Species proportions by area in mixtures of Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) and European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.)     

Gerald Dirnberger  Hubert Sterba  Sonia Condés  Christian Ammer  Peter Annighöfer  Admir Avdagić  Kamil Bielak  Gediminas Brazaitis  Lluís Coll  Michael Heym  Václav Hurt  Viktor Kurylyak  Renzo Motta  Maciej Pach  Quentin Ponette  Ricardo Ruiz-Peinado  Jerzy Skrzyszewski  Vít Šrámek  Géraud de Streel  Miroslav Svoboda  Tzvetan Zlatanov  Hans Pretzsch 《European Journal of Forest Research》2017,136(1):171-183

Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) dominate many of the European forest stands. Also, mixtures of European beech and Scots pine more or less occur over all European countries, but have been scarcely investigated. The area occupied by each species is of high relevance, especially for growth evaluation and comparison of different species in mixed and monospecific stands. Thus, we studied different methods to describe species proportions and their definition as proportion by area. 25 triplets consisting of mixed and monospecific stands were established across Europe ranging from Lithuania to Spain in northern to southern direction and from Bulgaria to Belgium in eastern to western direction. On stand level, the conclusive method for estimating the species proportion as a fraction of the stand area relates the observed density (tree number or basal area) to its potential. This stand-level estimation makes use of the potential from comparable neighboring monospecific stands or from maximum density lines derived from other data, e.g. forest inventories or permanent observations plots. At tree level, the fraction of the stand area occupied by a species can be derived from the proportions of their crown projection area or of their leaf area. The estimates of the potentials obtained from neighboring monospecific stands, especially in older stands, were poorer than those from the maximum density line depending on the Martonne aridity index. Therefore, the stand-level method in combination with the Martonne aridity index for potential densities can be highly recommended. The species’ proportions estimated with this method are best approximated by the proportions of the species’ leaf areas. In forest practice, the most commonly applied method is an ocular estimation of the proportions by crown projection area. Even though the proportions of pine were calculated here by measuring crown projection areas in the field, we found this method to underestimate the proportion by 25% compared to the stand-level approach.  相似文献   

Bioindication and modelling of atmospheric deposition in forests enable exposure and effect monitoring at high spatial density across scales     

Winfried Schröder  Stefan Nickel  Simon Schönrock  Roman Schmalfuß  Werner Wosniok  Michaela Meyer  Harry Harmens  Marina V. Frontasyeva  Renate Alber  Julia Aleksiayenak  Lambe Barandovski  Oleg Blum  Alejo Carballeira  Maria Dam  Helena Danielsson  Ludwig De Temmermann  Anatoly M. Dunaev  Barbara Godzik  Katrin Hoydal  Zvonka Jeran  Gunilla Pihl Karlsson  Pranvera Lazo  Sebastien Leblond  Jussi Lindroos  Siiri Liiv  Sigurður H. Magnússon  Blanka Mankovska  Encarnación Núñez-Olivera  Juha Piispanen  Jarmo Poikolainen  Ion V. Popescu  Flora Qarri  Jesus Miguel Santamaria  Mitja Skudnik  Zdravko Špirić  Trajce Stafilov  Eiliv Steinnes  Claudia Stihi  Ivan Suchara  Lotti Thöni  Hilde Thelle Uggerud  Harald G. Zechmeister 《Annals of Forest Science》2017,74(2):31

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Radioactivity of Selected Agricultural Soils in Croatia: Effects of Soil Properties,Soil Management,and Geological Parameters     

Marko Šoštarić  Željka Zgorelec  Dinko Babić  Ivana Šestak  Ivica Kisić  Milan Mesić  Aleksandra Perčin 《Water, air, and soil pollution》2017,228(6):218

We present a study on the radioactivity of selected Croatian agricultural soils that vary considerably with respect to geological background; physical, chemical, and biological characteristics; soil type; land use; and soil management. Our investigation is focused on the main naturally occurring radionuclides (⁴⁰K, ²³⁸U, ²²⁶Ra, ²³²Th, ²³⁵U) and ¹³⁷Cs as the most threatening long-lived anthropogenic radionuclide. We find that the radioactivity level is not influenced by the application of different soil amendments, at least in moderate quantities, and that no effect of soil management can be detected as well. In contrast, geological and location-specific properties influence radionuclide content in soil, especially regarding the naturally occurring ones. Moreover, physical and chemical soil properties such as texture and soil adsorption complex, respectively, seem to be the main factors regarding fixation of ¹³⁷Cs in soil. Calculated dose rates for external exposure to the gamma radiation originating from soil have been found to be generally low, except for two locations where they are higher but not at a level that would lead to health problems for workers on the field.  相似文献   

The effect of axial strain on crystalline cellulose in Norway spruce     

Marko Peura  Klaas Kölln  Ingo Grotkopp  Pekka Saranpää  Martin Müller  Ritva Serimaa 《Wood Science and Technology》2007,41(7):565-583

The effect of strain on dry, clear Norway spruce (Picea abies [L.] Karst.) wood was studied by tensile testing along the cell axis and by in situ X-ray diffraction measurements. The mean microfibril angle (MFA) was initially 3–12 degrees and did not decrease due to strain. Based on the positions of the reflections 200 and 004 of crystalline cellulose, cellulose chains elongated and the distance between the hydrogen bonded sheets of chains decreased due to the strain. The elongation of the unit cell parallel to the cellulose chains was twice as high in juvenile wood as in mature wood. The (X-ray) Poisson ratio ν _ca for crystalline cellulose in Norway spruce was calculated from the deformation of the unit cell. The average ν _ca of earlywood was 0.28 ± 0.10 in juvenile wood and 0.38 ± 0.23 in mature wood. In latewood, the average ν _ca was 0.48 ± 0.10 in juvenile wood and 0.82 ± 0.11 in mature wood. The average ν _ca values were not directly correlated to the crystallite dimensions or to the mean MFA in juvenile and mature earlywood and latewood. The results show that the amorphous matrix has a definite effect on the deformation of cellulose crystallites.  相似文献   

Morphological studies in different avian species on artefacts induced by euthanasia with T 61 " or Pentobarbital (Narcoren)     

Kummerfeld N  Legler M  Wohlsein P  Kummerfeld M 《Berliner und Münchener tier?rztliche Wochenschrift》2012,125(1-2):27-31

In mammals (e. g. macaques, dogs, cats, rats, sheep) as well as in men (suicides) euthanasia performed by intravenous injection of T 61 leads to serious lesions in lung, kidney or/and liver (endothelial damage, hyperemia, oedema, necrosis). This is caused by the solvent dimethylformamide (DMF). In this study, in contrast, in different species of birds (e. g. blackbird, carrion crow, kestrel, common buzzard, homer pigeon, common wood pigeon, mallard duck) and various modes of applications and dosages T 61, 1.0-3.0 ml/kg body mass, did not induce comparable artefacts in tissues of internal organs in the narcotized animals. Microscopically, only hyperemia and oedema of lung, kidney and/or liver were found. However, milder but similar lesions were detected also in groups of birds euthanized by pentobarbital (200 mg/kg body mass) as well as in control groups (overdosed ketamine intramusculary, 100 mg/kg body mass, and rapid exsanguination). In conclusion, euthanasia of narcotized birds performed by intravenous or intracardial injections ofT 61 seemed to be suitable. The observed lesions could therefore not be interpreted as T61 induced artefacts.  相似文献   

Social structure and spatial distribution of bottlenose dolphins (Tursiops truncatus) along the Croatian Adriatic coast     

Grgur Plesli&#x;  Nikolina Rako‐Gospi&#x;  Jure Mio i&#x;‐Sto&#x;i&#x;  Tihana Blazini&#x; Vu ur  Marko Radulovi&#x;  Peter Mackelworth  Ma&#x;a Frleta‐Vali&#x;  Dra&#x;ko Holcer 《水产资源保护:海洋与淡水生态系统》2019,29(12):2116-2132

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Provenance plasticity of European beech leaf traits under differing environmental conditions at two Serbian common garden sites     

Srđan Stojnić  Saša Orlović  Danijela Miljković  Zoran Galić  Marko Kebert  Georg von Wuehlisch 《European Journal of Forest Research》2015,134(6):1109-1125

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Evaluation of effects of transgenic Bt maize on microarthropods in a European multi-site experiment   总被引：2，自引：5，他引：2  

Jrme Cortet  Bryan S. Griffiths  Marko Bohanec  Damjan Demsar  Mathias N. Andersen  Sandra Caul  Andrew N. E. Birch  Cline Pernin  Elisabeth Tabone  Annette de Vaufleury  Xin Ke  Paul Henning Krogh 《Pedobiologia》2007,51(3):207-ECOGEN

The effects of maize expressing the Bacillus thuringiensis Cry1Ab protein (Bt maize) on soil microarthropods were assessed in the field at four European locations (two in Denmark and two in France) that differ in their climatic conditions or soil properties. Each site was considered as a separate experiment, with separate statistical comparison. Effects of farming practices using Bt maize were compared with conventional farming practices using near-isogenic non-Bt maize and also (at some of the sites) other conventional varieties. Furthermore, at one field site (Foulum, Denmark), the effects of Bt crops were studied in both conventional tillage and reduced tillage contexts. At another field site (Askov, Denmark), Bt maize effects were also compared to the effects of the chemical insecticide dimethoate. Moreover, at three of the field sites (all except Narbons, France), the possibility of a localised Bt effect around the rhizosphere compared to the bulk soil was assessed by sampling within and between maize rows. There were some significant negative effects of Bt maize on microarthropods in soils with a high clay content. Significant differences of the same magnitude also occurred between different conventional varieties of maize, but the effect of dimethoate appeared clearly greater than Bt effects. It is thus debatable if the Bt maize effect is an effect of the Bt toxin or just an effect of the maize variety. Based on the results, it can be concluded that the effect of Bt maize on soil microarthropods was small and within the normal variation expected in conventional agricultural systems.  相似文献   

Are phenolics leaching from the lichen Cladina stellaris sources of energy rather than allelopathic agents for soil microorganisms?     

Sari Stark  Marko Hyvärinen 《Soil biology & biochemistry》2003,35(10):1381-1385

Lichen phenolics that are known to leach out from lichen thalli during rainfall episodes are considered to be allelopathic or antimicrobial agents. On the other hand, small organic molecules originating from aboveground vegetation generally constitute an important C source for the soil microbial community. We studied the effects of leaching lichen acids on soil microbial processes by chemically removing usnic (UA) and perlatolic acid (PA) from the extracellular space of mat-forming lichen, Cladina stellaris, a dominant component of the ground vegetation in boreal oligotrophic forests. Removal of UA and PA did not affect the intracellular contents of the lichen. We hypothesized that if lichen acids have an adverse effect on soil biota, microbial respiration would increase underneath chemically manipulated lichen mats. In turn, if these substances provide energy source for the microorganisms, microbial respiration would decline under lichens from which PA and UA has been removed. Microbial metabolic activity, qCO₂ was significantly lower under the lichens from which UA and PA had been removed, thus supporting the latter hypothesis. Removing UA and PA did not affect the amount of microbial C, N and P, or soil nutrient concentrations. Our results suggest that the microbial community in the soil under a lichen carpet is adapted to the presence of these lichen secondary metabolites and can utilize them as a C source. The approach of removing lichen substances from the system could be used as an effective research tool as it can overcome several problems that are often common in the studies on allelopathic interactions.  相似文献   

Production potential,biodiversity and soil properties of forest reclamations: Opportunities or risk of introduced coniferous tree species under climate change?     

Vacek  Zdeněk  Cukor  Jan  Vacek  Stanislav  Linda  Rostislav  Prokůpková  Anna  Podrázský  Vilém  Gallo  Josef  Vacek  Oldřich  Šimůnek  Václav  Drábek  Ondřej  Hájek  Vojtěch  Spasić  Marko  Brichta  Jakub 《European Journal of Forest Research》2021,140(5):1243-1266

European Journal of Forest Research - In the time of ongoing climate change and the increasing area of post-mining landscape, the successful afforestation of reclamation sites by suitable adaptive...  相似文献