Evaluation of the forest growth model SILVA along an elevational gradient in Switzerland     

Stéphanie Schmid  Andreas Zingg  Peter Biber  Harald Bugmann 《European Journal of Forest Research》2006,125(1):43-55

The semi-empirical single-tree model SILVA 2.2 has been developed and parameterised using forest research and inventory data from Germany that range from the colline to the montane zone. The focus of the model evaluation presented in this study was to test the applicability of the model for the main Swiss forest types and at elevations ranging from the colline to the upper subalpine zone. To this end, SILVA was initialized using data from long-term forest yield research plots. The results at the end of the 30-year simulation were compared with observed data. The analysis of the results at each test site showed that there were no significant differences in model performance between forest types. However, the deviation between simulated and observed growth depended strongly on the elevational zone, i.e., on climate. As expected, the best results were found in the colline zone, for which the model had been calibrated, whereas the upper subalpine sites revealed the strongest differences. The quality of the data regarding forest structure that were available for model initialization had a strong impact on the simulation results, mainly at high-elevation zones (i.e., supalpine and upper subalpine). We conclude that SILVA 2.2 is a suitable tool to estimate the development of single trees and standing volume for a large fraction of the forests in Switzerland. However, extreme climate conditions should be avoided with the model, and the availability of detailed stand structure information is a key priority that has a strong effect on the quality of the simulation results.

Harald BugmannEmail:

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The genetic and economic gains from forest tree breeding programmes in Scandinavia and Finland     

Gunnar Jansson  Jon Kehlet Hansen  Matti Haapanen  Harald Kvaalen  Arne Steffenrem 《Scandinavian Journal of Forest Research》2017,32(4):273-286

Plantations of genetically improved forest trees are critical for economic sustainability in forestry. This review summarizes gains in objective traits and the resulting economic impact of tree breeding programmes in Scandinavia and Finland. Genetic improvement of forest trees in these countries began in the late 1940s, when the first phenotypically superior plus-trees were selected from natural environments. The main findings from this review are that (i) tree breeding can increase volume growth in the range 10–25%, and (ii) the bare land value associated with genetically improved trees gives a better return on investment and a shorter rotation period compared to the unimproved forests. As some Nordic countries are quite dependent on the forest industry, breeding programmes that have resulted in economic gains have been beneficial for society. Growth and wood quality traits are often adversely correlated, and the weighting of traits from an economic perspective could provide an index for determining maximum profit from breeding. Tree breeding faces an array of challenges in the future, such as changes in silviculture, climate, new pests and diseases, and demand for wood-based products.  相似文献   

The prospects of silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) Karst) in mixed mountain forests under various management strategies,climate change and high browsing pressure     

Klopčič  Matija  Mina  Marco  Bugmann  Harald  Bončina  Andrej 《European Journal of Forest Research》2017,136(5-6):1071-1090

European Journal of Forest Research - In the Dinaric Mountains, the future of silver fir and Norway spruce appears to be uncertain, especially given the threat of climate change to both species and...  相似文献   

Nitrogen compounds extracted by electroultrafiltration (EUF) or CaCl2 solution and their relationships to nitrogen mineralization in soils     

Konrad Mengel  Birgit Schneider  Harald Kosegarten 《植物养料与土壤学杂志》1999,162(2):139-148

The objective of the investigation was to identify the most important organic N-containing fractions extracted from soils by electroultrafiltration (EUF) or a CaCl₂ solution, respectively, and their importance for nitrogen mineralization. The investigation comprised 19 agricultural and one forest top soil. Net N mineralization was tested in Mitscherlich pot experiments with three treatments: (1) fallow soil without N fertilizer, (2) soil cultivated with rye grass without N fertilizer, (3) soil cultivated with rye grass with N fertilizer. The highest proportion of N in the extracts was the amino N fraction (amino acids + peptides) amounting to approximately 60% of the total N extracted by CaCl₂ and to about 40% of the total N extracted by EUF. The proportion of amino sugars from total N extracted was in average 10% for the CaCl₂ and 5.2% for the EUF extracts. The proportion of heterocyclic N bases derived from nucleic acids amounted in average to 4.8% and 3.6% for the CaCl₂ and EUF extract, respectively. Amino N (amino acids + peptides) were correlated best with net N mineralization (EUF, r = 0.81***, CaCl₂, r = 0.86***). The correlation between amino sugars and net N mineralization was r = 0.55* for the EUF extract and r = 0.49* for the CaCl₂ extract. The heterocyclic N bases did not correlate with net N mineralization. Correlations between Norg extracted by CaCl₂ versus net N mineralization were higher than those obtained by the EUF extract. Net N mineralization was about four times higher in the fallow soils than in the treatment with grass and no N fertilizer. In the treatment with grass + N fertilizer on average no net N mineralization occurred, moreover there was a tendency of N immobilization. It is assumend that in the treatments with grass cultivation, organic C released by roots stimulated the assimilation of mineral N and amino acids by soil microorganisms resulting in a low net N mineralization. Net N mineralization led to a highly significant depletion in the Norg pools and particularly in the amino N and amino sugar pools in the treatment with grass and without N fertilizer. This depletion was particularly evident in the CaCl₂ extracts. The results justify the conclusion that the Norg obtained with both extraction methods originates from a dynamic N pool into which N flows in and out. The amino N extractable with EUF or CaCl₂ is a reliable indicator for the net N mineralization potential of soils.  相似文献   

Monitoring infection with Piscine myocarditis virus and development of cardiomyopathy syndrome in farmed Atlantic salmon (Salmo salar L.) in Norway     

Julie Christine Svendsen  Stian Nylund  Anja B. Kristoffersen  Harald Takle  Julia Fossberg Buhaug  Britt Bang Jensen 《Journal of fish diseases》2019,42(4):511-518

An epidemiological study was carried out in Norway in 2015–2018, investigating the development of infection with Piscine myocarditis virus (PMCV) and development of cardiomyopathy syndrome (CMS) in farmed Atlantic salmon. Cohorts from 12 sites were followed and sampled every month or every other month from sea transfer to slaughter. PMCV was detected at all sites and in all sampled cages, and fish in six sites developed clinical CMS. The initial infection happened between 1 and 7 months post‐sea transfer, and the median time from infection with PMCV until outbreak of CMS was 6.5 months. Generally, fish from sites with CMS had higher viral titre and a higher prevalence of PMCV, compared to sites that did not develop clinical CMS. The virus persisted until the point of slaughter at most (11 out of 12) of the sites. The detection of PMCV in all sites suggests that PMCV is more widespread than previously known. Screening for PMCV as a tool to monitor impending outbreaks of CMS must be supported by observations of the health status of the fish and risk factors for development of disease.  相似文献   

Effects of chronic sub‐lethal nitrite exposure at high water chloride concentration on Atlantic salmon (Salmo salar,Linnaeus 1758) parr     

Xavier A. Gutirrez  Jelena Kolarevic  Harald Takle  Grete Baeverfjord  Elisabeth Ytteborg  Bendik Fyhn Terjesen 《Aquaculture Research》2019,50(9):2687-2697

The present study examined the protective effects of water chloride (Cl^?) towards nitrite toxicity in Atlantic salmon parr during 84‐day long nitrite exposure. Effects on growth, histology, blood indices and gene expression were studied at a fixed nominal Cl^? concentration of 200 mg/L and at several water nitrite concentrations (0, 0.5, 2, 5 and 10 mg/L NO₂^?–N). The specific growth rate was significantly reduced during the first three weeks at a Cl:NO₂^?–N ratio of 21:1, suggesting the activation of coping mechanisms at the later stages of the experiment. No significant effect of nitrite on gill histology and mortality was found. Nitrite accumulated in plasma; however, a Cl:NO₂^?–N ratio of 104:1 or higher prevented nitrite entry. The concentration of NO₂^?–N in plasma was significantly reduced at the end of the study, supporting the hypothesis of coping mechanisms. Cystic fibrosis transmembrane conductance regulator (cftr)‐1 showed a significant up‐regulation at highest nitrite concentration on day 22, and in three of the highest exposure groups at the end of the experiment. Our findings suggest that a Cl:NO₂^?–N ratio above 104:1 should be maintained through episodes of nitrite accumulation in water during the production of Atlantic salmon parr.  相似文献   

Depressed growth of non‐chlorotic vine grown in calcareous soil is an iron deficiency symptom prior to leaf chlorosis     

Bernd Gruber  Harald Kosegarten 《植物养料与土壤学杂志》2002,165(1):111-117

The development of iron deficiency symptoms (growth depression and yellowing of the youngest leaves) and the distribution of iron between roots and leaves were investigated in different vine cultivars (Silvaner, Riparia 1G and SO4) grown in calcareous soils. As a control treatment all cultivars were also grown in an acidic soil. Only the cultivars Silvaner and Riparia 1G showed yellowing of the youngest leaves under calcareous soil conditions at the end of the cultivation period. All cultivars including SO4 showed severe shoot growth depression, by 50 % and higher, before yellowing started or without leaf yellowing in the cultivar SO4. Depression of shoot growth occurred independently from that of root growth. In a further treatment the effect of Fe‐EDDHA spraying onto the shoot growth of the cultivar Silvaner after cultivation in calcareous soil was investigated. Prior to Fe application plants were non‐chlorotic, but showed pronounced shoot growth depression. Spraying led to a significant increase in shoot length, though leaf growth was not increased. Accordingly, depression of shoot growth of non‐chlorotic plants under calcareous soil conditions and with ample supply of nutrients and water has been evidenced to be at least partly an iron deficiency symptom. We suggest that plant growth only partially recovered because of dramatic apoplastic leaf Fe inactivation and/ or a high apoplastic pH which may directly impair growth. Since growth was impaired before the youngest leaves showed chlorosis we assume that meristematic growth is more sensitively affected by Fe deficiency than is chlorophyll synthesis and chloroplast development. In spite of high Fe concentrations in roots and leaves of the vines grown in calcareous soils plants suffered from Fe deficiency. The finding of high Fe concentrations also in young, but growth retarded green leaves is a further indication that iron deficiency chlorosis in calcareous soils is caused by primary leaf Fe inactivation. However, in future, only a rigorous study of the dynamic changes of iron and chlorophyll concentration, leaf growth and apoplastic pH at the cellular level during leaf development and yellowing will provide causal insights between leaf iron inactivation, growth depression, and leaf chlorosis.<?show $6#>  相似文献   

Fulvic acid composition in degraded fenlands     

Peter Leinweber  Hans‐Rolf Schulten  Karsten Kalbitz  Ralph Meißner  Harald Jancke 《植物养料与土壤学杂志》2001,164(4):371-379

Fulvic acids (FAs) from topsoil and ground water solutions were investigated to discover effects of land use and peat degradation on their molecular chemical composition and thermal properties. The FAs were extracted from three Gleysols under arable land, intensive and extensive grassland, and from three Histosols under alder forest, extensive grassland, and a natural succession in a long‐term (> 200 years) cultivated fen area. Functional groups and molecular subunits of the FAs were investigated by ¹³C Nuclear Magnetic Resonance (¹³C NMR) spectroscopy. Thermal properties and structural molecular subunits were investigated by off‐line pyrolysis, and Pyrolysis‐Field Ionization Mass Spectrometry (Py‐FIMS). The ¹³C NMR spectra showed that the FAs from topsoil solutions had smaller proportions of alkyl C (mean: —8 %) and more aromatic C (mean: + 6 %) than FAs from ground water. This clear differentiation of dissolved FAs in the soil profiles is consistent with Py‐FIMS data which have shown enrichments of lipids in ground water FAs. Furthermore, Py‐FIMS revealed that the FAs from topsoils were richer in phenols + lignin monomers, carbohydrates, as well as mostly aromatic N‐containing compounds. These molecular subunits of FAs, relatively enriched in topsoil, were also the main indicators of land use and peat degradation. For topsoil solutions, the proportions of phenols + lignin monomers and carbohydrates increased stepwise with peat degradation in Gleysols and Histosols. Correspondingly, the thermal properties indicated the incorporation of these compounds into FAs by chemical bonds of larger thermal stability. Statistical evaluation by principal component analysis of Py‐FIMS clearly supported the differentiation of FAs according to the origin from topsoils and ground water, different soil types, and land use and peat degradation. Hence, it is concluded that water soluble FAs can be utilized as objective ecological indicators for soil effects on adjacent ground and surface waters.  相似文献