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Element release in beech (Fagus sylvatica L.) forest gaps
No full textNutrient cycling in forest gaps has received little attention until now, although gap regeneration is important to natural dynamics and forest management practices in temperate forests. Four gaps of 30 m diameter were cut in a mature beech forest (Fagus sylvatica L.) in the Selling Kills in 1989. Two gaps were limed. Atmospheric deposition, plant nutrient uptake, nitrogen mineralization, seepage water chemistry and element losses were compared between gaps and the surrounding mature stand. The most obvious changes in element cycles in gaps occured in the ecosystem losses of nitrate, cations and nitrous oxcide. The major difference in seepage water concentrations of nutrients among gaps was caused by the development of the herbaceous vegetation in the limed gaps. The concentrations of nitrate in the seepage water from the unlimed gaps exceeded drinking water standards. The results stress the importance of effective and early coupling of decomposition and nutrient uptake by new vegetation after tree removal. If soil acidity limits rapid revegetation, liming may be considered as a vegetation management practice
Analyse und Lösungsansätze vor dem Hintergrund rechtlicher, ökologischer und ökonomischer Zusammenhänge
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Dynamics of woody debris in a beech stand (Fagus sylvatica L.) in Solling. Input, causes and decomposition of woody debris
No full textIn a 8 ha beech (Fagus sylvatica) stand of about 160 years in Solling, south Lower Saxony, the input and decomposition of woody debris were observed over a period of 12 years. Since the beginning of the investigation input has increased. In 2000 the volume of the coarse woody debris was 50,9 m 3 ha I (Tab. 4). Storm and the white rot resulting fungus Fomes fomentarius were identified as causes of mortality (Fig. 1). The infestation of Fomes fomentarius increased and resulted in death of single trees (Fig. 3). The oldest, still identifiable, strongly decomposed logs fell down 1970. Under the given climatic conditions the decomposition period is about 40 years. The determined volume of woody debris is in the range of the amounts from natural beech forests and natural forest reserves. The results indicate that the amount and origin of mortality as well as the mortality pattern depend on the age of the stand. On the basis of the properties of woody debris a decomposition key will be presented
Early seedling growth of pine (Pinus densiflora) and oaks (Quercus serrata, Q-mongolica, Q-variabilis) in response to light intensity and soil moisture
No full textIn climatic chambers seed germination and seedling growth of Pinus densiflora Sieb. et Zucc., Quercus serrata Thunb., Quercus mongolica Fisch. ex Turcz. and Quercus variablilis Bl. were investigated as functions of light intensity and soil moisture. In Korea these tree species occur widely and form mixed forests with different distributions. Species clearly differed in the pattern of germination and early seedling growth between light and soil treatments. The germination of pine did not differ between the experimental treatments until the breaking of the primary buds. After that, light intensity was the deciding factor for further development. In the most moist treatment (approx. field capacity) growth of the pine seedlings was strongly inhibited. For the three oak species, differences between experimental treatments first occurred after complete formation of primary leaves. Seed development strongly correlated with the weight of the acorn. The large seeded Q. variabilis (acorns with mean weight of 4.7 g) developed faster and reached larger dimensions towards the end of the experiment than Q. mongolica (2.8 g per acorn) and Q. serrata (0.9 g per acorn). Regarding height and biomass growth, the oak species showed a higher shade tolerance than pine. The proleptic shoot growth was clearly influenced by the light intensity. Root formation was favoured by a high exposure to light. In case of the oak species reduction of soil moisture increased the length of primary roots and the number of secondary roots
Dynamics of woody debris in a beech stand (Fagus sylvatica L.) in Solling. Input, causes and decomposition of woody debris
No full textIn a 8 ha beech (Fagus sylvatica) stand of about 160 years in Solling, south Lower Saxony, the input and decomposition of woody debris were observed over a period of 12 years. Since the beginning of the investigation input has increased. In 2000 the volume of the coarse woody debris was 50,9 m 3 ha I (Tab. 4). Storm and the white rot resulting fungus Fomes fomentarius were identified as causes of mortality (Fig. 1). The infestation of Fomes fomentarius increased and resulted in death of single trees (Fig. 3). The oldest, still identifiable, strongly decomposed logs fell down 1970. Under the given climatic conditions the decomposition period is about 40 years. The determined volume of woody debris is in the range of the amounts from natural beech forests and natural forest reserves. The results indicate that the amount and origin of mortality as well as the mortality pattern depend on the age of the stand. On the basis of the properties of woody debris a decomposition key will be presented
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