Vol. 59, nr 2

339-353

EN

It is known that the role of accessible light as a growth-determining factor in beech natural regeneration rises in importance with growth of individuals. However, the accompanied changes in leaf traits underlying this shift in light demands are not well known. The aim of this study was to investigate influence of ontogenetic stage (0.5 m high 'seedlings', 2.1 m 'saplings'), shoot type (terminal, lateral long and lateral short) and diffuse and direct light on morphological traits of leaves at spring-shoot-level in naturally regenerated beech individuals - shoot mean leaf area (mLA), shoot mean leaf weight (mLW), leaf mass per area (LMA), leaf area per shoot unit length (LAL), leaf mass per shoot unit length (LWL), number of leaves per shoot unit length (NLL), and ratio of mean-leaf width to its length (LSh). Ontogenetic drift affected the values of these traits; its influence depended on shoot type and component of light. The light explained more trait variability in saplings compared to seedlings (on average 45% vs 32%). The most evident shift was in the case of direct light - while direct light explained on average 18% of traits variability in seedlings, it was about 42% in saplings. The saplings compared with seedlings showed higher values of mLA, mLW, LMA, LAL on short shoots, LWL on lateral long and short shoots, LSh on terminal and lateral long shoots, and lower NLL values on terminal and long lateral shoots. Plastic response to light was higher in saplings than in seedlings (except mLA). Generally, the observed traits showed more plastic response to diffuse than to direct light in seedlings; the response of saplings was similar in both light components. The most plastic trait was LMA, the least LSh. Individuals of saplings displayed higher plasticity in traits close correlating with annual length growth of main axis, which suggests that saplings would benefit from increased light availability more than seedlings.