Obsah/Content: ZLV 1/2023ZLV, 68, 2023, Issue 1
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Considering the changing climatic conditions, the Czech and Slovakian vegetation has been vertically divided into Forest Vegetation Zones (FVZs) units. Each FVZ is represented by a specific tree species, i.e., the oaks (Quercus sp.), European beech (Fagus sylvatica L.), silver fir (Abies alba Mill.), Norway spruce (Picea abies (L.) H. Karst.) and dwarf pine (Pinus mugo Turra). The FVZ concept has been applied in the Czechoslovakian forestry classification practice since the 1950s. Due to the broad time span of the studied topic, this article is divided into five chapters regarding the evolution of the FVZ concept. Its currently applied form was established primarily in the 1970s on the grounds of data gathered during two decades of forest typology research. An FVZ unit has become an upper unit of the Czech Forest Ecosystem Classification since its legislative codification in the Forest Act (289/1995) in 1995. To this day, however, the FVZ concept has not been reassessed by advanced, multi-dimensional statistical methods. This paper aims to describe key moments of the development of this concept and provide a perspective on its limitations, also in connection with current trends in ecological research. This review aims to provide a better understanding of the forest vegetation-environment relationship in the Czech Republic in relation to climate change, indirect anthropogenic environmental impact, and prediction of forest and landscape ecosystems response.
Acidification of forest soils is a natural process, but it is amplified by anthropogenic factors. Forest soil regeneration is a very long and slow action, which is conditioned by the weathering rate and impact of forest management. Data from forest-site plots and from the national forest inventory were used to assess the development of pH/H2O in forest soils in the Czech Republic. The results of our survey suggest that not only higher positions (>700 m a.s.l.) but also middle (400–700 m a.s.l.) and lower positions (<400 m a.s.l.) were affected by significant acidification. A significant increase in the concentration of hydrogen ions was found throughout the soil profile. From the beginning of the 1990s to 2010, a very slight and gradual trend of regeneration of the soil environment was found in the forest soils of the Czech Republic. After 2010, this trend is stagnant. The increase in soil pH/H2O reached only a few tenths of a degree and was found in the A horizons as well as in the B and C horizons. The data also show that in positions above 700 m a.s.l., the trend of soil environment regeneration is significantly slower compared to lower positions.
In this study, presence of ophiostomatiod fungi (absence, presence) on wood cross-section samples (total 72) from freshly cut Scots pine (Pinus sylvestris L.) trees (total 24) at four sites (Valtice, Příšťpo, Brodce, Vrbová Lhota) affected by long-term drought was evaluated in relation to: sampling period (spring, summer, autumn), tree age (30–40, 50–90 years), wood sample origin (bottom trunk, middle trunk, twigs), tree defoliation (>25–60%, >60–99%), and presence of other taxa. Ophiostomatoid fungi were present on 33% wood cross-section samples from 50% trees. Presence of ophiostomatoid fungi was significantly different in relation to sampling period (i.e. the highest in autumn, the lowest in spring), and was directly proportional to both presence of mites and Nematocera larvae; it was insignificantly different in relation to site, tree age, wood sample origin, defoliation, and presence of other taxa. These results show: (1) frequent presence of ophiostomatoid fungi in wood tissues of Scots pine trees, (2) insignificant effect of ophiostomatoid fungi on health status of the trees, (3) relationship of presence of ophiostomatoid fungi with both presence of mites and Nematocera larvae.
Research was focused on determination of water-stable aggregates (WSA) distribution in soil (cambisol) under different land use (forest, arable land) taking into account also the age of forest stand. Soil samples were collected at three localities separately for arable and forest soil. The localities were selected from map in places where arable land had been afforested in the past. Afterwards 30 samples were dry sieved and then wet sieved to determine the percentage of individual soil fractions of WSA, which allowed comparison of localities. Results showed that from the land use perspective, no prominent differences were evident after dry sieving. However, after the subsequent wet sieving, there was a distinct change. For arable soil, the fraction larger than 2 mm was almost entirely (98.22–98.88%) dissolved into smaller fractions, while the results of forest soil showed much better soil properties, as the largest fractions (>2 mm and 2–1 mm) were still represented in the sample in the range of 34.18% to 69.14%. From the results, it is possible to conclude that aggregation already occurs between 10 and 24 years after the establishment of the forest stand, which should be more investigated during the following research.
Scots pine has been considered a resistant tree species not only to adverse habitats but also to drought for a long time for its pioneering character, enabling it to thrive at significantly nutrient-poor and dry sites where the competitive pressure of other tree species is reduced. It has also some physiological properties adapted for the increased efficiency of water management. However, the increased and cumulated drought stress in Central Europe after 2013, which has accelerated significantly since 2015, showed the limits of the Scots pine´s sustainable prosperity in many sites of its present occurrence. The research analyses 101 studies published in the period from 1975 to 2022, representing basic properties, ecophysiological aspects, health status development, growth and fertility of Scots pine related to drought stress. It also deals with the influence of the tree species mixing effect and silvicultural management on the health status of Scots pine stands. The review aims to provide comprehensive material for understanding the development of Scots pine´s health and growth, as well as optimising its use under ongoing global climate change conditions characterised by an increase in annual air temperatures and by irregular distribution of precipitation, leading to the increasing frequency of drought periods. Methodological recommendations for silviculture in pine forests are also mentioned here.
Runoff from forests predominates above runoff from adjacent agricultural and other land-use types during longer periods of climatic drought. The predominating forest runoff is 180 days per year, in average. There are streamflows of 180–366-day by 10-year average. To practical proving this hypothesis, the runoff study was done for upper part of the Svratka catchment with measuring profile in Dalečin, the Czech-Moravian Highlands. The catchment was segmented into four land-use types: 43% of forest stands, 29% of agricultural crops, 20% of permanent grasslands, and 8% other lands. Besides forest influence on streamflow directly in the Svratka River, the runoff from other land-use types of the agriculturalforestry catchment was also calculated. It was proved that greater runoff drained from the forest than from the remaining land uses of the catchment. The 43% share of the forest in the upper Svratka catchment increased during climatic drought mean runoff in by 6.2%.
Growing Norway spruce at relatively warmer and drier conditions poses a threat of its die-off. Despite recent focus of silviculture on conversion of tree species composition, foresters still have to cope with existence of monospecific young spruce stands. Four thinning experiments were established at lower altitudes to investigate a response of stand characteristics to early thinning. Experimental thinning accelerated diameter increment of spruce crop trees significantly. Thinning also slowed pace of the slenderness ratio development thus impacting on the h/d values positively. Live crowns got short more slowly following thinning compared to control. Spruce stands at lower altitudes must be thinned as early as possible when mean height of dominant trees achieves 5 m. Given the risk of growing spruce at lower sites, all suitable tree species should be left on site. Spruce should be no longer grown in monospecific stand over the whole rotation, however silviculture measures should focus on maintenance of its share in future species composition.
The subject of the research is to increase the stability of beech forests (Fagus sylvatica L.) by transforming them into forests of diameter classes. At the beginning of the experiment, the stands were 80 years old. Their transformation into the selection forest or the mosaic structure begun 24 years ago. The aim of the research was to obtain the information necessary for the design of models of beech selection forest and beech mosaic stand. The analyzed stands had a moderately differentiated height structure at the beginning of the experiment. In the permanent research plots (PRP 1-2) during 24 years of conversion and application of selective thinning and later selective cutting with an intensity of 14–18%, the phase of refinement of the selection structure took place. Based on the data analysis, we derived beech forest model with a target diameter of 50 cm, an optimal volume of 307 m3 ha-1 and a basal area of 27 m2 ha-1. The conversion of beech stand on PRP 3 to the mosaic structure resulted in the proposal of the model characterized by the Weibull diameter distribution (target diameter 50 cm, basal area 31 m2 ha-1, model stand volume 392 m3 ha-1).