Igor Štefančík

Effect of Tree Layer and Microsite on the Variability of Natural Regeneration in Autochthonous Beech Forests

ABSTRACT The present study describes natural regeneration on five permanent research plots (PRP) in juvenile growth and development phases (regrowth and advanced growth) in autochthonous beech forests in Broumovské stěny National Nature Reserve located in the Protected Landscape area in the northeast part of Czech Republic. The stands of herb-rich beech forests were studied in the optimum to break-up stage. Natural regeneration was not evenly spaced but rather was clustered. Mean regeneration density ranged from 1,472 to 44,888 recruits per ha. European beech (Fagus sylvatica L.) made up 78.5–98.0% of all regeneration. Sycamore maple (Acer pseudoplatanus L.) was also relatively abundant. Regeneration dominance and abundance responded to the mature stand canopy, soil skeleton, microrelief, ground vegetation cover, and surface characteristics. The results suggest a relationship between recruit height and microrelief in 4 out of 5 PRPs. We found statistically significant differences in height of natural regeneration (F(2,18843) = 191.8, P <0.001) on mounds (74.0 cm), on slopes (119.5 cm) and on pits (121.0 cm) due to high soil skeleton content on mounds with numerous rock outputs, minimum amount of fine earth and lower water retention, both necessary for recruit growth. In addition to the character of microrelief, the growth of natural regeneration was negatively influenced by mature stand density and canopy indicators.

Structure, development and health status of spruce forests affected by air pollution in the western Krkonoše Mts. in 1979–2014

Abstract The structure and health status of waterlogged or peaty spruce (Picea abies [L.] Karst.) forests in the summit parts of the Krkonoše Mts. in the Czech Republic were studied in 1979–2014. The objective was to evaluate the stand structure, dead wood, trend of the health status and productivity on four permanent research plots (PRP) in relation to air pollution (SO2 and NOx concentrations) and climatic conditions (temperatures and precipitation amounts). Stand structure was evaluated on the base of the measured parameters of individual trees on PRP. The health status of trees was evaluated according to foliage, and their vitality was assessed according to their radial growth documented by dendrochronological analyses. The radial growth was negatively correlated with SO2 and NOx concentrations. Stand dynamics during the observation period was characterised by increased tree mortality, the presence of dead wood and reduction of stand density from 1983 to 1992, while the most severe impairment of health status and stand stability occurred in 1982–1987. The foliage mass of living trees has been gradually increasing since 1988, but no pronounced improvement of tree vitality was documented after the decrease in SO2 concentration. However, particularly physiologically weakened spruce trees were attacked by the European spruce bark beetle (Ips typographus). The process of forest damage is manifested not only by foliage reduction but also by symptoms of various necroses on the assimilatory organs. In terms of climatic data, the weather in April had the most important effect on radial growth. Diameter increment showed positive statistically significant correlation with temperature in growing season, but the precipitation effect was low.

Current and simulated structure, growth parameters and regeneration of beech forests with different game management in the Lány Game Enclosure / Struktura, růstové parametry, obnova a modelový vývoj bukových porostů s odlišným způsobem mysliveckého hospodaření v podmínkách Lánské obory

Abstract The paper presents the results of the study of the current and simulated structure of beech forests in the Lány game preserve, which is situated in the Křivoklátsko Protected Landscape Area in the Czech Republic. The research was conducted at two permanent research plots (PRP) of 0.25 ha in size in a mature beech forest using the FieldMap technology. Typological, soil and phytocoenological stand characteristics and the history of management of both PRP are comparable; however, they differ in the protection against wildlife. The results demonstrated that deer species including red deer (Cervus elaphus L. - 300 head), sika deer (Cervus nippon nippon Temm. - 300 head), mouflon (Ovis musimon Pallas - 250 head) and fallow deer (Dama dama L. - 300 head) is a limiting factor for successful development of natural regeneration of European beech (Fagus sylvatica L.). Natural regeneration on PRP 1 with wild boar herd (Sus scrofa L. - 150 head) is sufficient in relation to site and stand conditions. On the contrary, there is no regeneration on PRP 2 with the occurrence of deer species. The results of biometric measurements and subsequent predictions by the SIBYLA forest biodynamics simulator indicate that the stands are insignificantly structured, mature, productive beech stands with the absence of individuals in the lower tree layer. Abstrakt V příspěvku jsou prezentovány výsledky studia struktury a dynamiky vývoje bukových porostů v Lánské oboře, která se nachází v Chráněné krajinné oblasti Křivoklátsko v České republice. Výzkum se uskutečnil v dospělém bukovém porostu na dvou trvalých výzkumných plochách (TVP), každá o velikosti 0,25 ha s použitím technologie FieldMap. Typologické, půdní, fytocenologické i porostní charakteristiky obou porovnávaných TVP jsou srovnatelné, odlišují se pouze způsobem ochrany proti zvěři. Výsledky ukázaly, že limitujícím faktorem zdárného vývoje přirozené obnovy buku (Fagus sylvatica L.) je vysoká zvěř, a to jelen evropský (Cervus elaphus L. - 300 ks), jelen sika (Cervus nippon nippon Temm. - 300 ks), muflon (Ovis musimon Pallas - 250 ks) a daněk skvrnitý (Dama dama L. - 300 ks). Přirozená obnova na TVP 1 s černou zvěří (Sus scrofa L. - 150 ks) je dostatečná vzhledem ke stanovištním a porostním poměrům. Naproti tomu na TVP 2 s ostatními druhy zvěře se obnova nevyskytuje. Z výsledků biometrických měření a následných vizualizací pomocí simulátoru biodynamiky lesa Sibyla vyplývá, že se jedná o nevýrazně strukturované, dospělé, produktivní bukové porosty s absencí jedinců spodního stromového patra.

Porovnanie kvalitatívnej produkcie dvoch bukových (Fagus sylvatica L.) porastov na kyslom stanovišti / A comparison of qualitative production of two beech (Fagus sylvatica L.) stands growing at acid sites

Abstract In this paper, a beech thinning experiment aimed at qualitative production issues was analysed. Two beech stands (93- and 105-year-old), growing at acid sites with similar ecological conditions were compared. The stands differ in the stand age, when their tending started (at the age of 40 years in one experiment versus 60 years for the second one). In the first stand, the thinning interventions were carried out during last 45 years, while in the second stand a 53-year-long period of investigation was recorded. The research was conducted in four treatment plots: (i) heavy thinning from below (C degree according to the German forest research institutes from 1902), (ii) free crown thinning with thinning intervals of 5 years, (iii) free crown thinning with thinning intervals of 10 years, and (iv) control plot (without thinning). The stand qualitative parameters (stem and crown quality, proportion of the best quality assortment and share of crop trees) were evaluated. From the point of qualitative production, the best results were most frequently obtained at the plots with the free crown thinning followed by heavy thinning from below. The worst parameters were found at the control plot Abstrakt Práca analyzuje kvalitatívnu produkciu prebierkového pokusu v bukovom poraste. Porovnali sa 2 bukové porasty (93 a 105 ročný) na kyslom stanovišti s podobnými ekologickými podmienkami. Porasty sa odlišovali vekom, kedy sa začalo s ich výchovou (jeden vo veku 40 rokov a druhý vo veku 60 rokov). V prvom poraste sa zásahy vykonávali počas ostatných 45 rokov, kým v druhom poraste sa sledovalo obdobie 53 rokov. Výskum pozostával zo štyroch sledovaných variant: (i) silná podúrovňová prebierka (C stupeň podľa Nemeckých výskumných ústavov lesníckych z roku 1902), (ii) úrovňová voľná prebierka s intervalom 5 rokov, (iii) úrovňová voľná prebierka s intervalom 10 rokov, (iv) kontrolná plocha (bez prebierok). Hodnotili sa kvalitatívne parametre porastu (kvalita kmeňa a koruny, podiel najkvalitnejších sortimentov a zastúpenie cieľových stromov). Najlepšie výsledky sa z hľadiska kvalitatívnej produkcie dosiahli na plochách s úrovňovou voľnou prebierkou a potom na ploche so silnou podúrovňovou prebierkou. Najhoršia kvalitatívna produkcia sa zistila na kontrolných plochách (bez výchovy)

Results of the research of Douglas-fir in the Czech Republic and Slovakia: a review

Abstract The paper summarises the results concerning the effects of cultivation of Douglas-fir (Pseudotsuga menziesii /Mirb./ Franco), especially in the last decades, on the intensity of production as well as non-production forest functions in the conditions of the Czech Republic and Slovak Republics. It analyses the research outcomes from the point of volume and value production in comparison with other native tree species, from the point of species effects on the soil and on the ground vegetation diversity, and from the point of stability and cultivation in the last period. The main aim was to compare this species with Norway spruce, which can be replaced by Douglas fir in suitable conditions. Douglas fir can have a favourable impact on the amount and the value of timber production, as well as on the soil and the biodiversity of ground vegetation. The stability of forest stands can also be considerably supported in this way. Hence, Douglas-fir represents a suitablealternative to Norway spruce at lower and middle altitudes and it can contribute to greater competitiveness of the Czech as well as Slovak forestry.

Struktura a modelový vývoj lesních porostů v NPR Trčkov – CHKO Orlické Hory, Česká republika

Abstract The paper deals with the research of structure and dynamic development of stands in National Nature Reservation Trčkov, located in Protected Landscape Area Orlické Mts. (Czech Republic). The research was carried out in spruce-beech stand with admixed fir and sycamore maple. Two permanent research plots (PRP 1 and PRP 2), for each with area of 0.25 hectare were chosen as an object of our research. FieldMap technology was used for field measurement. Compared PRP were characterized by the same typological, soil, phytocenology and stand parameters, but different method of protection against game damage. Results showed that deer is considered to be limiting factor for successful development of natural regeneration of autochthonous tree species. The tree species proportion of natural regeneration occurred in PRP 1 with fencing was sufficient, contrary to PRP 2 (outside fencing) owing to site and stand conditions. The results of biometric measurements and predicted simulation by Sibyla growth simulator showed multi-layer stand structure and productive spruce-beech stands with interspersed fir and sycamore maple. We also found depleted phase of regeneration according to frequency and tree species proportion, as well as beginning of grow up stadium, especially related to fir and sycamore proportion and/or beech and spruce. It is concluded that growth visualization and simulation confirmed the hypothesis about long-term effect of game to species, spatial and age structure and development of concerned autochthonous population.

Effect of different management on quality and value production of pure beech stands in Slovakia

Abstract Value production is one of the most important information for comparing different management strategies in forestry. Although the value production of forest stands is affected by various factors (stem and assortment quality, stem dimension, stem injury, price of assortments), thinning can be considered as one of the most important one. This paper aims at the evaluation of qualitative and value production in homogeneous beech stands, which were managed by two different thinning types for period of 45 to 55 years: (i) – heavy thinning from below (C grade according to the German forest research institutes released in 1902) and (ii) – Štefančík´s free-crown thinning. The third variant was control (iii) – subplot with no interventions. Silvicultural quality characteristics of the lower half of the stem were assessed using a 4-class scale (A – the best quality, D – the worst quality). Assortment structure (commercial quality) was estimated for each stem by an assortment model developed in the past. Nearly 3,000 individual trees aged from 83 to 105 years from 23 subplots established across the Slovakia territory were assessed. The highest volume of the best silvicultural quality of stems (A class) has been reached in forests where Štefančík´s free-crown thinning was applied (57 – 85%) while the lowest (22 – 56%) on subplots with no management. The proportion of two best commercial quality assortments (I + II) was highest in forests managed by heavy thinning from below (21 – 29%) and the lowest when no treatment was applied (7 – 19%). The highest value production (expressed in € ha−1) was reached in the forests treated by free-crown thinning. Results suggested the overall positive impact of thinning on the increase of value production in beech forests. Particularly, the free-crown thinning focusing on selection of best quality trees should be preferred as it leads, besides its sufficient value production, to a higher vertical differentiation of the beech forests.

Long-term transformation of submontane spruce-beech forests in the Jizerské hory Mts.: dynamics of natural regeneration

Abstract The paper deals with development of the natural regeneration of even-aged spruce-beech forests during their transformation to uneven-aged stands with diversified structure at the Jedlový důl area in the Protected Landscape Area Jizerské hory Mts., Czech Republic. Shelterwood management system and free felling policy based on selection principles has been applied there since 1979 with the support of admixed tree species of the natural species composition, especially silver fir (Abies alba Mill.). The research was focuses on structure and development of natural regeneration with the emphasis on ungulate damage and interaction with tree layer from 1979 to 2015. In the course of 36 years, the regeneration structure was diversified towards the close-to-nature tree species composition, spatial and age structure. The number of regeneration recruits increased in average from 941 to 41,669 ind ha-1. During this period share of European beech (Fagus sylvatica L.) significantly (p < 0.01) increased (by 53.6%), while the share of Norway spruce (Picea abies [L.] Karst.) decreased (by 51.5%), such as damage caused by ungulate (by 61.4%) with the highest loses on sycamore maple (Acer pseudoplatanus L.), rowan (Sorbus aucuparia L.) and silver fir. Moreover, the parent trees had a significant negative influence on natural regeneration at smaller spacing (within a 1 - 5 m radius from the stem). Both, regeneration potential and effective role of the tree layer during the forest transformation has been confirmed as important prerequisites for ongoing forest transformation.

Porovnání vybraných kvalitativních znaků kmene dubových porostů při různém vlivu pomocných dřevin / Comparison of selected qualitative characteristics of stem in oak stands under varying effects of auxiliary tree species

Abstract The paper analyses the influence of auxiliary trees species on selected qualitative characteristics of the parent oak stand aged 100-120 years from the tending aspect point of view. Stand structure described by relative height position, and stem straightness and branchiness as the main qualitative parameters were studied on 162 trees in three different forest stands: (i) without woody understorey, (ii) with understorey dominated by European hornbeam with an admixture of small-leaved linden and field maple, and iii) with understorey dominated by small-leaved linden. The results showed a positive effect of auxiliary tree species on the oak quality (straightness and branchiness of stems) in the lower part of the stem. Under the assumed elimination of genetic influences, better qualitative parameters of oak could be explained by the occurrence of auxiliary trees in the understorey. Abstrakt Práce analyzuje výsledky hodnocení vlivu pomocných dřevin na vybrané kvalitativní znaky mateřského dubového porostu ve věku 100- 120 let z aspektu výchovy porostu. Hodnotili se struktura porostu (relativní výškové postavení), křivost a zavětvení kmene na 162 jedincích ve třech porostech: (i) bez podrostu, (ii) s podrostem tvořeným hlavně habrem, méně lípou a javorem babykou (iii) s podrostem s lípou. Výsledky ukázali kladný vliv podrostu dřevinného patra jak lípy srdčité, tak i habru obecného, a to jednak při hodnocení křivosti kmene, jednak i při hodnocení výskytu větví ve spodní části kmene. Podstatně lepší výsledky v kvalitě dubů si při předpokládaném vyloučení genetických vlivů vysvětlujeme právě přítomností pomocních dřevin v dolní etáži porostů.

Modely výškových kriviek jedľovo-bukových porastov Východných Karpát / Models of height curves in fir-beech stands of the Eastern Carpathians

Abstract The models of height curves were derived from repeated measurements at six permanent research plots in the experimental object of Komárnik situated in the Eastern Carpathians. During more than 50 years of investigation, the heights of 1,346 beech and 1,208 fir trees were measured. Tree heights had a great variability, but the stage-shift of height curves was not confirmed. The non-linear regression models of height curves for beech and fir were derived, where tree height is a function of tree diameter and model height for a selected diameter class. They are based on the Korf growth curve with three parameters. The models explained 90% and 94% of beech and fir height variability, respectively. The models confirmed the actual knowledge that fir had higher tree height increment than beech especially for trees with greater diameters. The comparison of our models to those developed by other authors showed that the shape of height curves slightly differed. Beech curve was characterised by greater, while fir curve by lesser curvature in comparison with other published models. Our models have only local validity due to the limited scope of experimental data. They can be applied under the local conditions in order to perform valuation and simulation of growing stock development and increments of uneven-aged and multistoried fir-beech stands. Abstrakt Odvodili sa modely výškových kriviek z experimentálneho materiálu opakovaných meraní šiestich trvalých výskumných plôch na výskumnom objekte Komárnik vo Východných Karpatoch. Počas viac ako 50-ročného sledovania sa zmeralo 1 346 výšok pre buk a 1 208 pre jedľu. Výšky majú všeobecne veľkú variabilitu, ale nepreukázal sa štádiový posun výškových kriviek. Odvodili sa nelineárne regresné modely výškových kriviek pre buk a jedľu, kde výška stromu je funkciou jeho hrúbky a modelovej výšky pre zvolený hrúbkový stupeň. Ich základom je Korfova rastová krivka s tromi parametrami. Modelom je vysvetlených 90 % variability výšok pri buku a 94 % pri jedli. Modely potvrdili doterajšie poznatky, že jedľa má najmä pri hrubších stromoch vyššie výškové prírastky ako buk. V porovnaní k modelom iných autorov majú odvodené modely málo odlišný tvar výškových kriviek. Buk má väčšiu a jedľa menšiu krivosť ako porovnávané modely. Modely majú vzhľadom na obmedzený rozsah experimentálneho materiálu len lokálny charakter. Pre miestne pomery sa môžu aplikovať na bonitovanie a simulovanie vývoja zásob a prírastku nerovnovekých a viacetážových jedľovo-bukových porastov.