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1

Is natural regeneration of forest stands a continuous process? A case study of an old-growth forest of the Western Carpathians

100%
Szwagrzyk J., Szewczyk J.
Polish Journal of Ecology
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2008
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tom 56
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nr 4
623-633
Natural regeneration in temperate forests is known to be distributed unevenly, forming dense clumps or patches of young trees confined often to canopy gaps. However, in some studies no significant relationship between the presence of gaps and advanced regeneration was found. The analysis of the relationship between tree stand density and young trees density and growth rates was conducted to check if oldgrowth temperate forests with numerous canopy openings permit development of young trees throughout the forest floor, not only directly under canopy gaps. The study was conducted in an old-growth stand of Fagus sylvatica L., Abies alba Mill. and Picea abies (L.) Karst. in the Babia Góra National Park (Western Carpathians, Poland). The elevation is 940–1010 m a.s.l., slope inclination varies from 2 to 40%, mean annual temperature for that area is 4°C and annual precipitation amounts to 1300–1400 mm. Stand basal area in the study plot has increased from 38 m² ha⁻¹ in 1991 to 40.7 m² ha⁻¹ in 2004, and canopy openness has decreased from 15.6% in 1996 to 9.3% in 2003. Saplings were totally dominated by European beech; during 13 years of study sapling density has increased by 50%, along with the sum of sapling heights (from 0.79 mm⁻² to 1.59 mm⁻²) and the mean height (from 1.42 m to 2.46 m). The increase in sapling sizes strongly varied among individuals within plot and was only weakly related to the relative light intensities measured at the individual plot level (for sums of diameters t = 0.293, P > 0.05). The development of young generation of trees in the study area seems to support the “medium disturbance” hypothesis, with a non-continuous regeneration triggered by external disturbance, and several tree recruitment episodes during the lifespan of canopy trees.
2

Age and climate sensitivity of radial growth of Picea crassifolia to climate in a transitional climatic zone in Northwest China

100%
Zhang L., Jiang Y., Zhao S., Zhang W.
Polish Journal of Ecology
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2018
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tom 66
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nr 2
Study of the radial growth response to climate factors at different tree ages is essential for predicting forest dynamics and formulating correct management policies. In this study, we analysed the growth responsiveness of Picea crassifolia to climate conditions, and evaluated its relationship to tree age at the individual tree scale, in the transitional zone between regions affected by the East Asian monsoon and winds blowing from the west (westerlies) in the Qilian Mountains. On three study sites, 150 cores were taken from 75 trees. Pearson correlation coefficients were calculated between the standardized tree-ring series of each core (and chronology) and climatic factors which were utilized to research the climate-growth relationships. Quadratic polynomial fitting was used to test the relationships between tree age, chronological parameters, and the radial growth response to climate. Radial growth was positively influenced by total precipitation for the previous July-September and the current May-July. Additionally, radial growth was negatively correlated with the total monthly precipitation for the current September, and the mean monthly temperature for the previous July. Trees younger than 80 years old showed a stronger response to accumulative precipitation in the previous July-September, those older than 160 years old showed a stronger response to precipitation at the end of current growing season, while those of 140–160 years old showed a weaker response to precipitation in the current May-July.
3
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Can macrofungal biodiversity predict forest status and dynamics? A view from South European Mediterranean forests (Italy)

84%
Ambrosio E., Feest A.
Acta Mycologica
|
2021
|
tom 56
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nr 1
4
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Changes in horizontal structure of natural beech forests on an altitudinal gradient in the Sudetes

84%
Vacek Z., Vacek S., Bilek L., Remes J., Stefancik I.
Dendrobiology
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2015
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tom 73
The article describes horizontal structure of the tree layer, natural regeneration, snags and crown projections of natural beech stands on three permanent research plots in the wide altitudinal range in the Krkonoše Mts (Czech Republic). The spatial structure was classified from 1980 to 2010 and subsequently the prediction of spontaneous development with an outlook for 30 years (to 2040) was done by growth simulator. Hopkins-Skellam index, Pielou-Mountford index, Clark-Evans index and Ripley’s K-function were calculated. Further, the vertical structure and total diversity index was evaluated. The horizontal structure of individuals in the tree layer had not changed significantly during the monitored years. Tree spatial pattern of the lowest altitude lying herb-rich beech forest was mostly regular to random, in acidophilous mountain beech forest predominantly random and in fragments of beech groups around the timberline aggregated. Juvenile growth on all investigated plots was distributed aggregated and snags randomly. The horizontal structure of crown projection centroids had always higher values toward the regularity than tree layer and was random to regular. The result of principal component analysis also confirmed that spatial pattern was dependent on the altitude, but also on the number of trees.
5

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

84%
Szwagrzyk J., Gratzer G., Stepniewska H., Szewczyk J., Veselinovic B.
Polish Journal of Ecology
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2015
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tom 63
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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.
6

Dynamics of tree stands in the Gorce National Park [Southern Poland] during the period 1992-1997

84%
Chwistek K.
Nature Conservation
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2001
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tom 58
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