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Stanislav Kucbel - One of the best experts on this subject based on the ideXlab platform.
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canopy gap dynamics and tree understory release in a Virgin beech forest slovakian carpathians
Forest Ecology and Management, 2018Co-Authors: Eike Feldmann, Lars Drosler, Viliam Pichler, Stanislav Kucbel, Markus Hauck, Christoph LeuschnerAbstract:Abstract Canopy gaps play a crucial role for forest dynamics processes, as they largely determine light transmission to lower canopy strata, thereby controlling the turnover of tree individuals in the stand. Even though their functional importance is undisputed, quantitative data on the rate of gap creation and gap closure, and the temporal change in gap size distribution patterns in temperate Virgin Forests are scarce. We used a repeated inventory (line-intercept sampling) of gap size frequency and fraction in a Virgin beech (Fagus sylvatica) forest in the Slovakian Carpathians over a 10-year interval (2003–2013) to test the hypotheses that (i) disturbance intensity and thus gap creation and gap closure rate change only little over time, (ii) gaps persist or even expand, until they are filled primarily by vertical ingrowth of trees from lower strata, and (iii) gap creation promotes the height growth of released saplings and sub-canopy trees. In the 2003 and 2013 inventories, 37 and 30 gaps >20 m2 size were mapped along a total of 3217 m transect line investigated. The large majority of gaps was 500 m2 were very rare. Gap fraction decreased significantly from 13.6% in 2003 to 8.2% in 2013 (associated with a reduction in mean gap size from 261 to 96 m2), indicating considerable variation in disturbance intensity in the past decades. Before 2003, both large gaps (probably caused by wind throw) and small gaps (from dying trees) have been formed, while only small gaps developed in the period 2003–2013. Small gaps were closed within a few years through rapid horizontal canopy expansion of neighboring beech trees, while vertical gap filling through ingrowth of lower canopy layers and regeneration was the dominant process in larger gaps. Saplings and trees in lower canopy layers formed a heterogeneous understory in large parts of recently formed gaps and responded to this process with increased height growth. We conclude that, despite considerable variation in disturbance intensity over time, this beech Virgin forest responds to gap formation with high resilience through rapid lateral canopy expansion in small gaps and ingrowth of saplings and sub-dominant tree layers in larger gaps.
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Structure, growing stock, coarse woody debris and regeneration processes in Virgin Forests Dobroč (Slovakia) and Čorkova Uvala (Croatia).
2011Co-Authors: Milan Saniga, Stanislav Kucbel, Igor Anić, Stjepan Mikac, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh
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structure growing stock coarse woody debris and regeneration processes in Virgin Forests dobroc slovakia and corkova uvala croatia
Beskydy, 2011Co-Authors: Milan Saniga, Stanislav Kucbel, Stjepan Mikac, Igor Anic, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh <1 cm. In Virgin forest Dobroc, fir does not reach height over 50 cm due to the high number of red deer and their intensive browsing.
Milan Saniga - One of the best experts on this subject based on the ideXlab platform.
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Relation of dead wood course within the development cycle of selected Virgin Forests in Slovakia
Journal of forest science, 2019Co-Authors: Milan Saniga, Jean-philippe SchützAbstract:Following measurements of dead wood (20 to 40 years) at various developmental stages of the life cycle of selected Virgin Forests of the 1 st to 7 th altitudinal zone the relation of its course was derived. The dynamics and course of dead wood in the life cycle of Virgin Forests were best represented by a polynomial of the third degree. An analysis confirmed that Virgin Forests consisting of stable tree species with approximately the same physical age (Boky) showed small differences between maximal increase and decrease in necromass during the whole development cycle. Virgin Forests at sites rich in nutrients consisting of several tree species with various physical age had high values of necromass during their whole development cycle. Spruce stands at the upper forest boundary also had a relatively high ratio of necromass at the advanced optimum stage.
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Relation of dead wood course within the development cycle of selected Virgin Forests in Slovakia
Journal of Forest Science, 2019Co-Authors: Milan Saniga, Jean-philippe SchützAbstract:Following measurements of dead wood (20 to 40 years) at various developmental stages of the life cycle of selected Virgin Forests of the 1<sup>st</sup> to 7<sup>th</sup> altitudinal zone the relation of its course was derived. The dynamics and course of dead wood in the life cycle of Virgin Forests were best represented by a polynomial of the third degree. An analysis confirmed that Virgin Forests consisting of stable tree species with approximately the same physical age (Boky) showed small differences between maximal increase and decrease in necromass during the whole development cycle. Virgin Forests at sites rich in nutrients consisting of several tree species with various physical age had high values of necromass during their whole development cycle. Spruce stands at the upper forest boundary also had a relatively high ratio of necromass at the advanced optimum stage.
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Structure, growing stock, coarse woody debris and regeneration processes in Virgin Forests Dobroč (Slovakia) and Čorkova Uvala (Croatia).
2011Co-Authors: Milan Saniga, Stanislav Kucbel, Igor Anić, Stjepan Mikac, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh
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structure growing stock coarse woody debris and regeneration processes in Virgin Forests dobroc slovakia and corkova uvala croatia
Beskydy, 2011Co-Authors: Milan Saniga, Stanislav Kucbel, Stjepan Mikac, Igor Anic, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh <1 cm. In Virgin forest Dobroc, fir does not reach height over 50 cm due to the high number of red deer and their intensive browsing.
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Dynamik des Totholzes in zwei gemischten Urwäldern der Westkarpaten im pflanzengeographischen Bereich der Tannen-Buchen- und der Buchenwälder in verschiedenen Entwicklungsstadien | Deadwood dynamics in two mixed Virgin Forests in the West Carpathians
Schweizerische Zeitschrift fur Forstwesen, 2001Co-Authors: Milan Saniga, Jean-philippe SchützAbstract:An analysis was carried out, over a period of 40 years, of the dynamics of deadwood in two mixed Virgin Forests in the West Carpathians in the phytogeographic domain of pure beech and mixed fir-beech Forests. Deadwood (expressed as % of dendromass, i.e. living and dead biomass) is subject to great variations at different evolutive phases. The relation between deadwood and living biomass in the aggradation phase (juvenile growing phase) is 1:2 in the Badin forest and varies between 1:2 and 1:3 in the Dobroc forest, while a maximum is reached in the optimal phase with a variation between 1:5 and 1:6.
Stjepan Mikac - One of the best experts on this subject based on the ideXlab platform.
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Structure, growing stock, coarse woody debris and regeneration processes in Virgin Forests Dobroč (Slovakia) and Čorkova Uvala (Croatia).
2011Co-Authors: Milan Saniga, Stanislav Kucbel, Igor Anić, Stjepan Mikac, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh
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structure growing stock coarse woody debris and regeneration processes in Virgin Forests dobroc slovakia and corkova uvala croatia
Beskydy, 2011Co-Authors: Milan Saniga, Stanislav Kucbel, Stjepan Mikac, Igor Anic, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh <1 cm. In Virgin forest Dobroc, fir does not reach height over 50 cm due to the high number of red deer and their intensive browsing.
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characteristics of gap regeneration in dinaric beech fir Virgin Forests
Znanstveni skup Prašumski ekosustavi dinarskoga krša i prirodno gospodarenje šumama u Hrvatskoj, 2009Co-Authors: Stjepan Mikac, Dušan Roženbergar, Igor Anic, Jurij DiaciAbstract:Istraživanje je obavljeno u dvije tipicne dinarske bukovo-jelove (Omphalodo-Fagetum Marincek et al. 1992.) prasume: Corkova uvala (Hrvatska) i Rajhenavski rog (Slovenija). Obje prasume pridolaze u slicnim stanisnim prilikama. Prostiru se u rasponu nadmorskih visina 740 – 1030 m, na tipicnom krskom reljefu, geoloskoj podlozi vapnenca, uz prosjecnu godisnju temperaturu zraka od 6 – 8 °C i oborine u rasponu 1600 – 2000 mm/god. U obje prasume uzorkovano je 12 progala. Unutar svake progale postavljena je pravokutna kvadratna mreža dimenzija 5 x 5 m. Na mreži su mjerene i analizirane kvantitativne i kvalitativne osobine pomlatka te relativna pokrovnost vrsta prizemnog rasca. Na svakoj plohi snimana je hemisferna fotografija u svrhu analize svjetla. U prasumi Rajhenavski rog ustanovljeno je izrazito slabo pomlađivanje obicne jele i znakovito bolje pomlađivanje obicne bukve u usporedbi s prasumom Corkova uvala. Ustanovljene su znacajne razlike u povrsinama progala i razinama difuznog i direktnog zracenja između dvije prasume. Izrazito slabo pomlađivanje jele u Rajhenavskom rogu posljedica je prekobrojnog stanja divljaci u usporedbi sa prasumom Corkova uvala. Znakovito bolje pomlađivanje obicne bukve u Rajhenavskom rogu posljedica je vece razine svjetla prouzrokovane relativno vecom povrsinom progala prouzrokovanom odumiranjem jele.
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Natural regeneration of Norway Spruce (Picea abies (L.) Karst.) stands on northern Velebit
Periodicum Biologorum, 2008Co-Authors: Milan Oršanić, Damir Drvodelić, Igor Anić, Stjepan Mikac, Damir BarčićAbstract:Background and Purpose: Natural regeneration is a natural phenomenon that depends on numerous factors. Regeneration of Virgin Forests is successful even without any human interference. For the regeneration of economic Forests we do not have that much time and thus try to speed up the process. The study of factors involved in natural regeneration as the most perfect system of forest ecosystem regeneration requires long lasting research. Material and Methods: Numbers and heights of seedlings and new growths, as well as the species participating in natural regeneration were measured on four test plots over the period of four years (1995, 1998, 1999, 2000). The plots were located at different elevations and contained different plant communities. The Norway spruce seed yield and its quality (germination) were also researched. Results: Very poor appearance of seedlings and new growth and even the decline in the numbers were observed on all test plots. This can be directly correlated to management in which single-tree selection management and piling of timber supply result in poor light conditions and gradual disappearance of Norway spruce. Seed germination ranging from 13% on plot I to 48% on plot II shows that the seed has very low natural germination and only abundant crops can lead to greater natural regeneration. Conclusion: Norway spruce is a species whose natural regeneration in the above mentioned structural and site conditions is a difficult process. Natural regeneration of Norway spruce is affected by management, timber supply, condition of vegetation on the soil, as well as the intensity of light. The seed quality and its quantity did not affect regeneration on test plots.
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Characteristics of gap regeneration in Dinaric beech-fir Virgin Forests
2008Co-Authors: Stjepan Mikac, Igor Anić, Dušan Roženbergar, Jurij DiaciAbstract:Research was conducted in two typical Dinaric beech-fir Virgin Forests: Corkova Uvala (Croatia) and Rajhenavski Rog (Slovenia). Both Virgin stands belong to the forest community Omphalodo-Fagetum Marincek et al. 1992. Their species composition is dominated by European beech (Fagus sylvatica L.) and silver fir (Abies alba Mill.). There are sporadic occurrences of spruce (Picea abies /L/ Karsten), broad-leaved lime (Tilia platyphyllos Scop.), Wych elm (Ulmus glabra Huds.) and European ash (Fraxinus excelsior L.). Both Virgin Forests grow in similar stand conditions. They extend at altitudes between 700 and 1, 200 m and inhabit typical karst relief with limestone geological substrate. The average annual air temperature is 7 °C and precipitation oscillates between 1, 600 – 2, 500 mm/year. The goals of research were to compare quantitative and qualitative features of natural young growth, site conditions on the basis of indicator values of ground vegetation species and light conditions in the gaps of both Virgin Forests. Sampling was done in the gaps created by the death of old trees. In both Virgin Forests 4 large (0.07 – 0.2 ha) and 7 small (~0, 02 ha) gaps were sampled. A 5 x 5 m network was established in each gap. Quantitative and qualitative features of the young growth and relative cover of ground vegetation species were measured and analysed in the network. In addition, hemispheric photographs were taken in each plot for the purpose of light analysis. Compared to the Virgin forest of Corkova Uvala, the Virgin forest of Rajhenavski Rog manifested distinctly poor regeneration of silver fir and significantly better regeneration of European beech. Fluctuations in wood mass trends in the past several decades were also recorded.
Marko Prebeg - One of the best experts on this subject based on the ideXlab platform.
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Structure, growing stock, coarse woody debris and regeneration processes in Virgin Forests Dobroč (Slovakia) and Čorkova Uvala (Croatia).
2011Co-Authors: Milan Saniga, Stanislav Kucbel, Igor Anić, Stjepan Mikac, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh
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structure growing stock coarse woody debris and regeneration processes in Virgin Forests dobroc slovakia and corkova uvala croatia
Beskydy, 2011Co-Authors: Milan Saniga, Stanislav Kucbel, Stjepan Mikac, Igor Anic, Marko PrebegAbstract:Selected production characteristics and dynamics of regeneration processes in Virgin Forests Dobroc (Slovakia) and Corkova Uvala (Croatia) are analysed in this work. Despite the fact that compared Virgin Forests are approximately in the same elevation and the research plots were established in the same group of forest types, Virgin forest Corkova Uvala has significantly lower spruce representation, higher annual precipitation and different parent rock. Higher average volume of living trees with dbh over 8 cm was determined in Virgin forest Corkova Uvala in amount of 753.3 m3.ha-1. This production characteristic was lower in Virgin forest Dobroc (686.5 m3.ha-1). The reason for higher average volume of trees over 8 cm dbh in Corkova Uvala is significantly higher annual precipitation and more favourable texture of Virgin forest with a higher proportion of optimum stage. Regarding the production ability of tree species, higher maximum heights and diameters for all tree species were recorded in Virgin forest Dobroc. The average deadwood volume is higher in Corkova Uvala (290.8 m3.ha-1) and corresponds to the living tree volume. Dynamics of the regeneration processes is different regarding the seedbed. The trees occur very rarely on the decaying deadwood in Virgin forest Dobroc. Tree species regenerate on the decaying deadwood in Virgin forest Corkova Uvala with higher abundance, where Norway spruce is the dominant tree species. Despite the low surface of deadwood as the seedbed (4.14% from the total investigated plot), the number of natural regeneration individuals of all tree species on deadwood represents 71.5%. Regarding the tree species composition of the natural regeneration, there is a difference in shifting into the higher height category in case of fir. In Virgin forest Corkova Uvala, it continuously shifts into the height category over 50 cm up to dbh <1 cm. In Virgin forest Dobroc, fir does not reach height over 50 cm due to the high number of red deer and their intensive browsing.
Eike Feldmann - One of the best experts on this subject based on the ideXlab platform.
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Regeneration Dynamics Following the Formation of Understory Gaps in a Slovakian Beech Virgin Forest
Forests, 2020Co-Authors: Eike Feldmann, Jonas Glatthorn, Christian Ammer, Christoph LeuschnerAbstract:The frequency and size of canopy gaps largely determine light transmission to lower canopy strata, controlling structuring processes in the understory. However, quantitative data from temperate Virgin Forests on the structure of regeneration in gaps and its dynamics over time are scarce. We studied the structure and height growth of tree regeneration by means of sapling density, shoot length growth and cumulative biomass in 17 understory gaps (29 to 931 m2 in size) in a Slovakian beech (Fagus sylvatica L.) Virgin forest, and compared the gaps with the regeneration under closed-canopy conditions. Spatial differences in regeneration structure and growth rate within a gap and in the gap periphery were analyzed for their dependence on the relative intensities of direct and diffuse radiation (high vs. low). We tested the hypotheses that (i) the density and cumulative biomass of saplings are higher in gaps than in closed-canopy patches, (ii) the position in a gap influences the density and height growth of saplings, and (iii) height growth of saplings increases with gap size. Sapling density and biomass were significantly higher in understory gaps than under closed canopy. Density of saplings was positively affected by comparatively high direct, but low diffuse radiation, resulting in pronounced spatial differences. In contrast, sapling shoot length growth was positively affected by higher levels of diffuse radiation and also depended on sapling size, while direct radiation intensity was not influential. Conclusively, in this forest, regeneration likely becomes suppressed after a short period by lateral canopy expansion in small gaps (
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forest structure and structural dynamics of Virgin beech Forests in slovakia
2019Co-Authors: Eike FeldmannAbstract:European beech (Fagus sylvatica L.) Forests gain a special interest in Central Europe. The highly competitive species would most likely achieve dominance within a wide range of site conditions. Understanding the natural structure and dynamics of beech Forests is of great importance for forest ecosystem research from both a conservation and management perspective. Today, there are only few remnants of Virgin beech Forests and our knowledge on their structure and especially on structural dynamics is poor. This thesis focuses on gap dynamics processes, their effect on stand structure and the analytical description of stand structures in terms of forest development stages in Virgin beech Forests. Canopy gap formation is suggested being the main driver of structural processes in in natural beech Forests. However, information on spatio-temporal change of gap pattern, released understory structures and their reaction to canopy release are scarce. In the Virgin beech forest Kyjov a repeated gap inventory was conducted to quantify differences in gap size frequency and fraction over a 10-year interval (2003–2013). Further, the percentage cover of understory trees and regeneration were estimated in 2013. Gap fraction decreased significantly from 13.6% in 2003 to 8.2% in 2013. Within 10 years the mean rate of gap closure was > 80%. Saplings and trees in lower canopy layers formed a heterogeneous understory in large parts of recently formed gaps. The results indicate considerable variation in disturbance intensity in the past decades. The prevalent heterogeneous tree understory guarantees a high resilience to canopy disturbance. The effects of gap formation on the regeneration process are fundamental for understanding forest dynamics. There are only a few studies from temperate Virgin Forests on gap regeneration and its natural dynamics over time and results are partly contradictory. The regeneration structure was studied in understory gaps of variable size and age, and under closed-canopy conditions in the Kyjov forest. Further, spatial differences in regeneration structure and height growth within a gap and in the gap periphery were analyzed. Sapling density and cumulative biomass were significantly higher in understory gaps than under the closed canopy. Sapling density was positively affected by high direct radiation but low diffuse radiation intensities, resulting in pronounced spatial differences in sapling density across a gap. Sapling shoot length growth was positively affected by higher levels of diffuse radiation and increased sapling size, while direct radiation was not influential. The results suggest that regeneration in small gaps most likely ends in a suppressed heterogeneous understory while in gaps ≥ 100 m2, regeneration may be capable even at low plant densities to fill the gap center, often forming a rapidly growing cohort-like regeneration layer. V It is suggested that in natural temperate Forests gap induced regeneration processes imprint on forest structure in the way that trees establish on the approximate gap area and close the gap over time. This assumption lacks an empirical basis. To verify this assumption neighboring trees of similar size were assigned to tree groups on a continuous 12 ha plot in the Kyjov forest and the group size-frequency of such homogeneous patches was analyzed across diameter classes. The number of tree groups (cohorts) in a particular diameter class decreased exponentially as group size increased. Compared to random distributions, the Kyjov forest exhibited a more clumped distribution especially for small trees. The frequency distribution patterns for group sizes are similar to those for gap sizes reported from the same stand and many others. Even though a direct comparison (number of trees vs. m2) is not possible, the results indicate that gap initiated tree groups may persist through the forest cycle. Researchers defined a succession of forest development stages to explain the diversity of structures encountered in beech-dominated Virgin Forests. However, existing methods based on empirical stand structural data fail to display structural development comprehensively. A novel approach for determining the extension of development stages is proposed. The Development Stage Index (IDS) assigns living and dead trees to the Initial, Optimum and Terminal stage according to their DBH (7–39 cm, 40–69 cm and ≥ 70 cm, respectively) and quantifies their extension by means of stem density and basal area. It was applied to 40 spaced sample plots (500 m2 each) in three beech Virgin Forests in East Slovakia (Kyjov, Havesova and Stuižca; 120 plots in total). Based on thorough stand structural analyses in the three Virgin beech Forests, it is demonstrated that IDS is a promising tool for quantifying the proportion of the three stages on different scales, visualizing the complex mixing of stages and analyzing dynamic changes in old-growth forest structure. The results from the Kyjov forest derived by the IDS are in large agreement with the conclusions on how gap dynamics shape forest structure in this forest. This suggests that it might be possible to infer on past forest dynamics by analyzing stand structure with the IDS.
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canopy gap dynamics and tree understory release in a Virgin beech forest slovakian carpathians
Forest Ecology and Management, 2018Co-Authors: Eike Feldmann, Lars Drosler, Viliam Pichler, Stanislav Kucbel, Markus Hauck, Christoph LeuschnerAbstract:Abstract Canopy gaps play a crucial role for forest dynamics processes, as they largely determine light transmission to lower canopy strata, thereby controlling the turnover of tree individuals in the stand. Even though their functional importance is undisputed, quantitative data on the rate of gap creation and gap closure, and the temporal change in gap size distribution patterns in temperate Virgin Forests are scarce. We used a repeated inventory (line-intercept sampling) of gap size frequency and fraction in a Virgin beech (Fagus sylvatica) forest in the Slovakian Carpathians over a 10-year interval (2003–2013) to test the hypotheses that (i) disturbance intensity and thus gap creation and gap closure rate change only little over time, (ii) gaps persist or even expand, until they are filled primarily by vertical ingrowth of trees from lower strata, and (iii) gap creation promotes the height growth of released saplings and sub-canopy trees. In the 2003 and 2013 inventories, 37 and 30 gaps >20 m2 size were mapped along a total of 3217 m transect line investigated. The large majority of gaps was 500 m2 were very rare. Gap fraction decreased significantly from 13.6% in 2003 to 8.2% in 2013 (associated with a reduction in mean gap size from 261 to 96 m2), indicating considerable variation in disturbance intensity in the past decades. Before 2003, both large gaps (probably caused by wind throw) and small gaps (from dying trees) have been formed, while only small gaps developed in the period 2003–2013. Small gaps were closed within a few years through rapid horizontal canopy expansion of neighboring beech trees, while vertical gap filling through ingrowth of lower canopy layers and regeneration was the dominant process in larger gaps. Saplings and trees in lower canopy layers formed a heterogeneous understory in large parts of recently formed gaps and responded to this process with increased height growth. We conclude that, despite considerable variation in disturbance intensity over time, this beech Virgin forest responds to gap formation with high resilience through rapid lateral canopy expansion in small gaps and ingrowth of saplings and sub-dominant tree layers in larger gaps.
