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Spruce Stands (spruce + stand)
Selected AbstractsImpact of common European tree species on the chemical and physicochemical properties of fine earth: an unusual patternEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 1 2010L. Mareschal Case studies are necessary to assess the effects of changes to tree species on the physicochemical and chemical properties of soils. To achieve this, the fine earth under five tree species was investigated. This study was performed in the Breuil-Chenue experimental forest site located in the Morvan Mountains (France). This site contains two adjacent blocks with replicated stands. The native forest (old beech and oak coppice with standards) was partially clear-felled and replaced in 1976 with mono-specific plantations of European beech, Norway spruce, Laricio pine and Douglas fir. The same changes in soil properties were revealed in both blocks, thus confirming the tree species effect. The percentage of exchangeable acidity on the cation exchange capacity (CEC) was greater under spruce, Douglas fir and pine than under the other species. Spruce stands, and to a lesser extent those of Douglas fir and pine, had a less acidic soil pH than hardwood stands (which was unusual in view of the data in the literature) and smaller CEC values. The small quantities of carbon added to the soil under these tree species provide an explanation for these effects through a partial control of both CEC and pH. This case study thus demonstrated that the tree species effect was not unequivocal and different criteria are necessary for its interpretation. Tree species significantly influenced certain aspects of the chemical properties of topsoil and have the potential to have an impact on current soil fertility. [source] Conversion of hardwood forests to spruce and pine plantations strongly reduced soil methane sink in GermanyGLOBAL CHANGE BIOLOGY, Issue 6 2003WERNER BORKEN Abstract Well-drained forest soils are thought to be a significant sink for atmospheric methane. Recent research suggests that land use change reduces the soil methane sink by diminishing populations of methane oxidizing bacteria. Here we report soil CH4 uptake from ,natural' mature beech forests and from mature pine and spruce plantations in two study areas of Germany with distinct climate and soils. The CH4 uptake rates of both beech forests at Solling and Unterlüß were about two,three times the CH4 uptake rates of the adjacent pine and spruce plantations, indicating a strong impact of forest type on the soil CH4 sink. The CH4 uptake rates of sieved mineral soils from our study sites confirmed the tree species effect and indicate that methanotrophs were mainly reduced in the 0,5 cm mineral soil depth. The reasons for the reduction are still unknown. We found no site effect between Solling and Unterlüß, however, CH4 uptake rates from Solling were significantly higher at the same effective CH4 diffusivity. This potential site effect was masked by higher soil water contents at Solling. Soil pH (H2O) explained 71% of the variation in CH4 uptake rates of sieved mineral soils from the 0,5 cm depth, while cation exchange capacity, soil organic carbon, soil nitrogen and total phosphorous content were not correlated with CH4 uptake rates. Comparing 1998,99, annual CH4 uptake rates increased by 69,111% in the beech and spruce stands and by 5,25% in the pine stands, due primarily to differences in growing season soil moisture. Cumulative CH4 uptake rates from November throughout April were rather constant in both years. The CH4 uptake rates of each stand were separately predicted using daily average soil matric potential and a previously developed empirical model. The model results revealed that soil matric potential explains 53,87% of the temporal variation in CH4 uptake. The differences between measured and predicted annual CH4 uptake rates were less than 10%, except for the spruce stand at Solling in 1998 (17%). Based on data from this study and from the literature, we calculated a total reduction in the soil CH4 sink of 31% for German forests due in part to conversion of deciduous to coniferous forests. [source] Evidence for low-titre infections in insect symbiosis: Wolbachia in the bark beetle Pityogenes chalcographus (Coleoptera, Scolytinae)ENVIRONMENTAL MICROBIOLOGY, Issue 8 2009Arthofer Wolfgang Summary Wolbachia are obligatory endosymbiotic ,-proteobacteria found in many insect species. They are maternally transmitted and often exhibit reproductive phenotypes like cytoplasmic incompatibility. Pityogenes chalcographus is a bark beetle causing severe damage in spruce stands. Its European populations are divided into several mitochondrial clades separated by partial crossing barriers. In this study, we tested a large sample set covering the natural range of the beetle in Europe for the presence of Wolbachia and associations between infection pattern and mitotypes using a highly sensitive nested PCR technique. 35.5% of the individuals were infected with the endosymbiont and two distinct strains were identified. Both strains occur in low titre not accessible by conventional detection methods. The infections are present all over Europe, unlikely to cause the partial crossing barriers in this host and uncoupled from mitochondrial clades. This pattern is indicative for populations evolving towards endosymbiont loss and for repeated intraspecific horizontal transfer of Wolbachia. Alternatively, the low-titre infections found in P. chalcographus are yet another example for Wolbachia that can persist in host species at low densities and frequencies. [source] Occurrence of Heterobasidion basidiocarps on cull pieces of Norway spruce left on cutting areas and in mature spruce standsFOREST PATHOLOGY, Issue 6 2007M. M. Müller Summary Fruiting of Heterobasidion on cull pieces and stumps of Norway spruce was investigated in cutting areas and mature spruce stands located in southern Finland. Cull pieces of variable size and showing butt rot were left on three clear-cut areas and in one thinned stand. Additionally, a part of the cull pieces was transported to mature forest sites with closed canopy. During the succeeding 3,4 years the cull pieces were investigated annually for sporocarps of Heterobasidion, and the area of actively sporulating pore layer of each sporocarp was measured. Root bases of spruce stumps in the logging areas were excavated and sporocarps found on the stumps also measured. At the onset of the experiment, Heterobasidion spp. were isolated from 76% of the cull pieces showing butt rot; 85% of the isolates were identified as H. parviporum and 15% as H. annosum s.s. During the following 3,4 years sporocarps were found on 20% of the 1938 cull pieces where Heterobasidion butt rot was initially detected visually. Sporocarp formation was promoted by advancement of butt rot, increasing cull piece diameter and end-to-end ground contact, but restricted by the colonization of the cull piece by Stereum sanguinolentum. Between-site differences were significant but could not be explained by differences in tree cover. At the end of the investigation period the average sporulating area of Heterobasidion sporocarp per metre of cull piece was higher than the average sporulating area per stump at three of four logging sites. Hence, leaving cull pieces containing Heterobasidion butt rot at logging areas in southern Finland can considerably increase local production of Heterobasidion spores. [source] Effects of metals and pH on in vitro growth of Armillaria ostoyae and other root and butt rot fungi of red spruceFOREST PATHOLOGY, Issue 1 2001P. M. Wargo Armillaria ostoyae, Perenniporia subacida, Resinicium bicolor and Scytinostroma galactinum, root and butt rot fungi found on red spruce, Picea rubens, were tested, in vitro, for their sensitivity to metals typically found in high elevation forest soils where red spruce grows. Rhizomorph production by A. ostoyae from woody inocula in soils from red spruce stands at three elevations at each of five mountainous sites in the eastern United States was inhibited completely in the mineral soil from all elevations at all sites, and was also reduced significantly in the organic horizon from the upper two elevations at three of the sites. Inhibition was correlated with concentrations of metal ions in the soil. Growth of rhizomorphs into an agar medium containing lead and other heavy metals was inhibited for isolates of A. ostoyae from red spruce, but not for an isolate of Armillaria gallica from sugar maple; aluminium inhibited rhizomorph growth of isolates of both species. Mycelial growth of all four root and butt rot fungi was inhibited by lead, aluminium and other heavy metals depending on the solubility and concentration of metal and pH of the medium; growth inhibition was usually greater at an initial pH of 3.5 than at pH 4.5. Metal ions inhibited radial growth of Armillaria species more than that of the other three fungi. Rhizomorph growth of Armillaria was inhibited more than radial growth. Because local spread of A. ostoyae occurs frequently by means of rhizomorph growth between near roots, increases in lead, aluminium and other metals in the forest floor may contribute to this fungus' scarcity in high elevation soils and reduced incidence of infection at these sites in the eastern United States. [source] Conversion of hardwood forests to spruce and pine plantations strongly reduced soil methane sink in GermanyGLOBAL CHANGE BIOLOGY, Issue 6 2003WERNER BORKEN Abstract Well-drained forest soils are thought to be a significant sink for atmospheric methane. Recent research suggests that land use change reduces the soil methane sink by diminishing populations of methane oxidizing bacteria. Here we report soil CH4 uptake from ,natural' mature beech forests and from mature pine and spruce plantations in two study areas of Germany with distinct climate and soils. The CH4 uptake rates of both beech forests at Solling and Unterlüß were about two,three times the CH4 uptake rates of the adjacent pine and spruce plantations, indicating a strong impact of forest type on the soil CH4 sink. The CH4 uptake rates of sieved mineral soils from our study sites confirmed the tree species effect and indicate that methanotrophs were mainly reduced in the 0,5 cm mineral soil depth. The reasons for the reduction are still unknown. We found no site effect between Solling and Unterlüß, however, CH4 uptake rates from Solling were significantly higher at the same effective CH4 diffusivity. This potential site effect was masked by higher soil water contents at Solling. Soil pH (H2O) explained 71% of the variation in CH4 uptake rates of sieved mineral soils from the 0,5 cm depth, while cation exchange capacity, soil organic carbon, soil nitrogen and total phosphorous content were not correlated with CH4 uptake rates. Comparing 1998,99, annual CH4 uptake rates increased by 69,111% in the beech and spruce stands and by 5,25% in the pine stands, due primarily to differences in growing season soil moisture. Cumulative CH4 uptake rates from November throughout April were rather constant in both years. The CH4 uptake rates of each stand were separately predicted using daily average soil matric potential and a previously developed empirical model. The model results revealed that soil matric potential explains 53,87% of the temporal variation in CH4 uptake. The differences between measured and predicted annual CH4 uptake rates were less than 10%, except for the spruce stand at Solling in 1998 (17%). Based on data from this study and from the literature, we calculated a total reduction in the soil CH4 sink of 31% for German forests due in part to conversion of deciduous to coniferous forests. [source] Studies on the significance of pathogenic fungi in the population dynamics of the Lesser Spruce Sawfly, Pristiphora abietina Christ. (Hym., Tenthredinidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2001Führer The population dynamics of Pristiphora abietina, an important pest in Norway spruce in central Europe, is significantly influenced by factors causing nymph mortality during the cocoon stage. In contrast to other findings reported in the literature, pathogenic fungi of the genera Beauveria, Paecilomyces and Metarhizium were found to be important natural enemies. Their epizootics occur soon after cocoon formation by the larvae in the ground litter, i.e. in June/July, and progress only slightly in autumn and winter. ,Obscure' mortality, which is ascribed mainly to abiotic factors, is observed more in winter. Field and laboratory experiments as well as histological analyses suggest that the fungal disease in nymphs is due to spore contamination occurring before cocoon formation, and that penetration of fungi from outside through the intact cocoon wall appears very unlikely. Thus, the infection rate of cocoons depends on the spore density in the ground litter of spruce stands during the cocoon spinning period of May/June. Perspectives for biocontrol arising from these findings are discussed. [source] Soil biochemical and chemical changes in relation to mature spruce (Picea abies) forest conversion and regenerationJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2003Zheke Zhong Abstract To investigate soil changes from forest conversion and regeneration, soil net N mineralization, potential nitrification, microbial biomass N, L-asparaginase, L-glutaminase, and other chemical and biological properties were examined in three adjacent stands: mature pure and dense Norway spruce (Picea abies (L.) Karst) (110 yr) (stand I), mature Norway spruce mixed with young beech (Fagus sylvatica) (5 yr) (stand II), and young Norway spruce (16 yr) (stand III). The latter two stands were converted or regenerated from the mature Norway spruce stand as former. The studied soils were characterized as having a very low pH value (2.9 , 3.5 in 0.01 M CaCl2), a high total N content (1.06 , 1.94,%), a high metabolic quotient (qCO2) (6.7 , 16.9 g CO2 kg,1 h,1), a low microbial biomass N (1.1 , 3.3,% of total N, except LOf1 at stand III), and a relatively high net N mineralization (175 , 1213 mg N kg,1 in LOf1 and Of2, 4 weeks incubation). In the converted forest (stand II), C,:,N ratio and qCO2 values in the LOf1 layer decreased significantly, and base saturation and exchangeable Ca showed a somewhat increment in mineral soil. In the regenerated forest (stand III), the total N storage in the surface layers decreased by 30,%. The surface organic layers (LOf1, Of2) possessed a very high net N mineralization (1.5 , 3 times higher than those in other two stands), high microbial biomass (C, N), and high basal respiration and qCO2 values. Meanwhile, in the Oh layer, the base saturation and the exchangeable Ca decreased. All studied substrates showed little net nitrification after the first period of incubation (2 weeks). In the later period of incubation (7 , 11 weeks), a considerable amount of NO3 -N accumulated (20 , 100,% of total cumulative mineral N) in the soils from the two pure spruce stands (I, III). In contrast, there was almost no net NO3 -N accumulation in the soils from the converted mixed stand (II) indicating that there was a difference in microorganisms in the two types of forest ecosystems. Soil microbial biomass N, mineral N, net N mineralization, L-asparaginase, and L-glutaminase were correlated and associated with forest management. Chemische und biochemische Veränderungen der Bodeneigenschaften durch Verjüngung und Waldumbau eines Fichtenaltbestandes Um die durch den Waldumbau und die Regeneration bedingten Standortsveränderungen zu untersuchen, wurden die Netto-Stickstoffmineralisierung, die potenzielle Nitrifikation, der mikrobiell gebundene Stickstoff (Nmic), L-Asparaginase, L-Glutaminase sowie weitere chemische und biologische Parameter an drei benachbarten Standorten untersucht: Standort I, reiner Fichtenaltbestand (Picea abies (L.) Karst ,110 Jahre); Standort II, Fichtenaltbestand mit Buchenunterbau (Fagus sylvatica , 5 Jahre); Standort III, reine Fichtenaufforstung (16 Jahre). Die Standorte II und III entstanden infolge des Waldumbaus aus reinen Fichtenaltbeständen. Die untersuchten Böden sind gekennzeichnet durch sehr niedrige pH-Werte (pH(H2O) 3, 7 , 4, 2, pH (CaCl2) 2, 9 , 3, 5), hohe Gesamtstickstoffgehalte (1, 06 , 1, 94,%), hohe metabolische Quotienten (6, 7,16, 9g CO2 kg,1 h,1), geringe Nmic -Gehalte (1, 1 , 3, 3,% des Gesamt-N, ausgenommen LOf1 von Standort III) und eine relativ hohe N-Nettomineralisation (175 , 1213 mg N Kg,1 in LOf1 und Of2, nach 4 Wochen Inkubation). Am Standort II nahm das C,:,N-Verhältnis und der qCO2 im LOf1 -Horizont deutlich ab, wohingegen der Gehalt an austauschbarem Ca sowie die Basensättigung im Mineralboden geringfügig zunahmen. Am Standort III nahm der N-Vorrat (Auflagehumus + Mineralboden 0 , 10,cm) um 30,% ab. In den LOf1 - und Of2 -Lagen des Auflagehumus dieses Standortes traten eine hohe N-Nettomineralisation (1, 5- bis 3fach höher als in den Standorten I und II), hohe Gehalte an mikrobiell gebundenem C und N, eine erhöhte Basalatmung sowie erhöhte qCO2 -Werte auf. In den Oh-Lagen hingegen nahm die Basensättigung ab. Alle untersuchten Standorte zeigten in der ersten Periode der Inkubation (0 bis 2 Wochen) eine geringe Netto-Nitrifikation. An den Standorten I und III fand in der späteren Periode (7. bis 11. Woche) eine Anreicherung an NO3 (20 , 100,% des gesamten mineralischen N-Vorrates) statt. Im Gegensatz dazu wurde am Standort II keine NO3 -N- Anreicherung festgestellt. Dies deutet auf einen Unterschied in der Zusammensetzung der mikrobiellen Gemeinschaften in den zwei verschiedenen Forstökosystemen hin. Nmic, N-Nettomineralisation, L-Asparaginase und L-Glutaminase korrelieren miteinander und zeigen eine enge Beziehung zu den Bewirtschaftungsformen. [source] Characterization of microsatellite loci in the spruce bark beetle Ips typographus (Coleoptera: Scolytinae)MOLECULAR ECOLOGY RESOURCES, Issue 3 2003A. Sallé Abstract Ips typographus is an economically important pest of Norway spruce stands. We developed five polymorphic microsatellite markers using a biotin enrichment protocol. The number of alleles ranged from three to 11 per locus and no strong evidence for null alleles was found. Heterozygosity ranged from 0.3 to 0.97. These markers could be useful tools to study the population structure and genetic consequences of I. typographus population outbreaks. [source] | |||||||||||||