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The effects of climatic conditions and forest site types on disintegration rates in Picea abies occurring at the Modrava Peat Bogs in the Šumava National Park

100%

Krejci F., Vacek S., Bilek L., Mikeska M., Hejcmanova P., Vacek Z.

Dendrobiology

2013

tom 70

A survey of mountain spruce stand development in the Šumava National Park on Modrava peat bogs on an area of 1,370 ha resulting from spruce bark beetle outbreaks was performedby means of visual evaluation of aerial photographs from the period 1991–2000. In addition, our study addressed the influence of climatic effects (period1984–2000) andthe effect of forest site (climax, waterloggedandpeaty spruce stands) on the dynamics of disintegration of forest stands. We showed that new infestations were predominantly foundat short distances from their source, the average value was estimatedto be 40–60 m, whereas the longest distance for annual progress in west to east direction was estimated to be 120 m. Differences in the dynamics of disintegration between waterlogged stands and drier stands were confirmed. There was a positive relationship between the average temperature in the 2nd quarter of monitoring years which was registered as the period of the onset of bark beetle development and the proportion of degraded area in Norway spruce stands. Moreover, pronounced winter desiccation in January 1993 was a triggering mechanism with crucial importance for the outbreak of bark beetle in the studied area.

The dynamics and structure of dead wood in natural spruce-beech forest stand - a 40 year case study in the Krkonose National Park

100%

Vacek S., Vacek Z., Bilek L., Hejcmanova P., Sticha V., Remes J.

Dendrobiology

2015

tom 73

The study deals with long-term dynamics of snags and fallen dead wood from 1970 to 2010 in an unmanaged forest ecosystem dominated by European beech in the Bažinky area, Krkonoše National Park (Czech Republic). The volume of dead wood was estimated from 1970 separately for fallen dead wood (logs) and standing dead wood (snags and stumps). Total dead wood volume on permanent research plot (PRP) 6 increased from 41.9 to 241.6 m3 ha–1 and on PRP 7 from 27.7 to 170.0 m3 ha–1. During 40 year case study the mean total volume of fallen dead wood was 193.3 m3 ha–1 (± 29.8 S.E.) and 96.2 m3 ha–1 (± 19.4 S.E.) and the mean total volume of standing dead wood was 17.4 m3 ha–1 (± 3.4 S.E.) and 12.6 m3 ha–1(± 1.4 S.E.) on PRP 6 and PRP 7, respectively. Comparing tree species, the mean volume of fallen dead wood was significantly higher for Norway spruce than for beech in the decomposition class 1 (F(1, 14) = 5.7, P = 0.03) and significantly higher for beech in the decomposition classes 4 (F(1, 14) = 20.4, P < 0.001) and 5 (F(1, 14) = 25.5, P < 0.001). Dead wood was distributed from randomly to aggregated spatial pattern. Despite the rapid decay of beech wood, the amounts of deadwood are likely to increase further during the next decades with continuing disintegration of the forest stand.

Farmer decision making and its effect on subalpine grassland succession in the Giant Mts., Czech Republic

100%

Hejcman M., Pavlu V., Hejcmanova P., Gaisler J., Hakl J., Rauch O.

Acta Societatis Botanicorum Poloniae

2006

tom 75

nr 2

165-174

Nitrogen deposition is generally considered as a main reason for many recent plant expansions, but management changes are often not taken into account. Understanding the effects of agriculture management in the past can be decisive in the explanation of plant expansions at present. In order to understand the spread of Molinia caerulea and Calamagrostis villosa into Nardus stricta dominated subalpine grassland in the Giant Mts. (Krkonoše, Karkonosze), we undertook an experiment to explain farmer decision making and we discussed its effect on grassland succession. We measured mowing productivity, yields, biomass quality and nutrient removal in N. stricta, M. caerulea, and C. villosa dominated swards. With regard to defoliation management performed on the subalpine grasslands for at least 500 years and cancelled after the Second World War, we found the following results and conclusions. 1. Mowing productivity, yield and forage quality were lowest in the N. stricta sward, therefore farmers preferred to harvest C. villosa and M. caerulea stands if they had the possibility to select a sward for mowing. 2. Removal of all nutrients was the lowest in the N. stricta sward. With respect to these facts, the competitive advantage of N. stricta is obvious under long-term scything without fertilization. Consequently, the recent increase of defoliation sensitive species M. caerulea and C. villosa above the timber line must be evaluated with respect to both: termination of agricultural activities and recent nitrogen deposition.

Ograniczanie wyników

2 Dendrobiology

1 Acta Societatis Botanicorum Poloniae

3 Hejcmanova P.

2 Bilek L.

2 Vacek S.

2 Vacek Z.

1 Gaisler J.

1 Hakl J.

1 Hejcman M.

1 Krejci F.

1 Mikeska M.

1 Pavlu V.

1 Rauch O.

1 Remes J.

1 Sticha V.

1 2015

1 2013

1 2006

Wyniki wyszukiwania

The effects of climatic conditions and forest site types on disintegration rates in Picea abies occurring at the Modrava Peat Bogs in the Šumava National Park

The dynamics and structure of dead wood in natural spruce-beech forest stand - a 40 year case study in the Krkonose National Park

Farmer decision making and its effect on subalpine grassland succession in the Giant Mts., Czech Republic