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Value of merchantable timber in Scots pine stands of different densities

100%

Bembenek M., Karaszewski Z., Kondracki K., Lacka A., Mederski P. S., Skorupski M., Strzelinski P., Sulkowski S., Wegiel A.

Drewno. Prace Naukowe. Doniesienia. Komunikaty

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2014

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tom 57

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nr 192

Differences in the intensity of silvicultural treatments, as well as natural tree mort-ality, insect damage and fungal disease can eventually lead to variable stand density even on sites of the same quality. In addition, the bigger the initial stand density,the smaller the crown and trunk volume of single trees. The objective of theresearch was a detailed analysis of the impact of stand density on the total stand volume and value of merchantable timber. The area studied was in Drawno ForestDistrict, north-west Poland, on sites with sandy soil conditions typical for Scots pine (Pinus sylvestris L.). The total volume of merchantable roundwood wasmeasured on 20 sample plots (each covering an area of 0.5 ha) of which 19 were in 82-year-old stands and one in an 87-year-old stand. The stands were divided into three stand density groups (SDG), where the average number of trees growing per group was as follows: 547 (SDG I), 651 (SDG II) and 765 (SDG III). The volume ofa single tree was calculated using diameter (DBH) and height measurement. A qualityclassification of all 6432 tree stems was carried out in accordance with the Polish Standard. Statistical analysis did not indicate that density influenced the total timber volume of the stands studied, which was recorded as an average of 323 m3∙ha-1. However,statistically significant differences in the value of merchantable timber were observed:the highest value of 100 m3 of merchantable timber was recorded in SDG I (€ 5118.87), 6 and 12% higher than in SDGs II and III (€ 4842.09 and € 4565.80, respectively).The results obtained suggest that in the final phase (the last two age classes), pine stands growing in Polish conditions should be maintained at a lower stand density.

2

Adaptation of European beech [Fagus sylvatica L.] to different ecological conditions: leaf size variation

100%

Barna M.

Polish Journal of Ecology

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2004

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tom 52

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nr 1

This paper focuses on the issue related to the response of beech leaves to the opening of stand canopy resulting from a shelterwood cut of various intensity. Four research plots each with a different stand density provided different conditions for the development of foliage. The research was conducted on dominant, codominant and subdominant sample trees representing the mean stand diameter of all plots. The data were compared for the upper, middle and lower layer of tree crowns (each equals to one third of crown length). As for dominant and codominant trees, mean leaf area showed a tendency to increase towards the lower crown layer. As for subdominant trees, relation between the location of leaves in the crown and leaf area was similar to dominant and codominant trees but this trend was observed only on the plot most open. Only in the case of codominant trees the leaf area was decreasing with a decreasing stand density. Greater stand opening results in a proportionally smaller leaf area. Growing conditions for subdominant tree leaves were completely different when compared to conditions for upper tree classes. On the plots with harvest cutting we observed that a decreasing stand density resulted in a general increase of leaf size. The only exception to the rule was the control plot where the parameters recorded were higher and inconsistent with the above described trend.

3

Altitudinal variability of the soil water content in natural and managed beech [Fagus sylvatica L.] forests

80%

Pichler V., Durkovic J., Capuliak J., Pichlerova M.

Polish Journal of Ecology

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2009

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tom 57

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nr 2

313-319

European beech (Fagus sylvatica L.) ranks as one of the most adaptive species among European indigenous trees. Variable interactions between the trees and soil water depend on both phenotypic plasticity of the species and natural conditions. They are controlled through stomatal regulation and the ability of beech trees to accelerate quickly their growth if available resources increase. However, the effect of forest density at various altitudes on the soil water content in beech stands has been studied rather scarcely. Therefore, we monitored soil moisture by means of Time Domain Reflectometry in series of natural and managed stands located on sites representing the lower altitude (200–550 m a.s.l.), middle altitude (550–1050 m a.s.l.) and higher altitude (1050–1300 m a.s.l.) zones of the natural beech belt in the Western Carpathians, Slovakia. Forest stand density, expressed in terms of basal area, i.e. the sum of cross section areas of the tree stems at 1.30 m height, was unchanged in natural stands, but it was reduced by 60% in the shelterwood stands. In the clear-cuts, all trees were removed. Total soil water content (SWC) under forest stands was calculated in mm as the product of soil moisture and soil depth, the latter acquired by electrical resistivity tomography. SWC differences between natural and shelterwood stands of the lower altitude, middle altitude and higher altitude zones averaged 18 mm, 36 mm and –3 mm, respectively. According to the Friedman test on ranks, followed by post-hoc multiple comparison testing, the difference was only significant within the middle altitude zone. In it, soil water consumption by the natural stand was limited only by the hormonally controlled seasonal regulation. The comparatively low water loss in the shelterwood stand resulted from a small rainfall interception by forest canopy and a decreased soil water uptake due to reduced basal area, leaf area index and simple age-size forest structure. In the lower altitude zone, the precipitation deficit and limited extractability of soil water were responsible for the absence of larger SWC differences. As opposed to that, low potential evapotranspiration prevented any noticeable SWC differences within the higher altitude zone.

4

Reproductive potential of the alien species Asclepias syriaca [Asclepiadaceae] in the rural landscape

80%

Csontos P., Bozsing E., Cseresnyes I., Penksza K.

Polish Journal of Ecology

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2009

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tom 57

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nr 2

383-388

In the beginning of its introduction Common milkweed, Asclepias syriaca L. was used in Hungary as ornamental plant. After escaping from cultivation it has become wide spread during last decades of the 20th century. Nowadays, it covers large areas especially on sandy soils, and its further appearance is expected on dry, deforested and degraded areas. Two neglected fields and one abandoned vineyard were selected. For sampling two quadrates of size 4 m² were used at each stand. The stands were characterized by the following variables: density of stems, percentage of reproductive stems, average number of inflorescences, average number of fruits, fruits per all inflorescences on a stem, pods per fruited inflorescences on a stem, average number of seeds per fruit. In the same quadrates the soil seed bank was studied at two depths (0–5 cm and 5–10 cm). The results showed that the density of stand, percentage of reproductive specimens and average number of fruits were significantly higher on the neglected fields than on the abandoned vineyard. In the neglected fields large number of seeds were detected in the upper soil-layer (2.7– 18.6 × 10³ seeds m⁻²), but in the lower soil-layer much fewer seeds were found and only in one of the fields. Common milkweed seeds were almost completely missing from both soil layers of the abandoned vineyard. However, the seeds recovered from the soils practically did not germinated, indicating that seeds of earlier years sets have lost viability, i.e. the studied stands of A. syriaca did not form a persistent soil seed bank. Nevertheless, the fresh seed production of the neglected field populations, that can reach 7–10 thousands seeds m⁻², may cause a very strong propagulum load not only in the site but also on the surrounding areas.

5

Przestrzenne zróżnicowanie cech naturalnego odnowienia sosny zwyczajnej (Pinus sylvestris L.) w rębni zupełnej

71%

Czyzyk K.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2017

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tom 16

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nr 2

6

Dynamika procesu przebudowy drzewostanów górskich na gruntach porolnych

71%

Zieba S., Banas J., Bujoczek L., Kozuch A., Slupska A.

Acta Agraria et Silvestria. Series Silvestris

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2016

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tom 54

7

Wpływ intensywności cięć na postać i strukturę wybranych różnowiekowych drzewostanów jodłowych w Leśnym Zakładzie Doświadczalnym w Krynicy

61%

Banas J., Zieba S., Bujoczek L., Polak M., Zygmunt R.

Acta Agraria et Silvestria. Series Silvestris

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2015

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tom 53

Ograniczanie wyników

Value of merchantable timber in Scots pine stands of different densities

Adaptation of European beech [Fagus sylvatica L.] to different ecological conditions: leaf size variation

Altitudinal variability of the soil water content in natural and managed beech [Fagus sylvatica L.] forests

Reproductive potential of the alien species Asclepias syriaca [Asclepiadaceae] in the rural landscape

Przestrzenne zróżnicowanie cech naturalnego odnowienia sosny zwyczajnej (Pinus sylvestris L.) w rębni zupełnej

Dynamika procesu przebudowy drzewostanów górskich na gruntach porolnych

Wpływ intensywności cięć na postać i strukturę wybranych różnowiekowych drzewostanów jodłowych w Leśnym Zakładzie Doświadczalnym w Krynicy