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

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Szwagrzyk J. , Szewczyk J.

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.

Plant morphology and allometric relationships in competing and non-competing plants of Tagetes patula L.

100%

Jarzyna I.

nr 2

The use of space by translocated edible dormice, Glis glis [L.], at the site of their original capture and the site of their release: radio-tracking method applied in a reintroduction experiment

67%

Jurczyszyn M.

nr 3

A study was made of the use of space by two groups (each of 6 animals) of adult edible dormice (G. glis) at the sites of their origin and where they were released. The reintroduction took place in Szczeciński Landscape Park (north-western Poland; 53°17’N, 14°46’E). The source sites for the animals were in the Sie rakowski Landscape Park (western Poland; 52°38’N, 16°07’E) and a nature reserve “Buczyna Szprotawska” in south-western Poland (51°30’N, 15°40’E). All three sites had dense and extensive mixed forests. At release and source sites, dormice were radio-tracked during 10 successive nights between 20.00 and 05.00 at 1-hour intervals. At the source sites, the mean distance travelled per night and mean home range (95% Minimum Convex Polygon) (MCP) tended to be larger in males than in females but not significantly. At the release sites, the mean distance travelled per night and mean home range were significantly larger in females than in males. The mean distance travelled per night by males and their mean home range size did not differ significantly between source and release sites (although distances were larger at the source sites (source: 458 m; release: 265 m) and home ranges larger at the release sites (source: 1.3 ha; release: 1.8 ha). In contrast, the mean female distance travelled per night (source: 214 m; release: 404 m) and mean home range (source: 0.3 ha; release: 3.5 ha) were significantly larger at the release site than at the source sites.