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Sylwan
|
2007
|
tom 151
|
nr 05
60-72
Clear−cutting impacts site conditions seriously. However, in nutrient−poor sites the effects of stand removal can be minor than in nutrient−rich sites. The aim of this work was to assess whether the clear−cut can improve species diversity of ground Cladonia species, which decline has been observed in forest communities. In stands of different age classes (10, 11−20, 21−40, 41−60, 61−80, 81 years) in the Przymuszewo Forest District (northern Poland) ground Cladonia species and their cover were recorded on research plots (10×15 m). A total of 24 species were identified in the study area. There were more Cladonia species and they were more abundant in young stands (<20 years old) than in stands older than 60 years. Nine species are significantly more frequent and demonstrated high fidelity in young stands and only one was characteristic for old stands. Composition of Cladonia species depended primarily on stand age and subsequently on canopy or bryophyte cover. In nutrient−poor sites clear−cutting is favourable for Cladonia species diversity.
This study investigates the effect of the enrichment of Scots pine stands with a common beech understorey on changes in the species composition and selected life traits of an important zooindicator group, such as the ground beetles (Col. Carabidae). The field investigations were carried out in a fresh coniferous forest in the Myszyniec Forest District (N Poland) in stands with (P+) and without (P) beech in the understorey. Each treatment was repeated four times. In each repetition, six pitfalls were installed. The traps were replaced 13 times, every two weeks, from April to October. In total, 4412 specimens classified into 25 species of ground beetles were captured. The tree stands with the beech understorey were observed to contain a significantly higher number of species than the ones with the beech undergrowth. Also, the value of the Shannon index of species diversity (H’) and mean individual biomass (MIB) were significantly higher in the treatment with the beech understorey. Principal Component Analysis showed variations in Carabidae assemblages within the analysed types of forest. Pterostichus oblongopunctatus, Pterostichus aethiops and Pterostichus vernalis were more strongly correlated with the stands without beech understorey. The stands enriched with the beech understorey correlated with the occurrence of large zoophages: Carabus arvensis and Cychrus caraboides, and hemizoophages of the genus Amara. An in−depth ecological characterisation of the captured Carabidae showed that the dominant ground beetles in the investigated forest habitats, in terms of the number of caught individuals and species, belonged to forest zoophagous carabids characterised by moderate requirements for moisture in a habitat, and having the spring type of development. Representatives of large zoophages and species with the autumn type of development, i.e. species associated with later ecological succession stages, were more numerously caught in the pine stands without the beech understorey The study provides evidence that justifies the planting of deciduous undergowth in monoculture coniferous pine tree forests. The presence of an understorey contributes to higher: richness of Carabidae species, values of the MIB and abundance of large forest species presenting the autumn type of development, that is the species, which are characteristic for forest areas representing a highly advanced succession stage.
This study was carried out in the Słowiński National Park (SNP; northern Poland) in Scots pine forest stands. The aim of the research was to compare the accumulation of nitrogen, phosphorus, potassium, magnesium, calcium, zinc, nickel, iron and manganese in needles of pines growing on in dry (Bs), fresh (Bw) and moist (Bw) habitats. The age of needles, soil moisture and the content of examined components in the soil were taken into account. Needles and soil samples were collected in September from 15 sites (Bs – 5, Bśw – 3, Bw – 7). The nitrogen was determined with Kiejdahl method, and the phosphorus by the molybdate method after digestion in the mixture of 98% H2SO4and 30% H2O2. The content of K, Mg, Ca, Zn, Ni, Fe and Mn was assessed by atomic absorption spectrometry after digestion in the mixture of 65% HNO3 and 30% H2O2. The soils of SNP, developed from deep dune sands, were very poor in nutrients. The highest amounts of macro− and micronutrients were found in organic and humic levels. In mineral levels, the content of the ingredients decreased rapidly and in many cases was beyond the limit of determination. Extreme nitrogen, phosphorus and potassium deficiency was found in analysed needles, together with adequate amounts of magnesium, zinc, nickel, iron and manganese as well as an excess of calcium. Differences in the nutritional state of Scots pine in investigated habitats were apparent primarily in the sum of the components accumulated in the needles. Needles accumulated in total from 736.5 to 850.7 mmolc/kg of nutrients, with macronutrients ranging from 98.6 to 99.1%. The accumulation of macro− and micronutrients in the examined needles decreased in the series Bśw>Bw>Bs. Mn and Fe showed the largest share in the micronutrient pool. Zn and Ni were significantly less common. The comparison of the accumulation of macro− and micronutrients in the needles indicated that stands on Bśw have slightly better conditions for development under unfavourable soil and climatic conditions prevailing in the Łeba Spit than those in Bs and Bw habitats.
Gatunki wskazujące na typ siedliska borowego określono na podstawie badań roślinności borowej na terenie Obrębu Kliczków Nadleśnictwa Bolesławiec znajdującego się w zarządzie RDLP we Wrocławiu. Siedliska boru świeżego i boru mieszanego świeżego stanowią w Obrębie Kliczków znaczną powierzchnię: 55% (6254,35 ha) zajmują siedliska boru świeżego, a 33% (3768,32 ha) – siedliska boru mieszanego świeżego. W wybranych wydzieleniach leśnych o drzewostanach w różnym wieku założono powierzchnie kołowe jednakowej wielkości (200 m2), na których zinwentaryzowano gatunki naziemne mszaków, porostów i roślin naczyniowych. Na podstawie zebranego materiału wytypowano 10 gatunków preferujących siedliska boru świeżego i 9 przywiązanych do siedlisk boru mieszanego świeżego. Wśród tych gatunków dla obu badanych typów siedlisk dokonano rozróżnienia na gatunki wskaźnikowe i gatunki wyróżniające. Wskaźnikami siedlisk boru świeżego są: Cladonia chlorophaea, C. gracilis, C. macilenta, Dicranum spurium oraz Ptilidium ciliare, a gatunkami wyróżniającymi te siedliska: Cetraria islandica, Cladonia arbuscula, C. crispata, C. deformis oraz C. rangiferina. Wskaźnikami siedlisk boru mieszanego świeżego są natomiast: Brachythecium rutabulum, Carex pilulifera, Lophocolea bidentata, L. heterophylla, Plagiothecium curvifolium i Sciuro-hypnum oedipodium, a gatunkami wyróżniającymi te siedliska: Pseudoscleropodium purum, Pteridium aquilinum oraz Tetraphis pellucida.
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